Tendinopathy Racial and Ethnic Disparities: What the Evidence Shows

Why Race and Ethnicity Matter in Tendinopathy

Tendinopathy covers a spectrum of tendon pathology ranging from reactive tendinopathy to tendon disrepair and frank rupture. Prevalence estimates vary by tendon site, activity level, and the diagnostic method used. What is consistent across the literature is that who gets diagnosed, who gets treated, and who gets better differs by race and ethnicity.

A 2021 analysis published in the Journal of Bone and Joint Surgery found that Black patients undergoing orthopedic care for musculoskeletal conditions were significantly less likely to receive surgical intervention even after adjusting for insurance status and comorbidity burden [1]. Tendinopathy was not isolated as a separate diagnostic category in that study, but the pattern is consistent with broader musculoskeletal equity data.

Defining the Scope

Tendinopathy refers to tendon pain and dysfunction associated with pathological changes in tendon structure. The most studied sites include the Achilles, patellar, rotator cuff, and common extensor tendons of the elbow. Each site carries its own epidemiological profile, and race-stratified data are sparse for all of them.

Why Sparse Data Is Itself a Disparity

When a condition lacks race-stratified epidemiology, clinicians default to population-average estimates. For tendinopathy, that default overrepresents the experience of white, male, recreational-sport participants, who make up the majority of trial enrollees. The underrepresentation is not random. It reflects structural barriers to trial participation including geographic distance from academic medical centers, work schedule inflexibility, language concordance in consent materials, and historical mistrust of research institutions [2].

Achilles Tendinopathy and Rupture: The Clearest Racial Signal

Achilles tendon injury shows the strongest race-associated signal in the tendinopathy literature. Rupture rates, not just tendinopathy, differ measurably between Black and white patients in U.S. Administrative data.

Incidence by Race

A large retrospective cohort study using the Nationwide Inpatient Sample found that Black patients had a statistically higher adjusted incidence of Achilles tendon rupture compared with white patients (adjusted odds ratio approximately 1.4 to 1.7 depending on age stratum) [3]. The mechanism is debated. Proposed explanations include differences in plantar flexor muscle architecture, calf muscle pennation angle, tendon cross-sectional area, and activity-related loading patterns.

The Fluoroquinolone Complication Layer

Fluoroquinolone antibiotics (ciprofloxacin, levofloxacin, moxifloxacin) carry an FDA black-box warning for tendon rupture risk, added in 2008 and strengthened in 2016 [4]. Black patients in the United States are prescribed fluoroquinolones at higher rates for urinary tract infections and respiratory tract infections in some emergency department datasets, which could compound baseline Achilles rupture risk. Race-stratified pharmacovigilance data on fluoroquinolone-associated tendinopathy remain an acknowledged gap in the FDA Adverse Event Reporting System (FAERS) literature [5].

Surgical Access After Rupture

When rupture occurs, surgical repair is associated with lower re-rupture rates than conservative management in most meta-analyses. A Cochrane review of Achilles tendon rupture management (Wilkins et al.) found re-rupture rates of approximately 3.9% with operative versus 10.6% with non-operative treatment [6]. Whether Black patients access surgical repair at the same rate as white patients after rupture is incompletely studied, but orthopedic surgery access data suggest a persistent gap tied to insurance type and hospital proximity [1].

Rotator Cuff Tendinopathy: Diagnosis and Imaging Disparities

Rotator cuff disease is one of the most common causes of shoulder pain worldwide, with a population prevalence of full-thickness tears reaching 20-30% in adults over 60 years old on imaging studies [7]. The racial disparity pattern here differs from the Achilles literature: the dominant signal is underdiagnosis in non-white populations rather than elevated rupture risk.

Imaging Access as the Bottleneck

MRI is the standard imaging modality for characterizing rotator cuff pathology. Black and Hispanic patients are less likely to receive MRI for musculoskeletal complaints in U.S. Emergency department and primary care settings even after controlling for insurance status [8]. Without imaging, asymptomatic or mildly symptomatic tears go uncounted, which distorts prevalence estimates and delays intervention.

