Evaluation of the Painful Failed THR

Archival Presentation Notice: This article modernizes the multimedia presentation “Evaluation of the Painful Failed THR” originally presented by A.D. Hanssen, MD (Mayo Clinic, Rochester, MN). The historical Flash lecture has been reconstructed into the synchronized video slide presentation above, with the original file preserved in the digital archives (evaluation_of_the_painful_failed_thr_hanssen.swf).

1. Executive Summary & Clinical Paradigm

Total hip arthroplasty (THA) is one of the most reliable and clinically successful surgical procedures in modern medicine, with long-term implant survivorship exceeding 90% at 15 to 20 years. However, a defined subset of patients experiences persistent or newly developed disabling hip pain following surgery. The diagnostic evaluation of the painful total hip arthroplasty requires a rigorous, systematic, and algorithmic approach to distinguish between intra-articular (intrinsic) failure mechanisms and extra-articular or referred (extrinsic) pain generators.

The cardinal rule of revision hip arthroplasty is that surgical revision must never be performed for unexplained pain. Operating without a definitive, established diagnosis results in persistent symptoms and severe patient dissatisfaction in over 50% of cases. The primary clinical imperative is to systematically exclude periprosthetic joint infection (PJI) in every patient, followed by meticulous assessment of component fixation, adverse local tissue reactions (ALTR), soft tissue impingement, spinopelvic biomechanics, and lumbar spine or vascular pathology.

2. Clinical Etiology & Diagnostic Taxonomy

Differentiating intrinsic hip pathology from extrinsic sources forms the conceptual foundation of the clinical workup. Intrinsic etiologies originate directly from the prosthetic components, the bone-implant interface, or the surrounding articular soft-tissue envelope. Extrinsic etiologies represent pathology arising from anatomical regions remote from the hip joint that refer pain to the groin, thigh, buttock, or lateral pelvis.

3. Clinical History & Systematic Physical Examination

A comprehensive clinical evaluation begins with an exhaustive chronological review of the patient’s surgical history, the index operative report, implant specifications, and early postoperative recovery. The temporal pattern of symptom onset provides critical diagnostic clues:

• Absence of a Pain-Free Interval: Patients who never achieved pain relief following the index procedure are highly suspect for initial misdiagnosis (e.g., pain originally arising from lumbar spine stenosis or hip dysplasia), acute indolent periprosthetic infection, gross component malposition, acute nerve injury, or catastrophic early failure of component fixation.
• Late Pain Following a Prolonged Asymptomatic Period: A patient with years of excellent function who develops progressive symptoms is characteristic of progressive polyethylene wear, osteolysis, late aseptic loosening, fatigue failure of modular junctions, or hematogenous periprosthetic joint infection.
• Start-Up Mechanical Pain: Severe pain occurring during the first few steps after arising from a chair that gradually improves after walking a short distance is the classic pathognomonic presentation of mechanical stem loosening or unstable osseointegration.
• Positional and Activity-Related Pain: Pain provoked specifically when flexing the hip while seated (e.g., lifting the leg to tie shoes, getting into an automobile) strongly indicates iliopsoas tendon irritation over an anteriorly protruding acetabular component.

Anatomical Pain Mapping

The patient should be instructed to localize the primary pain generator with a single finger rather than a generalized gesture. Anatomical distribution strongly correlates with specific etiologies:

• Groin Pain: Most commonly reflects true intra-articular pathology, including acetabular component loosening, anterior iliopsoas impingement, infection, or occult stress fracture of the pubic ramus.
• Mid-Thigh Pain: Typically corresponds to femoral component pathology, such as distal stem tip toggle, loose un-cemented stem micro-motion, excessive modulus mismatch (cortical stress shielding), or pedestal formation.
• Lateral Hip Pain: Suggests greater trochanteric pain syndrome (trochanteric bursitis), gluteus medius or minimus tendon tears, trochanteric nonunion, or prominent hardware (e.g., trochanteric claw or cables).
• Posterior Buttock Pain: Frequently originates from extrinsic sources including sacroiliac joint degenerative changes, lumbar spine facet arthropathy, L5-S1 radiculopathy, or posterior ischiofemoral impingement.

