A guide to selecting upper thoracic versus lower thoracic uppermost instrumented vertebra in adult spinal deformity correction.

PURPOSE: Operative treatment of adult spinal deformity (ASD) has been shown to improve patient health-related quality of life (HRQOL). Selection of the uppermost instrumented vertebra (UIV) in either the upper thoracic (UT) or lower thoracic (LT) spine is a pivotal decision with effects on operative and postoperative outcomes. This review overviews the multifaceted decision-making process for UIV selection in ASD correction. METHODS: PubMed was queried for articles using the keywords "uppermost instrumented vertebra", "upper thoracic", "lower thoracic", and "adult spinal deformity". RESULTS: Optimization of UIV selection may lead to superior deformity correction, better patient-reported outcomes, and lower risk of proximal junctional kyphosis (PJK) and failure (PJF). Patient alignment characteristics, including preoperative thoracic kyphosis, coronal deformity, and the magnitude of sagittal correction influence surgical decision-making when selecting a UIV, while comorbidities such as poor body mass index, osteoporosis, and neuromuscular pathology should also be taken in to account. Additionally, surgeon experience and resources available to the hospital may also play a role in this decision. Currently, it is incompletely understood whether postoperative HRQOLs, functional and radiographic outcomes, and complications after surgery differ between selection of the UIV in either the UT or LT spine. CONCLUSION: The correct selection of the UIV in surgical planning is a challenging task, which requires attention to preoperative alignment, patient comorbidities, clinical characteristics, available resources, and surgeon-specific factors such as experience.

Which components of the global alignment proportionality score have the greatest impact on outcomes in adult spinal deformity corrective surgery?

PURPOSE: To investigate the impact of the Global Alignment and Proportion (GAP) score components on patient outcomes in Adult Spine Deformity (ASD) surgery. METHODS: Patients included underwent assessment via the GAP score and its individual components: pelvic version (GAP PV), lumbar lordosis (GAP LL), lumbar distribution index (GAP LDI) and spinopelvic component (GAP SP). Multivariable analyses assessed the association between alignment in these components and clinical outcomes in ASD patients. RESULTS: 762 ASD patients met inclusion criteria. Alignment in GAP SP independently predicted meeting MCID for SR-22S and ODI and was associated with a lower likelihood of developing mechanical complications. Patients aligned in GAP SP were less likely to develop proximal junctional kyphosis (OR 0.42, 0.26-0.73, p = 0.01) and PJF (OR 0.3, 0.13-0.74, p = 0.01). Proportioned alignment in GAP SP with disproportioned alignment in GAP LDI contributed to an increased risk of PJK and PJF (OR 2.67, 95% CI 1.95-6.82, p = 0.045). There was no significant association of GAP SP proportionality and GAP RPV (OR 1.1, 0.86-2.15, p = 0.253) or GAP LL (OR 1.34, 0.78-4.23, p = 0.673) disproportionality with outcomes. Disproportioned alignment in GAP SP but proportioned alignment in both GAP LL and GAP LDI was associated with decreased likelihood of PJK (OR 0.53, 95% CI 0.39-0.94, p = 0.02) and PJF (OR 0.31, 95% CI 0.19-0.67, p = 0.001). CONCLUSION: The spinopelvic component of the GAP score is the most significant independent predictor of clinical outcomes. Its interaction with the other components of the GAP score also aids assessment of the risk for mechanical complications.

Defining modern iatrogenic flatback syndrome: examination of segmental lordosis in short lumbar fusion patients undergoing thoracolumbar deformity correction.

