ObjectiveTo explore the effectiveness of knee extensor mechanism reconstruction in the treatment of recurrent patellar subluxation with bone anchor in adolescents.
MethodsBetween January 2010 and December 2013, 20 patients with patellar subluxation were treated by knee extensor mechanism reconstruction with bone anchor. There were 11 males and 9 females, aged from 12 to 17 years (mean, 15.3 years). The left knee was involved in 12 cases and the right knee in 8 cases. The disease duration was 5-10 years (mean, 7 years). All the patients had knee pain and lateral subluxation of the patella. Preoperative Lysholm knee score was 71.4±4.7. All the patients received the MRI examination to exclude menisci or ligaments lesion. CT examination showed the tibial tuberosity trochlear groove spacing ranged from 15 to 20 mm (mean, 17 mm). X-ray film examination indicated that no varus or valgus was observed, and bony structure was normal.
ResultsAll the incisions healed at first stage. The patients received follow-up of 12-24 months (mean, 13 months). Knee pain occurred in 2 cases and were cured after symptomatic treatment. The axial X-ray films showed good position of the patella and normal anatomic relationship of the patellofemoral joint. No anchor loosening and pulling out, internal fixation failure, pseudoarthrosis formation, and postoperative recurrent patellar subluxation occurred during follow-up. At 1 year, the Lysholm knee score was significantly improved to 94.2±3.4 (t=22.705, P=0.000). According to Insall criterion, the results were excellent in 9 cases, good in 9 cases, and fair in 2 cases, with an excellent and good rate of 90%.
ConclusionThe bone anchor for extensor mechanism reconstruction is a convenient and reliable way to treat the recurrent patellar subluxation, with a satisfactory early effectiveness and less complications; however, its long-term effectiveness is required a further follow-up.
ObjectiveTo explore the effectiveness of a new point contact pedicle navigation template (referred to as “new navigation template” for simplicity) in assisting screw implantation in scoliosis correction surgery. MethodsTwenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups (P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated. ResultsBoth groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups (P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group (P<0.05). There was no complications related to screws implantation during or after operation in the two groups. ConclusionThe new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.
