Introduction
Osteoarthritis (OA) is a leading cause of pain and disability, particularly among individuals over the age of 55 years, significantly impacting mobility, independence, and quality of life (1). It is associated with increased all-cause mortality, loss of quality-adjusted life years (QALYs), and a disability burden comparable to chronic diseases such as cardiovascular disease and cancer (2,3). In addition to its clinical impact, OA imposes a substantial economic burden.
Currently, an estimated 51 million Americans are living with OA, contributing to more than $100 billion in direct medical costs annually (4). As populations age, the burden of OA on both individuals and healthcare systems is expected to continue growing.
Hip OA is the third most common form of OA, after knee and hand OA (5,6). The global prevalence of hip OA has recently been estimated at 8.55% (7), while in the USA, symptomatic hip OA affects approximately 3% of adults over 30 years old (4). The incidence of hip OA in the USA is estimated at 0.09 cases per person-year (8).
Notably, the number of hip OA cases is projected to increase by 78.6 % by 2050, underscoring the growing clinical challenge this condition presents (5).
Hip OA is a progressive, degenerative joint disease characterized by structural changes in the articular cartilage, subchondral bone, and synovium of the hip joint (9,10). While advanced hip OA is well characterized and often managed with total hip arthroplasty (THA), the early stages of disease remain less well defined. Early hip OA generally refers to a mildly symptomatic stage of disease with minimal or absent radiographic changes.
Heterogeneity in patient symptoms and treatment responses makes it challenging to determine the most effective interventions to slow or prevent disease progression. A better understanding of early hip OA is therefore critical for preserving joint function and reducing long-term disability. This review aims to synthesize current evidence on the diagnosis and management of early hip OA, with an emphasis on hip preservation techniques.
The literature included in this review article was identified through a targeted search of the PubMed database for studies relevant to the diagnosis and management of early hip OA and hip preservation techniques. Additional relevant publications were identified by reviewing the reference lists of selected articles.
History and physical exam
History
A thorough history and physical exam are essential for early diagnosis of hip OA. Clinical features suggestive of hip OA include persistent hip pain (>3 months), morning stiffness lasting <60 minutes, groin or medial thigh pain, restricted hip range of motion (ROM), absence of pain while sitting, a family history of OA, coexisting knee OA, and pain with stair climbing or walking downhill (11-13). In patients over the age of 60 years, these features are strongly indicative of hip OA.
However, OA should still be considered in younger individuals with similar presentations, as early-onset disease can occur, particularly in those with underlying conditions such as acetabular dysplasia or femoroacetabular impingement (FAI) (11,14).
Physical exam
Physical examination plays a central role in the evaluation of suspected hip OA. Findings most strongly associated with hip OA include posterior hip pain elicited by squatting, abductor weakness, groin pain with abduction or adduction, and loss of adduction and internal rotation (12,15-17). Patients often demonstrate an antalgic gait or a Trendelenburg gait due to abductor weakness.
Palpation may reveal anterior joint line tenderness, while tenderness over the greater trochanter suggests extra-articular pathology such as trochanteric pain syndrome rather than OA. A log roll test, although nonspecific, may reproduce intra-articular pain and can be helpful when other provocative tests are equivocal (18). In more advanced disease, apparent leg length discrepancy may be present due to joint space narrowing and collapse.
Importantly, physical examination alone demonstrates limited diagnostic specificity, as many of these findings overlap with other intra-articular hip conditions such as FAI, dysplasia, and labral tears. Notably, patients with FAI often exhibit isolated restriction of hip internal rotation, whereas patients with hip OA more commonly demonstrate global restrictions in motion (12).
Provocative maneuvers
Several provocative maneuvers are commonly used to reproduce intra-articular pain and help localize pathology (Table 1). A test is considered positive if it reproduces the patient’s typical pain. While these maneuvers are sensitive for intra-articular pathology, they lack high specificity for OA (19,20):
Diagnostic injections
When the pain source remains uncertain, diagnostic intra-articular hip injections can provide valuable clarity. Relief of pain following an anesthetic injection strongly suggests the hip joint as the primary pain generator. In a prospective series by Byrd and Jones (21), intra-articular injection demonstrated a sensitivity of 92% and specificity of 97% for identifying intra-articular pathology when compared with arthroscopic findings.
