Treatment Of Avascular Necrosis Research Articles

Bone grafting for osteonecrosis of the femoral head

There has been a recent explosion of information relating to the etiology, pathophysiology, and treatment of avascular necrosis, or osteonecrosis, of the femoral head; however, few definitive conclusions have been made regarding either its development or treatment. Because of its tendency to progress to femoral head collapse and subsequent hip degeneration, and its propensity to afflict younger patients, osteonecrosis continues to serve as the subject of considerable debate and research. Conceptually, the ideal operation for this problem would be one which removes the necrotic bone from the femoral head, replacing it with viable and structurally sound bone, thus restoring vitality to the femoral head, and preventing collapse of the articular surface. To date, there is no consensual agreement among surgeons as to a single reliable surgical procedure which can consistently achieve these aforementioned objectives. Several treatment options for osteonecrosis of the femoral head have been described, including weight restriction and observation, core decompression, osteotomies, bone grafting (structural or nonstructural and vascularized or non-vascularized), and arthroplasty (hemiarthroplasty, resurfacing techniques, and total hip replacements). Bone grafting is an attractive treatment option in that it combines the benefit of decompressing the femoral head with the added benefit of introducing an osteoconductive and/or osteoinductive material into the devitalized head. Furthermore, such grafting preserves the natural hip geometry and articular cartilage, unlike the osteotomy and arthroplasty techniques described. We present a comprehensive list of the various and current bone grafting techniques for osteonecrosis of the femoral head.

Diagnosis and classification of avascular necrosis of the hip

Plain radiographs and MRI scanning are the most useful imaging studies for the diagnosis and treatment of avascular necrosis of the femoral head. Because treatment of early avascular necrosis may postpone or avoid joint replacement surgery, early diagnosis and staging are important aspects of the disease. Because it is easily understood and clinically relevant, the Ficat classification is currently the most widely used classification scheme. While the four stages of the Ficat classification are straightforward, it should be noted that it does not take into account the important factor of the size of the lesion.

Basic fibroblast growth factor stimulates osteoclast recruitment, development, and bone pit resorption in association with angiogenesis in vivo on the chick chorioallantoic membrane and activates isolated avian osteoclast resorption in vitro.

Increased local osteoclast (OC)-mediated bone resorption coincides with angiogenesis in normal bone development and fracture repair, as well as in pathological disorders such as tumor-associated osteolysis and inflammatory-related rheumatoid arthritis or periodontal disease. Angiogenic stimulation causes recruitment, activation, adhesion, transmigration, and differentiation of hematopoietic cells which may therefore enable greater numbers of pre-OC to emigrate from the circulation and develop into bone-resorptive OCs. A chick chorioallantoic membrane (CAM) model, involving coimplantation of a stimulus in an agarose plug directly adjacent to a bone chip was used to investigate if a potent angiogenic stimulator, basic fibroblast growth factor (bFGF), could promote OC recruitment, differentiation, and resorption in vivo. Angiogenesis elicited by bFGF on the CAM was accompanied by increased OC formation and bone pit resorption (both overall and on a per OC basis) on the bone implants in vivo. In complementary in vitro assays, bFGF did not directly stimulate avian OC development from bone marrow mononuclear cell precursors, consistent with their low mRNA expression of the four avian signaling FGF receptors (FGFR)-1, FGFR-2, FGFR-3, and FGFR-like embryonic kinase (FREK). In contrast, bFGF activated isolated avian OC bone pit resorption via mechanisms inhibited by a selective cyclo-oxygenase (COX)-2 prostaglandin inhibitor (NS-398) or p42/p44 MAPK activation inhibitor (PD98059), consistent with a relatively high expression of FGFR-1 by differentiated avian OCs. Thus, bFGF may sensitively regulate local bone resorption and remodeling through direct and indirect mechanisms that promote angiogenesis and OC recruitment, formation, differentiation, and activated bone pit resorption. The potential for bFGF to coinduce angiogenesis and OC bone remodeling may find clinical applications in reconstructive surgery, fracture repair, or the treatment of avascular necrosis. Alternatively, inhibiting such bFGF-dependent processes may aid in the treatment of inflammatory-related or metastatic bone loss.

Age Bias and Choice of Intervention for Treatment of Avascular Necrosis

Age Bias and Choice of Intervention for Treatment of Avascular Necrosis

Avascular necrosis of the femoral head in childhood: the results of treatment with articulated distraction method.

