Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Bone Joint J. 2020 Jun;102-B(6_Supple_A):116-122. doi: 10.1302/0301-620X.102B6.BJJ-2019-1511.R1.
Metaphyseal cones with cemented stems are frequently used in revision total knee arthroplasty (TKA). However, if the diaphysis has been previously violated, the resultant sclerotic canal can impair cemented stem fixation, which is vital for bone ingrowth into the cone, and long-term fixation. We report the outcomes of our solution to this problem, in which impaction grafting and a cemented stem in the diaphysis is combined with an uncemented metaphyseal cone, for revision TKA in patients with severely compromised bone.
A metaphyseal cone was combined with diaphyseal impaction grafting and cemented stems for 35 revision TKAs. There were two patients with follow-up of less than two years who were excluded, leaving 33 procedures in 32 patients in the study. The mean age of the patients at the time of revision TKA was 67 years (32 to 87); 20 (60%) were male. Patients had undergone a mean of four (1 to 13) previous knee arthroplasty procedures. The indications for revision were aseptic loosening (80%) and two-stage reimplantation for prosthetic joint infection (PJI; 20%). The mean follow-up was four years (2 to 11).
Survival free from revision of the cone/impaction grafting construct due to aseptic loosening was 100% at five years. Survival free from any revision of the construct and free from any reoperation were 92% and 73% at five years, respectively. A total of six patients (six TKAs, 17%) required a further revision, four for infection or wound issues, and two for periprosthetic fracture. Radiologically, one unrevised TKA had evidence of loosening which was asymptomatic. In all unrevised TKAs the impacted diaphyseal bone graft appeared to be incorporated radiologically.
When presented with a sclerotic diaphysis and substantial metaphyseal bone loss, this technique combining diaphyseal impaction grafting with a metaphyseal cone provided near universal success in relation to implant fixation. Moreover, radiographs revealed incorporation of the bone graft and biological fixation of the cone. While long-term follow-up will be important, this technique provides an excellent option for the management of complex revision TKAs. Cite this article: 2020;102-B(6 Supple A):116-122.
带骨水泥柄的干骺端骨水泥圆锥常用于翻修全膝关节置换术（TKA）。然而，如果骨干已经受到先前的侵犯，由此产生的硬化管会损害骨水泥柄的固定，这对骨长入圆锥和长期固定至关重要。我们报告了我们解决这个问题的结果，在这个问题中，我们将打压植骨和骨干中的骨水泥柄与非骨水泥干骺端圆锥结合起来，用于治疗严重骨质受损的翻修 TKA 患者。
在 35 例翻修 TKA 中，我们将干骺端圆锥与骨干打压植骨和骨水泥柄相结合。有 2 例患者的随访时间少于 2 年，被排除在外，因此研究中共有 32 例患者的 33 个手术。翻修时患者的平均年龄为 67 岁（32 至 87 岁）；20 例（60%）为男性。患者平均接受过 4 次（1 至 13 次）膝关节置换术。翻修的指征为无菌性松动（80%）和二期再植入治疗人工关节感染（PJI；20%）。平均随访时间为 4 年（2 至 11 年）。
5 年时，由于无菌性松动导致圆锥/打压植骨结构翻修的生存率为 100%。5 年时，结构无任何翻修且无任何再手术的生存率分别为 92%和 73%。共有 6 例患者（6 例 TKA，17%）需要进一步翻修，其中 4 例因感染或伤口问题，2 例因假体周围骨折。放射学上，1 例未翻修的 TKA 出现松动但无症状。所有未翻修的 TKA 中，打压的骨干骨移植物在放射学上均显示已被吸收。
当骨干出现硬化且干骺端骨质大量丢失时，这种将骨干打压植骨与干骺端圆锥相结合的技术在假体固定方面几乎普遍成功。此外，X 线片显示移植物的吸收和圆锥的生物学固定。虽然长期随访很重要，但该技术为治疗复杂的翻修 TKA 提供了一个极好的选择。引用本文：2020；102-B（6 增刊 A）：116-122。
