Archive for category: Editor’s Choice

Rethinking Femoroacetabular Impingement: Evidence, Indications, and Surgical Timing

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The Clinical Dilemma

Few conditions in contemporary sports medicine and joint preservation generate as much debate as femoroacetabular impingement (FAI). Every orthopaedic surgeon recognizes the classic presentation: an active young adult presenting with insidious groin pain, positive FADIR testing, and an anterolateral cam deformity on Dunn lateral radiography. The diagnostic dilemma lies not in identifying the bony morphology, but in determining which hips warrant surgical correction versus nonoperative preservation.

As advanced imaging modalities became widespread over the past two decades, our understanding of hip biomechanics shifted rapidly. Asymptomatic individuals frequently demonstrate elevated alpha angles and acetabular overcoverage. Operating strictly on imaging findings is an error: radiographic impingement morphology without mechanical symptoms does not justify surgical intervention. Conversely, delaying intervention in symptomatic patients with recurrent mechanical catching and progressive chondral delamination risks accelerating irreversible joint degeneration.

The Landmark Evidence: What the Data Shows

For years, proponents of hip arthroscopy relied on retrospective case series and single-surgeon cohorts. That paradigm changed with the publication of multi-center randomized controlled trials evaluating arthroscopic osteochondroplasty against structured conservative rehabilitation. The landmark investigation is the UK FASHIoN trial (Full Assessment of the Short-term effectiveness of arthroscopic Hip surgery compared with personalised Hip therapy), published by Griffin and colleagues in The Lancet.

The trial randomized 348 patients across 23 hospitals in the United Kingdom to either hip arthroscopy (labral repair and osteochondroplasty) or personalized hip therapy (a structured physiotherapist-led program). At 12 months of follow-up, both cohorts demonstrated clinically meaningful improvements. However, the surgical group achieved a statistically significant and clinically superior improvement in the primary endpoint, the International Hip Outcome Tool (iHOT-33), with an adjusted mean difference of 6.8 points favoring arthroscopy. Similar multi-center trials, including the Australian FAIT trial, corroborated that mechanical decompression yields superior functional relief in properly selected candidates.

Landmark StudyDesign / CohortPrimary OutcomeClinical SignificanceEvidence LevelDOI
Griffin et al. (UK FASHIoN, Lancet 2018)Multi-center Pragmatic RCT (n=348)iHOT-33 score at 12 months favored arthroscopy (difference 6.8 points; 95% CI 1.7 to 12.0; p=0.0093)Establishes superiority of surgical decompression over physiotherapy alone in symptomatic young adults.[Level I: Randomized Controlled Trial]DOI
Hunter et al. (FAIT Trial, Br J Sports Med)Multi-center Pragmatic RCTComparison of arthroscopic surgery vs physiotherapy and activity modificationCorroborated medium-term clinical superiority and patient retention for surgical decompression.[Level I: Randomized Controlled Trial]DOI
Reiman et al. (Br J Sports Med 2015)Systematic Review & Meta-AnalysisDiagnostic utility of physical exam maneuvers (FADIR, FABER)Demonstrated high sensitivity (>90%) but poor specificity; physical exam must pair with imaging.[Level I: Systematic Review]DOI

Connecting the Data to Practice: The OrthopaedicsOne Synthesis

While randomized trials prove the efficacy of surgical intervention, successful clinical outcomes depend entirely on surgical execution, anatomical precision, and avoiding common pitfalls. This is where our foundational knowledge base bridges trial data with daily operating room practice.

On OrthopaedicsOne, our fully modernized clinical guide, What Is the Latest Update on Hip Impingement, synthesizes the complete diagnostic and operative algorithm. The guide integrates Dr. Trousdale’s faculty lecture directly alongside detailed measurements: calculating the alpha angle on Dunn 45-degree lateral projections, identifying retroversion through the crossover sign and ischial spine sign, and evaluating chondral delamination staging.

