Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong, China.
J Orthop Surg (Hong Kong). 2020 Sep-Dec;28(3):2309499020958167. doi: 10.1177/2309499020958167.
The bone-implant junction is a potential site for aseptic loosening. Extracortical bone bridging at the bone-implant junction is advocated to improve implant fixation by forming a biological seal. We propose a novel technique with vascularised bone graft (VBG) to form an extracortical bone bridge at the bone-implant junction to enhance implant stability. We compared the clinical and radiological outcomes for tumour megaprostheses performed (1) with and without bone graft and (2) with non-vascularised versus VBG technique.
Forty-six tumour megaprosthesis procedures from 1 June 2007 to 31 October 2017 were identified from hospital records. Twenty-eight operations incorporated bone graft at the bone-implant junction, and 18 did not. Of these 28 bone graft procedures, 13 involved VBG, and 15 did not (non-VBG). The VBG technique involves resecting a short segment of healthy bone beyond the oncological margin with its preserved blood supply, splitting it, then securing it over the junction. Clinical outcomes assessed included loosening, fracture and recurrence. Extracortical bone growth at the bone-implant junction was quantified radiologically at intervals 0-24 months post-operatively. The mean follow-up was 4.27 years.
There were five incidences (27.8%) of loosening in the non-bone graft group compared to zero in the bone graft group ( = 0.03). There was a higher radiological score of extracortical bone growth in the bone graft group compared to no bone graft at 3-24 months post-operatively ( < 0.05). Within the bone graft group, the VBG group fared superior at 6 and 12 months post-operatively compared to non-VBG ( < 0.05), as well as a lower rate of radiological junctional resorption ( = 0.04).
We recommend bone grafting for its merits of less implant loosening. We propose the VBG technique to combat early aseptic loosening in megaprosthesis replacement as there was a higher radiological score compared to non-VBG.
骨-植入物交界处是无菌松动的潜在部位。在骨-植入物交界处形成皮质外骨桥被认为可以通过形成生物密封来改善植入物固定。我们提出了一种新的技术，使用带血管化的骨移植物（VBG）在骨-植入物交界处形成皮质外骨桥，以增强植入物的稳定性。我们比较了肿瘤假体手术的临床和影像学结果，这些手术（1）有无骨移植，（2）有无血管化与 VBG 技术。
从医院记录中确定了 2007 年 6 月 1 日至 2017 年 10 月 31 日期间进行的 46 例肿瘤假体手术。28 例手术在骨-植入物交界处结合了骨移植，18 例没有。在这 28 例骨移植手术中，13 例涉及 VBG，15 例不涉及（非 VBG）。VBG 技术涉及切除肿瘤边缘外带有其保留的血液供应的一段短的健康骨，将其分裂，然后将其固定在交界处。评估的临床结果包括松动、骨折和复发。术后 0-24 个月定期进行骨-植入物交界处皮质外骨生长的影像学定量。平均随访时间为 4.27 年。
在无骨移植组中，有 5 例（27.8%）发生松动，而在骨移植组中则为零（ = 0.03）。在骨移植组中，与无骨移植相比，在术后 3-24 个月时，皮质外骨生长的影像学评分更高（ < 0.05）。在骨移植组中，VBG 组在术后 6 个月和 12 个月的效果优于非 VBG 组（ < 0.05），并且影像学交界处吸收率较低（ = 0.04）。
我们建议进行骨移植，因为它可以减少植入物松动。我们提出 VBG 技术来对抗假体置换中的早期无菌松动，因为与非 VBG 相比，它具有更高的影像学评分。