Targeted Physical Examination Maneuvers

Physical examination must evaluate gait, spinal alignment, limb lengths, neurovascular integrity, and specific provocative stress tests:

• Gait Analysis: Assess for an abductor lurch (Trendelenburg gait indicating abductor insufficiency), an antalgic limp (shortened stance phase on the affected limb), or a foot drop reflecting common peroneal or sciatic nerve palsy.
• Stinchfield Test (Resisted Straight Leg Raise): With the patient supine and knee extended, active resisted hip flexion to 30 degrees generates substantial joint reactive forces across the hip joint. Severe groin pain suggests intra-articular pathology or iliopsoas irritation.
• Passive Internal and External Rotation (“Log Roll”): Gently rolling the supine lower extremity in extension isolates the hip joint while minimizing pelvic or lumbar motion. Exacerbation of deep groin discomfort confirms an intra-articular inflammatory or mechanical process.
• Patrick FABER and FADIR Tests: Flexion, abduction, and external rotation (FABER) stresses the sacroiliac joint when pain is posterior, or the hip joint when pain is anterior. Flexion, adduction, and internal rotation (FADIR) provokes anterior femoroacetabular or component-on-soft-tissue impingement.
• Abductor Strength Testing: Side-lying active hip abduction against resistance evaluates the structural continuity of the gluteus medius and minimus musculotendinous complex. Weakness accompanied by severe lateral trochanteric tenderness confirms abductor avulsion or severe trochanteric bursitis.

4. Ruling Out Periprosthetic Joint Infection (PJI)

Periprosthetic joint infection is the most devastating complication in joint arthroplasty and must be definitively ruled out in every painful total hip arthroplasty before entertaining revision for mechanical failure. Clinical presentation of chronic PJI is frequently indolent, lacking overt systemic signs such as fever, erythema, or wound drainage.

Laboratory Screening Protocol

Initial serological screening mandates simultaneous evaluation of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Serum D-dimer serves as an additional sensitive serologic adjunct in ambiguous cases:

• Normal Serum Biomarkers: If both ESR (<30 mm/hr) and CRP (<10 mg/L) are normal, the probability of periprosthetic joint infection is low (negative predictive value exceeding 96%), and attention should shift toward mechanical or extrinsic causes. However, low-virulence organisms such as Cutibacterium acnes may present with normal serologies.
• Elevated Serum Biomarkers: Elevation of either ESR or CRP mandates urgent image-guided hip aspiration prior to initiating antibiotic therapy or surgical exploration.

Diagnostic Arthrocentesis & Biomarker Criteria

Joint aspiration must be performed under strict sterile conditions using fluoroscopic or ultrasound guidance to verify intra-articular needle positioning. The patient must be off all antibiotic therapy for a minimum of 2 to 4 weeks prior to aspiration to maximize culture yield. Synovial fluid is analyzed for total white blood cell (WBC) count, polymorphonuclear cell differential (% PMN), leukocyte esterase strip testing, alpha-defensin immunoassay, and aerobic/anaerobic cultures held for 14 days.

Under the validated 2018 International Consensus Meeting (ICM) criteria, a cumulative aggregate score of 6 or greater is diagnostic of periprosthetic joint infection, a score of 2 to 5 indicates an inconclusive/possible infection requiring re-aspiration or advanced molecular testing (e.g., next-generation sequencing), and a score of 0 to 1 rules out infection.

5. Evaluation of Aseptic Mechanical Loosening & Osteolysis

Aseptic loosening represents the failure of biological or cementitious fixation between the prosthetic components and the host skeleton in the absence of active microbial infection. The diagnostic evaluation relies on serial comparison of standardized radiographs to detect progressive component migration, radiolucent line progression, and bone resorption.

Radiographic Analysis of the Acetabular Component

Acetabular fixation is systematically evaluated across the three zones defined by DeLee and Charnley on the anteroposterior pelvic radiograph:

• Zone I (Superior): Corresponds to the weight-bearing superior acetabular dome. Radiolucency here often indicates eccentric superior loading or polyethylene wear.
• Zone II (Middle): Spans the medial wall and teardrop region. Medial bone loss or component migration past the ilioischial (Köhler’s) line signifies medial cup loosening and protrusio.
• Zone III (Inferior): Corresponds to the inferior acetabular wall and obturator foramen border.

A continuous radiolucent line 2 mm or greater across all three DeLee and Charnley zones, cup rotation, or migration greater than 2 mm relative to the teardrop or inter-teardrop line definitively establishes acetabular component loosening.

