MCL augmentation using a peroneus longus split tendon autograft satisfactorily restores knee stability with no impairment in foot function and with a low failure rate for concurrent ACL reconstruction.

PURPOSE: Addressing grade 2 and 3 medial-sided instabilities during anterior cruciate ligament (ACL) reconstruction is crucial to reduce the risk of ACL graft failure. This study introduced a minimally invasive, medial collateral ligament (MCL) augmentation technique using a peroneus longus split tendon autograft, which was fixed to the femoral deep MCL insertion and tibial superficial MCL insertion. METHODS: This prospective, longitudinal, single-centre case series included patients who underwent MCL augmentation concurrent with primary or revision ACL reconstruction due to anteromedial instability. Preoperatively and at 1-year follow-up, clinical examinations, such as rolimeter test of anterior tibial translation and medial instability, knee (International Knee Documentation Committee subjective knee form [IKDC], Lsyholm, Knee Injury and Osteoarthritis Outcome Score [KOOS]) and foot function scores (American Orthopaedic Foot and Ankle Society score [AOFAS]) and complications, were analyzed. RESULTS: Thirty-one patients with a mean follow-up of 13.5 ± 2.6 months and a mean age of 27.8 ± 9.6 years were included. The side-to-side difference for anterior tibial translation significantly improved from preoperative to 1-year follow-up with an ACL reconstruction failure rate of 6.5%. No patient retained a grade 2 or 3 medial instability on valgus stress testing with 30° flexion. Significant improvements from preoperative to 1-year postoperative follow-up were observed in knee function scores: IKDC (48.9 ± 26.9- 71.3 ± 11.5, p < 0.001) and Lysholm (59.9 ± 28.5-80.5 ± 11.2, p = 0.002) as well as KOOS pain, ADL, sport and QoL, each reaching the respective minimal clinically important difference values. The foot function score AOFAS showed no significant impairment (100 ± 0-99.3 ± 2.5, p = 0.250). Complications included cyclops lesions of ACL reconstruction in three patients. CONCLUSION: At 1-year follow-up, MCL augmentation using a peroneus longus split tendon autograft for patients simultaneously undergoing ACL reconstruction satisfactorily restores knee stability, has a low ACL reconstruction failure rate and does not significantly impair foot function. LEVEL OF EVIDENCE: Level IV therapeutic study; case series.

Arthroscopic Shaver-based Harvest of Minced Cartilage Results in Reduced Chondrocyte Viability and Reduced Quality of Cartilaginous Repair Tissue Compared With Open Harvest and Conventional Fragmentation.

PURPOSE: To characterize and compare the quality of regenerative cartilage tissue (ReCT) after conventional minced cartilage (CMC) and arthroscopic minced cartilage (AMC), in terms of cell viability, gene expression, and matrix synthesis and to investigate the influence of different shaver types. METHODS: Chondral tissue was harvested from the knees of 8 porcine donors. Porcine specimens were euthanized one day before harvest. AMC was created with 2 shaver blades in 2 operating modes (oscillating vs forward) and compared with a scalpel-fragmented CMC control. Before histologic analysis, 50% of the tissue was digested to prevent dedifferentiation of chondrocytes to fibroblasts. Cells were cultured and analyzed for cell viability, gene expression of cartilage-specific markers (aggrecan [ACAN], collagen type II, alpha1 [COL2A1], collagen type I, alpha1 [COL1A1], fibronectin-1 [FN1]), and matrix synthesis (Alcian-blue). RESULTS: AMC tissue contained fewer viable chondrocytes (41%-54% vs 91%; P = .001-.048) compared with CMC. After culture, CMC showed greater expressions of ACAN (27 virtual copy numbers [VCN]/housekeeping gene) and COL2A1 (30 VCN) compared with AMC (ACAN 2-9 VCN, COL2A1 2-7 VCN, P = .001-.039). AMC presented greater expressions of COL1A1 (9-21 VCN) and FN1 (12-17 VCN) than CMC (1 and 6 VCN, P = .001-.050). The signal intensity of the cartilage matrix formed by CMC (86/mm2) was greater than by AMC (7-10 mm2, P = .001-.032). CONCLUSIONS: CMC contained high numbers of viable chondrocytes, resulting in high-quality, hyaline-like ReCT. In contrast, AMC showed impaired chondrocyte quantity and viability, showing greater expressions of fibroblast markers and a decreased formation of mature cartilage matrix in porcine samples. The high chondrogenic potential of CMC to form hyaline-like ReCT was not confirmed for AMC. CLINICAL RELEVANCE: On the basis of our findings, arthroscopic harvest of minced cartilage leads to reduced chondrocyte viability and ReCT quality. Accordingly, CMC and AMC cannot be regarded as synonymous techniques, as arthroscopic techniques seem to be less efficacious.