The treatment of avascular necrosis of the femoral head in children is still being debated. We performed articulated distraction in 11 children with avascular necrosis of the femoral head between March 1994 and February 1997. The reasons for avascular necrosis were: Perthes disease in eight patients, fracture of the femoral neck in two, and complication arising because of treatment of developmental hip dysplasia in one. Mean age was 7.9 years. Fixator duration time was 3.5 months and mean follow-up was 32 months. At follow-up, the femoral head was spherical and congruent in four patients, aspherical and congruent in five, and aspherical and incongruent in two according to Stulberg's criteria. The aim of the articulated distraction method is to neutralize muscle and weight-bearing forces, to prevent stress fractures of subchondral immature bone, to encourage synovial circulation, and to promote creeping substitution.

Decreased nitric oxide levels stimulate osteoclastogenesis and bone resorption both in vitro and in vivo on the chick chorioallantoic membrane in association with neoangiogenesis.

High nitric oxide (NO) levels inhibit osteoclast (OC)-mediated bone resorption in vivo and in vitro, and nitrate donors protect against estrogen-deficient bone loss in postmenopausal women. Conversely, decreased NO production potentiates OC bone resorption in vitro and is associated with in vivo bone loss in rats and humans. Previously, we reported that bone sections from rats administered aminoguanidine (AG), a selective inhibitor of NO production via inducible NO synthase, exhibited both increased OC resorptive activity as well as greater numbers of OC. Here, we investigated further whether AG promoted osteoclastogenesis, in addition to stimulating mature OC function, using a modified in vivo chick chorioallantoic membrane (CAM) system and an in vitro chick bone marrow OC-like cell developmental model. AG, focally administered in small agarose plugs placed directly adjacent to a bone chip implanted on the CAM, dose-dependently elicited neoangiogenesis while stimulating the number, size, and bone pit resorptive activity of individual OC ectopically formed in vivo. In addition to enhancing OC precursor recruitment via neoangiogenesis, AG also exerted other vascular-independent effects on osteoclastogenesis. Thus, AG promoted the in vitro fusion and formation from bone marrow precursor cells of larger OC-like cells that contained more nuclei per cell and exhibited multiple OC differentiation markers. AG stimulated development was inversely correlated with declining medium nitrite levels. In contrast, three different NO donors each dose-dependently inhibited in vitro OC-like cell development while raising medium nitrite levels. Therefore, NO sensitively regulates OC-mediated bone resorption through affecting OC recruitment (angiogenesis), formation (fusion and differentiation), and bone resorptive activity in vitro and in vivo. Possibly, the stimulation of neoangiogenesis and OC-mediated bone remodeling via AG or other pro-angiogenic agents may find clinical applications in reconstructive surgery, fracture repair, or the treatment of avascular necrosis.

Pretreatment bone scan in SCFE: a predictor of ischemia and avascular necrosis.

Sixty-two consecutive patients with 73 slipped capital femoral epiphyses (SCFEs) underwent pretreatment planar technetium bone scan to identify the presence of ischemia of the femoral head. The relationship of pretreatment ischemia and the development of avascular necrosis (AVN) was evaluated after a minimum follow-up of 12 months. All patients were treated with spica casting or pinning across the physis. No forceful manipulation was performed. None of the 63 stable SCFEs demonstrated ischemia by bone scan, and none developed AVN. Of the 10 unstable SCFEs, six demonstrated ischemia by bone scan, and five of the six developed AVN. None of the four unstable SCFEs without ischemia on bone scan developed AVN. Pretreatment bone scan is a sensitive predictor for development of AVN in unstable SCFEs and may provide a method for evaluating interventional treatments for AVN associated with SCFE.

Treatment of Avascular Necrosis of the Femoral Head with Free Vascularized Fibular Graft

Treatment of Avascular Necrosis of the Femoral Head with Free Vascularized Fibular Graft

(iii) Role of core decompression in the treatment of avascular necrosis of the femoral head

(iii) Role of core decompression in the treatment of avascular necrosis of the femoral head

(ii) Transient osteoporosis may represent a reversible early form of avascular necrosis of the hip joint

There is still controversy whether transient osteoporosis (TO) of the hip joint represents a distinct self-limiting disease, or reflects only an early, reversible subtype of non-traumatic avascular necrosis (AVN). Clinical presentation of patients with TO and AVN is similar with mechanical hip joint pain, AVN risk factors and a male preponderance. Radiographic, bone scintigraphic, and MRI patterns of TO are more diffuse, while focal in AVN. The histological bone marrow changes are similar in both diseases, but with diffuse and sufficient repair in TO, whereas in AVN only insufficient focal repair at the border of the necrotic lesion occurs. The clinical course and outcome are significantly different with restitution in TO, while progressive with destruction of the joint in AVN. Therefore the preferred treatment strategies are protected weight bearing for TO, but operative treatment for AVN. Based on our material, we believe that TO represents an early, reversible subtype of AVN and should be treated by core decompression. To explain the different imaging presentation, and the divergent clinical outcome for TO and AVN, two different pathophysiological pathways for these two seemingly different diseases will be presented.

