Femoral head necrosis is a common and frequent clinical disease. Due to its complex pathogenesis, numerous treatment methods have emerged in the clinic according to different pathogenesis or pathogenesis doctrines. Now, combined with the author’s clinical work experience, we will make a brief analysis of the common treatment methods.
1.Free fibula graft with vascular tip
This procedure was used clinically in 1981. Since the fibula is cortical bone, it has a supporting effect and can prevent the femoral head from collapsing, and the vascularized fibula can change the blood flow of the femoral head, so it has attracted the attention of clinical workers.
1.1 Complications The method is more complicated to operate and to use microsurgical techniques, therefore, there are more complications. According to the authors’ clinical observations, complications were found to be mainly to.
① slipping out of the fibular segment ;
②Vascular anastomosis embolism;
(iii) injury to the common peroneal nerve;
④ injury to the anterior tibial vessels and deep peroneal nerve.
1.2 Advantages The main advantages of this procedure are.
①The anatomical constancy of the peroneal artery and vein vessels, the large caliber, and the rich blood supply of the excised peroneal segment;
②The grafted peroneal artery anastomoses with the descending branch of the lateral rotor femoral artery, preserving the ascending branch, which does not destroy the original blood supply of the hip, but also enhances the blood circulation;
③The trophoid artery of the fibula can supply abundant blood to the femoral head;
④The periosteum with the arch artery covers the femoral head, rather like the surrounding synovial membrane, which can provide abundant blood to the femoral head;
⑤ The grafted fibula has a stimulating effect on the growth of osteoblasts in the recipient area;
⑥Grafting the fibula to the neck of the femoral head not only enhances the support of the femoral head, but also has a stimulating effect on the crawling replacement of cancellous bone;
(vii) After excision of the middle and upper segments of the fibula, there is no significant effect on the function of the donor calf.
1.3 Disadvantages The disadvantages of this procedure are also obvious, mainly.
(i) the muscles attached to the fibula are too many and require more extensive separation during surgery;
②The proximal vascular tip is short;
③The need to anastomose the vessels makes the operation complicated and difficult;
④Part of the periosteum of the fibula was stripped to cover the femoral head, which affected the blood supply to the fibula;
⑤ Because it is cortical bone, the supporting effect is strong at the same time, the ossification takes a long time, and there are some clinical cases where the bone graft does not heal.
2.Double support bone column grafting
This procedure is a combination of cancellous bone and cortical bone, bone flap implantation with myofibular and vascular tips, and has achieved certain clinical efficacy.
This procedure has the following advantages.
①Easy surgical exposure, convenient transposition, and high success rate;
②No significant posterior functional disorders in the donor area;
③Focus on complete removal of necrotic bone;
④The double bone column is thick and long, and the bone flap with femorotibial muscle tip is taken from the inter-rotor ridge, which is cortical bone with stronger support and can restore normal biomechanical properties;
⑤ The bone flap with the femoral tuberosity is rich in blood flow. Due to the characteristics of the blood supply of the femoral square muscle and the fact that the femoral square muscle terminates muscularly at the greater trochanter, the bone flap is actually a bone flap with a myotomy and a vascularity of the femoral square muscle, which has the dual role of a myotomy and a vascularity, and its blood supply is more secure;
(6) The implantation of new bone is abundant. Bone marrow mass and cancellous bone strips are good osteogenic materials;
(7) Bone extraction and bone flap are carried out below the greater trochanter, and only one incision is needed for surgery;
(8) The window is opened and decompressed, and the new blood circulation pathway enters the femoral head, restoring and ensuring the hemodynamic balance inside and outside the femoral head, thus rapidly relieving pain, accelerating new bone formation, and enabling the patient to recover as soon as possible;
9. This procedure causes less damage to the femoral neck and does not affect further hip replacement treatment in the future.
3.Iliac flap transposition with sutures muscle tip
The upper part of the sutures muscle is supplied by the deep femoral artery, the lateral rotor femoral artery and the proximal branches of the femoral artery, and the blood supply is relatively abundant, so it is used clinically as an iliopsoas lift with a sutures muscle.
The suture muscle is superficial and easy to separate, but its disadvantages are also obvious.