ACL reconstruction demonstrates better stability compared to ACL repair for patients with Schenck III and IV knee dislocations.

PURPOSE: This study compared mid-term outcomes of two anterior cruciate ligament (ACL) restoration techniques within an early total surgical care of acute knee dislocation: repair with additional internal bracing (ACLIB) and reconstruction with autograft (ACLR). Initial results at 12 months demonstrated that ACLR offered superior stability compared to ACLIB. METHODS: Retrospective clinical study of patients with acute type III or IV KD. ACLIB or ACLR procedures were performed accompanied by simultaneous suture and internal bracing of the posterior cruciate ligament (PCL) and repair with lateral augmentation of the medial and lateral complex injuries utilizing Arciero's reconstruction technique. Patient-reported outcome measurements (PROMs), instrumental stability assessment via the Rolimeter-Test, and stress radiographs were analyzed. RESULTS: The study involved 20 patients (5 IIIM, 5 IIIL, and 10 IV injuries) with an average follow-up of 35.2 ± 7.4 months. Notable differences in anterior tibial translation on stress radiography favouring ACLR persisted at 24-month follow-up in side-to-side difference (SSD) (ACLIB 2.8 ± 2.5 mm vs. ACLR 0.3 ± 2.6 mm; p = 0.0487), but Rolimeter test variance diminished (SSD ACLIB 2.5 ± 0.9 mm vs. ACLR 1.8 ± 1.7 mm). Both groups showed excellent PROMs (Lysholm Score: ACLIB 84.4 ± 15.8 vs. ACLR 89.9 ± 9.0; IKDC Score: ACLIB 77.1 ± 16.2 vs. ACLR 77.7 ± 8.6). CONCLUSION: Our results indicate improved anterior stability at 12 months, which persisted at 24 months after ACL reconstruction compared with ACL repair by stress radiography. Both groups showed favourable patient-reported outcomes throughout the follow-up period. Notable rates of postoperative knee stiffness were observed in both groups. These were successfully managed with early, one-time arthroscopic arthrolysis within the first seven months of treatment, resulting in no major range of motion limitations at the 24-month follow-up. LEVEL OF EVIDENCE: Retrospective cohort study, III.

Surgically treated acute knee dislocations with knee stiffness perform equally as well as non-stiff knees when treated with arthroscopic arthrolysis.

PURPOSE: Postoperative knee stiffness is a common issue in multiligament knee injuries (MLKIs). This study aims to compare outcomes between MLKI patients who underwent postoperative arthroscopic lysis of arthrofibrosis (LOA) for limited range of motion (ROM) and those who did not. METHODS: Thirty-one patients (10 IIIM, nine IIIL and 12 IV) were included in this retrospective clinical study with acute type III or IV knee dislocations, while two patients were lost to follow up. Thirteen patients underwent LOA at a mean of 18.7 ± 8.4 weeks (Group A), while 18 did not require this intervention (Group B). Patient-reported outcome measures (IKDC, Lysholm, VAS) and ROM were evaluated. RESULTS: The average follow up period was 31.0 ± 10.2 months. The mean time to LOA was 19.4 ± 7.6 weeks and a significant increase in ROM was observed after LOA (flexion: before LOA: 83.8° ± 19.2, after LOA: 119.6° ± 9.9; P < 0.0001). There were no significant differences between groups regarding clinical scores (Lysholm: Group A 85.0 ± 13.4, Group B 84.6 ± 14.5; IKDC: Group A 74.3 ± 10.8, Group B 76.7 ± 14.7) and ROM (flexion: Group A 118.6° ± 9.8, Group B 124.3° ± 12.8). There were no complications regarding LOA. CONCLUSIONS: Patients, whether undergoing LOA or not, performed equally well in terms of ROM and clinical scores at final follow up, while timing of LOA appears less critical. LOA is a simple, durable and safe method of treating ROM deficits in patients treated for acute knee dislocation, with very good results.