Other studies have reported similar trends, with sensitivity generally in the 85–95% range and specificity between 80% and 95% (22). While not infallible, a substantial reduction in pain following injection increases diagnostic confidence that the hip joint is the primary pain generator rather than an extra-articular source.
Imaging
Plain radiographs remain the gold standard for diagnosing hip OA. The standard views include an anteroposterior radiograph of the pelvis and a lateral view of the affected hip (23,24). Additional views, such as the Dunn view or false profile view (Figure 6), may be obtained to improve visualization of the anterosuperior joint space and to assess for FAI or acetabular dysplasia (14,23).
Radiographic features of hip OA include osteophyte formation, joint space narrowing, subchondral sclerosis, subchondral cysts, and, in more advanced cases, remodeling or deformity of the articular surface (25).
The severity of hip OA can be graded according to the Tönnis classification, originally described by Busse et al. (26), which ranges from grade 0 to grade 3 (Figure 7). Grade 0 indicates no radiographic evidence of OA.
Grade 1 demonstrates mild changes, including slight joint space narrowing, slight lipping at the joint margins, and mild sclerosis of the femoral head or acetabulum. Grade 2 is characterized by increased joint space narrowing, formation of small subchondral cysts, and moderate deformity of the femoral head. Grade 3 represents severe disease with marked joint space narrowing, large cysts, significant femoral head deformity, and possible evidence of avascular necrosis (27).
Rosinsky et al. (28) investigated the ratio of lateral-to-medial joint space (L/M ratio) as a predictor of hip arthroscopy survivorship in patients treated for FAI. They found that a larger L/M ratio, >0.75, was associated with increased survivorship at two years, indicating that lateral joint space narrowing may accelerate the progression of hip OA.
Although radiographs are essential in the evaluation of OA, it is primarily a clinical diagnosis based on a patient’s history and physical exam. Symptoms may precede radiographic changes, especially in early disease; therefore, normal imaging does not exclude an early OA diagnosis in patients with a clinical presentation strongly suggesting such a diagnosis (29,30).
While early signs of OA may not be evident on radiographs, magnetic resonance imaging (MRI) has the potential to detect early degenerative changes, including cartilage degradation and structural bone abnormalities. However, a validated MRI-based grading system for hip OA is not currently available. Additionally, the routine use of MRI is limited due to accessibility and cost in standard clinical settings (24).
Computed tomography (CT) has limited utility in detecting early hip OA but is frequently used in the evaluation and surgical planning of conditions like hip dysplasia and FAI, which may predispose patients to OA (31). Further research is warranted to define the role of advanced imaging modalities in the early diagnosis and management of hip OA.
Management
Non-operative management
Non-operative management is the first-line treatment for all patients with hip OA. It involves a multimodal approach, including nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, weight loss, assistive walking devices, and intra-articular injections. NSAIDs are considered first-line therapy for symptomatic OA and are strongly recommended by the American Academy of Orthopaedic Surgeons (AAOS) clinical practice guidelines to reduce pain and improve function, provided there are no contraindications (32,33).
Physical therapy and intraarticular injections are moderately recommended by the AAOS. Corticosteroid injections have demonstrated short-term pain relief and improvement in function (33-36). However, the duration of symptom relief is variable and repeated or high-dose injections may be associated with rapid acceleration of hip OA (37,38).
In contrast, intra-articular hyaluronic acid (HA) injections are not recommended, as current evidence shows no significant improvement in pain or function compared to placebo (32). Platelet-rich plasma (PRP) injections have also been investigated as a treatment option. While some studies report short-term improvements in pain and function, others have found outcomes comparable to those of HA injections; thus, the efficacy of PRP remains inconclusive (39-42).
Although disease-modifying osteoarthritis drugs (DMOADS) remain an active area of investigation, no pharmacologic therapy has demonstrated sufficient evidence of structural benefit or clinical efficacy to support routine clinical use in the management of early hip OA (43).