Pain Reporting and Clinical Assessment Bias

Research on pain assessment across racial groups shows that clinicians systematically underestimate pain intensity reported by Black patients. A study published in PNAS (Hoffman et al., 2016, N=222 medical students and residents) found that approximately half of white medical trainees endorsed at least one false belief about biological differences in pain sensitivity between Black and white patients [9]. These beliefs predicted lower pain ratings and less adequate treatment recommendations for Black patients. Applied to tendinopathy, this bias may translate into delayed physical therapy referral and lower rates of corticosteroid injection or imaging referral.

Corticosteroid Injection Utilization

Subacromial corticosteroid injection is a first-line office-based treatment for rotator cuff tendinopathy. A 2020 analysis of Medicare claims data found that Black and Hispanic beneficiaries received musculoskeletal injections at lower rates than white beneficiaries across all anatomical sites [10]. The gap persisted after controlling for rural versus urban residence and comorbidities.

Patellar and Quadriceps Tendinopathy: Limited Race-Stratified Data

Patellar tendinopathy ("jumper's knee") is strongly associated with jumping sports including basketball and volleyball. Basketball in particular has high participation rates among Black athletes in the United States. Yet the published tendinopathy literature on patellar tendon pathology draws overwhelmingly from European populations, primarily white Dutch, Danish, and Australian cohorts [11].

What Missing Data Means Clinically

The Visa-P questionnaire, the standard patient-reported outcome measure for patellar tendinopathy severity, was validated in predominantly white European samples. Its cross-cultural validity in Black, Hispanic, and Asian American populations has not been rigorously tested. Clinicians using Visa-P scores to guide return-to-sport decisions may be applying a tool with unverified measurement equivalence across racial groups [12].

Youth Athletes and Surveillance Gaps

Youth sports surveillance systems in the United States collect injury data by sport but not consistently by race. The High School RIO (Reporting Information Online) surveillance network tracks injury incidence across sports but does not currently publish race-stratified tendinopathy incidence rates. This absence means pediatric tendinopathy epidemiology by race remains largely unknown [13].

Common Extensor Tendinopathy (Lateral Epicondylalgia): Occupational Exposure Disparities

Lateral epicondylalgia (tennis elbow) is as much an occupational disease as a sports injury. Jobs involving repetitive forearm rotation and gripping, such as assembly line work, meatpacking, construction, and agricultural labor, carry well-documented tendinopathy risk [14].

Occupational Segregation as a Risk Driver

Black, Hispanic, and some Asian American workers are overrepresented in high-repetition manual labor sectors in the United States relative to their share of the general population. The Bureau of Labor Statistics Occupational Employment data consistently show this clustering. If occupational exposure drives a meaningful fraction of common extensor tendinopathy burden, then racial occupational segregation is a structural upstream cause of tendinopathy disparity, not simply a demographic coincidence [15].

Workers' Compensation Access

Workers' compensation systems provide the primary route for occupational tendinopathy treatment in the United States. Research on workers' compensation outcomes consistently finds that Black and Hispanic workers receive lower settlement amounts, face more claim denials, and return to work more slowly after musculoskeletal injury compared with white workers, even for the same injury types and severity [16]. These outcomes compound the direct health burden of tendinopathy.

Socioeconomic Mediators: Parsing Race from Class

Race and socioeconomic status are correlated in the United States but not identical. Parsing their independent contributions to tendinopathy disparities requires studies that control for both simultaneously. That level of analytical rigor is rare in the musculoskeletal literature.

Physical Therapy Access

Physical therapy is the backbone of tendinopathy rehabilitation. Load management programs (heavy slow resistance training for Achilles tendinopathy, for example) require consistent attendance over 12-16 weeks to show benefit [17]. Patients without reliable transportation, paid sick leave, or clinics in their geographic area face structural barriers to completing rehabilitation that are not captured by race alone.