Autologous matrix-induced chondrogenesis provides better outcomes in comparison to autologous minced cartilage implantation in the repair of knee chondral defects.

PURPOSE: In symptomatic mid-sized focal chondral defects, autologous matrix-induced chondrogenesis (AMIC) and minced cartilage implantation (MCI) offer two versatile treatment options. This study aimed to conduct a matched-patient analysis of patient-reported outcome measures to compare these two surgical treatment methods for focal chondral defects. METHODS: At the first centre, patients underwent a single-stage procedure in which autologous cartilage was hand-minced, implanted into the defect and fixed with fibrin glue. At the second centre, patients underwent AMIC, which was fixed in place with fibrin glue. All patients were seen 2-4 years postoperatively. Postoperative outcomes were assessed using the visual analogue scale for pain (VAS), the Lysholm score and the five domains of the knee osteoarthritis outcome score (KOOS). Patients from each surgical centre were matched by age, sex, defect size and defect localisation. RESULTS: In total, 48 patients from two surgical centres (24 from each site) were matched for sex, age (MCI 30.3 ± 14.9 years vs. AMIC 30.8 ± 13.7 years) and defect size (MCI 2.49 ± 1.5 cm2 vs. AMIC 2.65 ± 1.1 cm2). Significantly better scores in the AMIC cohort were noted for VAS (p = 0.004), Lysholm (p = 0.043) and the KOOS subscales for pain (p = 0.016) and quality of life (p = 0.036). There was a significantly greater proportion of positive responders for Lysholm in the AMIC group (92%) compared with the MCI group (64%). CONCLUSIONS: The AMIC procedure delivers superior patient outcomes compared with hand-minced autologous cartilage implantation. These are mid-term outcomes, with follow-up between 2 and 4 years. LEVEL OF EVIDENCE: Level III.

Personalised blood pressure management during major noncardiac surgery and postoperative neurocognitive disorders: a randomised trial.

Background: It remains unknown whether there is a causal relationship between intraoperative hypotension and postoperative neurocognitive disorders. We tested the hypothesis that personalised-compared to routine-intraoperative blood pressure management reduces the incidence of postoperative neurocognitive disorders in patients having major noncardiac surgery. Methods: In this single-centre trial, 328 elective major noncardiac surgery patients were randomly allocated to receive personalised blood pressure management (i.e. maintaining intraoperative mean arterial pressure [MAP] above preoperative baseline MAP from automated 24-h blood pressure monitoring) or routine blood pressure management (i.e. maintaining MAP above 65 mm Hg). The primary outcome was the incidence of neurocognitive disorders (composite of delayed neurocognitive recovery and delirium) between postoperative days 3 and 7. Results: The primary outcome, neurocognitive disorders, occurred in 18 of 147 patients (12%) assigned to personalised and 21 of 148 patients (14%) assigned to routine blood pressure management (odds ratio [OR]=0.84, 95% confidence interval [CI]: 0.40-1.75, P=0.622). Delayed neurocognitive recovery occurred in 17 of 146 patients (12%) assigned to personalised and 17 of 145 patients (12%) assigned to routine blood pressure management (OR=0.99, 95% CI: 0.45-2.17, P=0.983). Delirium occurred in 2 of 157 patients (1%) assigned to personalised and 4 of 158 patients (3%) assigned to routine blood pressure management (OR=0.50, 95% CI: 0.04-3.53, P=0.684). Conclusions: Personalised intraoperative blood pressure management maintaining preoperative baseline MAP neither reduced the incidence of the composite primary outcome neurocognitive disorders between postoperative days 3 and 7 nor the incidences of the components of the composite primary outcome-delayed neurocognitive recovery and delirium-compared to routine blood pressure management in patients having major noncardiac surgery. Clinical trial registration: ClinicalTrials.gov (NCT03442907).

