The vertebral cage has been widely used in posterior lumbar interbody fusion. The risk of cage dislodgment is high for patients undergoing lumbar fusion surgery. Therefore, the main objective of this study was to use a lumbar fusion model to investigate the effects of cage dislodgment on different cage arrangements after PLIF. Finite element analysis was used to compare three PEEK cage placements, together with the fibula-type cage, with respect to the four kinds of lumbar movements. The results revealed that a horizontal cage arrangement could provide a better ability to resist cage dislodgment. Overall lumbar flexion movements were confirmed to produce a greater amount of cage slip than the other three lumbar movements. The lower part of the lumbar fusion segment could create a greater amount of cage dislodgment for all of the lumbar movements. Using an autograft with a fibula as a vertebral cage cannot effectively reduce cage dislodgment. Considering the maximum movement type in lumbar flexion, we suggest that a horizontal arrangement of the PEEK cage might be considered when a single PEEK cage is placed in the fusion segment, as doing so can effectively reduce the extent of cage dislodgment.

暂无摘要。

OBJECTIVE: Using a fibula autograft (FA) to reconstruct defects after en bloc resection of giant cell tumor of bone (GCTB) in the distal radius is classic but has high complication rates. We describe a novel reconstruction method employing the cooperative application of LARS® and a 3D-printed prosthesis (L-P) and investigate whether it improves postoperative outcomes.
METHODS: From April 2015 to August 2022, 14 patients who underwent the cooperative L-P reconstruction method after en bloc resection of distal radial GCTBs and 31 patients who received FA reconstruction were enrolled as two retrospective cohorts in this comparative study. The properties of the implants and critical surgical techniques were elaborated in the L-P group. Preoperative function, intraoperative data, and postoperative clinical, functional, and radiographic outcomes of all patients were recorded and compared between the two groups. The grip strength and range of wrist motion, including extension, flexion, radial deviation, and ulnar deviation, were measured. The Mayo modified wrist and Musculoskeletal Tumor Society scores were chosen to assess wrist function and surgical functional outcomes, respectively. Kaplan-Meier curves were generated to analyze the significant differences in complication rates and implant survival between the two groups.
RESULTS: In both groups, all 45 patients underwent the operation without complication with similar average osteotomy lengths and bleeding volumes, while a shorter operative duration was achieved in the L-P group (201.43 ± 22.87 min vs. 230.16 ± 51.44 min, P = 0.015). At a mean follow-up of 40.42 ± 18.43 months (range, 14-72 months), both reconstruction methods effectively ameliorated postoperative function. Patients who received L-P showed higher postoperative modified Mayo wrist scores (81.43 ± 5.49 vs. 71.13 ± 16.10, P = 0.003), Musculoskeletal Tumor Society scores (27.64 ± 1.34 vs. 25.06 ± 2.95, P = 0.004), and grip strength on the normal side (68.71% ± 8.00% vs. 57.81% ± 12.31%, P = 0.005) than the FA group. Better wrist extension (63.21° ± 8.99° vs. 45.32° ± 14.53°, P < 0.001) and flexion (45.36° ± 7.90° vs. 30.48° ± 12.07°, P < 0.001) were also observed in the L-P group. The complication rate was significantly higher in the FA group (29/31, 93.55%) than in the L-P group (1/14 7.14%, P < 0.001). The L-P group showed higher implant survival than the FA group, but the difference was not statistically significant.
CONCLUSIONS: The cooperative application of LARS® and 3D-printed prostheses is an effective modality for reconstructing musculoskeletal defects after en bloc resection of distal radial GCTBs, which can improve functional outcomes, diminish complication rates, and promote wrist joint stability and motion.

Management of neglected femoral neck fracture in a trans-femoral amputee is difficult and challenging. There are limited options available for management of such a fracture. While arthroplasty (hemi or total) can be offered in older individuals, young patients should be offered an attempt of salvage of their native hips. Neglected femoral neck fracture in two young male patients who were trans-femoral amputees was managed by fixation through a Watson-Jones approach. Strategically placed Schanz screws and K-wires were used as joysticks for obtaining reduction and three 6.5mm cannulated screws were placed in a triangular fashion. An augmentation of the fixation was done with free fibula autograft placed in the center of the triangle. Union was achieved in both the cases. Patients were pain-free at the latest follow-up visit. Meticulous clinical and radiological evaluation is mandatory in multiply injured patients to avoid missing fractures. Fixation of neglected femoral neck fractures in young transfemoral amputees with three screws and a fibula can be considered a viable alternative to valgus osteotomy in cases where the stump is small for successful placement of the implant and where implant availability is an issue or the surgeon is comfortable in using screws and fibula for non-unions of femoral neck.