[Clinical evaluation of small diameter decompression and arthroscopy in the treatment of early avascular necrosis of femoral head].

OBJECTIVE: To investigate the therapeutic effect of small diameter, multiple porous, low drill velocity decompression and hip arthroscopy in treatment of early avascular necrosis of femoral head (ANFH).

METHODS: 226 ANFH patients (383 hips), 169 males (296 hips) and 57 females (87 hips), aged 36.5 (14 - 64), underwent drilling decompression with 3.5 mm Steinmann pin at a low velocity under the C-arm X-ray monitoring, all the 383 hips were decompressed with Steinmann pin, small diameter, multiple porous, low drill velocity. Synovectomy and cartilage trimming were performed through hip arthroscopy at the same time on the 209 hips combined with hip arthrosynovitis or cartilage trauma. 164 cases were followed up for 35 months (3 - 60 months).

RESULTS: The Harris score was increased from 68 (56 - 78) pre-operatively to 79 (58 - 92) post-operatively. Excellent curative effect was found in 198 of the 383 hips (69.5%) with a Harris score > 80, medium curative effect was found in 70 hips (24.5%) with a Harris score between 70 and 79; and bad effect found in 17 hips (6.0%) with a Harris score < 69. During the follow-up, these 17 hips presented progress in staging of clinical course and collapse of femoral head. 139 hips with hydrops articuli were treated with arthroscopy, and 87 of the 139 hips underwent hip MRI during the follow-up. It was found that the hydrops articuli decreased in 59 hips and increased in 10 hips. Complications were found in 10 cases and all of them were recovered after treatment.

CONCLUSION: The effect of small diameter, multiple porous and low drill velocity decompression is equal to or surpasses traditional core decompression. Small diameter decompression has the advantage of less osseous destruction of femoral head, delaying femoral head collapse and improving blood circulation in the necrosis zone of femoral head. Hip arthroscopy can greatly improve the therapeutic effect of ANFH through scavenging pain-producing substance, removing the cartilage chips caused by isolation or undermining dissection, and correcting internal environment disorder.