Department of Surgery, Orthopaedic Service, Memorial Sloan Kettering Cancer Center, affiliated with Weill Medical College of Cornell University, New York, NY, USA.
Clin Orthop Relat Res. 2021 Jul 1;479(7):1577-1585. doi: 10.1097/CORR.0000000000001663.
Compliant compression fixation was developed to promote permanent bone-prosthesis osteointegration while preserving bone stock in patients needing endoprosthetic reconstructions. This has demonstrated durability in the distal femur, with reliable cortical hypertrophy adjacent to the implant. However, the extent of bone formation and prosthetic survivorship of proximal femoral replacements with compliant compression fixation has not been established.
QUESTIONS/PURPOSES: (1) How much bone formation occurs across the compression segment in patients treated with a proximal femoral replacement implant using compliant compression fixation? (2) What were the Musculoskeletal Tumor Society (MSTS) scores at minimum 24-month follow-up of patients who received this reconstruction? (3) What is the implant survivorship free from implant removal or revision for any reason at final follow-up?
From 2006 to 2018, we performed 213 proximal femoral replacements in patients with oncologic conditions of the proximal femur where the trochanters could not be preserved. Of these, 6% (12 of 213) were performed with an implant that used compliant compression fixation. We used this device in primary oncologic reconstructions in patients younger than 65 years of age without metastases who had nonirradiated bone with the requisite ≥ 2.5 mm of cortical thickness in the hope that it would provide more durable fixation and bone stock preservation than conventional reconstructions. All patients were followed for longer than 2 years except one who died in that interval. Median (range) follow-up was 6 years (2 to 10 years). Seven patients received diagnosis-specific chemotherapy in a consistent manner based on Children's Oncology Group chemotherapy protocols. Using the NIH-developed ImageJ open-access software, we measured the area of bone under compression on 3-, 6-, 9-, 12-, 18-, and 24-month radiographs and the length of the traction bar potential-compression distance, reconciling independent measures from two investigators using the identical method as published for the distal femur with compression fixation. The duration of prosthesis retention was evaluated using a competing risk analysis for the 11 surviving patients.
Bone hypertrophy in the compression segment was scant. At the final analysis, cortical bone formation was a median (range) of 4 (-7 to 14) above baseline. The median (range) MSTS score was 27 (19 to 30). One implant failed after trauma, and the patient underwent revision of the implant.
Despite scant bone formation across the compression segment and drastically less formation than reported for distal femoral replacements, compliant compression fixation of the proximal femur demonstrated good survivorship in patients 65 years or younger with localized sarcoma and nonirradiated, adequate bone stock in this small, retrospective series. Patients achieved good functional outcomes at final follow-up. The potential benefit of this reconstruction method should be weighed against the initial period of limited weightbearing and the life expectancy of the patient.
Level IV, cohort study.
顺应性加压固定技术的发展旨在促进永久性骨-假体骨整合，同时保留需要进行假体重建的患者的骨质。在股骨远端，该技术已经证明了其耐用性，在假体周围有可靠的皮质肥大。然而，在股骨近端使用顺应性加压固定的假体的骨形成程度和假体存活率尚未确定。
问题/目的：（1）使用顺应性加压固定的股骨近端假体置换患者，在加压段有多少骨形成？（2）接受这种重建的患者在至少 24 个月的随访时，肌肉骨骼肿瘤学会（MSTS）评分是多少？（3）在最终随访时，有无因任何原因而需要取出或翻修假体的假体存活率？
2006 年至 2018 年，我们对 213 例股骨近端有骨肿瘤的患者进行了股骨近端置换术，这些患者的转子无法保留。其中，6%（12/213）采用了一种使用顺应性加压固定的假体。我们在 65 岁以下无转移的年轻患者中，将该装置用于原发性骨肿瘤重建，这些患者的非放射性骨皮质厚度至少为 2.5 毫米，希望它能提供比传统重建更耐用的固定和骨质保留。除 1 例患者在随访期间死亡外，所有患者的随访时间均超过 2 年。中位（范围）随访时间为 6 年（2 至 10 年）。7 例患者根据儿童肿瘤组化疗方案，以一致的方式接受了基于诊断的化疗。使用 NIH 开发的 ImageJ 开放获取软件，我们测量了 3、6、9、12、18 和 24 个月的 X 线片上受压骨的面积和牵引杆潜在压缩距离，使用与已发表的用于股骨远端加压固定的相同方法，由两名研究人员独立测量，以协调一致的方法来解决。使用竞争风险分析评估 11 例存活患者的假体保留时间。
在受压段的骨肥大很少见。在最终分析时，皮质骨形成中位数（范围）为 4（-7 至 14）高于基线。MSTS 评分中位数（范围）为 27（19 至 30）。1 例患者因外伤导致假体失败，随后进行了假体翻修。
尽管在受压段的骨形成很少，而且比报道的股骨远端置换术少得多，但在 65 岁或以下的局限性肉瘤患者和非放射性、骨质充足的患者中，股骨近端的顺应性加压固定显示出良好的存活率，在这个小的回顾性系列中。患者在最终随访时获得了良好的功能结果。这种重建方法的潜在益处应与初始的有限负重期和患者的预期寿命相权衡。
IV 级，队列研究。