Crucially, our article details the hard exclusion criteria that prevent surgical failure: hips presenting with advanced Tonnis osteoarthritis (Grade 2 or 3) or joint space narrowing below 2 mm fail rapidly after arthroscopic debridement. For those patients, arthroplasty provides reliable pain relief, whereas arthroscopy merely delays definitive reconstruction.

Surgical Decision-Making Pearls

From an academic reconstructive perspective, three fundamental rules govern the management of femoroacetabular impingement:

  • Define the Target Morphology with Exact Radiographs: Standard anteroposterior pelvis views are inadequate in isolation. Always obtain a Dunn 45-degree or Dunn 90-degree lateral view to evaluate the anterior femoral head-neck junction where cam deformities predominate. An alpha angle exceeding 55 degrees confirms pathologic asphericity in a symptomatic joint.
  • Respect the Femoral Neck Resection Margin: Over-resection of the femoral neck is a catastrophic error that predisposes the patient to post-arthroscopy femoral neck fracture. The osteochondroplasty resection must never exceed 30 percent of the femoral neck diameter. Intraoperative dynamic fluoroscopy or optical navigation confirms complete clearance without compromising cortical hoop strength.
  • Prioritize Labral Refixation Over Debridement: The acetabular labrum provides a crucial fluid suction seal that distributes hydrostatic pressure across articular cartilage. Selective debridement should be restricted to degenerative, non-viable fraying. Whenever viable tissue exists, anatomically repair the labrum back to the acetabular rim using knotless or low-profile suture anchors.

The Bottom Line

The management of FAI has matured from speculative intervention into an evidence-based discipline. Level I randomized trials support arthroscopic osteochondroplasty for young patients with mechanical symptoms, defined cam or pincer deformities, and preserved joint space. Precision in patient selection remains the single most important variable: identify the deformity accurately, preserve the labral suction seal, and avoid operating on joints that have already progressed to advanced chondrosis.

How is your practice approaching borderline dysplasia with concomitant cam lesions? Review our complete clinical monograph and share your perspective:

Read the Full FAI Clinical Guide on OrthopaedicsOne →

Bearing Surfaces and Wear in Total Joint Arthroplasty: Lessons from Long-Term Registry Surveillance

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The Clinical Dilemma

Bearing surface selection in total hip arthroplasty (THA) has generated passionate debate across three decades of reconstructive surgery. Surgeons who trained during the era of conventional ultra-high-molecular-weight polyethylene vividly recall the devastating consequences of particle-induced osteolysis: extensive pelvic osteolysis, loose acetabular components, and catastrophic bone loss requiring complex structural augments. That institutional memory catalyzed the search for alternative hard-on-hard articulations, leading to the rapid adoption of ceramic-on-ceramic and metal-on-metal bearings.

Today, our clinical landscape is far more nuanced. The introduction of highly cross-linked polyethylene (HXLPE) in the late 1990s dramatically altered wear kinetics, dropping volumetric wear well below the critical threshold for osteolysis. Simultaneously, the orthopaedic community confronted the catastrophic worldwide failures of large-head metal-on-metal implants due to adverse local tissue reactions (ALTR) and metallosis. Reconstructive surgeons now face a practical dilemma: does the marginal reduction in wear offered by modern delta ceramic-on-ceramic justify its higher implant cost and unique risks of squeaking, stripe wear, and brittle ceramic component fracture?

The Landmark Evidence: What the Data Shows

The definitive answers to these tribological questions come not from short-term laboratory simulators, but from comprehensive multi-decade national joint replacement registries. Over the past 20 years, data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the National Joint Registry for England and Wales (NJR) have established the real-world survivorship of modern bearing combinations across hundreds of thousands of patient years.

In a landmark investigation published in The Lancet, Smith and colleagues analyzed over 31,000 metal-on-metal hip procedures from the National Joint Registry, proving that stemmed large-diameter metal-on-metal articulations demonstrated unacceptably high revision rates compared with ceramic-on-polyethylene and metal-on-polyethylene. Conversely, systematic reviews published in the British Medical Journal by Sedrakyan and colleagues established that while ceramic-on-ceramic bearings offer minimal volumetric wear, they provide no statistically significant clinical advantage in revision survivorship over ceramic on highly cross-linked polyethylene at 10 to 15 years.

