[Reliability of tibial anterior crest as the anatomical reference of rotating alignment for tibial component in total knee arthroplasty].

OBJECTIVE: This study aimed to research whether anterior tibial crest is a reliable anatomical reference for rotational alignment of tibial component in TKA. METHODS: The study included 122 patients who underwent computed tomography angiography (CTA) examination for unilateral lower extremity trauma with normal contralateral lower extremities, including 89 males and 33 females, with an average age of(51.4±16.4) years old(ranged 18 to 81 years old). Picture archiving and communication system (PACS) was used to mark 11 lines including the surgical epicondylar axis (SEA) connecting the most prominent points of the lateral epicondyle and the deepest point of the sulcus on the medial epicondyle of the femur, axis of medial border of patellar tendon (MEPT)connecting the middle of the posterior cruciate ligament (PCL) and medial border of the patellar tendon at the level of a standard tibial cut from 8 mm distal of the lateral tibial joint surface, transverse axis of tibia (TAT) at the level of a standard tibial cut from 8 mm distal of the lateral tibial joint surface, Akagi line connecting the projected middle of the PCL and medial border of the patellar tendon at the tibial attachment, the axis of the medial 1/3 of patellar tendon(M1/3) connecting the projected middle of PCL and the medial 1/3 of the patellar tendon at the patellar tendon attachment level, Insall line connecting the projected middle of the PCL and the medial 1/3 of tibial tubercle, the axis of medial border of tibial tubercle (MBTT) connecting the projected middle of the PCL and medial border of tibial tubercle, as well as the axis of the proximal anterior tibial crest (PATC), axis 1 of the middle anterior tibial crest (MATC1), axis 2 of the middle anterior tibial crest (MATC2) and the axis of the distal anterior tibial crest (DATC) which were marked by connecting the 4 equidistant points on the sharp anterior tibial crest and the projected middle of the PCL. The angles between TAT and SEA as well as the angles between other axes and the perpendicular to SEA were measured. Pairwise differences among the 10 tibial axes were examined using One-Way ANOVA and paired t-test. RESULTS: The angles between the axes of MEPT, Akagi line, M1/3, Insall line, MBTT, PATC, MATC1, MATC2, DATC and the perpendicular to SEA were (-1.6 ±4.5)° , (1.4 ±5.0)° , (10.2±5.1)°, (11.9±5.4)°, (3.6±4.8)°, (12.0±6.9)°, (7.2±8.6)°, (7.1±10.4)°, (6.6±13.5)°, respectively. The angle between TAT and SEA was (4.1±5.3)°. MEPT was external rotation compared to SEA. M1/3, Insall line and PATC were significantly greater than Akagi line, MBTT, TAT (P<0.001). MATC1, MATC2 and DATC were also significantly greater than Akagi line, MBTT axis and TAT (P<0.001). However, MATC1, MATC2 and DATC were also significantly less than M1/3 axis, Insall line and PATC(P<0.01). There were no significant statistical differences between MATC1, MATC2 and DATC(P>0.05). CONCLUSION: The middle tibial anterior crest can be used as a reference for rotational alignment of tibial component in TKA, and its reliability is better than Insall line, but worse than Akagi line, TAT and MBTT.

Comparison of Clinical and Radiologic Outcome Between Mini-Open Wiltse Approach and Fluoroscopic-Guided Percutaneous Pedicle Screw Placement: A Randomized Controlled Trial.

OBJECTIVE: To compare clinical efficacy, radiographic outcome, and radiation exposure between mini-open pedicle screw (MPS) fixation with the Wiltse approach and percutaneous pedicle screw (PPS) fixation in treatment of young and middle-aged patients with thoracolumbar burst fractures. METHODS: Of 60 patients with thoracolumbar vertebrae fractures treated in our hospital from January 2017 to January 2018, 30 were randomly assigned to the MPS group and 30 were randomly assigned to the PPS group. Clinical efficacy, radiographic outcome, and radiation exposure were compared between the 2 groups. RESULTS: The average age of patients was 42.2 ± 6.7 years in the MPS group and 43.0 ± 6.9 years in the PPS group (P = 0.668). There was no significant difference between the 2 groups in blood loss, hospital stay, postoperative visual analog scale score for back pain, and Oswestry Disability Index score. The vertebral body height and vertebral body angle of the MPS group were significantly better than those of the PPS group at the last follow-up. There was no significant difference in the accuracy rate of pedicle screw placement between the MPS group and the PPS group; the facet joint violation was significantly higher in the PPS group. The average radiation exposure dosage was lower in the MPS group. CONCLUSIONS: Both MPS fixation with the Wiltse approach and PPS fixation are safe and effective in the treatment of single-segment thoracolumbar vertebral fractures. Nevertheless, considering the surgical duration, radiation exposure, facet joint violation, vertebral body height, and vertebral body angle at the last follow-up, MPS fixation with the Wiltse approach is a better choice than PPS.