[Treatment of Injuries to the Posterior Cruciate Ligament]. / Therapie von Verletzungen des hinteren Kreuzbandes.

Compared to the anterior cruciate ligament injury, the rupture of the posterior cruciate Ligament (PCL) is the rarer condition. A high healing potential is attributed to the PCL in the literature, which is why conservative therapy is also considered important in addition to surgical treatment 1. Posterior cruciate ligament rupture is often associated with concomitant injuries. Among other things, up to 70% of cases are associated with accompanying injuries to the posterolateral corner 2. The detection of concomitant injuries has a significant influence on the outcome, as isolated surgical PCL stabilization does not lead to satisfactory results in these cases.

Influence of variable hinge positioning on coronal and sagittal alignment in uniplanar medial open-wedge high tibial osteotomy.

Purpose: There is a high risk of increasing the posterior tibial slope (PTS) during medially opening-wedge high tibial osteotomy (mowHTO). Most recently, the idea of intentional simultaneous coronal and sagittal correction, using uniplanar cutting techniques has emerged. This study aims to examine the influences of variable hinge positioning and osteotomy gap height on the sagittal and coronal plane. Methods: Twenty uniplanar mowHTOs were performed in standardised (left) solid-foam proximal tibia models. In the different models, hinge position was rotated stepwise by 10°, between 90° (cutting straight medial to lateral) and 0° (cutting straight anterior to posterior) (n = 10). Additionally, gap heights of 5 and 10 mm were produced and analysed. Logistic regression analysis was performed to calculate a predictive regression formula for the relation between gap height, hinge rotation and the changes of medial proximal tibia angle (MPTA), medial and lateral PTS. Results: Between cutting angles of 90 and 20°, the MPTA was mainly influenced by the gap height (0.95° MPTA per 1 mm gap height), but not by the cutting angle. Between 20 and 0°, the MPTA was decreased by 3.6° per 10° of rotation, but not by the gap height. Between cutting angles of 90 and 10°, the PTS was increased linearly by 0.97° per 10° of rotation and by 0.61° per 1 mm gap height. Conclusion: In mowHTO with lateral hinge positions, the MPTA is mainly influenced by gap height. Changes of PTS can be avoided by a straight lateral hinge position. In posterior hinge locations (0-20°), changes of MPTA are mainly caused by hinge rotation, but not by gap height. Level of Evidence: Level III, Case-control study.

Arthroscopic and open reconstruction of the posterolateral corner of the knee have equally good clinical results: first results of a prospective 12-month follow-up study.

