Department of Orthopaedics, Alingsås Hospital, Alingsås.
The Swedish Arthroplasty Register, Gothenburg; Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg; Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg/Mölndal, Sweden.
Acta Orthop. 2023 Aug 16;94:438-446. doi: 10.2340/17453674.2023.18263.
The Lubinus SP2 stem has been associated with a very low risk of periprosthetic femoral fractures (PPFFs). We aimed, primarily, to study the radiographic morphology of PPFFs close to a Lubinus SP2 stem. Secondarily, we analyzed whether higher reoperation rate was correlated to the revision method chosen or to the characteristics of the fracture and of the bone.
The study included 156 femoral fractures close to a Lubinus cemented stem. These fractures were treated in 40 hospitals in Sweden between 2006 and 2011 and were followed up until 2019. Data from the Swedish Arthroplasty Register was used. Medical records and radiographs were studied. The fractures were classified according to the Vancouver classification. The fracture location and anatomy were delineated. We also measured the remaining attachment index (RAI) and the canal thickness ratio.
Vancouver type C (n = 101) and spiral fractures (n = 67, 41 in Vancouver C and 26 in Vancouver B) were the most common fracture types. 4 fractures were avulsion of the greater trochanter. The remaining 51 fractures occurred around the stem (B1: 25, B2: 16, and B3: 10). B fractures were more commonly reoperated on (18 of 51, 35%) than type C fractures (11 of 101, 11%, P = 0.001). In most femurs with type B3 fracture, the fracture line covered an area only around the stem, but in all B1 and in 11 of 16 B2 fractures, it was extended even distal to the stem. ORIF instead of stem revision in B2 fractures, use of short stems or plates, and inadequate reduction of the fractures were risk factors for subsequent reoperations.
The higher reoperation rate in type B fractures, compared with fractures distal to the stem, could be caused by their higher degree of complexity and reduced capacity for healing in the region around the stem.
Lubinus SP2 柄与极低的股骨假体周围骨折（PPFF）风险相关。我们主要旨在研究与 Lubinus SP2 柄相邻的 PPFF 的影像学形态。其次，我们分析了更高的再手术率是否与所选择的翻修方法、骨折特征和骨特征相关。
该研究纳入了 156 例与 Lubinus 骨水泥柄相邻的股骨骨折。这些骨折于 2006 年至 2011 年在瑞典的 40 家医院进行治疗，并随访至 2019 年。使用瑞典关节置换登记处的数据。研究了病历和 X 线片。根据温哥华分类对骨折进行分类。勾勒出骨折位置和解剖结构。我们还测量了剩余附着指数（RAI）和管腔厚度比。
温哥华 C 型（n = 101）和螺旋骨折（n = 67，温哥华 C 型 41 例，温哥华 B 型 26 例）是最常见的骨折类型。4 例为大转子撕脱。其余 51 例骨折发生在柄周围（B1：25 例，B2：16 例，B3：10 例）。B 型骨折的再手术率（51 例中的 18 例，35%）高于 C 型骨折（101 例中的 11 例，11%，P = 0.001）。在大多数 B3 型骨折的股骨中，骨折线仅覆盖柄周围区域，但在所有 B1 型和 16 例 B2 型骨折中的 11 例中，它甚至延伸到柄的远端。B2 型骨折采用切开复位内固定而非柄翻修、使用短柄或钢板以及骨折复位不充分是再次手术的危险因素。
与柄远端骨折相比，B 型骨折的再手术率更高，这可能是由于该区域骨折的复杂性更高，愈合能力降低所致。
