Bone grafting and internal fixation of intracapsular femoral neck fracture. Two years follow up in five patients with a novel fixation device.

摘要

Objectives: To test the safety and effectiveness of a novel procedure and device for fixation of displaced or non-displaced intracapsular femoral neck fractures, in order to preserve the natural femoral head and prevent the need for partial or total hip replacement. Design: Single- arm, prospective clinical investigation. Setting: Patients admitted to the Orthopedic Department. Participants: Male and female patients between the ages of 50 and 75 with a Garden I-III type intracapsular femoral fracture. Intervention: Internal fixation with the WaisFix 100i device, and bone graft with bone substitute. Measurements: Experimental and computer simulator testing prior to clinical evaluation by mechanical and numerical modeling, and clinical and radiological follow-up. Results: Five women with Garden I-III type intracapsular femoral fracture underwent internal fixation and bone graft with the WaisFix 100i device. The operations were performed 8 to 26 hours following the traumatic event. There were no peri-operative complications or infections, and bleeding was negligible. The average hospitalization following surgery was 4 days, and hospital rehabilitation time was two weeks. Clinical and radiological bone union (eight to ten weeks) and optimal alignment were achieved in all cases. No cases of avascular necrosis, mechanical device failure or indication for hip replacement were observed after >2 years. Conclusion: At >2-years follow-up, the WaisFix100i internal fixation device and bone graft for intracapsular femoral neck fractures demonstrated safety, assessed by lack of complications; and effectiveness, assessed by rigid and stable fixation and short healing time. Introduction As the average lifespan increases, so do the health and financial burdens posed by hip fractures. Even if the incidence rates remain stable, estimated worldwide incidence is expected to increase from 1.7 million annually in 1990 to 6.3 million in 2050 [1]. A rising trend in osteoporosis [2] will further boost this figure; a mere 1% increase in incidence is expected to result in 8.2 million cases annually [1]. A recent study of 7753 residents in Canada revealed that one in six women over age 50 will sustain hip fracture, and that hip fracture increases the risk of death 3.2 fold [3]. Hip fracture treatment is costly, comprising 72% of the total costs of bone fractures in the year 2005, compared with only 14% of the total incidence [4]. One-year mortality rates range from 14% to 36% [5]. Deep vein thrombosis, pulmonary embolism, pneumonia, chronic pain, restricted mobility and poor rehabilitation are consequences of hip fracture that negatively impact patients? health and quality of life. Fifty percent of hip fractures are displaced or non-displaced intracapsular fractures [6]. Intracapsular fracture is also called “the unsolved fracture” of the femoral neck. Cannulated screws, sliding hip screws and Hansson pin-hook are commonly used for internal fixation of intracapsular femoral neck fractures. Less invasive than hemiarthroplasty or hip replacement, such techniques have demonstrated relatively few perioperative and postoperative complications [7, 8] and less operative blood loss. However, mechanical failure, non-union, cut-out and avascular necrosis are drawbacks of internal fixation procedures. As a result, many orthopaedic surgeons prefer partial or total hip arthroplasty [5, 8-12]. In randomized trials, more repeat procedures were required following internal fixation (34– 43%) than hemiarthroplasty (4-6%) [13-16]. A meta-analysis of 106 published reports [17] showed that within two years of internal fixation of a displaced fracture of the femoral neck, non-union presented in 33 percent of the patients and avascular necrosis of the femoral neck in 16 percent. In a recent randomized controlled trial, functional outcome, as assessed by higher Harris Hip Scores at 4 and 12 months postoperatively, was greater for hemiarthroplasty than for internal fixation [18].