PURPOSE: Arthroscopic reconstruction techniques for higher-grade posterolateral corner (PLC) injuries (Fanelli Type B, PoLIS LI-B) have not yet been validated in clinical studies. The open reconstruction technique described by Arciero is well-established and showed good restoration of joint stability in previous studies. This study aimed to compare clinical outcomes of this established open surgery technique to a newly developed arthroscopic technique in a prospective randomized clinical trial. METHODS: Between 2019 and 2021, this study focused on chronic high-grade PLC injuries (Fanelli Type B, PoLIS LI-B). Group A consisted of patients treated with conventional open surgery following Arciero's technique, while Group B included patients treated with Arciero's arthroscopic technique. All cases underwent additional PCL reconstruction. After a minimum 12-month follow-up, clinical scores and objective stability assessments were compared between the groups. RESULTS: In total, 26 (group A 12, group B 14) eligible patients with a mean follow-up of 14.9 ± 7.2 months were evaluated in the present study. Knee stability and patient-reported outcome scores (PROMS) were significantly improved when comparing pre- and post-operative values (p < 0.0001). No clinically relevant differences in PROMS (Lysholm: A 83.9 ± 11.4 vs. B 85.3 ± 13.8; IKDC: A 76.91 ± 12.6 vs. B 76.8 ± 15.7) were shown in both groups. Additionally, no statistically significant differences were detected between groups with respect to external rotation, range of motion and instrumental stability testing. Arthroscopic reconstruction showed significantly shorter operation time (p = 0.0109). There were no clinical failures or neurovascular complications of the surgical procedures. CONCLUSION: Both surgical techniques for isolated chronic PLC Fanelli Type B injuries significantly improved the knee stability, were equivalent with respect to PROMs and led to good clinical results. However, arthroscopic PLC reconstruction was associated with a shorter surgery time compared to open PLC reconstruction. Therefore, arthroscopic PLC reconstruction may be a viable option in the hands of an experienced surgeon. LEVEL OF EVIDENCE: Prospective cohort study, II.

Impact of body mass index on fracture severity, clinical, radiological and functional outcome in distal radius fractures: a retrospective observational study after surgical treatment.

INTRODUCTION: Distal radius fracture (DRF) is one of the three most common fractures of the human body with increasing incidences in all groups of age. Known causes of increasing incidence, such as ageing of the population or increased obesity, have been described and discussed. So far, literature reports ambivalent effects of body mass index (BMI) on bone physiology. It is worthwhile to examine the influence of BMI on the outcome of fractures more detailed. This study aims to investigate the influence of an abnormal BMI on fracture severity and treatment, as well as clinical, radiological, and functional outcome to improve clinical decision making. MATERIALS AND METHODS: A retrospective observational study was conducted on data obtained from patients, who underwent open reduction and internal fixation (ORIF) of a DRF at a local Level 1 Trauma Center between May 2018 and October 2021. Follow-up examinations were performed approximately 1 year after surgical fracture treatment, during which various questionnaires and functional measurements (CMS, DASH, NRS, ROM) were applied. In addition, postoperative complications were recorded and radiological examinations of the affected hand were performed. After excluding incomplete data sets and applying set exclusion criteria, the complete data of 105 patients were analyzed. RESULTS: 74 patients were female and 31 male with significant difference in mean BMI [p = 0.002; female: 23.8 (SD ± 3.3), men: 26.2 (SD ± 3.9)]. Patients with higher BMI had significantly more severe fractures (p = 0.042). However, there was no significant difference in surgery time for fracture management. At follow-up, patients with lower BMI showed a smaller difference in hand strength between the fractured and the other hand (p = 0.017). The BMI had no significant effect on the clinical and radiological outcome. CONCLUSION: Despite the ambivalent effects of BMI on the skeletal system, our findings indicate that a higher BMI is associated with more severe DRF. Thereby BMI does not correlate with surgery time for fracture treatment. Furthermore, no evidence of an influence on the clinical and radiological outcome could be detected.

App-based analysis of the femoral tunnel position in ACL reconstruction using the quadrant method.

PURPOSE: The purpose of this study was to examine the intra- and interobserver variability of an app-based analysis of the femoral tunnel position using the quadrant method in primary anterior cruciate ligament reconstruction. MATERIALS AND METHODS: Between 12/2020 und 12/2021 50 patients who underwent primary anterior cruciate ligament reconstruction were included in this retrospective study. Intraoperative strictly lateral fluoroscopic images of the knee with marked femoral tunnel were analyzed by four observers using the quadrant method. For retest reliability analysis, measurements were repeated once by 2 observers after 4 weeks. RESULTS: The femoral tunnel position of all included patients averaged 27.86% in the depth relation and 15.61% in the height relation. Statistical analysis showed an almost perfect intra- and interobserver reliability in the depth and height relation. The ICC was 0.92 in the depth relation and 0.84 in the height relation. The Pearson's correlation coefficient in the depth and height relation of observer 1 (0.94/0.81) was only slightly different from the Pearson's correlation coefficient of observer 2 (0.92/0.85). The app-based tunnel analysis took on average 59 ± 16 s per measurement. CONCLUSION: The femoral tunnel analysis with the app-based quadrant method has an almost perfect intra- and interobserver reliability. By smartphone camera, a fast and highly accurate, if necessary also intraoperative, control of the tunnel position can be performed. LEVEL OF EVIDENCE: Level 3-diagnostic retrospective cohort study.

