Non-modifiable Risk Factors Associated with Avascular Necrosis in the US Military

Evaluation of the Tensor Fascia Lata Muscle Pedicle Bone Grafting Technique in the Management of Avascular Necrosis of the Femoral Head: An Observational Clinical Study

BACKGROUND

Osteonecrosis of the hip is defined as necrosis of the bone tissue due to some form of vascular insult, subsequently leading to the collapse of the femoral head and secondary osteoarthritis, which leads to pain and impaired joint function. This disease is widely known to affect middle-aged groups; however, in the Indian population, even younger people are more commonly affected. The disease has a debilitating effect on the activities of daily living (ADL) and the productivity of individuals and has financial consequences. With the increased utilization of magnetic resonance imaging (MRI) in society, the disease is diagnosed in its early stages. Hip-preserving surgery like tensor fascia lata (TFL) muscle pedicle iliac bone grafting should be given a chance to preserve the native femoral head.

METHODOLOGY

At a tertiary care teaching hospital in Gorakhpur, India, an observational clinical study was carried out. This study comprised 40 patients, ages 18-50 years, with femoral head osteonecrosis (stages II and III of the Ficat-Arlet staging system), who came to our institute's orthopedic outpatient department. Patients were treated with multiple drillings, curettage, and cheilectomy of the femoral head, in addition to TFL muscle pedicle bone grafting. The Harris hip score (HHS) was utilized to assess the clinical results, and the radiological assessment focused on signs of revascularization.

RESULT

In our study, the most prevalent age group was 20-30 years (67.5%), with a male predominance (85%). Among our cohort of 40 patients, the HHS indicated excellent outcomes (90-100) in 14 cases (35%), good outcomes (80-89) in 19 cases (47.5%), fair outcomes (70-79) in six cases (15%), and poor outcomes (<70) in one case (2.5%), at the time of the final follow-up. The final follow-up period varied from one to 10 years.

CONCLUSION

TFL muscle pedicle bone grafting procedure provides excellent clinical and radiological outcomes, especially in young patients in whom femoral head-preserving surgery is preferred over total hip arthroplasty. This procedure is effective in both early and advanced stages of femoral head osteonecrosis, provided there are no arthritic changes. It reduces symptoms and improves functional outcomes.

Genetic ancestry and skeletal toxicities among childhood acute lymphoblastic leukemia patients in the DFCI 05-001 cohort

Hispanic children have a higher incidence of acute lymphoblastic leukemia (ALL) and inferior treatment outcomes relative to non-Hispanic White children. We previously reported that Hispanic children with ALL had lower risk of fracture and osteonecrosis. To unravel the genetic root of such ethnic differences, we genotyped 449 patients from the DFCI 05-001 cohort and analyzed their ancestry. Patients with discordant clinical and genetic ancestral groups were reclassified, and those with unknown ancestry were reassigned on the basis of genetic estimates. Both clinical and genetic ancestries were analyzed in relation to risk of bone toxicities and survival outcomes. Consistent with clinically reported race/ethnicity, genetically defined Hispanic and Black patients had significantly lower risk of fracture (Hispanic: subdistribution hazard ratio [SHR], 0.42; 95% confidence interval [CI], 0.22-0.81; P = .01; Black: SHR, 0.28; 95% CI, 0.10-0.75; P = .01), and osteonecrosis (Hispanic: SHR, 0.12; 95% CI, 0.02-0.93; P = .04; Black: SHR, 0.24; 95% CI, 0.08-0.78; P = .02). The lower risk was driven by African but not Native American or Asian ancestry. In addition, patients with a higher percentage of Native American ancestry had significantly poorer overall survival and event-free survival. Our study revealed that the lower risk of bone toxicities among Black and Hispanic children treated for ALL was attributed, in part, to the percentage of African ancestry in their genetic admixture. The findings provide suggestive evidence for the protective effects of genetic factors associated with African decent against bone damage caused by ALL treatment and clues for future studies to identify underlying biological mechanisms.

Hip preserving surgery for avascular hip necrosis: does terminating exposure to known risk factors improve survival?

Introduction: Avascular necrosis of the hip is rarely detected in early pre-radiographic stages (Arlet-Ficat stages I and II) where conservative treatment would still be possible. Studies of risk factors were often merely descriptive. The aim of the present study was to make a retrospective assessment of treatment survival rate for conservative management of avascular hip necrosis according to whether exposure to avoidable risk factors is eliminated or not. The study hypothesis was that eliminating avoidable risk factors is effective and reduces the risk of failure, and hence of hip replacement. Material and method: A single-center retrospective study was performed for conservatively managed avascular hip necrosis. Thirty-seven consecutive hips in 34 patients underwent decompression drilling, with a minimum 3-year follow-up. Known risk factors for osteonecrosis were classified as avoidable or non-avoidable. Results were analyzed according to the elimination of avoidable risk factors. The main endpoint was survival, with failure defined as femoral head collapse and/or recourse to total hip replacement. Avoidable risk factors (corticosteroids, smoking, alcohol consumption, blood pressure elevation, hypercholesterolemia) persisted for 17 hips (45.9%) and were prevented for 15 (40.5%). Five patients (5 hips: 13.5%) did not show preoperatively identified risk factors. Groups were demographically comparable. Results: Mean follow-up was 7.5 ± 3.7 years (range, 3.1-16.0 years). At last follow-up, there was a significant difference in survival at cumulative 9-year follow-up between patients with no risk factors (100%), with risk factors eliminated (59.3%; 95% CI, 0.273-0.012), and with persisting risk factors (23.5%; 95% CI, 0.013-0.458) (p = 0.001). Discussion: No studies were found in the literature assessing the survival of hip preserving surgery according to persistence or elimination of known risk factors for osteonecrosis. Eliminating risk factors significantly improved the survival rate for conservative treatment of femoral head necrosis.