Citations

AbstractPurposeTo compare the accuracy and reliability of the anatomic and radiographic techniques for identifying the isometric point of the knee.MethodsOnly four specimens were used; however, eight experienced multiligament knee injury surgeons were recruited to address this limitation. Surgeons estimated the isometric point (EIP) on the medial and lateral sides using an anatomic and radiographic method. The x and y coordinates of the EIP were compared to the true isometric point (TIP). T‐tests and interclass correlation coefficients (ICC) were performed to determine the accuracy and reliability between the methods.ResultsThere was no difference in placement of the EIP on the medial side of the knee in the anterior/posterior (x; p = n.s.) and superior/inferior direction (y;p = n.s). The EIP was anterior (p = 0.001) to the TIP with the radiographic method on the lateral side and approached significance (p = 0.05) in the superior/inferior direction. The ICC (95 % CI) for identifying the EIP on the medial side in the anterior/posterior direction using the anatomic method was 0.64 (0.28–0.96) and 0.11 (−0.06 to 0.77) in the superior/inferior direction. Using the radiographic method, the ICC in the anterior/posterior and superior/inferior direction was 0.49 (0.14–0.94) and 0.15 (−0.47 to 0.81), respectively. On the lateral side, the ICC for the anatomic method was 0.84 (0.56–0.99) in the anterior/posterior direction and 0.36 (0.05–0.90) in the superior/inferior direction. Using the radiographic method, the ICC in the anterior/posterior and superior/inferior direction was 0.61 (0.26–0.96) and 0.89 (0.67–0.99), respectively.ConclusionsThere was no difference in accuracy on the medial side of the knee. On the lateral side, the anatomic method was more accurate in the anterior/posterior direction. Reliability was greater in the anterior/posterior direction on both sides of the knee. Surgeons were most likely to place the isometric point anterior and superior to the TIP on both the medial and lateral sides of the knee with either method which has the potential to cause graft lengthening. This should be taken into consideration during reconstruction/repair of the MCL/PMC and LCL/PLC.

This conversation represents an attempt by several arthroplasty surgeons to critique several abstracts presented over the last year as well as to use them as a jumping off point for trying to figure out where they fit in into our current understanding of multiple issues in modern hip and knee arthroplasty.

Background and Purpose— In clinical trials and observational studies there is considerable inconsistency in the use of definitions to describe delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. A major cause for this inconsistency is the combining of radiographic evidence of vasospasm with clinical features of cerebral ischemia, although multiple factors may contribute to DCI. The second issue is the variability and overlap of terms used to describe each phenomenon. This makes comparisons among studies difficult. Methods— An international ad hoc panel of experts involved in subarachnoid hemorrhage research developed and proposed a definition of DCI to be used as an outcome measure in clinical trials and observational studies. We used a consensus-building approach. Results— It is proposed that in observational studies and clinical trials aiming to investigate strategies to prevent DCI, the 2 main outcome measures should be: (1) cerebral infarction identified on CT or MRI or proven at autopsy, after exclusion of procedure-related infarctions; and (2) functional outcome. Secondary outcome measure should be clinical deterioration caused by DCI, after exclusion of other potential causes of clinical deterioration. Vasospasm on angiography or transcranial Doppler can also be used as an outcome measure to investigate proof of concept but should be interpreted in conjunction with DCI or functional outcome. Conclusion— The proposed measures reflect the most relevant morphological and clinical features of DCI without regard to pathogenesis to be used as an outcome measure in clinical trials and observational studies.