Hip function in patients undergoing conservative treatment for osteonecrosis of the femoral head

Factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head

PURPOSE

This study aimed to identify factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head (ONFH) and to identify patients who would benefit from surgical treatment.

METHODS

This study included 41 patients (56 hips) with type B ONFH with a minimum follow-up of three years. Based on a ≥ 3 mm collapse progression in ONFH, we categorised patients into two groups: collapse progression and no collapse progression. Sagittal and coronal computed tomography images were used to measure the necrotic region relative to the intact femoral head diameter. The ratios of the necrotic regions of transverse and vertical diameter in coronal and sagittal images are defined as mediolateral transverse and mediolateral vertical, anteroposterior transverse and anteroposterior vertical, respectively. Demographic data and these imaging findings were compared between the two groups. We established a cut-off value for predicting collapse progression through receiver operating characteristic analysis and determined survival rates.

RESULTS

Type B ONFH had a 17.8% collapse progression rate. The mediolateral transverse, mediolateral vertical, anteroposterior transverse, and anteroposterior vertical were significantly higher in the collapse progression group (P < 0.01). Mediolateral transverse was an independent risk factor of collapse progression (hazard ratio, 1.27; 95% confidence interval, 1.03-1.57; P = 0.03), with an optimal cut-off of 45.6%. The 5-year survival rates with collapse progression as the endpoints were 57.0 and 94.9% in the mediolateral transverse of ≥ 45.6 and < 45.6%, respectively.

CONCLUSION

A mediolateral transverse of ≥ 45.6% predicts collapse progression in patients with type B ONFH.

Evaluation of the long-term patient-reported outcomes after hip arthroplasty or joint preserving with Sugioka femoral osteotomy in patients with femoral head osteonecrosis

PURPOSE

This study retrospectively evaluated long-term clinical outcomes and patient-reported outcome measures (PROMs) in patients with osteonecrosis of the femoral head (ONFH) who underwent transtrochanteric rotational osteotomy (TRO), curved varus osteotomy (CVO), and total hip arthroplasty (THA).

METHODS

We retrospectively reviewed the 109 hips in 96 patients (46 men, 50 women) who underwent CVO, TRO, or THA for ONFH treatment. The mean follow-up period for the TRO, CVO, and THA groups was 14.8, 11.5, and 13.3 years, respectively.

RESULTS

The THA conversion rate of the TRO patients was significantly higher than that of the patients with CVO, and the final clinical scores in the patients with TRO did not improve compared with preoperative scores. Postoperative PROMs showed that the total and pain scores of the patients with THA were significantly higher than those of patients with TRO and CVO, while the PROM score did not change between patients with TRO and CVO. The analysis further showed that the preoperative type C2, stage 3A, or postoperative type C1 and C2 were significant predictors of decreased final PROM scores.

CONCLUSION

This study found that CVO and THA are clinically effective treatments for ONFH, with significant improvements compared with preoperative scores. However, THA was associated with significantly higher PROMs and pain scores than those of CVO and TRO in long-term follow-up. Furthermore, our results suggest that postoperative PROMs depend mainly on the preoperative level of collapse and postoperative transposed intact ratio of the articular surface of the femoral head.

Anti-sclerostin antibody therapy prevents post-ischemic osteonecrosis bone collapse via interleukin-6 association