(1) The suturing muscle starts with the tendon from the anterior superior iliac spine and the underlying bone surface, and the tendon structure is less vascularized, so the blood supply to the bone is poor;
(2) The suturing muscle is superficially located, and there are more tissues between the bone graft and the bone graft, which has a greater impact on the blood supply of the suturing muscle;
(3) The proximal end of the suture muscle needs to be free about 6 cm, which has a greater impact on the blood supply. From the clinical observation, most of the removed live bone blocks have poor bleeding.
4.Bone flap grafting with vascular tip
So far, there are three commonly used bone flap transfers with vascular tips in the anterolateral approach to the hip: iliac (membrane) flap transfer with ascending branch of the lateral femoral vessel, greater trochanteric flap transfer with transverse branch of the lateral femoral vessel, and iliac (membrane) flap transfer with the deep iliac vessel.
4.1 Advantages
①These three flaps are two types of flat bone and one type of curved bone block, which create the basis for femoral head shaping;
②Three methods can be accomplished simultaneously within one incision;
③The deep iliac vessels are thick in caliber, with long trunk and constant stroke, few branches, relatively easy to dissect, and rich blood supply to the anterior part of the iliac bone and periosteum;
④The iliac cancellous bone is abundant, the bone and periosteum are rich in blood flow, and the bone flap is rich in blood supply, high healing rate, fast healing, and strong resistance to infection, which can promote the re-vascularization of ischemic necrosis of the femoral head;
⑤ The deep iliac vascular stem has two terminal branches (iliac branch and abdominal wall muscle branch), using its iliac flap and vascular bundle, the iliac flap can be embedded in the bone groove of the femoral head and neck, while the vascular bundle is implanted in another bone cavity of the femoral head, forming a combined iliac flap and vascular bundle graft. It not only supports the cartilage surface of the femoral head to prevent its further collapse, but also rapidly rebuilds the blood supply to the femoral head to speed up the repair and obtain a better treatment effect. The vascular bundle formed by the main stem of the deep iliac vessels and its ventral muscle branch is long and can reach the femoral head satisfactorily after transposition;
(6) The site of the iliac bone is hidden, and the osteotomy does not affect the appearance, has no effect on the function of the lower limb, has no sequelae, and is readily accepted by patients;
(7) The location of the grafted bone flap is superficial, and the anatomy of the inguinal region is familiar to most orthopaedic surgeons, so the procedure can be easily promoted.
4.2 Disadvantages
①When the three procedures are performed simultaneously, the incision must be enlarged and the damage is relatively large;
②After taking the iliac bone (membrane) flap with deep iliac vessels, if the abdominal muscle is not properly repaired, ventral hernia may be formed;
(3) The lateral femoral cutaneous nerve, inferior iliac abdominal nerve and inguinal nerve are easily damaged when separating the vessels;
(4) The combined grafting of the iliac flap and vascular bundle with the deep iliac vessel as the tip is complicated and difficult;
⑤ The deep iliac vessels are located deep in the abdominal wall muscles, which makes dissection more difficult and affects the surgical process in case of muscle bleeding;
⑥During the peeling of the periosteum and the turning of the periosteum, the trophoid artery entering the bone block is damaged, which affects the blood supply to the bone block;
(7) Rotation and jamming during bone grafting may cause blockage of blood vessels and deprive the bone block of blood supply.
5.Vascular bundle implantation
This procedure was used clinically in 1978, and Professor Yuan Hao in China carried out multiple vascular implantation earlier and achieved better results.
5.1 Mechanism of action
①Provides the most abundant blood supply to the femoral head;
②It can effectively prevent or delay the development of osteoarthritis of the hip joint.
