Adult Reconstruction & Joint Replacement Division, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA.
Clin Orthop Relat Res. 2013 Dec;471(12):3998-4003. doi: 10.1007/s11999-013-3212-3. Epub 2013 Aug 6.
High tibial osteotomy and unicompartmental knee arthroplasty are surgical treatment options for unicompartmental knee arthritis; these procedures are indicated for patients who do not have severe arthritis in the lateral compartment. Valgus stress radiographs sometimes are used to make this evaluation, but this test has not been critically evaluated.
QUESTIONS/PURPOSES: We sought to determine (1) whether valgus stress radiographs help to evaluate the integrity of the cartilage in the lateral compartment in patients undergoing TKA for noninflammatory arthritis, and (2) whether valgus stress radiographs can identify patients whose varus deformity is correctable.
We reviewed preoperative hip-to-ankle standing radiographs, AP standing radiographs, and valgus stress radiographs of 84 patients (91 knees) who underwent TKA for varus knee arthritis between July 2010 and January 2012. Valgus stress radiographs were obtained with the patient supine with the knee 20° flexed and a firm manual valgus force was applied through the knee. On valgus stress radiographs, the lateral compartment joint space width and the corrected mechanical alignment were measured. Intraoperative cartilage assessment (Outerbridge grade) was compared with lateral compartment joint space width. Knees with mechanical leg alignment of 3° varus to 3° valgus on valgus stress radiographs were considered correctable deformities.
The lateral compartment joint space width on valgus stress radiographs did not correlate with the intraoperative Outerbridge grading of the lateral compartment cartilage (rs = -0.154; p = 0.146). The majority of knees (93%; 55 of 59) with 10° or less mechanical varus on hip-to-ankle standing radiographs were correctable within the range of 3° varus to 3° valgus.
Valgus stress radiographs provided no added benefit to the radiographic assessment of the lateral compartment cartilage and regarding the correctability of the varus deformity.
高位胫骨截骨术和单髁膝关节置换术是治疗单间室膝关节骨关节炎的手术选择；这些手术适用于外侧间室没有严重关节炎的患者。外翻应力量线片有时用于进行此评估，但该检查尚未经过严格评估。
问题/目的：我们旨在确定（1）外翻应力量线片是否有助于评估接受非炎症性关节炎 TKA 患者外侧间室软骨的完整性，以及（2）外翻应力量线片是否能识别出其可矫正的内翻畸形患者。
我们回顾性分析了 2010 年 7 月至 2012 年 1 月期间因内翻性膝关节炎接受 TKA 的 84 例患者（91 膝）的术前髋踝站立位 X 线片、AP 站立位 X 线片和外翻应力量线片。外翻应力量线片的拍摄方法为：患者仰卧，膝关节弯曲 20°，通过膝关节施加牢固的手动外翻力。在外翻应力量线片上，测量外侧间室关节间隙宽度和校正机械对线。将术中软骨评估（Outerbridge 分级）与外侧间室关节间隙宽度进行比较。外翻应力量线片上机械下肢对线为 3°内翻至 3°外翻的膝关节被认为是可矫正的畸形。
外侧间室关节间隙宽度在外翻应力量线片上与术中外侧间室软骨的 Outerbridge 分级无相关性（rs = -0.154；p = 0.146）。在髋踝站立位 X 线片上机械性内翻 10°或以下的膝关节中，有 93%（55/59）在 3°内翻至 3°外翻的范围内是可矫正的。
外翻应力量线片对外侧间室软骨的放射学评估以及内翻畸形的可矫正性没有提供额外的益处。
