Popovic Nebojsa, Lemaire Roger, Georis Pierre, Gillet Philippe
Orthopaedic Department, University Hospital Sart-Tilman, B-4000 Liège, Belgium.
J Bone Joint Surg Am. 2007 Nov;89(11):2469-76. doi: 10.2106/JBJS.F.00723.
Metal prostheses are useful for restoring elbow and forearm stability when the radial head cannot be fixed after a fracture. Because the anatomy of the radial head is difficult to reproduce with a prosthesis, two different options have been proposed: a bipolar prosthesis with a fixed stem and a mobile head, and a monoblock prosthesis with a smooth stem that is intentionally fixed loosely in the neck of the radius. One concern with a fixed-stem implant with a mobile head has been the risk of osteolysis. The purpose of this study was to evaluate radiographic changes reflecting or suggesting progressive osteolysis in patients with a bipolar radial head prosthesis.
The functional and radiographic outcomes following treatment of fifty-one comminuted fractures of the radial head with a bipolar radial head prosthesis in fifty-one consecutive patients were evaluated at a mean of 8.4 years postoperatively. There were eleven isolated comminuted fractures involving the entire radial head. Thirty-four fractures were associated with a posterior elbow dislocation, and six patients had a posterior Monteggia lesion.
According to the Mayo Elbow Performance Index, fourteen elbows were graded as excellent; twenty-five, as good; nine, as fair; and three, as poor. Radiographic changes reflecting or suggesting progressive osteolysis were present in thirty-seven patients. Complications occurred in ten patients, but only one underwent surgical treatment, for an ulnar neuropathy.
Although satisfactory midterm functional results were achieved in thirty-nine of the fifty-one patients, the high prevalence of adverse radiographic changes suggesting periprosthetic osteolysis should alert clinicians to this possible drawback of the use of bipolar radial head prostheses, especially in young and/or active patients.
当桡骨头骨折后无法固定时，金属假体有助于恢复肘部和前臂的稳定性。由于假体难以复制桡骨头的解剖结构，因此提出了两种不同的选择：一种是带有固定柄和活动头的双极假体，另一种是带有光滑柄的一体式假体，该柄有意松散地固定在桡骨颈部。带活动头的固定柄植入物的一个问题是存在骨溶解的风险。本研究的目的是评估双极桡骨头假体患者中反映或提示进行性骨溶解的影像学变化。
对51例连续患者采用双极桡骨头假体治疗51例桡骨头粉碎性骨折后的功能和影像学结果进行评估，平均随访时间为术后8.4年。其中11例为累及整个桡骨头的孤立性粉碎性骨折。34例骨折合并肘关节后脱位，6例患者合并孟氏骨折。
根据梅奥肘关节功能指数，14例肘关节评定为优；25例为良；9例为中；3例为差。37例患者出现反映或提示进行性骨溶解的影像学变化。10例患者出现并发症，但只有1例因尺神经病变接受了手术治疗。
虽然51例患者中有39例取得了满意的中期功能结果，但提示假体周围骨溶解的不良影像学变化的高发生率应提醒临床医生注意使用双极桡骨头假体可能存在的这一缺点，尤其是在年轻和/或活跃的患者中。
