Staging of osteoncrosis of femoral head – Problems and countermeasures
Osteoncrosis of femoral head (ONFH) is defined as ONFH is a disease in which the blood supply to the femoral head is interrupted or impaired, causing the death of bone cell components and the death of bone marrow components and their subsequent repair, which subsequently leads to that change in the structure of the femoral head, collapse of the femoral head, and joint dysfunction. The most common causes are alcoholism, hormones and trauma. The disease is mostly bilateral, and about 80% of the patients suffer from femoral head collapse 1-4 years after the onset of the disease, resulting in a very high disability rate and loss of mobility.
Most patients have to undergo artificial hip replacement. There are more than 150,000 new cases in China every year, and the cumulative cases range from 1.5 to 3 million. The main purpose of treating ONFH is to relieve joint pain, prevent femoral head collapse, restore function, and avoid artificial joint replacement or delay replacement time. Only by correctly formulating a staged treatment strategy according to the treatment principles and giving the appropriate treatment to patients with different etiologies, stages and ages, can we obtain better results. Only by using scientific efficacy evaluation methods can we obtain the real efficacy results.
First, the concept and method of early diagnosis of femoral head necrosis
At present, the staging method often used in the international are stipulated in the concept of early diagnosis of femoral head necrosis for the 0-2 stage, 0 stage diagnosis rely on bone biopsy; 1 stage diagnosis rely on bone scan or magnetic resonance imaging (MRI); 2 stage diagnosis rely on CT, high-quality X-ray can also make a diagnosis. Only on the basis of early diagnosis can we carry out treatment to preserve the femoral head.
Second, the staged treatment strategy of femoral head necrosis
1, conservative treatment: for early cases, asymptomatic, such patients are in fact rarely seen, and the treatment effect is uncertain.
2, surgical treatment.
1) I-A-I-C stage fine-needle drilling decompression (3 holes of 3-4mm in diameter), or pro-channel marrow core decompression (1 decompression channel of 8mm or 10mm in diameter), reaching 3-5mm under the cartilage of the femoral head, which can be implanted with autologous bone marrow cells, bone marrow stem cells, autologous bone or osteoinductive active material, etc. Tantalum rod implantation is also feasible.
2) Stage II-A-II-C: Bone grafting, hip surface replacement, etc. can be performed. Stage II-A can also use the above-mentioned marrow core decompression and tantalum rod implantation, but the efficacy is not as good as that of stage I.
3) Stage III-A-III-B: Bone grafting and hip joint surface replacement can still be performed in this stage. However, since the femoral head has collapsed or the area of necrosis has increased, the effect is not as good as that for stage II patients.
4) Stage III-C and IV: Artificial hip replacement should be performed. Artificial hip arthroplasty is suitable for: elderly patients; bilateral lesions, up to ARCO stage III-C and above; those with severe pain, affecting joint function.
Evaluation of the efficacy of treatment of ONFH
Clinical and imaging changes are not completely synchronized in the same patient, so the efficacy evaluation should include both clinical evaluation and X-ray evaluation. To date, there is no unanimously accepted standard for the best efficacy evaluation. Experience tells us that the effect of the same treatment method for ONFH can differ significantly, with good results in the early stage and poor results in the late stage. Therefore, the results of the treatment should be scored separately for different cases of the same period, and the analysis and summary should be made for each period.
Some reports calculate early and late cases together, so that their method also has a high excellent rate for late cases, then it cannot accurately reflect the treatment effect, but shows wrong results and conclusions, which is inevitably misleading, which not only affects the evaluation of the merits of treatment means, but also affects the mutual academic communication. Therefore, the correct application of evaluation criteria is very important.
1. Evaluation of the efficacy of preserving the femoral head
There are various methods to evaluate the efficacy of non-surgical and surgical treatments for preserving the femoral head, but most of them are original or modified by some authors, and have not been widely used. At present, the most widely used methods in foreign countries are the Harris scale and the Merl D aubigne scale modified by Charnley. The evaluation method is based on pre-treatment and post-treatment comparison, and for the first time, the clinical evaluation and X-ray evaluation are summarized in a simple table, which is highly practical.
The clinical evaluation accounts for 60 points of the whole percentage method, including 25 points for pain, 18 points for function and 17 points for joint mobility, and 40 points for X-ray evaluation of the percentage method. It has been confirmed by a large number of clinical cases that it is reproducible and can truly and objectively reflect the objective effect of ONFH treatment. This method is not used for the evaluation of the efficacy of artificial hip arthroplasty.
2.Efficacy evaluation of artificial hip arthroplasty
The hip function score has been used to evaluate the efficacy of artificial hip joint after surgery. There are many such scoring methods in the literature, and the Harris score is mostly used in North America, the Charnley score in Europe, the Harris score in China, and the Beijing program. The Harris score is the most widely used in the domestic and international literature, and is applicable to the evaluation of the efficacy of various hip disorders, with a comprehensive assessment content and scope and reasonable score distribution.
It includes four aspects: pain, function, deformity and joint mobility, and its score distribution ratio is 44:47:4.5. The total score of these four items is 100, and the grading is: 90-100 is excellent, 80-89 is good, 70-79 is moderate, and less than 70 is poor. The score attaches importance to postoperative pain and changes in joint function, while joint activity is given less weight, believing that it is better to have a motionless and painless hip than an active and painful one. Of course, there are also its shortcomings, such as calculating the score is more complicated.
In recent years, as research has progressed, new systems for assessing disease and health have been developed and applied to a wider range of fields. For example, the WOMAC questionnaire method of medical disposition outcome assessment system , the SF-36 health questionnaire of disease characteristics and overall commonality scoring system, the latter includes 36 questions with 8 aspects, including somatic function, functional limitation, body pain, social interaction ability, whole body perception, and living ability (energy/fatigue).
Functional limitation and general mental health due to emotional problems were calculated as 0 to 100 points for each item, respectively. The methods designed to assess the patient’s functional status and to rate the benefits of surgical interventions fall under the concept of quality of life and can be used for patients with different degrees of disability and for the entire population, and are therefore called comprehensive and common evaluation systems. Health-related quality of survival is evaluated by whole-body health-related surveys.
Although various scoring systems have been widely used for the evaluation of the efficacy of ONFH, their applicability is still deficient due to the lack of standardization of terminology, different evaluation focus, and different scales. For the current period, it is still recommended to apply the percentage evaluation method to preserve the efficacy of femoral head and the Harris score to evaluate the efficacy of artificial hip arthroplasty according to the adopted system by all. It is expected that a more objective, reliable, reasonable, comprehensive, simple and clinically practical scoring standard will be developed in the near future, which is an important task that our orthopaedic colleagues still need to work hard to accomplish.