Letter to the Editor: Re-evaluating conservative hip preservation in osteonecrosis of the femoral head: Lessons from long-term follow-up

Abstract

Osteonecrosis of the femoral head (ONFH) remains a clinically challenging orthopedic condition that affects young and middle-aged adults predominantly. The recent study by Chen et al, published in the recent issue of the World Journal of Orthopedics, provides valuable long-term evidence supporting the efficacy of conservative hip preservation strategies, demonstrating favorable outcomes in select patients with careful follow-up. This letter emphasizes the significance of reappraising non-surgical interventions as part of a comprehensive treatment paradigm. Beyond symptomatic relief, conservative approaches may contribute to delaying femoral head collapse and postponing the need for arthroplasty. Nonetheless, several questions remain, particularly regarding patient selection criteria, radiological predictors, and integration of biological adjuvants to enhance bone repair. Future research combining advanced imaging, molecular biomarkers, and biomechanical assessment may refine individualized therapeutic strategies. The present commentary underscores the importance of sustained evidence-based evaluation and multidisciplinary collaboration to optimize hip preservation outcomes for patients with osteonecrosis of the femoral head.

Key Words: Osteonecrosis of the femoral head; Hip preservation; Conservative treatment; Long-term outcomes; Commentary

Core Tip: This letter evaluates a study by Chen et al, describing conservative hip preservation in osteonecrosis of the femoral head. The study highlights a high hip-preservation rate and introduces the concept of “survival with collapse”, whereby radiographic progression does not equate to functional decline. This commentary emphasizes appropriate patient selection, radiological predictors, and the value of individualized non-surgical strategies in managing osteonecrosis of the femoral head.

TO THE EDITOR

We read with great interest the recent article by Chen et al[1], published in the recent issue of the World Journal of Orthopedics, titled “Outcomes of the conservative hip preservation treatment in patients with osteonecrosis of the femoral head: With 4-year follow-up”. The authors provided compelling evidence that conservative management may offer substantial benefits for patients with osteonecrosis of the femoral head (ONFH)[2], particularly those in the early stages of the disease.

Their 4-year follow-up of 73 patients (119 hips) demonstrated an impressive 90.76% success rate, accompanied by significant improvements in the Harris Hip Score measure of pain, function, range of motion and deformity, the Western Ontario and McMaster Universities Osteoarthritis Index self-administered pain questionnaire, the International Hip Outcome-12 assessment of patient’s ability to return to an active lifestyle, and Visual Analogue Scale score of pain. These findings are important because they challenge the prevailing assumption that ONFH inevitably progresses to femoral head collapse that requires surgical intervention[3].

Notably, renewed attention has been drawn to steroid-associated ONFH in the post-coronavirus disease 2019 era[4,5], given the widespread corticosteroid exposure in some clinical settings. In Chen et al’s study[1], steroid-related ONFH accounted for 59 of the 119 hips investigated, highlighting the need for etiology-stratified reporting of success, collapse[6], and conversion-to-arthroplasty rates to better define conservative indications in this subgroup.

One aspect of the study that stands out is the authors’ discussion of “survival with collapse”. This notion reflects a clinically relevant scenario in which radiographic deterioration does not inevitably translate into functional failure. In daily practice, we often encounter patients whose imaging suggests disease progression while their symptoms remain stable or even improve. Chen et al’s study[1] reinforces this clinical phenomenon and provides data-driven support for the idea that functional preservation, rather than absolute radiographic stability, may be the more meaningful outcome for many patients.

Importantly, this concept is unlikely to apply uniformly across early-stage ONFH cases; a risk-stratified interpretation informed by baseline lesion characteristics is therefore essential to identify patients most likely to achieve “survival with collapse”. Moreover, the natural history of earlier-stage ONFH is heterogeneous, with progression to collapse strongly influenced by lesion burden and location (particularly lateral weight-bearing involvement), as well as ongoing risk factors such as continued steroid exposure[7]. Accordingly, conservative management coupled with structured follow-up could be considered a risk-stratified strategy, providing benefit over a uniform “watch-and-wait” approach.

Chen et al’s real-world cohort[1] (mean age of 39.10 ± 11.22 years; baseline predominantly Association Research Circulation Osseous osteonecrosis class I-IIIb; mean follow-up of 53.58 ± 26.92 months) is clinically informative; however, the retrospective, non-controlled design and the inherently heterogeneous, multimodal regimen limit causal inference and preclude attribution of benefit to any single component. Outcome reporting stratified by etiology (steroid-related vs non-steroid-related), Association Research Circulation Osseous grouping, and lateral (weight-bearing) involvement (e.g., the Japanese Investigation Committee subtype) would improve interpretability and better contextualize conversion-to-surgery decisions. In addition, reporting objective lesion metrics (e.g., extent/Location of necrosis and lateral column involvement) as well as standardizing and reporting “success” definitions and criteria for conversion to surgery would further enhance clinical applicability. Regarding the herbal component[8], the evidence published to date remains largely indirect or preclinical[9]. Although studies of Huo Xue Tong Luo capsules[10] and Sheng Mai Cheng Gu tablets[11] provide biological plausibility (e.g., osteogenic pathways related to mesenchymal stem cell differentiation and bone repair), definitive mechanistic proof is still lacking. Further controlled or component-deconstruction studies are warranted to identify key contributors and refine thresholds for surgical conversion.

In conclusion, Chen et al’s study[1] makes a significant contribution by validating the clinical potential of conservative hip preservation for ONFH. Their work encourages orthopedic clinicians to reconsider non-surgical management as a viable and evidence-based component of the treatment continuum. We commend the authors for providing long-term data that bridge clinical practice with functional outcomes, and we look forward to further research exploring the mechanisms and optimization of conservative hip preservation.