Operative management
Hip arthroscopy
When patients with hip OA fail to improve with conservative management, surgical intervention may be considered. Hip arthroscopy commonly involves procedures such as labral repair or reconstruction, femoral or acetabular osteoplasty, chondroplasty, microfracture, and capsular management (14). These interventions aim to address underlying bony and soft tissue abnormalities, alleviate symptoms, and preserve joint integrity, ultimately delaying the need for a THA (44).
Careful patient selection is critical to optimize surgical outcomes.
Previous evidence suggests that patients with persistent symptoms despite conservative treatment, minimal joint deformity, and mild arthritic changes are more likely to experience favorable outcomes following hip arthroscopy (45-48). Measures of joint degeneration, including Tönnis grade and joint space narrowing, are important predictors of success, with joint space narrowing potentially serving as a more reliable indicator of OA progression than Tönnis grade alone (49-52). For instance, patients with <2 mm of joint space were 12 times more likely to require conversion to THA than those with greater joint space (51).
Overall, these findings suggest that arthroscopy is most likely to benefit patients with Tönnis grade ≤1 or joint space >2 mm, whereas patients with more advanced radiographic changes may be better suited for alternative interventions, including THA or articular resurfacing (53).
While Tönnis grade and joint space width provide indirect assessments of hip cartilage, they may underestimate the severity of chondral damage, which is associated with poorer outcomes and earlier conversion to THA following arthroscopy (14,50,53-59). Haviv and O’Donnell (58) stratified patients by intraoperative chondral injury and reported a mean time to THA of 1.5 years, increasing to 2.2 years in patients with mild OA and decreasing to 1.2 and 1.1 years in those with moderate and severe OA, respectively. Additionally, lower preoperative functional scores have been associated with increased risk of arthroscopy failure, suggesting that prolonged symptom duration or significant functional decline before surgery may negatively affect long-term results (60).
Age also influences outcomes, with individuals over 40 years generally experiencing less favorable outcomes and higher rates of conversion to THA than younger patients (56,57,59,61-63). When strict selection criteria are applied, such as limiting arthroscopy to patients with Tönnis grades 0–1 and minimal joint space narrowing, older patients can achieve functional improvements and satisfaction similar to younger individuals, although they still demonstrate higher conversion rates and lower survivorship (57). These findings suggest that in older patients, the potential benefit of delaying arthroplasty must be carefully weighed against the risks and burden of undergoing multiple procedures.
Wyles et al. (64) provided valuable insight into the natural history of hip OA, finding that patients with Tönnis grade 1 and hip dysplasia had approximately a one-in-three probability of requiring THA within 10 years, increasing to two-in-three at 20 years. Patients with FAI demonstrated a similar natural history to those with morphologically normal hips, with a one-in-five probability at 10 years and one-in-two at 20 years.
Based on these findings, the authors concluded that surgical correction of FAI may only minimally alter the natural course of the disease, especially once degenerative changes are already present.
More recent evidence suggests that hip arthroscopy, particularly when performed with modern techniques, including labral preservation, femoroplasty, and capsular closure, can meaningfully modify disease progression in patients with FAI. Ramkumar et al. (65) compared operative hips with contralateral nonoperatively managed hips and observed radiographic progression to a worse Tönnis grade in 48% of nonoperative hips compared with 28% of operative hips, with 25% of operative hips demonstrating improvement in Tönnis grade.
These findings indicate that while arthroscopy does not universally alter the natural history of hip OA, modern techniques can delay progression and preserve joint health in carefully selected patients.
These studies highlight that the benefit of hip arthroscopy in early OA is highly dependent on patient selection and underlying pathology (64,65). Patients with concomitant impingement and instability experience faster OA progression even with arthroscopic treatment, whereas individuals with isolated impingement, smaller cam deformities, preserved joint space, and low preoperative Tönnis grades are most likely to benefit from arthroscopy. The role of modern surgical technique in optimizing outcomes is further emphasized by Nepple et al.
(66), who demonstrated that in patients with isolated cam-type FAI, femoroplasty at the time of arthroscopy increased 15-year survivorship from 41% to 78% and improved functional outcomes. Together, these findings underscore that successful arthroscopic intervention depends on careful patient selection and modern surgical techniques that correct underlying pathology.