PURPOSE: Understanding the mechanism and extent of preoperative deformity in revision procedures may provide data to prevent future failures in lumbar spinal fusion patients. METHODS: ASD patients without prior spine surgery (PRIMARY) and with prior short (SHORT) and long (LONG) fusions were included. SHORT patients were stratified into modes of failure: implant, junctional, malalignment, and neurologic. Baseline demographics, spinopelvic alignment, offset from alignment targets, and patient-reported outcome measures (PROMs) were compared across PRIMARY and SHORT cohorts. Segmental lordosis analyses, assessing under-, match, or over-correction to segmental and global lordosis targets, were performed by SRS-Schwab coronal curve type and construct length. RESULTS: Among 785 patients, 430 (55%) were PRIMARY and 355 (45%) were revisions. Revision procedures included 181 (23%) LONG and 174 (22%) SHORT corrections. SHORT modes of failure included 27% implant, 40% junctional, 73% malalignment, and/or 28% neurologic. SHORT patients were older, frailer, and had worse baseline deformity (PT, PI-LL, SVA) and PROMs (NRS, ODI, VR-12, SRS-22) compared to primary patients (p < 0.001). Segmental lordosis analysis identified 93%, 88%, and 62% undercorrected patients at LL, L1-L4, and L4-S1, respectively. SHORT patients more often underwent 3-column osteotomies (30% vs. 12%, p < 0.001) and had higher ISSG Surgical Invasiveness Score (87.8 vs. 78.3, p = 0.006). CONCLUSIONS: Nearly half of adult spinal deformity surgeries were revision fusions. Revision short fusions were associated with sagittal malalignment, often due to undercorrection of segmental lordosis goals, and frequently required more invasive procedures. Further initiatives to optimize alignment in lumbar fusions are needed to avoid costly and invasive deformity corrections. LEVEL OF EVIDENCE: IV: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Does the Application of Topical Vancomycin Reduce Surgical Site Infections in Spine Surgery? A Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Surgical site infections (SSIs) represent a major challenge in spine surgery, leading to severe morbidity, mortality, and increased costs. The local application of antibiotics, particularly vancomycin, has emerged as a potential strategy. Individual randomized controlled trials (RCTs) have disagreed about the efficacy of topical vancomycin in preventing SSIs after spine surgery, and so a meta-analysis that pools data from those RCTs might be helpful to inform clinicians' decisions on the topic. QUESTIONS/PURPOSES: This meta-analysis of RCTs asked: Does intrawound topical vancomycin reduce the risk of (1) SSIs, (2) deep SSIs, and (3) superficial SSIs in patients undergoing spine surgery? METHODS: PubMed, Cochrane, and Google Scholar (pages 1-20) were searched up through March 13, 2024 (search performed on March 13, 2024). Inclusion criteria consisted of English or non-English-language RCTs comparing the implementation of topical vancomycin in spine surgery to its nonuse and assessing its efficacy in preventing SSI, while exclusion criteria consisted of nonrandomized comparative studies, single-arm noncomparative studies, comparative studies based on national databases or from the same center as other included studies, studies posted to preprint servers, studies reporting incomplete/nonrelevant outcomes, and studies adding another SSI preventive measure. The studies were assessed using the Cochrane Risk of Bias tool. Heterogeneity was evaluated by Q tests and I2 statistics. We used a random-effects model when considerable heterogeneity was observed (all SSIs, deep SSIs); otherwise, a fixed-effects model was used (all SSIs subanalysis, superficial SSIs). Furthermore, the fragility index was calculated for each of the assessed outcomes when there was no difference between the two groups to assess how many patients were needed to experience the outcomes for a difference to become present. The studied outcomes were the risks of SSIs, deep SSIs, and superficial SSIs. Deep SSIs were defined by the included trials as SSIs underneath the fascia, otherwise they were considered superficial. Six RCTs representing a total of 2140 patients were included, with 1053 patients in the vancomycin group and 1087 in the control group. Using an alpha of 0.05, our meta-analysis had 80% power to detect a risk difference of 1.5% for the primary outcome between patients who did and did not receive vancomycin. The age of the patients in the vancomycin group ranged from 37 to 52 years, while the age in the control group ranged from 34 to 52 years. The surgical procedures consisted of both instrumented and noninstrumented spinal procedures. Overall, the risk of bias in the included studies was either low or unclear, with none of the studies having a high risk of bias in any of the assessed categories (selection bias, performance bias, detection bias, attrition bias, and reporting bias). RESULTS: We found no difference in the risk of SSI between the vancomycin and control groups (3.0% [32 of 1053] versus 3.9% [42 of 1087], relative risk 0.74 [95% CI 0.35 to 1.57]; p = 0.43). Ten additional patients (4.8% infection risk) in the control group would need to experience an SSI for a difference to be observed between the two groups. We found no difference in the risk of deep SSI between the vancomycin and control groups (1.8% [15 of 812] versus 2.7% [23 of 860], relative risk 0.69 [95% CI 0.24 to 2.00]; p = 0.50). Seven additional patients (3.5% infection risk) in the control group would need to experience a deep SSI for a difference to be observed between the two groups. We found no difference in the risk of superficial SSI between the vancomycin and control groups (1.0% [6 of 620] versus 1.4% [9 of 662], relative risk 0.68 [95% CI 0.25 to 1.89]; p = 0.46). Seven additional patients (2.4% infection risk) in the control group would need to experience a superficial SSI for a difference to be observed between the two groups. CONCLUSION: This meta-analysis of randomized trials examining use of topical vancomycin in spine surgery failed to show efficacy in reducing infection, and thus we do not recommend routine use of topical vancomycin for this indication. Future large-scale trials would be needed if surgeons believe that between-group differences smaller than those for which we were powered here (this meta-analysis had 80% power to detect a between-group difference of 1.5% in infection risk) are clinically important, and large database surveys may be informative in terms of assessing for postoperative adverse events associated with the use of vancomycin powder. LEVEL OF EVIDENCE: Level I, therapeutic study.

What Is the Epidemiology of Cervical and Thoracic Spine Fractures?

BACKGROUND: Vertebral fractures are associated with enduring back pain, diminished quality of life, as well as increased morbidity and mortality. Existing epidemiological data for cervical and thoracic vertebral fractures are limited by insufficiently powered studies and a failure to evaluate the mechanism of injury. QUESTION/PURPOSE: What are the temporal trends in incidence, patient characteristics, and injury mechanisms of cervical and thoracic vertebral fractures in the United States from 2003 to 2021? METHODS: The United States National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP) database collects data on all nonfatal injuries treated in US hospital emergency departments and is well suited to capture epidemiological trends in vertebral fractures. As such, the NEISS-AIP was queried from 2003 to 2021 for cervical and thoracic fractures. The initial search by upper trunk fractures yielded 156,669 injuries; 6% (9900) of injuries, with a weighted frequency of 638,999 patients, met the inclusion criteria. The mean age was 62 ± 25 years and 52% (334,746 of 638,999) of patients were females. Descriptive statistics were obtained. Segmented regression analysis, accounting for the year before or after 2019 when the NEISS sampling methodology was changed, was performed to assess yearly injury trends. Multivariable logistic regression models with age and sex as covariates were performed to predict injury location, mechanism, and disposition. RESULTS: The incidence of cervical and thoracic fractures increased from 2.0 (95% CI 1.4 to 2.7) and 3.6 (95% CI 2.4 to 4.7) per 10,000 person-years in 2003 to 14.5 (95% CI 10.9 to 18.2) and 19.9 (95% CI 14.5 to 25.3) in 2021, respectively. Incidence rates of cervical and thoracic fractures increased for all age groups from 2003 to 2021, with peak incidence and the highest rate of change in individuals 80 years or older. Most injuries occurred at home (median 69%), which were more likely to impact older individuals (median [range] age 75 [2 to 106] years) and females (median 61% of home injuries); injuries at recreation/sports facilities impacted younger individuals (median 32 [3 to 96] years) and male patients (median 76% of sports facility injuries). Falls were the most common injury mechanism across all years, with females more likely to be impacted than males. The proportion of admissions increased from 33% in 2003 to 50% in 2021, while the proportion of treated and released patients decreased from 53% to 35% in the same period. CONCLUSION: This epidemiological study identified a disproportionate increase in cervical and thoracic fracture incidence rates in patients older than 50 years from 2003 to 2021. Furthermore, high hospital admission rates were also noted resulting from these fractures. These findings indicate that current osteoporosis screening guidelines may be insufficient to capture the true population at risk of osteoporotic fractures, and they highlight the need to initiate screening at an earlier age. LEVEL OF EVIDENCE: Level III, prognostic study.

