Weber Markus, Woerner Michael, Messmer Benedikt, Grifka Joachim, Renkawitz Tobias
Department of Orthopedic Surgery, Asklepios Klinikum Bad Abbach, Regensburg University Medical Center, Kaiser-Karl V-Allee 3, 93077, Bad Abbach, Germany.
Clin Orthop Relat Res. 2017 Jan;475(1):196-203. doi: 10.1007/s11999-016-5061-3. Epub 2016 Sep 7.
Iliopsoas tendon impingement is one possible reason for persistent groin pain and diminished functional outcome after THA. So far, estimation by eye and palpation is the standard procedure to intraoperatively assess the distance of the cup to the anterior rim. However, novel technologies such as imageless navigation enable intraoperative measurements of the cup in relation to the psoas tendon and bony landmarks.
QUESTIONS/PURPOSES: We asked whether psoas impingement (1) can be reduced using imageless navigation compared with the standard technique and (2) is associated with specific patient characteristics. Furthermore, we investigated (3) if anterior cup protrusion (overhang) is associated with lower outcome scores for pain and function.
The current study is a reanalysis of data from a randomized controlled trial evaluating navigation for THA; 135 patients were randomized for surgery with or without the use of imageless navigation. The risk for anterior protrusion of the cup above the acetabular rim and thus potential psoas impingement, defined as an overhang of the cup above the anterior acetabular rim as measured on postoperative CT, was either controlled with the help of navigation or standard control by eye and palpation intraoperatively. Postoperatively, the anterior protrusion of the cup above the acetabular rim was measured on three-dimensional (3-D) CT by a blinded, external institute. In addition to patient-related outcome measures, the Harris hip score, Hip disability and Osteoarthritis Outcome Score, and EuroQol were obtained 1 year postoperatively. Altogether 123 data sets were available for primary analysis and 115 were available for 1-year followup.
There was no difference, with the numbers available, between the navigated and the control groups in terms of the mean distance of the cup below the anterosuperior acetabular rim (3.9 mm; -5.3 to 12.6 mm versus 4.4 mm; -7.9 to 13.7 mm; p = 0.72) or the anteroinferior acetabular rim (4.7 mm; -6.2 to 14.8 mm versus 4.2 mm; -7.1 to 16.3 mm; p = 0.29). There was no difference, with the numbers available, in terms of the proportion of cups with anterior overhang (7%, four of 57 versus, 15%, 10 of 66; p = 0.16), respectively. After controlling for potential confounding variables such as cup inclination, cup size, patient age, BMI, stage of arthritis, and length of skin incision, we found cup anteversion (hazard ratio [HR], 0.87; 95% CI, 0.81-0.93; p < 0.001) and female sex (HR, 3.88; 95% CI, 1.01-14.93; p = 0.049) were associated with a propensity to potential psoas impingement. With the numbers available, there were no differences observed in clinical scores between groups with and without anterior cup protrusion.
We found no differences between imageless navigation and estimation by eye and palpation in preventing potential psoas impingement. Despite the comparable clinical outcome for patients with and without cup protrusion, the orthopaedic surgeon should be especially aware of propensity for psoas impingement in women.
Level II, therapeutic study.
髂腰肌肌腱撞击是全髋关节置换术（THA）后腹股沟区持续疼痛和功能预后不良的一个可能原因。目前，术中通过目测和触诊评估髋臼杯与髋臼前缘的距离是标准操作方法。然而，诸如无影像导航等新技术能够在术中测量髋臼杯与腰大肌肌腱及骨性标志的关系。
问题/目的：我们探讨了与标准技术相比，（1）使用无影像导航能否减少腰大肌撞击；（2）腰大肌撞击是否与特定患者特征相关。此外，我们还研究了（3）髋臼杯前凸（悬垂）是否与疼痛和功能的较低预后评分相关。
本研究是对一项评估THA导航的随机对照试验数据的重新分析；135例患者被随机分为接受或不接受无影像导航辅助的手术。髋臼杯高于髋臼缘从而导致潜在腰大肌撞击的风险，定义为术后CT测量的髋臼杯高于髋臼前缘的悬垂，术中通过导航或标准的目测和触诊控制。术后，由外部独立机构的人员在三维（3-D）CT上测量髋臼杯高于髋臼缘的前凸情况。除了患者相关的预后指标外，术后1年还获取了Harris髋关节评分、髋关节功能障碍和骨关节炎预后评分以及欧洲五维度健康量表。共有123个数据集可用于初步分析，115个可用于1年随访。
在可获取的数据中，导航组和对照组在髋臼杯低于髋臼前上缘的平均距离（3.9 mm；-5.3至12.6 mm对比4.4 mm；-7.9至13.7 mm；p = 0.72）或髋臼前下缘的平均距离（4.7 mm；-6.2至14.8 mm对比4.2 mm；-7.1至16.3 mm；p = 0.29）方面无差异。在可获取的数据中，髋臼杯有前悬垂的比例（7%，57例中的4例对比15%，66例中的10例；p = 0.16）也无差异。在控制了诸如髋臼杯倾斜度、髋臼杯大小、患者年龄、体重指数、关节炎分期和皮肤切口长度等潜在混杂变量后，我们发现髋臼杯前倾角（风险比[HR]，0.87；95%可信区间，0.81 - 0.93；p < 0.001）和女性性别（HR，3.88；95%可信区间，1.01 - 14.93；p = 0.049）与潜在腰大肌撞击倾向相关。在可获取的数据中，有和没有髋臼杯前凸的组之间在临床评分上未观察到差异。
我们发现在预防潜在腰大肌撞击方面，无影像导航与目测和触诊评估没有差异。尽管有和没有髋臼杯前凸的患者临床预后相当，但骨科医生应特别注意女性患者发生腰大肌撞击的倾向。
二级，治疗性研究。