Biologic augmentation has also been explored to further enhance outcomes following hip arthroscopy. Bone marrow aspirate concentrate (BMAC) is an orthobiologic that has shown potential benefit in reducing pain and improving function when used as an adjunct during hip arthroscopy for patients with symptomatic labral tears and early OA (67-69). Although evidence for BMAC, like PRP, remains limited and there is no consensus regarding its efficacy or standardized use (15), recent studies suggest that BMAC may offer short- and intermediate-term benefits.
Day et al. (70) compared patients with labral tears and early OA who underwent hip arthroscopy combined with BMAC injection to a control group of patients with symptomatic labral tears without arthritis who underwent hip arthroscopy alone. At 2-year follow-up, both groups demonstrated significant improvements in patient-reported outcomes, with no statistically significant difference observed between treatment groups.
Although five patients in the BMAC group ultimately required conversion to THA compared with one in the control group, this difference was not statistically significant, suggesting that hip BMAC may serve as a viable short-term adjunct for symptomatic labral tears and early OA.
Potential long-term benefits are reported by Martin et al. (68), who evaluated patients undergoing labral repair with and without BMAC augmentation. At 5-year follow-up, patients who received BMAC demonstrated greater functional improvement than controls, with differences reaching statistical significance after two years and continuing to increase through five years.
These findings suggest that BMAC may not only support short-term recovery but also contribute to sustained improvements in patient function following hip arthroscopy.
Overall, hip arthroscopy can be an effective intervention for select patients with early OA, particularly when modern techniques and biological adjuncts are applied. Shared decision-making is crucial, and patients should be thoroughly counseled on the risks and benefits, including the potential need for future conversion to THA. Proper expectation management remains essential to optimizing outcomes and patient satisfaction (14,44).
Peri-acetabular osteotomy (PAO)
In patients with early hip OA and acetabular dysplasia, PAO is a viable treatment option; however, like hip arthroscopy, it requires careful patient selection (14,44). Multiple studies have demonstrated favorable outcomes and long-term survivorship with PAO (40,71-73). However, certain factors, most notably advanced age and severe arthritic changes, are important predictors of outcomes and risk of failure (74).
Ziran et al. (73) reported a 10-year survivorship of 86% and a 20-year survivorship of 60% for native hips following PAO. However, outcomes were influenced by preoperative arthritis and patient age.
Patients with lower Tönnis grades [0–1] exhibited approximately double the survivorship of those with Tönnis grade >2, and 10-year survival rates declined progressively with age, from 90% at age 30 years to 81.6% at 40 years and 63.2% at 50 years. These findings were further supported by Wyles et al. (75), who evaluated the natural progression of dysplastic hips after PAO and reported that Tönnis grade 1 hips had a 2% and 11% probability of conversion to THA at 5 and 10 years, respectively, compared to 23% and 53% in Tönnis grade 2 hips.
These data demonstrate that while PAO can modify the natural history of hip dysplasia, its benefit is limited once moderate OA has developed.
At 30-year follow-up, Lerch et al. (76) reported less favorable outcomes, with 70% of patients experiencing progressive OA, pain, or conversion to THA. Only 8% of hips with advanced preoperative arthritis survived at 30 years, compared to 42% among hips without preoperative arthritis.
Additionally, no hip survived to final follow-up in patients older than 45 years at the time of surgery. Based on these findings, the authors concluded that patients with Tönnis grade >2 or those older than 45 years are poor candidates for PAO, and proposed that the ideal candidate is under 40 years, has minimal preoperative pain, and Tönnis grade <1.
Despite these long-term results, mid-term outcomes suggest that selected older patients may still benefit from PAO. Novais et al. (72) reported favorable mid-term outcomes in patients over 40 years, with a mean survivorship of 15.5 years and survival rates of 90%, 71%, and 54% at 5, 10, and 15 years, respectively.
Early survivorship in this age range was similar in the Lerch study (76), although a marked decline occurred beyond 20 years, suggesting that longer follow-up in the Novais cohort might reveal similar late declines. These findings indicate that while PAO can provide meaningful symptom relief and joint preservation in the mid-term for older patients, long-term outcomes remain less certain. Nevertheless, both studies agree that patients with advanced preoperative OA are poor candidates for PAO, and that lower preoperative function and higher baseline pain are associated with an increased risk of failure.