Testosterone Replacement Therapy and Associated Rates of Trigger Finger, de Quervain Tenosynovitis, and Their Subsequent Management.

PURPOSE: Anabolic steroid therapy has been associated with tendon injury, but there is a paucity of evidence associating physiologic testosterone replacement therapy (TRT) with tenosynovitis of the hand, specifically trigger finger and de Quervain tenosynovitis. The purpose of this study was to evaluate the relationship between TRT and tenosynovitis of the hand. METHODS: This was a one-to-one exact matched retrospective cohort study using a large nationwide claims database. Records were queried between 2010 and 2019 for adult patients who filled a prescription for TRT for 3 consecutive months. Rates of new onset trigger finger and de Quervain tenosynovitis and subsequent steroid injection or surgery were identified using ICD-9, ICD-10, and Current Procedural Terminology billing codes. Single-variable chi-square analyses and multivariable logistic regression were used to compare rates in the TRT and control cohorts while controlling for potential confounding variables. Both unadjusted and adjusted odds ratios (OR) are reported for each comparison. RESULTS: In the adjusted analysis, patients undergoing TRT were more than twice as likely to develop trigger finger compared to their matched controls. TRT was also associated with an increased likelihood of experiencing de Quervain tenosynovitis. Of the patients diagnosed with either trigger finger or de Quervain tenosynovitis over the 2-year period, patients with prior TRT were roughly twice as likely to undergo steroid injections or surgical release for both trigger finger and de Quervain tenosynovitis compared to the controls. CONCLUSIONS: TRT is associated with an increased likelihood of both trigger finger and de Quervain tenosynovitis, and an increased likelihood of requiring surgical release for both conditions. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

The effect of concurrent cervical spine degenerative disease on the outcome of rotator cuff repair: a national database study.

BACKGROUND: Cervical spine degenerative disease (CSD) can cause shoulder pain, potentially confounding the management of patients with rotator cuff tears. This study aimed to investigate the relationships between CSD and rotator cuff repair (RCR). METHODS: A national administrative database (PearlDiver) was used to study 4 patient cohorts: (1) RCR only (RCRo), (2) RCR with concurrent CSD (RCRC), (3) RCR after a cervical spine procedure (RCRA), and (4) RCR before a cervical spine procedure (RCRB). The outcomes of RCR were compared using multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index, as well as preoperative opioid utilization in the analysis of opioid use. RESULTS: Between 2010 and 2021, a total of 889,977 patients underwent RCR. Of these patients, 784,230 (88%) underwent RCRo whereas 105,747 (12%) underwent RCRC, of whom 21,585 (2.4%) underwent cervical spine procedures (RCRA in 9670 [1.1%] and RCRB in 11,915 [1.3%]). At 2 years after RCR, compared with RCRo patients, RCRC patients had an increased risk of surgical-site infection (adjusted odds ratio [aOR] = 1.25, P = .0004), deep vein thrombosis (aOR = 1.17, P = .0002), respiratory complications (aOR = 1.19, P = .0164), and ipsilateral shoulder reoperations (débridement [aOR = 1.66, P < .0001], manipulation under anesthesia or arthroscopic lysis of adhesions [aOR = 1.23, P < .0001], distal clavicle excision [aOR = 1.78, P < .0001], subacromial decompression [aOR = 1.72, P < .0001], biceps tenodesis [aOR = 1.76, P < .0001], incision and drainage [aOR = 1.34, P = .0020], synovectomy [aOR = 1.48, P = .0136], conversion to shoulder arthroplasty [aOR = 1.62, P < .0001], revision RCR [aOR = 1.77, P < .0001], and subsequent contralateral RCR [aOR = 1.71, P < .0001]). At 2 years, compared with RCRC patients who did not undergo cervical spine procedures, RCRC patients who underwent cervical spine procedures had an increased risk of incision and drainage (aOR = 1.50, P = .0255), conversion to arthroplasty (aOR = 1.40, P < .0001), and revision RCR (aOR = 1.11, P = .0374), as well as a lower risk of contralateral RCR (aOR = 0.89, P = .0469). The sequence of cervical spine procedures did not affect the risk of shoulder reoperations. At 1 year, the risk of opioid use after RCR was less for RCRA patients compared with RCRB patients (aOR = 1.71 [95% confidence interval, 1.61-1.80; P < .0001] vs. aOR = 2.01 [95% confidence interval, 1.92-2.12; P < .0001]). CONCLUSION: Concurrent CSD has significant detrimental effects on RCR outcomes. Patients with concurrent CSD undergoing cervical spine procedures have a greater risk of ipsilateral shoulder reoperations but a decreased risk of contralateral RCR. The risk of prolonged opioid use was lower if RCR followed a cervical spine procedure. Concurrent CSD must be considered and possibly treated to optimize the outcomes of RCR.