Osteonecrosis of the femoral head (ONFH) is a debilitating condition characterized by subchondral bone necrosis, which frequently culminates in joint destruction. Although total hip arthroplasty is conventionally practiced to remediate ONFH, for patients under the age of 60, the outcomes can be suboptimal. Chronic inflammation, particularly that mediated by interleukin-6 (IL-6), has been conjectured to be a potential mechanism underlying the etiology of ONFH. This study aimed at exploring the interplay between IL-6, the canonical Wnt signaling pathway, and ONFH to provide insights for potential therapeutic interventions. Human ONFH specimens depicted an elevation in β-catenin expression in the transitional layer, while IL-6 levels were pronounced in the same region. Subsequently, mouse models of ischemic osteonecrosis were treated with an anti-sclerostin antibody to assess its effects on bone metabolism and cellular processes. Histological analysis revealed that the administration of anti-sclerostin antibodies effectuated early recovery from bone necrosis, reduced empty lacunae, and suppressed IL-6 expression. The treatment evidently initiated the activation of the Wnt/β-catenin signaling pathway, presenting a potential mechanism associated with IL-6-mediated inflammation. Furthermore, the antibody upregulated osteoblast formation, downregulated osteoclast formation, and increased bone volume. Micro-CT imaging demonstrated increased bone volume, prevented epiphyseal deformity, and improved compression strength. Therefore, this study yields significant findings, indicating the potency of anti-sclerostin antibodies in effectively modulating the Wnt/β-catenin pathway, associating with IL-6 expression, and preventing post-ONFH bone collapse. Additionally, this preclinical investigation in mouse models offers an avenue for prospective research on potential therapeutic interventions against human ONFH.

Cellular senescence is associated with osteonecrosis of the femoral head while mesenchymal stem cell conditioned medium inhibits bone collapse

Osteonecrosis of the femoral head (ONFH) is a type of ischemic osteonecrosis that causes pain, loss of function, and femoral head collapse. Here, we analyzed samples of femoral heads excised from patients with ONFH to clarify the relationship between ischemic osteonecrosis and cellular senescence. X-gal staining was strong and p16INK4a-positive cells were abundant in the transitional region of ONFH. The β-galactosidase-positive cells in the transitional region were also positive for nestin, periostin, or DMP-1. In contrast, no β-galactosidase-positive cells were detected in the healthy region. The senescence-associated p16INK4a, p21, and p53 were upregulated in ONFH tissue. We also examined and analyzed a mouse ischemic femoral osteonecrosis model in vivo to verify the association between ONFH and cellular senescence. Human mesenchymal stem cell-conditioned medium (MSC-CM) was administered to determine its therapeutic efficacy against cellular senescence and bone collapse. MSC-CM reduced the number of senescent cells and downregulated the aforementioned senescence-related genes. It also decreased the number of empty lacunae 4 weeks after ischemia induction and promoted bone formation. At 6 weeks post-surgery, MSC-CM increased the trabecular bone volume, thereby suppressing bone collapse. We conclude that cellular senescence is associated with ONFH and that MSC-CM suppresses bone collapse in this disorder.

Extension of the Antero-Posterior Necrotic Regions Associated With Collapse Cessation in Osteonecrosis of the Femoral Head

BACKGROUND

Collapse cessation is of utmost importance following a long period of collapse due to osteonecrosis of the femoral head (ONFH). This study investigated the relationship between collapse cessation and the extent of the necrotic regions of ONFH.

METHODS

Overall, 74 patients who had symptomatic ONFH (collapse < 3 mm) at the first visit with a minimum follow-up of 3 years were included in this study. Patients were categorized based on collapse progression or cessation into the progression and stable groups. The extent of the antero-posterior (AP) and medio-lateral necrotic regions between the groups was assessed using sagittal and coronal sections of T1-magnetic resonance imaging. Additionally, the most effective cutoff value was determined from the receiving operating characteristic curve where collapse cessation could be obtained, while the survival rates were determined with collapse progression as the endpoints were evaluated.

RESULTS

Overall, 45 and 29 patients were in the progression and stable groups, respectively. The AP and medio-lateral necrotic regions were significantly different (P < .01 and P < .01, respectively) between the progression and stable groups. A cutoff value of 62.1% of the AP necrotic regions was determined from the receiving operating characteristic curve analysis. The 5-year survival rates with collapse progression as the endpoints were 5.4 and 77.8% in the AP necrotic regions of ≥62.1 and <62.1%, respectively (P < .01).

CONCLUSIONS

Cases with AP necrotic regions of ≤62.1% can be expected to have collapse cessation, which could be a useful index for ONFH treatment strategies.

LEVEL OF EVIDENCE

Level IV.