Radiographic Analysis of the Femoral Component

Femoral component fixation is evaluated using the 7 Gruen zones on the anteroposterior radiograph (Zones 1-3 laterally, Zone 4 at the distal tip, and Zones 5-7 medially) and Zones 8 to 14 on the lateral projection:

• Cemented Femoral Fixation (Harris & Gruen Criteria): Definite loosening is characterized by complete radiolucent lines at the bone-cement or stem-cement interface in all zones, cement mantle fracture, or stem subsidence within the cement mantle. Probable loosening is defined by continuous radiolucency involving 50% to 99% of the mantle.
• Uncemented Porous-Coated Fixation (Engh Criteria): Stable osseointegration is confirmed by the presence of spot welds (endosteal bone bridging into the porous coating), absence of progressive radiolucent lines, and absence of distal pedestal formation. Unstable loose stems exhibit progressive axial subsidence, varus/valgus tilt, extensive divergent radiolucent lines surrounded by sclerotic demarcation, and dense hypertrophic cortical pedestal plugging at the distal stem tip.

6. Adverse Local Tissue Reactions (ALTR) & Trunnionosis

Adverse local tissue reactions (ALTR), also termed adverse reaction to metal debris (ARMD), represent an inflammatory, destructive soft-tissue and osseous response to particulate metal wear and soluble metallic ions. While historically linked to metal-on-metal (MoM) bearing couples, ALTR is now widely recognized in metal-on-polyethylene designs resulting from mechanically assisted crevice corrosion (MACC) at the modular femoral head-neck junction (trunnionosis) or modular neck-stem junctions.

Pathophysiology and Risk Factors

Trunnionosis develops when cyclic micro-motion between a cobalt-chromium femoral head and a titanium femoral stem disrupts the passive titanium dioxide protective oxide layer. The resulting crevice environment experiences hypoxia, drop in pH, and accelerated galvanic corrosion, releasing cobalt and chromium ions, particulate corrosion products, and metal oxides into the joint capsule.

• Biomechanical Drivers: Large-diameter femoral heads (≥36 mm) generate higher frictional torque and longer lever arms, increasing bending moments across the taper interface.
• Material Drivers: Dissimilar metal coupling (cobalt-chromium head on titanium stem), mismatched taper angles, insufficient impaction force during seating, or contamination of the trunnion with fluid or debris prior to head assembly.

Diagnostic Evaluation of Trunnionosis

• Serum Metal Ion Testing: Whole blood or serum cobalt and chromium levels should be quantified via inductively coupled plasma mass spectrometry (ICP-MS). In metal-on-polyethylene bearings, an isolated elevation of cobalt with a cobalt-to-chromium ratio exceeding 2:1 is highly characteristic of trunnion corrosion (since chromium is preferentially retained locally as insoluble phosphate or oxide deposits). Absolute cobalt levels exceeding 3 to 7 parts per billion (ppb, μg/L) warrant close cross-sectional imaging surveillance.
• Multi-Acquisition Variable-Resonance Image Combination (MAVRIC) / SEMAC MRI: Cross-sectional MRI with advanced metal artifact reduction software (MARS) is the definitive diagnostic modality. MARS-MRI accurately visualizes periarticular cystic or solid pseudotumors, thick-walled synovial expansion, abductor muscle necrosis, and cortical bone deossification that are completely occult on plain radiographs.

7. Soft Tissue Impingement Syndromes

Soft tissue impingement represents a critical category of intrinsic mechanical pain where the prosthetic hardware is solidly fixed but irritates adjacent muscular or tendinous structures during dynamic joint motion.

Iliopsoas Tendon Impingement

Iliopsoas impingement occurs when the iliopsoas tendon rubs over a prominent anterior structure during active hip flexion or passive hyperextension. The anatomical culprit is most commonly an anteriorly prominent acetabular component cup edge resulting from:

• Inadequate acetabular cup anteversion (retroversion causes the anterior metal rim to project beyond the bony acetabular margin).
• Oversized acetabular component that overhangs the anterior acetabular wall by greater than 4 to 8 mm.
• Prominent, unseated anterior fixation screws or residual anterior acetabular cement extrusions.

Clinical Signs and Diagnostic Confirmation: Patients report severe groin pain when actively lifting the leg from a seated position (e.g., getting into a car, ascending stairs). Tenderness is localized directly over the psoas tendon at the pelvic brim or femoral triangle. The definitive diagnostic test is a fluoroscopically guided injection of local anesthetic into the iliopsoas bursa or sheath: complete, immediate resolution of dynamic pain confirms the diagnosis and differentiates it from acetabular loosening.

Abductor Tendon Avulsion & Greater Trochanteric Pain Syndrome

Lateral hip pain following total hip arthroplasty frequently stems from pathology of the abductor mechanism (gluteus medius and minimus tendons), particularly following direct lateral (Hardinge) or anterolateral surgical exposures where the abductor tendon is detached and repaired. Chronic degeneration, surgical tear, or frank tendon detachment manifests as persistent lateral pain, severe Trendelenburg lurch, and weakness on resisted abduction. MARS-MRI or high-resolution dynamic ultrasound confirms tendon retraction, fatty muscular atrophy, and peritrochanteric fluid collections.