Decreased prevalence of new-onset adhesive capsulitis in patients prescribed angiotensin receptor blockers.

BACKGROUND: Angiotensin receptor blockers (ARBs) are commonly prescribed antihypertensive agents that have well-known antifibrotic properties. The purpose of this study was to examine the association between ARB use and the rates of new-onset adhesive capsulitis as well as adhesive capsulitis requiring operative treatment. METHODS: Using a large national insurance database, a randomly generated cohort of patients with at least 3 continuous months of ARB use between January 2010 and December 2019 (n = 1,000,000) was compared to a separate randomly generated cohort without ARB use (n = 3,000,000). Rates of newly diagnosed adhesive capsulitis and associated manipulation under anesthesia (MUA) and/or arthroscopic capsulotomy were calculated over a 1- and 2-year period following the completion of at least 3 continuous months of ARB therapy. Rates were compared using multivariable logistic regression to control for demographics and comorbidities. Both unadjusted and adjusted odds ratios and 95% confidence intervals were calculated and reported for each comparison. Statistical significance was set at P <.05. RESULTS: The mean age in the ARB cohort was 61.8 years (standard deviation [SD] = 10.0), whereas in the control cohort, it was 54.8 years (SD = 12.3) (P < .001). The ARB cohort had significantly lower rates of newly diagnosed adhesive capsulitis compared with the control cohort at both 1 year (0.15% vs. 0.55%, P < .001) and 2 years (0.3% vs. 0.78%, P < .001). Similar findings were observed for the arthroscopic capsular release/MUA cohort associated with adhesive capsulitis. After adjusting for confounding factors, the lower rates of adhesive capsulitis and arthroscopic capsular release/MUA associated with adhesive capsulitis in the ARB cohort remained statistically significant (P < .001). CONCLUSION: Patients prescribed ARBs experienced a decreased rate of newly diagnosed adhesive capsulitis, as well as adhesive capsulitis requiring surgical intervention when compared to a control cohort. These findings suggest a potential protective effect of ARBs against the development of adhesive capsulitis. Further investigations are warranted to elucidate the underlying mechanisms and establish a causal relationship.

Medicaid Expansion Is Associated With Increases in Medicaid-Funded Total Joint Arthroplasty.

BACKGROUND: Existing literature presents competing views concerning the impact of Medicaid expansion on total joint arthroplasty (TJA) utilizations. While some reports demonstrate that expansion does not increase Medicaid acceptance by surgeons, others show increases in Medicaid-funded TJA via limited analyses. We conducted a nationwide, multi-insurance, econometric study to determine if Medicaid-funded and all-funding-source total hip arthroplasty (THA) or total knee arthroplasty (TKA) utilizations increased following expansion. METHODS: This study examined 999,015 THA and 2,099,975 TKA from 2010 to 2017 using a commercially available national payer database. Difference-in-differences analyses, econometric regression methods used to assess the impact of policy change, were used to examine the impact of Medicaid expansion on TJA utilizations, and event analyses were used to confirm the parallel trends assumption, which helps to ensure that the estimated effect is not a result of existing differences in trends between treatment and nontreatment groups. RESULTS: Event analyses confirmed parallel trends in the pre-expansion period. Difference-in-differences analyses found a persistent increase in Medicaid-funded THA (40.4%, P = .001, confidence interval [CI]: 12.7, 62.1%), but not THA from all funding sources (4.6%, P = .128, CI: -1.3, 10.8%). Medicaid-funded TKA (35.8%, P < .001, CI: 17.4, 68.0%) increased, but not TKA from all funding sources (3.4%, P = .321, CI: -3.1, 10.1%). CONCLUSION: While the number of Medicaid-funded TJAs increased, expansion had no significant effect when examining all funding sources. This suggests that Medicaid expansion primarily affected source of TJA funding, not overall volume. Further research is needed to examine state-specific predictors of response to Medicaid expansion.

Shoulder Adhesive Capsulitis Prior to Total Knee Arthroplasty is Associated With Increased Rates of Postoperative Stiffness Requiring Manipulation Under Anesthesia and Arthroscopic Lysis of Adhesions.

BACKGROUND: Arthrofibrosis following total knee arthroplasty (TKA) and adhesive capsulitis (AC) of the shoulder develop via a similar pathologic process. The purpose of this study was to examine the relationship between these two conditions. METHODS: This was a retrospective cohort study using a large nationwide claims database. Patients who had a history of shoulder AC prior to TKA were compared to TKA patients who did not have AC history comparing rates of postoperative stiffness, manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOAs), and revision arthroplasty at postoperative timepoints (3 months, 6 months, 1 year, and 2 years). RESULTS: Within 3 months, 6 months, 1 year, and 2 years of their TKAs, patients who had a history of AC prior to TKA were significantly more likely to experience stiffness (OR [odds ratio] = 1.29, 1.28, 1.32, and 1.36, respectively) and LOAs (OR = 6.78, 3.65, 2.99, and 2.81, respectively). They also showed increased risk of MUA within 6 months, 1 year, and 2 years (OR = 1.15, 1.15, and 1.16, respectively) of their TKAs. Patients having a preoperative diagnosis of AC did not have an increased risk of undergoing revision surgery 1 year or 2 years after their TKAs (P > .05). CONCLUSIONS: Patients diagnosed with AC prior to TKA experience higher rates of postoperative stiffness, resulting in additional interventions such as MUA and LOAs. These findings identify a particularly high-risk patient population that may benefit from additional interventions prior to and following TKA. LEVEL OF EVIDENCE: This is a level III prognostic study.