The use of extracorporeal shock wave therapy (ESWT) in treating osteonecrosis of the femoral head (AVNFH): a retrospective study

PURPOSE

As most of the cases of avascular necrosis (AVN) in Saudi Arabia is seen in young population and as literature showed good effect of extracorporeal shock wave therapy (ESWT) in reducing pain and oedema in avascular necrosis and delaying the need of surgical intervention. Our purpose of this study is to assess the effectiveness of ESWT in reducing pain, improving range of motion (ROM) and delaying the surgical intervention in patient with AVN of femoral head and compare our results to published literature.

MATERIAL AND METHODS

We have treated 24 patients, 13 males and 11 females with a mean age of 29 years (range 14-48) with 34 hips affected. There were 14 unilateral and ten bilateral lesions. In our series 11 out of 24 patients (45.8%) were due to sickle cell disease. Other causes included idiopathic in five patients (20.8%), corticosteroids use and systemic lupus erythematous in three patients each (12.5% each) and post-traumatic AVN in two patients (8.3%). Extracorporeal shock wave therapy was implanted in FICAT stage I, II and III. All patients had two sessions of extracorporeal shock wave therapy, four to six weeks apart, each with 4000 impulses divided into four points. Radiological and MRI assessment were performed at regular time intervals with a minimum follow-up of two years. Clinical assessment was based on Visual Analog Scale and Harris Hip Score (HHS). The end point outcome measurement was the need for any operative intervention.

RESULTS

Operative intervention was necessary in eight out of 34 hips (23.5%), within an average of 2.5 years (range 1 to 5 years). A hip salvage was achieved in 76.5%. Function was improved with the Harris Hip Score from a mean of 54.6 to 80.4 (P value using paired t test ≤ 0.05). Pain assessed with Visual Analog Scale improved from 5.73 to 2.75 (P value using paired t test ≤ 0.05).

CONCLUSION

We do recommend the use of ESWT in treating AVN of bone whether of femoral head or other sites prior to the collapse of the articular surface. Further studies are needed to compare using two or more sessions as well as using four or six points for ESWT.

Revisiting prediction of collapse in hip osteonecrosis with artificial intelligence and machine learning: a new approach for quantifying and ranking the contribution and association of factors for collapse

PURPOSE

This study proposes machine learning to analyze the risk factors of the collapse in patients with non-traumatic hip osteonecrosis of the femoral head.

METHODS

We collected data of 900 consecutive patients (634 males) with bilateral (428) or unilateral non-traumatic osteonecrosis diagnosed before collapse (at stage I or stage II). The follow-up was average five years (3 to 8 years). A total of 50 variables related to the osteonecrosis were included in the study. The osteonecroses were randomly divided into a training set (80%) and a validation set (20%) with a similar percentage of hips with collapse in the two groups. Machine learning (ML) algorithms were trained with the selected variables. Performance was evaluated and the different factors (variables) for collapse were ranked with Shapley values. The primary outcome was prediction of occurrence of collapse from automated inventory systems.

RESULTS

In this series of patients, the accuracy with machine learning for predicting collapse within three years follow-up was 81.2%. Accuracies for predicting collapse within six to 12-24 months were 54.2%, 67.3%, and 71.2%, respectively, demonstrating that the accuracy is lower for a prevision in the short term than for the mid-term. Despite none of the risk-factors alone achieving statistical significance for prediction, the system allowed ranking the different variables for risk of collapse. The highest risk factors for collapse were sickle cell disease, liver, and cardiac transplantation treated with corticosteroids, osteonecrosis volume > 50% of the femoral head. Cancer (such as leukemia), alcohol abuse, lupus erythematosus, Crohn's disease, pemphigus vulgaris treated with corticosteroids, and osteonecrosis volume between 40 and 50% were medium risk factors for collapse. Familial cluster of collapse, HIV infection, chronic renal failure, nephrotic syndrome, and renal transplantation, when treated with corticosteroids, stage II, osteonecrosis volume between 30 and 40%, chemotherapy, hip pain with VAS > 6, and collapse progression on the contralateral side, were also significant but lowest risk factors. A heat map is proposed to illustrate the ranking of the combinations of the different variables. The highest risk of collapse is obtained with association of various risks factors.

CONCLUSION

This study, for the first time, demonstrated prediction of collapse and ranking of factors for collapse with a machine learning system. This study also shows that collapse is due to a multifactorial risk factors.