Reconstruction of the extensor mechanism augmented with reverse transferred iliotibial band after proximal tibia tumor resection and mega-prosthetic replacement

Iliotibial band autograft is an increasingly popular option for pediatric anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to compare recovery of knee extensor mechanism function among pediatric patients who underwent ACLR using iliotibial band (IT), hamstring tendon (HT), quadriceps tendon (QT), and patellar tendon (PT) autografts. One hundred forty-five pediatric athletes (76 female; age 15.0, range 7–21 years) with recent (3–18 months) unilateral ACLR performed drop-jump landing and 45° cutting with 3D motion capture. Knee extensor mechanism function (maximum knee flexion angle, maximum internal knee extensor moment, energy absorption at knee) during the loading phase (foot contact to peak knee flexion) was compared among graft types (20 IT, 29 HT, 39 QT, 57 PT) and sides (ACLR or contralateral) using linear mixed models with sex, age, and time since surgery as covariates. Overall, knee flexion was significantly lower on the operated vs. contralateral side for HT, QT, and PT during both tasks (p < 0.03). All graft types exhibited lower knee extensor moments and energy absorption on the operated side during both movements (p ≤ 0.001). Kinetic asymmetry was significantly lower for IT compared with QT and PT during both movements (p ≤ 0.005), and similar patterns were observed for HT vs. QT and PT (p ≤ 0.07). Asymmetry was similar between IT and HT and between QT and PT. This study found that knee extensor mechanism function recovers fastest in pediatric ACLR patients with IT autografts, followed by HT, in comparison to QT and PT, suggesting that IT is a viable option for returning young athletes to play after ACLR.

Download Full-text

The Role of Nickel-titanium Shape Memory Alloy Embracing Fixator in Determination of the Implantation Angle of Hip Tumor Prosthesis Stem Following Tumor Resection and the Analysis of Its Efficacy: a Retrospective Study

10.21203/rs.3.rs-138932/v1 ◽

2021 ◽

Author(s):

Yang Wang ◽

Panyu Zhou ◽

Demeng Xia ◽

Yunyun Wang ◽

Sheng Wang ◽

...

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Tumor Resection ◽

Hip Dislocation ◽

Nickel Titanium ◽

Prosthetic Replacement ◽

Limb Function ◽

Tumor Prosthesis

Abstract Background: To explore the role of nickel-titanium(NiTi) shape memory alloy embracing fixator in determination of implantation angle of hip tumor prosthesis stem and analyze its efficacy. Methods: 36 patients with proximal femur tumor were treated with extended tumor resection and prosthetic replacement. 14 patients received prosthetic replacements with the embracing fixators fixing between the junction of the prosthesis stem and the femur temporarily, while the other 22 patients received the same replacements but without the fixators. Following aspects were compared: occurrence of complications, limb function and active hip ROM.Results: There are fewer cases of hip dislocation in the group received prosthetic replacements with the use of embracing fixators. Occurrence of deep infection presented no difference between the two groups. Better limb function and higher active range of motion (ROM) on abduction or flexion were also found in the group using embracing fixators. Conclusion: Ni-Ti shape memory alloy embracing fixator plays a key part in assisting the accurate implantation angle of the prosthesis stem in the prosthetic replacement. The prosthesis stem can be adjusted to the optimal angle with the help of the embracing fixator. Patients have lower chance of dislocation, better limb function, and higher active hip ROM. Trial registration: retrospectively registered.

Download Full-text