Chronic Anticoagulation in Patients Who Have Atrial Fibrillation Undergoing Outpatient Total Knee Arthroplasty: A Retrospective Matched Cohort Study.

BACKGROUND: Patients who have atrial fibrillation frequently require long-term anticoagulation with warfarin or a direct-acting oral anticoagulant (DOAC), such as apixaban or rivaroxaban, to avoid vascular complications. However, the impact of anticoagulant use on postoperative complications following total knee arthroplasty (TKA) in an outpatient setting has not been thoroughly elucidated. The purpose of this study was to examine the impact of anticoagulant use on early postoperative complications among atrial fibrillation patients undergoing outpatient TKA. METHODS: An insurance claims database was queried to identify all patients who underwent outpatient TKA between January 2010 and April 2022. There were two cohorts of patients, with associated 1:1 matched controls, who had atrial fibrillation and filled a prescription of either warfarin (N = 4,396) or DOAC (N = 5,383) for at least 30 days. The mean age was 70 years (range, 51 to 84), and 47.9% were women in the warfarin cohort, while the mean age was 70 years and 49.2% were women in the DOAC cohort. Postoperative 30-day medical and 90-day surgical complications were subsequently compared. RESULTS: Patients on warfarin had a higher incidence of pulmonary embolism (1.1 versus 0.2%, P < 0.001) and a lower incidence of TKA revision (0.1 versus 0.4%, P = 0.003) than matched controls. Similarly, patients on DOACs exhibited a higher incidence of pneumonia (1.4 versus 0.6%, P < 0.001) and myocardial infarction (3.2 versus 1.5%, P < 0.001) and a lower incidence of wound dehiscence (0.1 versus 0.5%, P < 0.001), joint infection (0.4 versus 0.9%, P = 0.002), and TKA revision (0.1 versus 0.4%, P = 0.002) than matched controls. CONCLUSIONS: Atrial fibrillation patients on long-term anticoagulants undergoing outpatient TKA experience higher rates of medical complications and lower rates of surgical complications than matched controls. Thus, patients on long-term anticoagulants may be considered for outpatient TKA but should be counseled appropriately on associated medical risks.

Postoperative Angiotensin Receptor Blocker Use is Associated With Decreased Rates of Manipulation Under Anesthesia, Arthroscopic Lysis of Adhesions, and Prosthesis-Related Complications in Patients Undergoing Total Knee Arthroplasty.

BACKGROUND: The cellular mechanisms underlying excess scar tissue formation in arthrofibrosis following total knee arthroplasty (TKA) are well-described. Angiotensin receptor blockers (ARB), particularly losartan, is a commonly prescribed antihypertensive with demonstrated antifibrotic properties. This retrospective study aimed to assess the rates of 1- and 2-year postoperative complications in patients who filled prescriptions for ARBs during the 90 days after TKA. METHODS: Patients undergoing primary TKA were selected from a large national insurance database, and the impact of ARB use after TKA on complications was assessed. Of the 1,299,106 patients who underwent TKA, 82,065 had filled at least a 90-day prescription of losartan, valsartan, or olmesartan immediately following their TKA. The rates of manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOA), aseptic loosening, periprosthetic fracture, and revision at 1 and 2 years following TKA were analyzed using multivariable logistic regressions to control for various comorbidities. RESULTS: ARB use was associated with decreased rates of MUA (odds ratio [OR] = 0.94, 95% confidence interval (CI), 0.90 to 0.99), arthroscopy/LOA (OR = 0.86, 95% CI, 0.77 to 0.95), aseptic loosening (OR = 0.71, 95% CI, 0.61 to 0.83), periprosthetic fracture (OR = 0.58, 95% CI, 0.46 to 0.71), and revision (OR = 0.79, 95% CI, 0.74 to 0.85) 2 years after TKA. CONCLUSIONS: ARB use throughout the 90 days after TKA is associated with a decreased risk of MUA, arthroscopy/LOA, aseptic loosening, periprosthetic fracture, and revision, demonstrating the potential protective abilities of ARBs. Prospective studies evaluating the use of ARBs in patients at risk for postoperative stiffness would be beneficial to further elucidate this association.

Incidence of Tibial Tubercle Fractures in Patients With and Without Osgood-Schlatter Disease.

