Gopinath Rohan, DePalma Brian J, Costales Timothy, Chapman Danielle M, Dalury David F
Department of Orthopaedic Surgery, University of Maryland Medical Center, 110 South Paca Street 6th Floor Suite 300, Baltimore, MD 21201, United States.
Orthopaedic Institute at University of Maryland St. Joseph's Medical Center, 7601 Osler Dr., Towson, MD 21204, United States.
Knee. 2022 Dec;39:203-208. doi: 10.1016/j.knee.2022.09.008. Epub 2022 Oct 7.
Radiolucent lines (RLLs) following unicompartmental knee arthroplasty (UKA) can be concerning as aseptic loosening remains a cause of failure in UKA. The aim of our study was to report on the history of RLLs surrounding the components in a cemented medial compartment fixed-bearing UKA as well as the long-term functional outcomes in this group of patients.
In this retrospective consecutive case-series, twenty-eight patients (37 knees) were treated with medial, fixed-bearing cemented unicompartmental knee arthroplasty. At average final follow-up of 7.1 years, 36 knees were available for review. Radiographs were taken at six weeks, one year, and final follow up. RLLs were measured using a novel modification to the Knee Society scoring (KSS) system.
At six-weeks, we identified RLLs in 26 tibias and two femurs out of 37 total knees. At one-year, four additional tibias and both femurs showed some progression of their radiolucencies but were < 2 mm total. At final follow-up, 31 of the 36 tibias (86.1%) and five of the 36 femurs (13.9%) had any RLLs. On the tibial side, RLLs were most common in medial/lateral and anterior/posterior aspects of the tibial tray with few found centrally. On the femoral side, the posterior femoral cut accounted for the most RLLs of any zone at all time points. KSS averaged 93.8 at final follow-up and none of the patients required revision surgery.
RLLs are common following cemented, fixed-bearing UKA. Many seem to progress slowly up to one year but not thereafter. There does not appear to be any association between the presence of these radiolucencies and long-term follow-up function in this group of patients.
单髁膝关节置换术（UKA）后出现的透亮线（RLLs）可能令人担忧，因为无菌性松动仍是UKA失败的一个原因。我们研究的目的是报告骨水泥固定内侧单髁膝关节置换术中假体周围RLLs的情况，以及该组患者的长期功能结果。
在这个回顾性连续病例系列研究中，28例患者（37个膝关节）接受了内侧骨水泥固定单髁膝关节置换术。平均最终随访7.1年，36个膝关节可供复查。在术后6周、1年和最终随访时拍摄X线片。使用对膝关节协会评分（KSS）系统的一种新改进方法来测量RLLs。
在术后6周时，37个膝关节中，我们在26个胫骨和2个股骨中发现了RLLs。在1年时，另外4个胫骨和2个股骨的透亮线有一定进展，但总进展小于2mm。在最终随访时，36个胫骨中有31个（86.1%）和36个股骨中有5个（13.9%）有任何RLLs。在胫骨侧，RLLs最常见于胫骨托的内侧/外侧和前/后方面，中央部位较少见。在股骨侧，股骨后髁截骨处始终是所有区域中RLLs最多的部位。最终随访时KSS平均为93.8，没有患者需要翻修手术。
骨水泥固定、固定平台UKA术后RLLs很常见。许多RLLs在1年内似乎进展缓慢，但之后不再进展。在这组患者中，这些透亮线的存在与长期随访功能之间似乎没有任何关联。
