Biomedical subjects

C C Büll

Publications and source records attributed to C C Büll.

3 recordsLinked to original sources

PubMed1995

Cine MR imaging before and after realignment surgery for patellar maltracking -- comparison with axial radiographs.

OBJECTIVE: Comparison of motion-triggered cine magnetic resonance (MR) imaging and conventional radiographs for the assessment of operative results of patellar realignment. SUBJECTS AND METHODS: Fifteen patients with recurrent patellar dislocation or patellar subluxation were evaluated with conventional axial radiographs before and after realignment surgery by measuring the congruence angle (CA), lateral patellofemoral angle (LPFA), and lateral displacement (d). In eight patients the patellofemoral joint was additionally evaluated pre- and postoperatively with motion-triggered cine MR imaging by determining the bisect offset (BSO), lateral patellar displacement (LPD), and patellar tilt angle (PTA). RESULTS AND CONCLUSIONS: Significant differences between the pre- and postoperative measurements were found for all MR imaging parameters (BSO, LPD, PTA: p<0.01) but not for the conventional X-ray parameters (CA: p = 0.70, LPFA: p = 0.56; d: p = 0.04). Motion-triggered cine MR imaging was superior to conventional tangential radiographs for assessing the effectiveness of patellar realignment surgery.

Adolescent↗

PubMed1994

Evaluation of patellar tracking in patients with suspected patellar malalignment: cine MR imaging vs arthroscopy.

OBJECTIVE: The purpose of this study was to compare results of motion-triggered cine MR imaging of active extension of the knee with arthroscopic findings in cases of suspected femoropatellar malalignment. SUBJECTS AND METHODS: Twenty patients with clinically proved or suspected patellar subluxation or dislocation were examined prospectively with motion-triggered cine MR imaging to analyze patellar tracking from 30 degrees of flexion to full extension during active extension of the knee. The patellar tracking pattern was evaluated by measuring the following: bisect offset and lateral patellar displacement to assess lateralization of the patella and the patellar tilt angle to assess tilting of patella. The slopes of the linear regression lines of the MR findings vs the knee angle position, representing the patellar tracking, and the position of the patella at 30 degrees and 0 degrees of flexion were correlated with a semiquantitative arthroscopic classification of patellar tracking that had four categories ranging from normal to highly abnormal. RESULTS: The results showed a significant correlation between the semiquantitative arthroscopic findings of patellar tracking and the slopes of the linear regression lines of the bisect offset, lateral patellar displacement, and patellar tilt angle, as measured with cine MR imaging (p < .01). The arthroscopic findings also correlated significantly with the position of the patella when the knee was extended (p < .01), but not with the knee flexed 30 degrees. CONCLUSION: We conclude that motion-triggered cine MR imaging of active extension of the knee enables the dynamic evaluation of patellar bracing and is therefore suitable for noninvasive analysis of patellar tracking.

Adult↗

PubMed1993

Patellar tracking patterns during active and passive knee extension: evaluation with motion-triggered cine MR imaging.

To evaluate the critical range of the patellofemoral joint motion from 30 degrees of knee flexion to full extension, motion-triggered cine magnetic resonance (MR) imaging was performed during active extension in 13 patients with confirmed patellar maltracking and 15 healthy subjects. Cine MR images were compared with static MR images obtained during incremental extension of the knee joint. To evaluate the patellar tracking pattern, the same imaging parameters (patellar tilt angle, bisect offset, and lateral patellar displacement) and section locations were used in the static and motion-triggered studies. Statistically significant differences between the passive and active knee motions were found in all three parameters in the group of patients and in the bisect offset in the control group. The comparison between patients and healthy subjects yielded statistically significant differences for all parameters in actively extended knees but not in passively extended knees. The results demonstrate the importance of dynamic patellar motion studies for diagnosis of patello-femoral maltracking.

Adolescent↗