Is total hip replacement still the best option for a male patient with severe hip pain, functional impairment, and walker dependence, given the discrepancy between x-ray findings of moderate to severe arthritis and MRI findings of mild degenerative changes with preserved joint space?

Orthopedic Consultation is Warranted Before Proceeding with Total Hip Replacement

Given the significant discrepancy between x-ray findings suggesting "bone-on-bone" arthritis and MRI demonstrating only mild degenerative changes with preserved joint space, total hip replacement should NOT proceed as scheduled until orthopedic evaluation reconciles this imaging conflict and identifies the true pain generator. The severity of functional impairment (walker dependence, 10/10 pain) is grossly disproportionate to the mild MRI findings, suggesting alternative diagnoses that must be excluded before irreversible surgery 1, 2.

Why This Imaging Discrepancy is Critical

MRI is significantly more sensitive than radiographs for detecting true joint pathology, with 95.4% sensitivity for osteolytic lesions compared to only 51.7% for radiographs 2. When MRI contradicts x-ray interpretation, MRI findings should take precedence for surgical decision-making 3. The ACR Appropriateness Criteria establish that radiographs are the initial screening tool for chronic hip pain, but when findings are equivocal or discordant with clinical presentation, MRI without contrast is the definitive next step 1.

The MRI findings do NOT support end-stage arthritis requiring arthroplasty:

• Preserved joint space directly contradicts "bone-on-bone" interpretation 2
• Only mild diffuse cartilage thinning and small peripheral osteophytes 1
• Probable mild anterior superior labral tear (commonly asymptomatic per radiologist) 1

Alternative Pain Generators That Must Be Evaluated

The clinical presentation suggests non-arthritic pathology:

Femoroacetabular Impingement (FAI)

• X-ray demonstrated femoral neck cortical thickening suggestive of FAI 1
• FAI can cause severe pain and functional limitation without end-stage arthritis 1
• MR arthrography (not standard MRI) is the gold standard for evaluating labral tears with impingement, rated 9/9 "usually appropriate" by ACR 1
• The mild labral tear identified may be symptomatic in the context of FAI 1

Sacroiliac Joint Pathology

• Moderate degenerative changes of bilateral SI joints were noted on x-ray 1
• SI joint dysfunction commonly refers pain to the hip and buttock region 1
• Image-guided anesthetic injection of the hip joint can differentiate intra-articular hip pain from referred pain (especially from spine/SI joints), with significant pain relief after injection suggesting true intra-articular pathology 1

Extra-articular Soft Tissue Pathology

• Severe pain with mild imaging findings raises suspicion for tendinopathy, bursitis, or other soft tissue abnormalities 1
• MRI without contrast is rated 9/9 "usually appropriate" for suspected extra-articular soft tissue abnormalities when radiographs are non-diagnostic 1

Recommended Diagnostic Algorithm Before Surgery

Step 1: Orthopedic review of all imaging with specific attention to:

• Reconciling x-ray vs MRI joint space assessment 2
• Evaluating for FAI morphology and symptomatic labral pathology 1
• Assessing whether SI joint changes could explain symptoms 1

Step 2: Consider diagnostic hip joint injection:

• Image-guided anesthetic injection to determine if pain is truly intra-articular 1
• Significant pain relief (>50%) suggests hip joint as pain generator 1
• Minimal relief suggests alternative diagnosis (SI joint, spine, soft tissue) 1

Step 3: If labral tear/FAI is suspected as primary pathology:

• MR arthrography is superior to standard MRI for labral tear characterization 1
• Hip arthroscopy with labral repair/FAI correction may be appropriate instead of arthroplasty 1

Step 4: If SI joint is suspected:

• Targeted SI joint imaging and/or diagnostic injection 1
• SI joint dysfunction treatment before considering hip replacement 1

Critical Pitfalls to Avoid

Do not proceed with total hip arthroplasty based solely on x-ray interpretation when:

• MRI contradicts the severity of arthritis 2, 3
• Clinical symptoms are disproportionate to imaging findings 1
• Alternative pain generators have not been excluded 1

Total hip replacement is one of the most effective orthopedic procedures when appropriately indicated, but performing arthroplasty on a hip without end-stage arthritis will not address the patient's pain if the true pathology is FAI, labral tear, SI joint dysfunction, or extra-articular soft tissue disease 4, 5. The patient will continue to have severe pain post-operatively with an unnecessary prosthetic joint 5.

Normal or near-normal MRI findings in the setting of severe functional impairment should prompt consideration of:

• Non-orthopedic causes (neurologic, vascular, referred pain) 1
• Psychological factors contributing to pain perception 5
• Medication-seeking behavior (though this should not be assumed) 5

Strength of Recommendation

This recommendation is based on ACR Appropriateness Criteria (2017,2023), which represent consensus expert opinion from the American College of Radiology using established RAND/UCLA methodology 1, 2. The guidelines explicitly state that MRI is superior to radiographs for detecting true joint pathology and that diagnostic hip injection is appropriate for differentiating intra-articular from extra-articular pain sources 1, 2.