Avascular osteonecrosis of the femoral head treated with a vascularized iliac bone graft: preliminary results and follow-up with radiography and MR imaging.

Treatment of avascular necrosis (AVN) of the femoral head with a vascularized iliac bone graft was studied in nine patients (12 hips). The condition of the femoral head was classified radiographically before and after surgery. Magnetic resonance (MR) imaging was performed to demonstrate the extent and signal intensity characteristics of the area of AVN and to assess the viability of the graft. The radiologic results were correlated with the clinical findings. Although radiography showed progression of disease in six patients, seven of the nine patients demonstrated clinical improvement. The MR imaging results correlated better with the clinical findings: MR imaging demonstrated progression of AVN in only two patients (two hips) and no progression or reduced necrosis in six patients (nine hips). Nine of the 11 grafts (eight patients) evaluated with MR imaging appeared viable after a mean follow-up of 50 months. MR imaging appears useful in assessing marrow changes and graft viability after treatment of AVN of the femoral head with a vascularized iliac bone graft.

Treatment of avascular necrosis in the young patient.

Treatment of avascular necrosis in the young patient.

Evaluation and staging of avascular necrosis

Abstract Much of the confusion and contradiction currently existing regarding the treatment of avascular necrosis can be eliminated by the use of an effective method of evaluation. This requires not only a comprehensive history and physical examination but also an objective and quantitative system for determining both the stage and extent of involvement of the hip. Such a system, based on plain x-rays, bone scans, and magnetic resonance imaging is described in this article. This system allows us to compare the results of the various methods of treating avascular necrosis and to determine the best method of treatment in specific cases.

Core decompression for the treatment of avascular necrosis of the femoral head

Abstract Core decompression for the treatment of avascular necrosis of the femoral head was introduced by Ficat and Arlet in 1962 with results first reported in 1968. Since 1973 the author has used the technique with good results in the precollapse stage and a low complication rate. The recent literature has reported varied results. Bone functions as a closed compartment (as a Starling resistor). Markedly elevated bone marrow pressures have been recorded in all stages of avascular necrosis of the femoral head, making core decompression a rational procedure. However, to avoid the pitfalls, the following precautions must be exercised: (a) biplane image intensification avoids articular perforation; (b) clearance of the coring device avoids femoral head blow-out; and (c) metaphyseal rather than diaphyseal entry site dramatically lowers the incidence of secondary fracture. Core decompression in the author's experience provides an effective procedure with low morbidity in the precollapse stages of the disease.

Capacitive Coupling as an Adjunctive Treatment for Avascular Necrosis

The purpose of this study was to determine the effectiveness of capacitive coupling, a noninvasive method for applying electrical stimulation to biologic tissues, when used as an adjunct to decompression and grafting in the treatment of avascular necrosis (AVN) of the femoral head. It also compared the results of core decompression and grafting with nonoperative management. Forty patients with Stages I-III AVN of the femoral head were treated with core decompression and grafting. All wore capacitive coupling units with electrodes placed over the femoral head continuously for six months. One-half of these units were active and one-half were inactive. Patients were followed for two to four years. Results were determined by preoperative and postoperative Harris ratings, quantitative roentgenographic measurements, and the number of hips that required total hip arthroplasty (THA). After all evaluations were completed, patients were divided into stimulated and nonstimulated groups. Patients in both groups were similar regarding gender, etiology, and roentgenographic stage of involvement. Results were also compared to 55 hips previously treated symptomatically, without surgery or electrical stimulation. There were no fractures, infections, or other significant complications in any of the hips operated on. Hips treated with decompression and grafting, both with and without electrical stimulation, were more satisfactory than hips treated symptomatically in regard to roentgenographic progression and the need for THA. There was, however, no indication that the addition of capacitive coupling gave better results than decompression and grafting alone.

Surgical treatment of avascular necrosis of the proximal pole of the capitate–Case report

Surgical treatment of avascular necrosis of the proximal pole of the capitate–Case report

Treatment of Avascular Necrosis of the Femoral Head by a Combination of Bone Grafting, Decompression, and Electrical Stimulation

The goal in the treatment of avascular necrosis is to preserve, not replace, the femoral head. Although many methods have been proposed, none has proved completely satisfactory. Electrical stimulation as a supplement to bone grafting and decompression is an attractive approach to this problem because it combines the desirable features of other procedures, each of which has shown a certain degree of effectiveness in stimulating bone growth and repair. Preliminary results indicate that patients treated with decompression and grafting alone and those in whom electrical stimulation was added to these had better results than patients treated by "conservative" means. The effectiveness of the electrical stimulation itself, however, has not yet been established and remains an important area for investigation. Further improvements in delivery systems and techniques are required to develop better methods for the treatment of avascular necrosis.