BACKGROUND: Patients with Osgood-Schlatter disease (OSD) may be at increased risk of tibial tubercle fractures due to an underlying weakness of the tibial tubercle apophysis relative to the patellar tendon as a result of repetitive microtrauma. HYPOTHESIS/PURPOSE: The purpose of this study is to analyze the incidence of tibial tubercle fractures in patients with and without Osgood-Schlatter disease. We hypothesized that the incidence of tibial tubercle fractures would be higher in patients with Osgood-Schlatter disease. METHODS: A retrospective cohort analysis of the PearlDiver database was performed by querying all patients diagnosed with Osgood-Schlatter disease between January 2010 and October 2022. An OSD cohort of 146,672 patients was captured using International Classification of Diseases, Ninth Revision (ICD-9), Tenth Revision (ICD-10) billing codes, and age as inclusion/exclusion criteria. The Student t test and the χ 2 analyses were used to compare the demographics and obesity between the OSD and control cohorts. Multivariable logistic regressions, controlling for residual differences in age, sex, and obesity, were used to compare rates of tibial tubercle fractures. RESULTS: Patients with a recent history of OSD were found to have higher rates of tibial tubercle fractures than the control group at all measured time points ( P <0.001). The 1-year rate of tibial tubercle fractures was 0.62% in the OSD group. The incidence of tibial tubercle fractures in the OSD group was 627.3 cases per 100,000 person-years compared with 42.7 cases per 100,000 person-years in the control group ( P <0.001). Male sex and obesity were also associated with an increased risk of sustaining a tibial tubercle fracture within these patient populations ( P <0.001). CONCLUSION: We report a significantly higher incidence of tibial tubercle fractures among patients with OSD compared with controls. This increase was most significant at 1 month following OSD diagnosis, however, held true for all measured time points. In addition, male patients and those with obesity were also noted to have increased incidence of tibial tubercle fractures regardless of an OSD diagnosis.

Epidemiology of Acute Compartment Syndrome After Pediatric Tibial Tubercle and Tibial Shaft Fractures.

BACKGROUND: While acute compartment syndrome (ACS) is a well-reported complication after pediatric tibial shaft fractures, prior literature has suggested that pediatric patients with tibial tubercle fractures may be at increased risk of ACS due to the proximity of the tibial tubercle to the anterior tibial recurrent artery. However, this theory was largely based on a series of early case reports without substantiation in larger-scale studies. HYPOTHESIS/PURPOSE: The purpose of this study is to conduct a population-level analysis of the incidence and risk factors of acute compartment syndrome following pediatric tibial tubercle and tibial shaft fractures. We hypothesize that the rate of ACS would be lower in patients with tibial tubercle fractures when compared with those with tibial shaft fractures. METHODS: A retrospective cohort analysis of the PearlDiver Mariner database was performed by querying all patients diagnosed with tibial tubercle and tibial shaft fractures between January 2010 and October 2022. Matched cohorts (n=25,483) of patients with pediatric tibial tubercle and tibial shaft fractures were captured using International Classification of Diseases, Ninth Revision (ICD-9), Tenth Revision (ICD-10) billing codes, and age as inclusion/exclusion criteria. Rates of subsequent compartment syndrome were calculated by querying for insurance claims with associated CPT codes for fasciotomy and/or ICD-9/ICD-10 billing codes for compartment syndrome. Student t test and χ2 analyses were used to compare demographics between the tibial tubercle and tibial shaft cohorts. RESULTS: The rate of ACS was significantly lower in the tibial tubercle cohort (0.46%) than in the tibial shaft cohort (0.70%, P<0.001). Male sex and increased age were associated with an increased risk of developing ACS in both cohorts (P<0.001). In addition, polytrauma was found to be a risk factor for ACS among patients with tibial shaft fractures (P<0.001). CONCLUSION: We report a low rate of ACS following both pediatric tibial tubercle fractures and pediatric tibial shaft fractures. Among patients with tibial tubercle fractures, male sex, and increased age were noted to be risk factors for ACS, whereas male sex, older age, and polytrauma were risk factors for ACS among patients with tibial shaft fractures.

Outpatient Versus Inpatient Total Hip and Knee Arthroplasty in Morbidly Obese Patients.

BACKGROUND: Morbidly obese patients undergoing total joint arthroplasty (TJA) face increased postoperative complications, yet studies assessing the safety of this surgery in the outpatient setting for this population are lacking. This study aimed to fill this gap by assessing the safety and benefits of outpatient TJA in morbidly obese patients. METHODS: This study is a retrospective review of a commercial claims database. Based on the setting of the procedure, the patients were divided into four groups: inpatient-TKA (total knee arthroplasty), outpatient-TKA, inpatient-THA (total hip arthroplasty), and outpatient-THA. The two TKA groups were matched based on age, sex, and the Charlson comorbidity index (CCI). The THA groups were matched similarly. The 30- and 90-day medical and surgical complications were compared between these groups. There were 5,500 patients included in each of the outpatient and inpatient TKA groups, and 1,550 in each of the outpatient and inpatient THA groups RESULTS: Patients undergoing inpatient TKA had higher rates of pulmonary embolism, UTI (urinary tract infection), transfusions, ICU (intensive care unit) admissions, ED (emergency department) visits, readmissions at 30 days, surgical site infections, periprosthetic joint infection, prosthetic dislocations, and costs. As for the inpatient THA group, they had higher rates of pulmonary embolism, UTI, transfusions, ICU admissions, ED visits, and costs. CONCLUSION: It is well established that morbidly obese patients undergoing total joint arthroplasty have higher complication rates than normal-weight patients, and patients should be counseled before arthroplasty. This study highlights the safety and benefits of outpatient TJA in morbidly obese patients. However, one should note that this was done using an insurance database, in which results may differ if it was done in a public and lower socioeconomic setting. Therefore, future prospective studies are needed to confirm the findings before implementing outpatient TJA in morbidly obese patients.

Testosterone Therapy Is Associated With Increased Odds of Quadriceps Tendon Injury.

