3D printed fracture reduction guides planned and printed at the point of care show high accuracy - a porcine feasibility study.

PURPOSE After surgical treatment of comminuted diaphyseal femoral and tibial fractures, relevant malalignment, especially rotational errors occur in up to 40-50%. This either results in a poor clinical outcome or requires revision surgery. This study aims to evaluate the accuracy of reduction if surgery is supported by 3D guides planned and printed at the point of care. METHODS Ten porcine legs underwent computed tomography (CT) and 3D models of femur and tibia were built. Reduction guides were virtually constructed and fitted to the proximal and distal metaphysis. The guides were 3D printed using medically approved resin. Femoral and tibial comminuted diaphyseal fractures were simulated and subsequently reduced using the 3D guides. Postoperative 3D bone models were reconstructed to compare the accuracy to the preoperative planning. RESULTS Femoral reduction showed a mean deviation ± SD from the plan of 1.0 mm ± 0.9 mm for length, 0.9° ± 0.7° for varus/valgus, 1.2° ± 0.9° for procurvatum/recurvatum and 2.0° ± 1.7° for rotation. Analysis of the tibial reduction revealed a mean deviation ± SD of 2.4 mm ± 1.6 mm for length, 1.0° ± 0.6° for varus/valgus, 1.3° ± 1.4° for procurvatum/recurvatum and 2.9° ± 2.2° for rotation. CONCLUSIONS This study shows high accuracy of reduction with 3D guides planned and printed at the point of care. Applied to a clinical setting, this technique has the potential to avoid malreduction and consecutive revision surgery in comminuted diaphyseal fractures. LEVEL OF EVIDENCE Basic Science

Staged treatment of a comminuted femoral fracture with Masquelet technique and 3D printed reposition guides.

Background Comminuted femoral fractures pose a challenge to the trauma surgeon due to the absence of bony references during surgery. Therefore, malalignment of length and axis can occur and necessitate revision surgery. During the last decade, 3D-planning has evolved as a surgical aid in difficult cases. Case report An 18-year-old male patient suffered a polytrauma following a motorcycle accident. This report is about the treatment of a 3rd degree open and comminuted fracture of the left distal femur. The fracture was treated with Masquelet's two-staged technique. With the intent of avoiding malalignment, the second stage surgery was performed with the aid of 3D-planned reduction guides. Despite complex fracture pattern, complete fracture union was achieved with acceptable final alignment (side-to-side comparison of length, axis and femoral torsion). Conclusion In this case, performing Masquelet's two-staged surgery with the aid of 3D-printed reposition guides yielded favorable results in regards to rotational malalignment. The malrotation of the femur was reduced after the second operation to a clinically acceptable side-to-side difference (10°). This technique remains technically challenging due to soft tissue tension and limited possibility of soft tissue release

Indications, clinical outcome and survival of rotating hinge total knee arthroplasty in a retrospective study of 63 primary and revision cases.

PURPOSE The purpose of this study is to report and compare outcome data of both primary and revision cases using a rotating hinge knee (RHK) implant. METHODS This study retrospectively analyzed 63 cases (19 primary, 44 revisions) at a mean follow-up of 34 ± 8 months after RHK implantation. Outcome parameters were stability, range of motion (ROM), loosening, Hospital of Special Surgery Score (HSS), Knee Society Score (KSS), Oxford Knee Score (OKS), EQ-5D-3L, and Visual Analog Scale (VAS) for overall function. Revision rates and implant survival are reported. RESULTS Eleven percent showed medio-lateral instability < 5 mm, a mean ROM of 115° ± 17° and radiologic loosening occurred in 8% (2% symptomatic). PROMS showed the following results: HSS 79 ± 18, KSS 78 ± 27, OKS 26 ± 10, EQ-5D index 0.741 ± 0.233 and VAS 70 ± 20. Primary cases revealed better outcomes in HHS (p = .035) and OKS (p = 0.047). KSS, EQ-5D index and VAS did not differ between primary and revision cases (p = 0.070; p = 0.377; p = 0.117). Revision rate was 6.3% with an implant survival of 96.8%. CONCLUSIONS RHK arthroplasty can be performed with good clinical outcome and low revision rate in revision and complex primary cases. RHK is an option in cases where standard arthroplasty and even implants with a higher degree of constraint have reached their limits. LEVEL OF EVIDENCE Level III, retrospective cohort study

Collagen wrapping and local platelet-rich fibrin do not improve the survival rates of ACL repair with dynamic intraligamentary stabilization: a retrospective case series after ≥5 years postoperatively.

PURPOSE Anterior cruciate ligament (ACL) repair has been recommended as a treatment principle for ACL tears. Several authors have advocated a potential role for primary repair techniques in the ACL decision tree. However, long-term results have been controversial. This study aims to determine the survival of the primarily repaired ACL after dynamic intraligamentary stabilization (DIS) with and without augmentation. METHODS Between 2014 and 2019, 102 patients with isolated proximal ACL ruptures underwent DIS repair within 21 days from injury and were available for follow-up either clinically or telephonically after ≥5 years postoperatively. In 45 cases, DIS repair was augmented with collagen fleece wrapping, platelet-rich fibrin (PRF) or both. Failure was defined as traumatic re-rupture or conversion to ACL reconstruction. The patients being available for physical examination underwent a.-p. stability measurement with a KT-1000 device. Functional outcome was measured with the IKDC, Tegner and Lysholm scores. Kaplan-Meier survival analysis, Log-Rank Test and Binominal logistic regression were performed. RESULTS After a minimum 5-year follow-up, 71/102 (69.6%) DIS repairs were not re-reptured and clinically and/or subjectively stable. Augmentation did not improve survival rates (p = 0.812). The identified factors influencing failure were a younger age and a pre-injury Tegner activity level of ≥7. 95.7% of those patients with an intact ACL repair had normal or near normal knee function based on the IKDC scoring system. CONCLUSIONS The 5-year overall survival rate of DIS was 69.6%. Collagen fleece wrapping and local PRF application did not improve survival. Patients not suffering failure of repair demonstrated high satisfaction. Nevertheless, the results are inferior to those of established ACL reconstruction procedures. LEVEL OF EVIDENCE Case series, Level IV

Treatment of Knee Dislocation With Primary Repair and Suture Augmentation: A Viable Solution.