8. Biomechanical Malalignment, Impingement, & Instability

Implant malalignment can induce persistent pain through repetitive micro-subluxation, prosthetic-on-bone impingement, or edge-loading of bearing surfaces. Historical concepts of the “Lewinnek safe zone” (acetabular cup inclination 40° ± 10°, anteversion 15° ± 10°) have evolved toward a dynamic understanding of patient-specific spinopelvic mobility.

Spinopelvic Mobility and the Stiff Spine

In a physiologically normal individual moving from standing to sitting, the pelvis rotates posteriorly (pelvic tilt increases, sacral slope decreases), which dynamically increases functional acetabular anteversion and inclination to accommodate hip flexion and prevent anterior impingement. In patients with lumbar spinal fusion, ankylosing spondylitis, or severe lumbar degenerative disc disease:

• The Stiff, Flatback Pelvis: The pelvis fails to tilt posteriorly upon sitting. When the hip flexes, the femoral neck impinges prematurely against the rigid anterior acetabular rim, driving the femoral head out posteriorly and causing posterior dislocation or chronic rim wear.
• The Anteriorly Tilted Pelvis: In a fixed hyperlordotic posture, the pelvis remains tilted anteriorly upon standing, functionally reducing acetabular anteversion and predisposing the hip to anterior edge-loading or anterior instability upon standing and hip extension.
• Diagnostic Requirement: Preoperative evaluation of suspected mechanical instability or unexplained motion pain must include lateral spinopelvic radiographs in both standing and relaxed seated positions to quantify change in sacral slope (ΔSS) and pelvic tilt (ΔPT).

9. Extrinsic & Referred Causes of Hip Pain

Extrinsic sources account for a substantial proportion of patients presenting with persistent pain following total hip arthroplasty. Failure to identify these entities before surgery leads to inappropriate and ineffective revision arthroplasty.

Lumbar Spine Pathology

Lumbar spinal stenosis, spondylolisthesis, and degenerative disc disease frequently co-exist with hip pathology (the “hip-spine syndrome”). Compression of the upper lumbar nerve roots (L2, L3, L4) refers pain directly to the groin and anterior thigh, precisely mimicking the distribution of hip joint pathology. Lower lumbar radiculopathy (L5, S1) refers pain to the buttock and posterior-lateral thigh.

• Discriminatory Features: Spinal pain is frequently aggravated by prolonged standing, lumbar extension, or walking down slopes (neurogenic claudication), and relieved by lumbar flexion (“shopping cart sign”). Sensation changes in dermatomal distributions, reflex abnormalities (patellar or Achilles), and positive straight leg raise testing confirm a spinal etiology.

Vascular Claudication

Peripheral arterial disease with internal or external iliac artery stenosis produces exercise-induced gluteal or thigh cramping that resolves promptly with cessation of ambulation. Unlike start-up arthroplasty pain, vascular claudication is strictly distance-dependent and relieved by standing motionless. Palpation of femoral, popliteal, and pedal pulses and non-invasive vascular studies (ankle-brachial index) establish the diagnosis.

Pelvic Insufficiency & Stress Fractures

Occult stress fractures of the superior or inferior pubic ramus, anterior acetabular column, or sacrum can occur spontaneously in osteopenic or irradiated bone following THA. Pain is typically sudden in onset, severe during weight-bearing, and accompanied by exquisite pubic or pelvic tenderness. Bone scintigraphy, SPECT/CT, or pelvic MRI definitively reveals marrow edema and fracture lines that are invisible on standard radiographs.

10. Advanced Multimodality Imaging Modalities

When plain radiographs and standard serological markers are inconclusive, advanced multimodality cross-sectional imaging provides essential structural and physiological insights:

• Computed Tomography with Metal Artifact Reduction (MARS-CT): Enables accurate 3D assessment of component rotational alignment (femoral anteversion, acetabular anteversion, and combined anteversion), delineates periprosthetic osteolytic bone loss, and identifies anterior or posterior acetabular wall deficiency.
• Advanced Metal Artifact Reduction MRI (MAVRIC / SEMAC): Represents the gold standard for soft-tissue evaluation around metallic implants. Visualizes fluid-filled collections, pericapsular pseudotumors, abductor tendon continuity, and subtle muscle denervation with high anatomical fidelity.
• Single Photon Emission Computed Tomography (SPECT/CT): Combines 3D volumetric anatomical localization with functional osteoblastic metabolic activity. Focal tracer uptake at the bone-implant interface accurately distinguishes true mechanical micro-motion from normal bone remodeling.
• Three-Phase 99mTc-MDP Bone Scintigraphy: High sensitivity for increased bone turnover. A negative scan at least 12 to 24 months following primary arthroplasty provides a very high negative predictive value, virtually ruling out loosening or infection.

