Dekker Travis J, Hamid Kamran S, Easley Mark E, DeOrio James K, Nunley James A, Adams Samuel B
1Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
J Bone Joint Surg Am. 2017 Apr 5;99(7):576-582. doi: 10.2106/JBJS.16.00606.
This study attempted to identify where motion occurs after total ankle replacement, the difference in range-of-motion contributions between fixed-bearing and mobile-bearing total ankle replacements, and the contribution of abnormal peritalar motion. We hypothesized that sagittal plane radiographic assessment would demonstrate that actual ankle motion through the prosthesis is less than the total arc of ankle motion that may be observed clinically secondary to contributions from adjacent joints.
Patients underwent routine standardized weight-bearing maximum dorsiflexion and plantar flexion sagittal radiographs. Sagittal plane ankle and foot measurements were performed on each dorsiflexion and plantar flexion radiograph to determine the total arc of ankle motion, actual ankle motion through the prosthesis, motion through the subtalar and talonavicular joints, and midfoot motion. Motion radiographs were routinely made at 1 year postoperatively and at the time of the most recent follow-up. A minimum follow-up of 2 years was required of all patients.
There were 197 patients who met the inclusion criteria (75 INBONE, 52 Salto Talaris, and 70 STAR prostheses). The mean time to the latest radiographs (and standard deviation) was 42.9 ± 18.8 months. The mean actual ankle motion through the prosthesis was 25.9° ± 12.2°, which was significantly less (p < 0.001) than the mean total motion arc of 37.6° ± 12.0°. The motion of the ankle accounted for 68% of total range of motion, and motion of the peritalar joints accounted for 32%. There was no significant difference (p > 0.05) among the 3 prostheses or when comparing fixed and mobile-bearing designs for both ranges of motion.
This study demonstrates that actual ankle motion after total ankle replacement is approximately 12° less than the total arc of motion that might be observed clinically because of increased midfoot and subtalar motion.
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
本研究试图确定全踝关节置换术后运动发生的部位、固定平台和活动平台全踝关节置换在活动度贡献方面的差异，以及距周异常运动的贡献。我们假设矢状面影像学评估将显示，通过假体的实际踝关节运动小于临床上可观察到的踝关节总运动弧，这是由于相邻关节的贡献所致。
患者接受常规标准化负重下最大背屈和跖屈矢状位X线片检查。在每张背屈和跖屈X线片上进行矢状面踝关节和足部测量，以确定踝关节总运动弧、通过假体的实际踝关节运动、通过距下关节和距舟关节的运动以及中足运动。术后1年和最近一次随访时常规拍摄动态X线片。所有患者的随访时间至少为2年。
有197例患者符合纳入标准（75例使用INBONE假体、52例使用Salto Talaris假体和70例使用STAR假体）。至最新X线片的平均时间（及标准差）为42.9±18.8个月。通过假体的平均实际踝关节运动为25.9°±12.2°，显著小于平均总运动弧37.6°±12.0°（p<0.001）。踝关节运动占总活动度的68%，距周关节运动占32%。在这3种假体之间，或比较固定平台和活动平台设计的两种活动度时，均无显著差异（p>0.05）。
本研究表明，全踝关节置换术后的实际踝关节运动比临床上可能观察到的总运动弧小约12°，这是由于中足和距下运动增加所致。
治疗性四级证据。有关证据水平的完整描述，请参阅作者指南。