5.2 Analysis
①For severe collapse and deformation of the necrotic femoral head, cephaloplasty must be performed;
If the cartilage surface is collapsed and folded, the cartilage will be raised by bone tunnel implantation of cancellous bone, and if the weight-bearing surface is defective or broken, the cartilage will be repaired or repaired from the periapical cartilage graft as much as possible;
(3) For late stage IV femoral head with non-existent weight-bearing surface cartilage (apatite or ivory), only the pericapital repair will be shaped without damaging the weight-bearing area;
④After surgery, active functional exercise, appropriate traction and rehabilitation are important for functional recovery and prevention or delay of osteoarthritis;
⑤ The surgical operation should be gentle, requiring the application of microsurgical techniques for vascular separation under surgical magnification, and the arteries and veins should be separated together, and the soft tissues around the vascular bundle should be appropriately preserved to reduce the damage to small vessels; the length of the separated vessels should be adequately ensured; the number should be sufficient;
(6) The bone tunnel where the vascular bundle is implanted must be wide enough, and the implanted vascular bundle must pass through the center of the necrotic bone to reach under the cartilage surface of the femoral head;
(7) Since this procedure is mainly designed for ischemia, it has an impact on the strength of the femoral head neck, so it should be applied in combination with bone grafting;
(8) After bone grafting, attention should be paid to late weight-bearing to prevent collapse and secondary collapse.
The most important feature of this procedure is that it can increase the blood supply to the femoral head in a large amount, while the disadvantages mainly lie in
(1) Microsurgical technique is used, which makes the operation more difficult;
(2) The implantation of vascular bundles alone cannot solve the problem of mechanical strength, and often needs to be combined with other surgical procedures, which makes the operation more complicated.
6.Medullary decompression
Medullary decompression was originally used for the treatment of osteoarthritis, and was used for the treatment of femoral head necrosis as an unexpected finding during diagnosis.
6.1 Principle of action
①Reducing intraosseous pressure, promoting blood circulation and reducing pain;
②The trauma during decompression acts as a stimulus for vascular renewal.
6.2 Analysis of advantages
①Good pain relief due to the obvious decompression effect;
②The surgery does not cut the joint capsule and does not affect the peripheral blood flow of the femoral head;
(3) The surgery is relatively less traumatic and does not affect other surgeries in the future.
(2) Disadvantages The mechanical strength of the femoral head is reduced after decompression, and weight-bearing is not allowed for at least 2 months after surgery, otherwise collapse is likely to occur.
7.Interventional treatment
In recent years, surgical techniques tend to be minimally invasive, i.e., minimizing the medical trauma as much as possible in order to obtain the ideal treatment, and interventional techniques are working in this direction.
7.1 Operation points Using Seldinger technique, a variety of effective drugs such as thrombus tolerance, anticoagulation and vasodilatation are injected directly into the internal and external spinous femoral artery under the “C” shaped arm.
7.2 Analysis The greatest advantages of interventional therapy compared with surgical techniques are the relative simplicity of the operation and less trauma. Therefore, with the increasing incidence of ANFH, interventional therapy is bound to gain great momentum. However, due to the complexity of ANFH etiology, there are more than 100 kinds of causes. The treatment of ANFH is not only for the relief of pain and improvement of motor function, but also for the treatment of osteonecrosis to stop or reverse the pathological process and repair the femoral head again, which is a long-term process. In the selection of indications, Ficat stage I-II should be chosen, while stage III or above should be studied experimentally first, and then applied clinically after achieving success in repairing the original morphology of the femoral head, in order to avoid the collapse of the femoral head due to improper treatment and increase the difficulty of treatment.
Interventional treatment of ANFH is still in the preliminary exploration stage, and there are many problems that need further exploration and research.
(1) Children with thin blood vessels, if the corresponding catheter and general anesthesia in radiology can be solved, the treatment scope will be significantly expanded, thus expanding the treatment indications;
(ii) Due to the one-time administration of drugs, the duration of drug action is relatively short, although some drugs can continue to be given orally or intravenously after surgery, but the long-term effect is yet to be confirmed, coupled with the fact that interventional therapy can only temporarily increase the blood circulation of the femoral head, but cannot improve the blood circulation of the femoral head for a long time, the clinic has to repeatedly puncture the interventional injection of drugs. Due to repeated interventions, injection of a large number of anticoagulant and blood-activating drugs can produce repeated bleeding, which should cause the idea of doctors and patients;
③Although some scholars reported that traumatic femoral head necrosis has also achieved certain efficacy after intervention, however, femoral neck fracture, mechanical dissection of blood vessels, the resulting effect of ANFH intervention needs to be further confirmed;
The therapeutic mechanism of ANFH intervention with drug injection is still not very clear. Under the guidance of the pathogenesis of non-traumatic femoral head necrosis with abnormal intravascular coagulation mechanism, clinical imaging shows that the number of blood vessels increases significantly in the early stage of femoral head necrosis after intervention, which increases the blood supply to the femoral head, but the changes of intramedullary pressure before and after treatment lack accurate data, and the pathological change process of osteonecrosis with intervention is still not very clear. The long-term efficacy of interventional treatment needs to be further summarized.