Landmark StudyRegistry / DesignPrimary EndpointClinical SignificanceEvidence LevelDOI
Sedrakyan et al. (BMJ 2011)Systematic Review & Network Meta-AnalysisComparative revision rates across hip bearing surfacesFound no survivorship advantage for ceramic-on-ceramic over ceramic-on-polyethylene in primary THA.[Level I: Systematic Review]DOI
Smith et al. (Lancet 2012)NJR England & Wales Cohort (n=31,109)Failure rates of metal-on-metal hip resurfacing and stemmed bearingsDocumented accelerated failure rates in stemmed metal-on-metal, leading to global regulatory alerts.[Level II: Registry Cohort Study]DOI
Lachiewicz et al. (J Arthroplasty 2018)Prospective Cohort (5 to 13-Year Follow-up)Linear wear and osteolysis in 36-mm heads with HXLPEReported ultra-low mean linear wear (0.016 mm/year) and zero osteolysis with highly cross-linked polyethylene.[Level II: Prospective Cohort]DOI

Connecting the Data to Practice: The OrthopaedicsOne Synthesis

Registry outcomes provide population-level guidance, but surgical outcomes depend on the mechanical and biological details executed in the operating theater. On OrthopaedicsOne, two companion clinical monographs provide the comprehensive scientific foundation for this discussion.

Our clinical guide, Why I Use Cross-Linked Polyethylene, explains the free radical scavenging chemistry behind modern sequential irradiation and vitamin E stabilization. The guide details how eliminating free radicals prevents oxidative degradation and shelf aging, maintaining tough mechanical properties even in thin cross-sections. Furthermore, our dedicated review on Evidence-Based Data for Bearing Surfaces breaks down friction coefficients, lubrication regimes, and fluid film thicknesses across competing material combinations.

Together, these knowledge assets illustrate why a ceramic femoral head articulating against highly cross-linked polyethylene represents the contemporary gold standard for primary reconstructive surgery: combining forgiving mechanical compliance with ultra-low wear rates below 0.02 mm per year.

Surgical Decision-Making Pearls

To optimize bearing longevity and avoid premature revision, three intraoperative principles must be maintained:

  • Balance Head Diameter Against Liner Thickness: While a 36-mm femoral head significantly increases jump distance and reduces dislocation risk, it necessitates a thinner polyethylene liner in smaller acetabular cups. Never compromise polyethylene thickness below 5 mm at the superior weight-bearing dome. In acetabular components smaller than 50 mm, a 32-mm head provides an optimal balance between stability and liner thickness.
  • Meticulously Clear the Locking Mechanism: Backside wear and liner dissociation often stem from incomplete seating. Prior to impacting the polyethylene liner, thoroughly irrigate the interior of the metal shell and remove every trace of soft tissue or bone slurry. Inspect the circumference under direct visualization to confirm concentric locking tab engagement.
  • Prepare the Morse Taper to Mitigate Trunnionosis: Mechanically assisted crevice corrosion at the head-neck taper junction (trunnionosis) remains a recognized failure mode. Always clean and dry the femoral stem trunnion with a dry sponge before seating the femoral head. Mount the head with a firm twisting motion, followed by a single crisp axial mallet strike using a dedicated plastic-tipped impactor.

The Bottom Line

Long-term registry surveillance has brought clarity to bearing tribology. Highly cross-linked polyethylene paired with a ceramic or cobalt-chromium femoral head has effectively solved wear-related osteolysis in primary hip reconstruction. Hard-on-hard ceramic-on-ceramic articulations remain a viable tool for exceptionally young patients, but require flawless positioning to avoid edge loading, stripe wear, and squeaking. For the vast majority of our patients, ceramic-on-HXLPE provides the most reliable, forgiving, and cost-effective clinical solution.

What is your routine bearing selection for patients under 50 years of age? Review our detailed monographs on OrthopaedicsOne and share your intraoperative strategy:

Read Why I Use Cross-Linked Polyethylene on OrthopaedicsOne →