Treatments of avascular osteonecrosis of the hip: Current treatments

Method for reconstructing femoral head blood supply by anastomosing the intraosseous artery

Background

The reconstruction of femoral head blood supply is crucial in the management of avascular necrosis and related conditions. This study presents a method for reconstructing the femoral head blood supply by anastomosing the intraosseous artery.

Methods

The femoral heads of six male Landrace swine were surgically exposed, and subcranial fractures of the femoral neck were intentionally created. Under microscopic guidance, the trophoblastic foramen of the posterior supporting artery was identified. Subsequently, a triangular bone window was carefully crafted to expose the intraosseous artery. Following the fixation of the femoral head, an anastomosis was performed between the intraosseous artery and the posterior inferior supporting artery located at the distal end of the fracture. The assessment of femoral head blood supply was conducted using Kirschner's pinhole and angiography techniques.

Results

The anastomotic intraosseous artery exhibited a vibrant red color, indicating adequate blood perfusion, and demonstrated pulsatile flow. Observation through pinholes in the surface of the femoral head revealed continuous blood flow. Angiography further confirmed the successful circulation, as the contrast agent entered the inferior retinacular artery branch originating from the deep femoral artery. The contrast agent then proceeded to enter the femoral head through the retinacular artery, reaching the anastomosis site of the intraosseous artery. Notably, the angiography also revealed the presence of visible internal branches, highlighting the establishment of a functional vascular network.

Discussion

The method of reconstructing the blood supply to the femoral head through anastomosis of the intraosseous artery enables utilization of the existing blood supply system within the femoral head. This study is just a preliminary study of this innovative technique that has the potential to prevent and/or treat femoral head necrosis following a femoral neck fracture. By restoring adequate blood flow to the affected area, this approach holds promise in preserving the viability and functionality of the femoral head, ultimately improving patient outcomes.

A Comparative Analysis of Osteochondritis Dissecans and Avascular Necrosis: A Comprehensive Review

Musculoskeletal disorders, standing as the fifth leading cause of disability-adjusted life years globally, present significant challenges in orthopedics. Osteochondritis dissecans (OCD) and avascular necrosis (AVN) are distinct but closely related conditions within this spectrum, impacting patients' quality of life with pain, limited mobility, and dysfunction. OCD, involving cartilage and bone detachment in joints, predominantly affects young athletes, but its exact etiology and optimal management remain subjects of ongoing research. Conversely, AVN, marked by bone tissue death due to compromised blood supply, is linked to systemic factors like corticosteroid use and traumatic injuries. Diagnosis for both conditions relies on radiography and magnetic resonance imaging. Conservative treatment for AVN includes the use of a cane or crutches, pharmacological therapy, or physical therapy. On the other hand, in OCD, the primary approach is activity/sports restriction. Surgical treatment options for AVN patients encompass core decompression, bone grafting, or, in the most advanced cases, total hip arthroplasty. OCD may be surgically treated through subchondral drilling or fixation of unstable lesions. Advanced cases of OCD involve cartilage salvage with resurfacing techniques. The presentation of differences between these conditions enhances our understanding, facilitating improved diagnosis and management strategies.

Biomechanical research of medial femoral circumflex vascularized bone-grafting in the treatment of early-to-mid osteonecrosis of the femoral head: a finite element analysis

Purpose

Hip preservation therapy of early ONFH (Osteonecrosis of the femoral head) has emerged as one of the hot areas of research. We have optimized the procedure of traditional MFCVBG (medial femoral circumflex vascularized bone grafting) by using specialized surgical tools and used the finite element analysis to guide the implantation position of the bone flap during surgery and validate the biological mechanical stability of the modified MFCVBG.

Methods

This study was based on the data of a male patient with left hip (ARCO stage IIB, JIC type C) hormonal ONFH. Harris score (HHS), anteroposterior and lateral hip radiographs, frog position hip radiographs and SPECT/CT of femoral head flow imaging were performed postoperatively to evaluate clinical efficacy. The patient’s CT data were used to establish upper femur finite element model of the normal group, osteonecrosis group and postoperative group, respectively. The force on the femoral structure of each group was analyzed under four different loads in the gait cycle of 0.5 times the body weight (0.5 G, standing on two feet), 2.75 G (standing on one foot), 4 G (walking with the middle foot on the ground) and 7 G (walking with the toe off the ground) to validate the biological mechanical stability of the modified MFCVBG, predict femoral head collapse risk, simulate of the different healing conditions of postoperative bone flap, and analyze the postoperative effect of non-ideal surgical model.

Results

According to the follow-up results, the bone flap and the inner wall of decompression channel healed well, no osteonecrosis progression, no local collapse or micro-fracture occurred in the femoral head, and the articular surface was intact and the necrosis was well repaired. According to the result of the finite element analysis, compared with the osteonecrosis group, the overall stress and displacement peak of the upper femur and the cortical bone stress peak of the femoral head in the postoperative group and normal group were significantly reducing; modified MFCVBG can significantly improve the biomechanical stability of necrotic femoral head and reduce the risk of femoral head collapse; there was no obvious abnormal stress distribution in the greater trochanter and intertrochanter region after the flap was removed; the bone flap of the complete removal of necrotic focus + long bone flap group was directly placed at the bottom of the decompression passage, and the bone flap cortical bone can provide substantial mechanical support; in theory, patients can try to reduce the load with crutches or walking aids and carry out appropriate flat activities to effectively promote the early postoperative recovery.

Conclusions

The modified MFCVBG resulted in good efficacy, safety and feasibility. The necrotic focus should be completely removed during the operation, and the long bone flap should be placed directly under the subchondral bone. For patients with better bone healing ability, a more positive attitude can be taken to promote early postoperative weight-bearing.