At present, we have carried out a study on bilateral osteonecrosis of the femoral head treated by intubation on one side, in order to reduce the number of interventions and the cost of interventions; at the same time, we have also carried out a study on osteonecrosis of the femoral head treated by arterial infusion of mannitol, in order to better reduce the pressure in the femoral head.
8.Summary
The first six treatment methods are all invasive and have common features in their therapeutic effects – they all reduce the intramedullary pressure during treatment, which the authors believe is the common mechanism of action of the above methods, and therefore have better effects in relieving pain symptoms immediately. Various invasive surgeries require the removal of as much dead bone as possible, and after the removal of dead bone, there is a decrease in the mechanical strength of the femoral head, which is prone to collapse, especially for simple vascular implantation and medullary decompression. The authors found in the clinic that many bone grafting procedures are difficult to achieve complete removal of dead bone. And in the process of fracture healing, it is difficult to heal when there is dead bone present. When the bone block is implanted, it is difficult to complete the “crawling replacement” due to the presence of dead bone, so many implants are not found to be viable years after the implant is completed.
However, the authors found that many bone grafting procedures are difficult to be performed in the same direction as the stress direction due to various conditions, and most of the bone grafting is implanted in the head and neck joint, which affects the effect of increasing the mechanical strength of the femoral head.
The most direct effect of interventional therapy is to improve the blood supply to the femoral head without destroying the femoral head and the periprosthetic structure, which is an ideal therapy. Inspired by “clinical use of mannitol to reduce intracranial and intraocular pressure”, we have used mannitol for the treatment of femoral head necrosis by transarterial perfusion intervention and achieved good results. However, animal studies are still lacking in this study. Therefore, it should be studied in the future.
In the current lack of targeted western drugs for the treatment of femoral head necrosis, Chinese medicine treatment has a broad application prospect because of its comprehensive therapeutic effect and its ability to regulate the patient as a whole.
The difficulty of treatment lies in the prevention of collapse. According to the authors, the occurrence of collapse is related to the stage of development of femoral head necrosis, the extent of necrosis and the site where necrosis occurs, as well as the treatment method. The earlier the stage of the lesion, the better the treatment outcome; the smaller the extent of necrosis, the better the treatment outcome; the necrosis is in a non-weight-bearing area, the less chance of collapse and the better the treatment outcome. Therefore, while the treatment focuses on the immediate effect, the prevention of collapse becomes the main purpose. In the treatment, the damage to the original tissue should be reduced as much as possible, and the medical source damage should be reduced to the minimum.
A large amount of clinical experience shows that various treatment methods targeting the pathogenesis are effective, but no single treatment method can finally solve the treatment of femoral head necrosis, except for the early stage (before fracture occurs under the cartilage) and limited lesions, which can be cured by a single treatment method. Therefore, treatment should be a combined treatment plan.
The authors advocate that: Chinese medicine treatment should be used throughout the treatment; in the early stage (before the fracture occurs under the cartilage), interventional therapy is mainly used. After the formation of the sclerotic zone, although intervention alone can increase the blood supply, it has limited effect on pain relief; it should be combined with medullary decompression to open the pathway between normal bone tissue and dead bone and accelerate the repair. When performing medullary decompression, it should be combined with autologous fibula or resorbable hollow screw implantation, especially for large necrosis, to increase blood supply and reduce intramedullary pressure while increasing strength and preventing collapse. As for the non-weight-bearing area necrosis and those with smaller necrosis, it is not necessary to require increased mechanical strength in the treatment, as long as the blood supply is addressed and the intramedullary pressure is lowered, because the chance of collapse is smaller.
For patients over 60 years of age who have developed to an advanced stage, whose femoral head has collapsed and formed severe osteoarthritis, artificial total hip replacement should be the best choice, which can restore the function of the hip joint in a shorter period of time and improve the quality of life of patients.