Can Hip Osteoarthritis Cause Knee Pain?
Yes, hip osteoarthritis frequently causes referred knee pain, and this is a commonly missed diagnosis that can lead to unnecessary knee interventions and delayed appropriate treatment. 1
Clinical Recognition of Hip-Referred Knee Pain
Hip pathology presenting as knee pain is a well-documented but frequently overlooked phenomenon, even among musculoskeletal specialists:
- Hip osteoarthritis can manifest as isolated knee pain without groin or thigh symptoms, leading to misdiagnosis and inappropriate knee-focused treatments 1
- In one institutional series, 21 patients were referred for knee pain but ultimately diagnosed with hip pathology as the primary cause—15 of these referrals came from musculoskeletal providers, including 12 from orthopaedic surgeons 1
- Twelve patients underwent surgical knee interventions (including total knee arthroplasty) with minimal to no pain relief before the hip etiology was identified 1
- After total hip arthroplasty, 14 of 17 patients had complete resolution of their knee pain 1
Mechanism and Patterns
- Referred pain from hip joint pathology is a recognized pattern, particularly in adolescents with slipped capital femoral epiphysis, but occurs across all age groups 2
- The referred pain pattern follows dermatomal and myotomal distributions from the hip joint 2
- Pain with internal hip rotation on physical examination is a key diagnostic finding for hip osteoarthritis 3
Critical Diagnostic Approach
Always examine the hip in any patient presenting with knee pain, especially when:
- Knee examination findings are inconsistent with the severity of symptoms 1
- Previous knee-directed treatments have failed 1
- The patient has progressed to requiring assistive devices (16 of 21 patients in one series required wheelchairs or major assistive devices before hip diagnosis) 1
- Knee imaging shows minimal pathology relative to symptoms 1
Common Pitfall to Avoid
The most critical error is attributing knee pain solely to knee pathology without performing a thorough hip examination. This oversight persists even among experienced orthopaedic surgeons and can result in unnecessary knee surgeries, prolonged disability, and delayed definitive treatment 1. The American College of Radiology explicitly warns against this: "Never attribute migratory knee pain solely to osteoarthritis without excluding crystal disease or infection" 4, and this principle extends to excluding hip pathology as well.
Management Implications
- When hip osteoarthritis is the source of knee pain, treating the hip (including total hip arthroplasty when indicated) resolves the knee symptoms 1
- Unlike knee OA, which can often be managed nonsurgically, hip OA with significant symptoms typically requires total hip arthroplasty, which is considered one of the most effective orthopedic procedures 5
- There is no evidence that delaying total hip arthroplasty is beneficial when hip OA is causing significant symptoms 5