Service d'orthopédie traumatologie, hôpital Nord, CHU d'Amiens, place Victor-Pauchet, 80053 Amiens cedex, France.
Orthop Traumatol Surg Res. 2010 Feb;96(1):14-20. doi: 10.1016/j.rcot.2009.12.006.
Although the use of the metal-on-metal bearings has been validated over the long term in total hip arthroplasty (THA) for standard 28 and 32 mm diameters, and over the medium term in resurfacing procedures, the use of larger metal head size in conventional THA has not yet been extensively reported.
The large-diameter metal-on-metal head is beneficial in terms of implant stability without altering the result in terms of function and bone fixation compared to the standard 28 and 32 mm diameters.
The objective was to test this hypothesis by assessing the short-term clinical and radio graphic results of a metal-on-metal large-diameter heads THA system, using cups from the resurfacing hip concept.
We conducted a retrospective study on a continuous series of 106 uncemented acetabular cups (Durom) implanted in 102 patients (mean age, 66 years): 93 cases of primary or secondary coxarthrosis, 11 cases of aseptic osteonecrosis, one fracture of the femoral neck, and one case of rheumatoid arthritis of the hip. At 30 months of follow-up,the Harris Hip Score and the Merle d'Aubigné (PMA) score were calculated. The radiological investigation included comparison of the implant head with native head diameters, variations of acetabular center of rotation, inspection for implant migration, and search for a gap or radiolucent line.
The series included two post-traumatic dislocations as well as spontaneously receding tendinitis of the gluteus medius with no further recurrence. The mean Harris Hip Score improved from 49.3 preoperatively to 91.6 at the latest follow-up and the mean PMA score ranged from 12 to 17. The results were excellent for 70 cases, good for 31 cases, fair for three cases, and poor for two cases. In the last five cases, the overall results were undermined by low pain subscore,with no identifiable explanation. Restoration of the original head diameter was verified for 65 hips. No cup migration was observed. Measurement of the acetabular centre of rotation showed a mean lateralization of 1.1mm. Of the 67 immediate postoperative gaps, only two did no disappear at follow-up. Implant head diameter, cup position, and the existence of a gap were not correlated with the clinical results.
These results are comparable to 28 mm-diameter metal-on-metal heads in uncemented cups but with improved stability but without demonstrable alteration of the quality of the bone fixation. We found no mechanical or medical cause that could explain the five cases of persistent pain leading to fair or poor results. Long-term follow-up will validate these theoretical advantages in terms of wear and implant survival.
IV. Retrospective series.
虽然金属对金属轴承在全髋关节置换术（THA）中已被证实可长期（用于标准 28 和 32 毫米直径）和中期（用于翻修手术）使用，但在传统 THA 中使用更大直径的金属头尚未得到广泛报道。
与标准 28 和 32 毫米直径相比，大直径金属对金属头在植入物稳定性方面是有益的，而在功能和骨固定方面的结果没有改变。
本研究旨在通过评估金属对金属大直径头 THA 系统的短期临床和影像学结果来检验这一假设，该系统使用来自髋关节翻修概念的髋臼杯。
我们对 102 例患者（平均年龄 66 岁）的 106 个非骨水泥髋臼杯（Durom）进行了连续系列回顾性研究：93 例原发性或继发性髋关节骨关节炎，11 例无菌性股骨头坏死，1 例股骨颈骨折，1 例髋关节类风湿关节炎。在 30 个月的随访时，计算了 Harris 髋关节评分和 Merle d'Aubigné（PMA）评分。影像学检查包括比较植入物头与原生头直径、髋臼旋转中心的变化、检查植入物迁移情况以及寻找间隙或透亮线。
该系列包括两例创伤后脱位以及一例自发性臀中肌肌腱退缩性炎，无进一步复发。平均 Harris 髋关节评分从术前的 49.3 分提高到末次随访时的 91.6 分，平均 PMA 评分为 12-17 分。70 例为优秀，31 例为良好，3 例为可，2 例为差。在最后 5 例中，低疼痛亚评分导致整体结果不佳，但无法确定原因。65 例髋关节证实恢复了原始头直径。未观察到杯迁移。测量髋臼旋转中心显示平均侧移 1.1mm。67 例即刻术后间隙中，只有 2 例在随访时未消失。植入物头直径、杯位置和间隙的存在与临床结果无关。
这些结果与非骨水泥杯的 28 毫米直径金属对金属头相当，但稳定性更好，而骨固定质量无明显改变。我们没有发现任何机械或医学原因可以解释导致结果为可或差的 5 例持续性疼痛。长期随访将验证这些在磨损和植入物存活率方面的理论优势。
IV. 回顾性系列。