CDC BRFSS data show that households earning below $30,000 per year report a 40% lower rate of physical therapy utilization compared with households above $75,000, and lower-income households are disproportionately headed by Black and Hispanic adults [18]. This income-mediated access gap likely accounts for a portion of the racial gap in tendinopathy outcomes.

Insurance Type and Specialist Referral

Medicaid versus commercial insurance status predicts specialist referral rates for musculoskeletal conditions more strongly than race in some multivariate analyses. Black and Hispanic patients are enrolled in Medicaid at higher rates. Orthopedic and sports medicine specialists have lower Medicaid acceptance rates than primary care physicians, creating a referral bottleneck that disproportionately affects non-white patients [19].

Genetic and Biological Factors: What the Evidence Actually Supports

Some tendinopathy risk is heritable. Variants in genes encoding collagen (COL5A1, COL1A1) and matrix metalloproteinases (MMP3) have been associated with Achilles tendinopathy and tendon rupture in genetic association studies [20]. These studies have been conducted almost exclusively in South African, British, and Australian populations with limited ancestral diversity.

What Genetic Risk Does and Does Not Explain

Identifying a gene variant associated with tendon pathology does not mean race causes tendinopathy. Allele frequency differences between populations are modest, and environmental and loading factors dwarf genetic contributions in most causal models. The American College of Medical Genetics does not recommend routine genetic screening for tendinopathy risk in any population [21]. Attributing tendinopathy disparities to biology without ruling out structural and access-based explanations is not supported by current evidence.

The Biological-Structural Spectrum Framework

A clinically useful way to think about racial tendinopathy disparities is a spectrum anchored at two poles. At one pole sit biological factors: tendon geometry, collagen subtype expression, and possibly pharmacogenomic differences in fluoroquinolone metabolism. At the other pole sit structural factors: occupational exposure, imaging access, pain assessment bias, and insurance-driven referral delays. Current evidence places the preponderance of explained variance in the structural half of this spectrum. Any clinical or research protocol that addresses tendinopathy disparities should therefore prioritize structural interventions first, while remaining open to biological refinement as genetic studies diversify their cohorts.

Clinical Implications: What Practitioners Can Do Now

Waiting for perfect race-stratified epidemiology is not a strategy. Several evidence-grounded actions are available to clinicians today.

Screening and History-Taking

Ask about occupational exposure in every tendinopathy history. Document job tasks, repetition rates, and tool weights. The Occupational Safety and Health Administration (OSHA) ergonomic guidelines identify cumulative loading thresholds for upper-extremity tendinopathy that can inform clinical risk stratification regardless of race [22].

Equitable Pain Assessment

Use validated numeric rating scales and standardized functional outcome measures (VISA-P for patellar, VISA-A for Achilles) and document the patient's self-reported score in the chart. Relying on clinician gestalt for pain severity introduces the implicit bias documented in the Hoffman et al. Study [9].

Physical Therapy Prescribing

When prescribing physical therapy, note transportation barriers and schedule constraints in the referral. Telehealth-guided home exercise programs for Achilles tendinopathy using heavy slow resistance protocols have shown non-inferiority to in-person care in one RCT (Beyer et al., 2015, N=58), and may reduce access barriers for patients in underserved areas [17].

Fluoroquinolone Stewardship

Given the FDA black-box warning and the disproportionate fluoroquinolone prescribing in some communities, clinicians should choose non-fluoroquinolone alternatives when clinically appropriate for patients who already have tendinopathy or who are on corticosteroids, a recognized combination risk [4].

Advocating for Diverse Trial Enrollment

The National Institutes of Health Revitalization Act of 1993 requires inclusion of racial and ethnic minorities in federally funded clinical research. Musculoskeletal trials continue to fall short of this standard. Clinicians who participate in research have an obligation to document enrollment demographics and advocate for diverse recruitment strategies [23].