11. Diagnostic Injections & Joint Aspiration Strategy

An image-guided intra-articular local anesthetic challenge is the single most valuable diagnostic discriminator when distinguishing between intrinsic hip pathology and extrinsic (lumbar spine or vascular) pain generators.

Technique and Protocol

Under strict fluoroscopic or ultrasound guidance, a needle is advanced into the pseudocapsule of the hip joint. Aspiration is attempted first for microbiological and cytological evaluation. Following aspiration, 5 to 10 mL of local anesthetic (e.g., 1% lidocaine or 0.5% bupivacaine) is injected into the joint capsule, with or without radiographic contrast to document an intra-articular arthrogram pattern.

Interpretation of the Anesthetic Challenge

• Complete Immediate Relief (Positive Block): Greater than 80% to 100% temporary pain relief during provocative physical testing confirms unequivocally that the primary pain generator resides within the hip joint capsule. This confirms an intrinsic etiology (loosening, impingement, infection, or synovitis) and justifies focused revision planning.
• Zero or Minimal Relief (Negative Block): Persistence of pain following a verified intra-articular local anesthetic injection strongly indicates an extrinsic pain generator. Surgical revision of the hip joint in this setting is strictly contraindicated, and the patient must be directed toward lumbar spine, vascular, or abdominal evaluation.

12. Algorithmic Surgical Decision-Making & Revision Indications

Revision arthroplasty is a major surgical undertaking associated with increased morbidity, higher complication rates, and inferior patient-reported outcome scores compared to primary total hip arthroplasty. Surgical intervention is strictly justified only when an objective, verifiable cause of failure has been definitively confirmed.

13. Evidence-Based Synthesis

Modern clinical decision-making is grounded in high-quality randomized controlled trials and prospective registry analyses, corroborated by seminal biomechanical and anatomical descriptions.

14. References

• Parvizi J, Tan TL, Goswami K et al. The 2018 Definition of Periprosthetic Hip and Knee Infection: An Evidence-Based and Validated Criteria. J Arthroplasty. 2018. doi:10.1016/j.arth.2018.02.078 [Level II: Multicenter Diagnostic Validation & Consensus Study]
• Della Valle C, Parvizi J, Bauer TW et al. American Academy of Orthopaedic Surgeons clinical practice guideline on: the diagnosis of periprosthetic joint infections of the hip and knee. J Bone Joint Surg Am. 2011. doi:10.2106/JBJS.9314ebo [Level I: Evidence-Based Clinical Practice Guideline]
• Bozic KJ, Rubash HE. The painful total hip replacement. Clin Orthop Relat Res. 2004. doi:10.1097/00003086-200403000-00004 [Level V: Comprehensive Diagnostic Review & Algorithmic Consensus]
• Lanting BA, MacDonald SJ. The painful total hip replacement: diagnosis and deliverance. Bone Joint J. 2013. doi:10.1302/0301-620X.95B11.32948 [Level V: Systematic Diagnostic & Decision-Making Review]
• Hanssen AD, Osmon DR. Evaluation of a staging system for infected hip arthroplasty. Clin Orthop Relat Res. 2002. doi:10.1097/00003086-200210000-00004 [Level IV: Validation of Clinical & Host Staging System]

15. Master Class Pro-Tip

Master Class Surgical Pearl: Algorithmic Discipline in the Painful Total Hip Replacement

Never perform an exploratory revision total hip arthroplasty for unexplained pain. Revision surgery performed in the absence of an identifiable, objective mechanical or infectious etiology demonstrates unacceptably high rates of persistent pain and patient dissatisfaction. When standard radiologic and laboratory evaluations are equivocal, an image-guided intra-articular local anesthetic challenge provides the ultimate anatomical discriminator: complete temporary symptom relief definitively localizes the pain generator to the hip joint (compelling targeted investigation of subtle micro-motion, early osteolysis, adverse local tissue reaction, or occult impingement), whereas absence of pain relief mandates cessation of surgical intervention and focused investigation of lumbar spine pathology, sacroiliac dysfunction, or pelvic vascular compromise.

Master Class Surgical Pearl: Diagnostic Discipline in Revision Arthroplasty