股骨头缺血性坏死髓心减压术

nullCore Decompression for Osteonecrosis of the hip Core Decompression for Osteonecrosis of the hip Clin Orthop.2004;418:29-33DEVELOPMENT OF CORE DECOMPRESSION OF THE FEMORAL HEAD DEVELOPMENT OF CORE DECOMPRESSION OF THE FEMORAL HEAD Core decompression of the hip is the most common pro­cedure currently used to treat the early stages of ON of the femoral head. Ficat and Arlet then hypothesized that ON could be treated successfully by decompressing the femoral head. nullThe goal of core decompression was to decompress the femoral head pressure, restore normal vascular flows, and alleviate pain in the hip.Even though numerous studies have been published no general consensus has been developed regarding patient selection, surgical technique, classification systems used, or postoperative treatment of these patients. CLASSIFICATION AND STAGING CLASSIFICATION AND STAGING The purpose of any classification system is to provide guidelines for treatment and prognosis. Over the years, numerous different classifications systems have been developed to evaluate patients with ON of the femoral head but currently, there is no standard unified classification system used by all investigators. There is general agreement that the prognosis for a patient with ON of the hip is influenced by the extent and the location of the necrotic area in the femoral head and whether there is involvement of the acetabulum.nullFicat and Arlet originally developed a four-stage classification system based on radiographic changes and the functional exploration of bone that included intraosseous venography and measurement of bone marrow pressure (Table 1). nullSince that time, numerous different classification systems have been developed but the University of Pennsylvania System of Classification and Staging has the most potential as a useful clinical and research tool. Because it included MRI evaluations, which allow for the quantification of the extent of femoral head involvement (Table 2). nullCORE DECOMPRESSION CORE DECOMPRESSION There have been numerous extensive literature reviews published assessing the clinical results of core decompression. Smith et al reviewed 12 articles published between 1979 and 1991 that included 702 hips with an average followup of 38 months. Using the University of Pennsylvania Staging System, successful results were reported as follows: Stage I, 78%; Stage II, 62%; and Stage III, 41%. nullMont and associates assessed 42 reports in which 1206 hips were treated by core decompression and 819 hips were treated by various nonoperative means. nonoperative treatment was not successful. Only 23% of hips in 21 studies had a satisfactory clinical result when treated nonoperatively. In 24 studies, 65% of the hips treated with core decompression had an overall satisfactory clinical result. Furthermore, when assessing hips treated before collapse, good results were obtained in 71% of the hips treated with core decompression and in 35% of hips treated nonoperatively. nullStulberg et al compared core decompression alone with conservative treat­ment in a prospective randomized study that included 55 hips. Core decompression was successful in 70% of the hips that were either Ficat Stage I, II, or III. In contrast, there was limited success with nonoperative treatment (Ficat Stage I, 20%; Ficat Stage II, 0%; Ficat Stage III, 10%). It was concluded that core decompression was more effective than nonoperative treatment for patients with early stages of ON. nullKoo and associates did a randomized trial on 71 hips that were treated by core decompression or nonoperatively. Radiographic progression was seen in 72% of the hips treated with core decompression and in 79% of the hips that were treated symptomatically. Seventy-two percent of the hips treated with a core decompression eventually required a THA and 68% of the hips treated symptomatically required a THA. The investigators concluded that there was no significant advantage in the outcome when patients with ON of the femoral head were treated with core decompression. null Smith and associates evaluated 114 hips and showed that there was a significant decrease in satisfactory results when a crescent sign was present. The success rate in hips with Ficat Stage I ON was 81% but in hips with the crescent sign or definitive collapse of the femoral head the success rates were 20% and 0% null Steinberg analyzed 205 patients (297 hips) with a minimum 2-year followup. The stage of the hip, according to the University of Pennsylvania Classification System, and the lesion site clearly influenced the success rates of core decompression. nullAaron et al’ evaluated 118 hips with Ficat Stage II or Ill ON which was treated with core decompression and core decompression and human DBM . Survival percent is show below:nullThere also has been an interest in combining core decompression of the femoral head with bone grafting or electrical stimulation or both to enhance bone repair in the femoral head. Steinberg et al found no advantage to supplementing core decompression with either direct current or capacita­tive coupling. nullBozic et al studied 54 hips that had ON of the femoral head with a mean duration of followup of 120 months (range, 24-196 months). A successful result was defined as one in which the hip was asymptomatic with no progression of the disease. An unsuccessful result was defined as radiographic failure or clinical failure or both. The authors showed that the significant predic­tors of overall failure included an advanced preoperative radiographic stage, a short duration of symptoms, and the use of corticosteroids. No association was seen between age, gender, excessive intake of alcohol or renal transplantation and a successful outcome. SURGICAL TECHNIQUE SURGICAL TECHNIQUE There is general agreement that the procedure should be done with fluoroscopic guidance in two planes. Before begin-fling the procedure, the area of ON should be identified on AP and lateral radiographs. It is critical that the starting hole for the core decompression site be made just above the level of the lesser trochanter to reduce the risk of development of a stress fracture in the femur. Fluoroscopic views are taken in both radiographic planes. Progressively larger reamers are used over the guide wire (Fig. 1). nullnullReaming should stop at least 5 mm from the articular surface of the femoral head depending on the position of the guide wire. A burr then is used to remove as much necrotic bone as possible. The core tract then can be grafted with autogenous bone obtained from the greater tro­chanter and DBM. The goal is to provide osteoprogenitor cells and an osteoinductive matrix to enhance bone repair in the femoral head. The size of one core tract can range from 9 to 12 mm depending on the diameter of the patient’s femur. nullIt is preferable to obtain a biopsy specimen from the femoral head to provide a definitive confinnation of the diagnosis. Protec­tive weightbearing is recommended for a minimum of 6 weeks after the surgical procedure. Core decompression seems to be more effective than symptomatic treatment. To optimize the results of core decompression, the ON must be diagnosed and treated early. The success of core decompression is improved in precollapse hips in which the lesion is small and there is a sclerotic rim surrounding the necrotic bone. END thanks by wbj