Overall, these data suggest that while PAO is an effective hip preservation option for patients with acetabular dysplasia and early OA, careful consideration of age, arthritis severity, and preoperative pain is essential. Younger patients with minimal arthritis tend to demonstrate the most favorable long-term outcomes, whereas older individuals or those with advanced disease and significant preoperative pain should be counseled on the increased likelihood of progression and eventual need for THA.
Hip arthroplasty
Hip resurfacing is an appealing option for younger, active patients due to its benefits of bone preservation, lower dislocation rates, and the potential for improved function. However, its use has declined over time due to concerns about complications, including femoral neck fractures, implant loosening, metal ion production, and adverse local tissue reactions caused by metal debris (14,77,78). Careful patient selection is critical to minimize these risks.
The literature suggests that the ideal candidate is a young, active male with good bone quality and minimal femoral head deformity. Outcomes in women have been less favorable, with differences potentially related to smaller femoral head size, variations in hip morphology, and differences in bone quality. Short-term outcomes have been favorable, with survivorship at 5 to 10 years comparable to that of THA (78-80).
Dhawan et al. (81) demonstrated long-term implant survival of 91.5% at 20 years, including a 96.5% survival rate in males, along with excellent functional outcome scores. Hip resurfacing has also demonstrated favorable outcomes in facilitating return to sport, including among high-level athletes (82-84).
Total hip replacement remains the standard for patients with end-stage disease. However, in patients who have exhausted conservative treatment but do not yet demonstrate significant radiographic OA, outcomes following THA may be less predictable. Some studies have shown that individuals with minimal joint space narrowing and early radiographic changes may experience persistent pain or dissatisfaction after surgery (85-90).
Therefore, it is critical to fully exhaust non-operative treatments and joint-preserving options before proceeding with arthroplasty in this population. If THA is pursued, patients should be thoroughly counseled and expectations carefully managed, including the possibility of limited symptom relief.
Surgical decision-making
Managing early hip OA is complex, and treatment decisions should be individualized. Before considering surgery, conservative measures must be optimized. If symptoms persist, surgical options include hip preservation surgery or arthroplasty.
Key factors influencing this decision will include patient age, activity level, Tönnis grade, joint space narrowing, L/M ratio, correctable deformity, and extent of chondral damage.
To aid in this process, we have provided an algorithm for surgical decision-making (Figure 8) and demonstrate its application with two patient examples (Figure 9). Both patients presented with persistent hip pain and similar radiographs showing minimal degenerative changes.
While this algorithm provides a structured framework, shared decision-making remains essential. Patient preferences must be considered, and discussions should address expectations, benefits, and risks to ensure optimal outcomes.
Strengths and limitations
This review provides a comprehensive and up-to-date synthesis of the current evidence on the diagnosis and management of early hip OA, with a particular focus on hip preservation techniques. It integrates findings from both short- and long-term outcome studies and highlights key factors influencing treatment success, providing practical guidance for clinical decision-making and patient selection. However, as a review article, these findings are subject to selection bias, as no formal systematic methodology was used to identify or appraise the included studies.
Additionally, the quality of the available literature varies considerably, with many studies relying on retrospective data or single-center experiences. Due to variation in study quality and heterogeneity, these findings may have limited generalizability across diverse patient populations and clinical settings.
Conclusions
The management of early hip OA is complex and often challenging, requiring a comprehensive approach. Initial treatment should focus on conservative measures, including NSAIDs, physical therapy, and corticosteroid injections. For appropriately selected patients, hip preservation techniques, such as hip arthroscopy and PAO, are viable options that may alleviate symptoms, improve function, and delay or even prevent the need for THA or hip resurfacing.
However, the success of these interventions depends heavily on proper patient selection. Factors such as age, the extent of arthritic changes, and baseline function are critical in determining outcomes. Therefore, shared decision-making and thorough preoperative counseling are essential to optimize results and ensure patient satisfaction.
Future research should focus on improving the characterization of early hip OA and identifying patient-specific factors associated with treatment response. Better differentiation of patients based on underlying disease characteristics may help refine treatment selection, improve patient outcomes, and guide the development of more targeted therapeutic strategies.
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