BACKGROUND: Anabolic steroid use at supraphysiologic doses has been associated with an increased risk of tendon injury. However, the musculoskeletal effects of testosterone therapy in the clinical setting are not well understood. QUESTIONS/PURPOSES: (1) Is prescription testosterone associated with a higher odds of subsequent quadriceps muscle or tendon injury? (2) Is prescription testosterone associated with a higher odds of surgical repair of the quadriceps tendon? METHODS: The PearlDiver Database, which contains data on Medicaid, Medicare, and commercially insured patients, allows for a large representative sample of the US population including both publicly and privately insured patients. The database was queried for all patients between 2011 and 2018 who filled a testosterone prescription. Additionally, all quadriceps injuries using ICD-9 and ICD-10 codes between 2011 and 2018 were queried. Propensity score matching based on age, sex, Charlson comorbidity index, and specific comorbidities allowed us to create matched control groups. We used the t-test and chi-square analysis to compare the unmatched and matched cohorts. A total of 151,797 patients (123,627 male patients and 28,170 female patients) with a history of filled testosterone prescriptions were included in the study after matching with the control group, which was of equal size and representation of age, male-female proportions, and comorbidities. Chi-square and logistic regression analyses were performed to compare odds of quadriceps injury and quadriceps tendon repair among the testosterone groups to that of their respective control groups by age and sex. RESULTS: Within 1 year of filling prescriptions for testosterone, 0.06% (97 of 151,797) of patients experienced a quadriceps injury compared with less than 0.01% (18 of 151,797) of patients in the control group (OR 5.4 [95% CI 3.4 to 9.2]; p < 0.001). Within the sex-specific matched groups, filling a testosterone prescription was associated with an increase in the odds of quadriceps injury in male patients within 1 year of the prescription (OR 5.8 [95% CI 3.5 to 10.3]; p < 0.001). Additionally, patients who filled a testosterone prescription were at increased risk of having quadriceps tendon repair within a year of the injury than were patients in the matched control group (OR 4.7 [95% CI 2.0 to 13.8]; p = 0.001). CONCLUSION: Considering these findings, it is important for physicians to counsel patients receiving testosterone replacement therapy of the substantially increased odds of quadriceps tendon injury. Future investigations into the mechanisms of influence of exogenous anabolic steroids on tendon injury remains of interest. LEVEL OF EVIDENCE: Level III, therapeutic study.

A Diagnosis of Vitamin D Deficiency Is Associated With Increased Rates of Anterior Cruciate Ligament Tears and Reconstruction Failure.

PURPOSE: To characterize the association between a diagnosis of hypovitaminosis D and primary anterior cruciate ligament (ACL) tear, primary anterior cruciate ligament reconstruction (ACLR), and revision ACLR in different sex and age cohorts. METHODS: In this retrospective cohort study of the PearlDiver claims database, records were queried between January 1, 2011, and October 31, 2018 for all patients aged 10 to 59 years who received a diagnosis of hypovitaminosis D. Rates of primary ACL tears, primary reconstruction, and revision reconstruction were calculated for sex- and age-specific cohorts and compared with a control of patients without a diagnosis of hypovitaminosis D. Incidence rates for primary ACL injuries were calculated, and multivariable logistic regression was used to compare rates of ACL injury, primary reconstruction, and revision reconstruction while controlling for age, sex, Charlson Comorbidity Index, and several other comorbidities. RESULTS: Among the 328,011 patients (mean age 41.9 ± 12.6 years, 65.8% female) included in both the hypovitaminosis D and control cohorts, the incidence of ACL tears was 115.2 per 100,000 person-years (95% confidence interval [CI] 107.2-123.7) compared with 61.0 (95% CI 55.2-67.2) in the demographic- and comorbidity-matched control cohort. The study cohort was significantly more likely to suffer an ACL tear over a 1- (aOR 1.67, 95% CI 1.41-1.99, P < .001) and 2-year (aOR 1.81, 95% CI 1.59-2.06, P < .001) period. This trend remained for both male patients at the 1- (aOR 1.66, 95% CI 1.29-2.14, P < .001) and 2-year (aOR 1.68, 95% CI 1.37-2.06, P < .001) mark and female patients at the 1- (aOR 1.69, 95% CI 1.33-2.14, P < .001) and 2-year (aOR 1.80, 95% CI 1.51-2.14, P < .001) mark. Finally, patients with vitamin D deficiency had a significantly increased likelihood of undergoing a revision ACLR within 2 years of a primary reconstruction (aOR 1.28, 95% CI 1.05-1.55, P = .012). CONCLUSIONS: This study reports an association between patients previously diagnosed with hypovitaminosis D and significantly increased rates of both index ACL tears (81% increase within 2 years of diagnosis) and revision ACLR (28% within 2 years). These results identify a population with increased odds of injury and provide valuable knowledge as we expand our understanding of the relationship between vitamin D and musculoskeletal health. LEVEL OF EVIDENCE: Level III, retrospective database study.

The use of prescription testosterone is associated with an increased likelihood of experiencing a distal biceps tendon injury and subsequently requiring surgical repair.