BACKGROUND Different surgical techniques have been described for the treatment of knee dislocation (KD). Nonoperative approaches are frequently combined with surgical reconstruction using auto- or allograft. PURPOSE To evaluate the midterm results of primary surgical repair and suture augmentation to treat KD. STUDY DESIGN Case series; Level of evidence, 4. METHODS A total of 22 patients (5 women, 17 men; mean age, 45 ± 15 years) with KD were evaluated at a mean of 49 ± 16 months after surgical treatment that included primary repair and suture augmentation. Magnetic resonance imaging, stress radiographs, and outcome scores were obtained at the follow-up. Clinical examination including hop tests and force measurements for flexion and extension was performed. RESULTS The mean difference in pre- to postinjury Tegner scores was -2 ± 1. The outcome scores showed mean values of 84 ± 15 (Lysholm), 73 ± 15 (International Knee Documentation Committee) and 65 ± 25 (Anterior Cruciate Ligament-Return to Sport after Injury scale). Compared with the uninjured knee, the range of motion of the injured knee was reduced by 21° ± 12°. Twelve patients felt fit enough to perform hop tests and showed a mean deficit of 7% ± 17%° compared with the uninjured leg. The mean force deficit was 19% ± 18% for extension and 8% ± 16% for flexion. Stress radiographs revealed an 11 ± 7-mm higher anteroposterior translation on the injured side. Four patients had secondary ligament reconstructions due to persistent instability and 7 underwent arthroscopic arthrolysis due to stiffness. A significant increase of osteoarthritis was found for the medial, lateral, and patellofemoral compartments (P = .007, .004, and .006, respectively). CONCLUSION Primary repair and suture augmentation of KD led to satisfactory clinical midterm results despite persistent radiological instability and a significant increase in osteoarthritis. This technique allows the return to activities of daily living without subjective instability in most nonathletic patients. Secondary ligament reconstructions should be performed if relevant instability persists to decrease the risk of secondary meniscal and cartilage damage

Aurora kinase A drives the evolution of resistance to third-generation EGFR inhibitors in lung cancer.

Although targeted therapies often elicit profound initial patient responses, these effects are transient due to residual disease leading to acquired resistance. How tumors transition between drug responsiveness, tolerance and resistance, especially in the absence of preexisting subclones, remains unclear. In epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells, we demonstrate that residual disease and acquired resistance in response to EGFR inhibitors requires Aurora kinase A (AURKA) activity. Nongenetic resistance through the activation of AURKA by its coactivator TPX2 emerges in response to chronic EGFR inhibition where it mitigates drug-induced apoptosis. Aurora kinase inhibitors suppress this adaptive survival program, increasing the magnitude and duration of EGFR inhibitor response in preclinical models. Treatment-induced activation of AURKA is associated with resistance to EGFR inhibitors in vitro, in vivo and in most individuals with EGFR-mutant lung adenocarcinoma. These findings delineate a molecular path whereby drug resistance emerges from drug-tolerant cells and unveils a synthetic lethal strategy for enhancing responses to EGFR inhibitors by suppressing AURKA-driven residual disease and acquired resistance

Standardized multi-planar reformation improves the reliability of the assessment of the anterolateral ligament in ACL-deficient knees.

PURPOSE The anterolateral ligament (ALL) is an important structure for controlling anterolateral rotatory stability of the knee. Its assessment, however, is difficult using standardized MRI images. The goal of this study was to assess the reliability of judging the integrity of the ALL on multi-planar reformatted (MPR) MRI images and on standard coronal reformatted (SCR) MRI images in knees with an anterior cruciate ligament (ACL) rupture. METHODS Forty-eight patients (14 females, 34 males, 30 ± 6 years (mean age ± standard deviation)) with acute ACL ruptures (< 2 weeks) and no additional knee injuries (except segond fractures) were included. Images were assessed by two independent raters twice with at least a 2-week interval in between. The assessment was first performed on SCR images and thereafter on MPR images. Images were judged for assessability of the ALL and then the integrity of the ALL was rated. RESULTS Depending on rater and read, the ALL was judged as "torn" in between 5 (10.4%) and 11 (22.9%) patients out of 48 patients on SCR images. On MRP images, the ALL was judged as "torn" in between 5 (10.4%) and 6 (12.5%) patients out of 48 patients, depending on rater and read. Inter- and intra-rater reliability for the assessment of the ALL using MPR images was "substantial" to "almost perfect". Inter- and intra-rater reliability for the assessment using SCR was "fair" to "substantial". CONCLUSION MPR images should be used when assessing the integrity of the ALL. Assessment quality is independent of patient positioning during MRI acquisition and the ALL can be displayed in full length on one image. LEVEL OF EVIDENCE Level III