Tibiofemoral rotation alignment in the normal knee joints among Chinese adults: a CT analysis.

BACKGROUND: Consensus on tibial rotation in total knee arthroplasty (TKA) remains controversial. The present study aimed to investigate the closest anatomical reference to surgical epicondylar axis (SEA) among 10 tibial markers in Chinese adults. METHODS: This study included examination of 122 normal lower extremities. Briefly, 10 axes were drawn on the axial sections: transverse axis of tibia (TAT), axis of medial edge of patellar tendon (MEPT), axis of medial 1/3 of patellar tendon attachment (M1/3), Akagi line, Insall line, axis of medial border of tibial tubercle (MBTT), and axis of anterior border of the tibia 1-4 (ATC1-4). The mean angles between TAT and SEA and that between other axes and the line perpendicular to SEA were measured. Pairwise differences among the 10 tibial axes were examined by applying one-way analysis of variance (ANOVA) and paired t-test. RESULTS: In all the knees, the mean angles of M1/3, Akagi line, Insall line, MBTT, ATC1, ATC2, ATC3, and ATC4 axes were compared to the line perpendicular to the projected SEA and found to be 10.2 ± 5.1°, 1.4 ± 5.0°, 11.9 ± 5.4°, 3.6 ± 4.8°, 12.0 ± 6.9°, 7.2 ± 8.6°, 7.1 ± 10.4°, and 6.6 ± 13.5° external rotation, respectively, and the MEPT axis was 1.6 ± 4.5° internal rotation. The mean angle for TAT was 4.1 ± 5.3° external rotation. The M1/3 and Insall line were significantly more externally rotated than Akagi line, MEPT, MBTT, TAT, ATC2, ATC3, and ATC4 axes. No significant differences were noted between the TAT axis and the MBTT axis and among the ATC2, ATC3, and ATC4 axes. CONCLUSION: The Akagi line, MBTT, and TAT showed good consistency with SEA in the axial femorotibial alignment with knee in extension. The middle segment of the anterior tibial crest also demonstrated good alignment consistency with SEA for the axial femorotibial alignment. Hence, these markers can be used as reliable references for rotational alignment of the tibial component in TKA.

Treating Huge Tear-Drop Fracture of Axis With Trapezoidal Bone: A Case Report and Literature Review.

STUDY DESIGN: Case report and review of relevant literature. OBJECTIVE: To discuss the surgical strategies and clinical outcome of managing huge tear drop fracture of axis. SUMMARY OF BACKGROUND DATA: Teardrop fracture of axis is rarely seen, especially the huge type. The surgical technique is demanding because of the special anatomical structure and difficulty with bone grafting. Moreover, the surgical approach is controversial in the literature. METHODS: A 51-year-old male patient suffered from neck pain after falling from the bicycle, neck movement was limited with no neurological compromise. X-ray suggested huge tear-drop fracture of anterior-inferior corner of axis, narrowing of C2/3 intervertebral disc. Fusion with self-designed tricortical trapezoidal iliac bone was performed. RESULTS: Treating huge teardrop fracture of axis by anterior bone grafting with self-designed tricortical trapezoidal iliac bone is effective and stable. A 3-month follow-up showed fusion was achieved, upper cervical curvature was restored, and neck pain disappeared. CONCLUSION: Self-designed tricortical trapezoidal iliac bone provided adequate fusion area of bone grafting, restoring the normal intervertebral height and cervical alignment, and the midterm outcome is satisfactory. LEVEL OF EVIDENCE: 5.