BACKGROUND: In the United States, the use of testosterone therapy has increased over recent years. Anabolic steroid use has been associated with tendon rupture, although there is a paucity of evidence evaluating the risk of biceps tendon injury (BTI) with testosterone therapy. The aim of this study was to quantify the risk of BTI after the initiation of testosterone therapy. METHODS: This was a retrospective cohort study using the PearlDiver database. Records between 2011 and 2018 were queried to identify patients aged 35-75 years who filled a testosterone prescription for a minimum of 3 months. A control group was created, comprising patients aged 35-75 years who had never filled a prescription for exogenous testosterone. International Classification of Diseases, Ninth Revision, International Classification of Diseases, Tenth Revision, and Current Procedural Terminology codes were used to identify patients with distal biceps injuries and those undergoing surgical repair. Three matching processes were completed: one for the overall cohort, one for the cohort comprising only male patients, and one for the cohort comprising only female patients. Each cohort was matched to its control on age, sex, Charlson Comorbidity Index, diabetes, tobacco use, and osteoporosis. Multivariate logistic regression was used to compare rates of distal BTI and subsequent surgical repair in the testosterone groups with their control groups. RESULTS: A total of 776,974 patients had filled a prescription for testosterone for a minimum of 3 consecutive months. In the overall matched analysis between the testosterone and control groups (n = 291,610 in both), the mean age of the patients was 53.9 years and 23.1% were women. Within 1 year of filling exogenous testosterone prescriptions for a minimum of 3 consecutive months, 650 patients experienced a distal BTI compared with 159 patients in the control group (odds ratio [OR], 4.10; 95% confidence interval [CI], 3.45-4.89; P < .001). At any time after testosterone therapy, patients with testosterone use were more than twice as likely to experience a distal BTI as their matched controls (OR, 2.07; 95% CI, 1.94-2.38). Patients who filled prescriptions for testosterone were more likely to undergo surgical repair within a year of the injury compared with the control group. A similar trend was seen in the cohort comprising male patients (OR, 1.63; 95% CI, 1.29-2.07). CONCLUSION: Patients with prior prescription testosterone exposure have an increased rate of BTI and biceps tendon repair compared with patients without such exposure. This finding provides insight into the risk profile of testosterone therapy, and doctors should consider counseling patients about this risk, particularly male patients.

Increased Risk of Hospital Readmissions and Implant-Related Complications in Patients Who Had a Recent History of Fragility Fracture: A Matched Cohort Analysis.

BACKGROUND: With the increasing utilization of total knee arthroplasty (TKA) in a continually aging US population, the number of patients who have low bone mineral density who undergo TKA may concomitantly increase. This study aimed to assess the rates of short-term complications following TKA in patients who did and did not have a recent history of a prior fragility fracture. METHODS: A matched retrospective cohort study analyzing 48,796 patients was performed using a national database to determine the impact of a preceding fragility fracture on rates of short-term complications following TKA. The rates of complications at 1 and 2 years post-TKA were analyzed using multivariate logistic regressions. RESULTS: Prior fragility fracture was associated with increased rates of 1-year hospital readmissions (hazard ratio = 1.30, 95% CI, 1.22-1.38), periprosthetic fractures (odds ratio [OR] = 2.72, 95% CI, 1.89-3.99), non-infection-related revisions (OR = 1.32, 95% CI, 1.09-1.60), secondary fragility fractures (OR = 4.62, 95% CI, 4.19-5.12), prosthesis dislocations (OR = 1.76, 95% CI, 1.22-2.56), prosthesis instabilities (OR = 1.64, 95% CI, 1.25-2.15), and periprosthetic infections (OR = 1.49, 95% CI, 1.29-1.71), with similar trends in implant-related complications also seen at the 2-year mark. Patients who filled a prescription for osteoporosis pharmacotherapy had clinically similar rates of these complications compared to those who did not. CONCLUSION: Sustaining a fragility fracture prior to TKA is associated with an increased risk of hospital readmission and significant implant-related postoperative complications, potentially increasing the morbidity and mortality of TKA in these patients.

Risk of Dislocation and Revision Following Primary Total Hip Arthroplasty in Patients With Prior Lumbar Fusion With Spinopelvic Fixation.

BACKGROUND: The effect of spinopelvic fixation in addition to lumbar spinal fusion (LSF) on dislocation/instability and revision in patients undergoing primary total hip arthroplasty (THA) has not been reported previously. METHODS: The PearlDiver Research Program was used to identify patients aged 30 and above undergoing primary THA who received (1) THA only, (2) THA with prior single-level LSF, (3) THA with prior 2-5 level LSF, or (4) THA with prior LSF with spinopelvic fixation. The incidence of THA revision and dislocation/instability was compared through logistic regression and Chi-squared analysis. All regressions were controlled for age, gender, and Elixhauser Comorbidity Index (ECI). RESULTS: Between 2010 and 2018, 465,558 patients without history of LSF undergoing THA were examined and compared to 180 THA patients with prior spinopelvic fixation, 5,299 with prior single-level LSF, and 1,465 with prior 2-5 level LSF. At 2 years, 7.8% of THA patients with prior spinopelvic fixation, 4.7% of THA patients with prior 2-5 level LSF, 4.2% of THA patients with prior single-level LSF, and 2.2% of THA patients undergoing only THA had a dislocation event or instability (P < .0001). After controlling for length of fusion, pelvic fixation itself was associated with higher independent risk of revision (at 2 years: 2-5 level LSF + spinopelvic fixation: aHR = 3.15, 95% CI 1.77-5.61, P < .0001 vs 2-5 level LSF with no spinopelvic fixation: aOR = 1.39, 95% CI 1.10-1.76, P < .0001). CONCLUSION: At 2 years, spinopelvic fixation in THA patients were associated with a greater than 3.5-fold increase in hip dislocation risk compared to those without LSF, and an over 2-fold increase in THA revision risk compared to those with LSF without spinopelvic fixation. LEVEL OF EVIDENCE: III.