Analysis of postoperative complications 5 years after osteosynthesis of patella fractures-a retrospective, multicenter cohort study.

PURPOSE: The study aims to investigate the influence of patient- and fracture-specific factors on the occurrence of complications after osteosynthesis of patella fractures and to compare knee joint function, activity, and subjective pain levels after a regular postoperative course and after complications in the medium term. METHODS: This retrospective, multicenter cohort study examined patients who received surgery for patella fracture at level 1 trauma centers between 2013 and 2018. Patient demographics and fracture-specific variables were evaluated. Final follow-up assessments included patient-reported pain scores (NRS), subjective activity and knee function scores (Tegner Activity Scale, Lysholm score, IKDC score), complications, and revisions. RESULTS: A total of 243 patients with a mean follow-up of 63.4 ± 21.3 months were included. Among them, 66.9% of patients underwent tension band wiring (TBW), 19.0% received locking plate osteosynthesis (LPO), and 14.1% underwent screw osteosynthesis (SO). A total of 38 patients (15.6%) experienced complications (TBW: 16.7%; LPO: 15.2%; SO: 11.8%). Implant-related complications of atraumatic fragment dislocation and material insufficiency/dislocation, accounted for 50% of all complications, were significantly more common after TBW than LPO (p = 0.015). No patient-specific factor was identified as a general cause for increased complications. Overall, particularly following complications such as limited range of motion or traumatic refracture, functional knee scores were significantly lower and pain levels were significantly higher at the final follow-up when a complication occurred. Implant-related complications, however, achieved functional scores comparable to a regular postoperative course without complications after revision surgery. CONCLUSION: The present study demonstrated that implant-related complications occurred significantly more often after TBW compared to LPO. The complication rates were similar in all groups.

The infraacetabular screw versus the antegrade posterior column screw in acetabulum fractures with posterior column involvement: a biomechanical comparison.

INTRODUCTION: Traditionally, plate osteosynthesis of the anterior column combined with an antegrade posterior column screw is used for fixation of anterior column plus posterior hemitransverse (ACPHT) acetabulum fractures. Replacing the posterior column screw with an infraacetabular screw could improve the straightforwardness of acetabulum surgery, as it can be inserted using less invasive approaches, such as the AIP/Stoppa approach, which is a well-established standard approach. However, the biomechanical stability of a plate osteosynthesis combined with an infraacetabular screw instead of an antegrade posterior column screw is unknown. MATERIAL AND METHODS: Two osteosynthesis constructs were compared in a synthetic hemipelvis model with an ACPHT fracture: Suprapectineal plate + antegrade posterior column screw (APCS group) vs. suprapectineal plate + infraacetabular screw (IAS group). A single-leg stance test protocol with an additional passive muscle force and a cyclic loading of 32,000 cycles with a maximum effective load of 2400 N was applied. Interfragmentary motion and rotation of the three main fracture lines were measured. RESULTS: At the posterior hemitransverse fracture line, interfragmentary motion perpendicular to the fracture line (p < 0.001) and shear motion (p < 0.001) and at the high anterior column fracture line, interfragmentary motion longitudinal to the fracture line (p = 0.017) were significantly higher in the IAS group than in the APCS group. On the other hand, interfragmentary motion perpendicular (p = 0.004), longitudinal (p < 0.001) and horizontal to the fracture line (p = 0.004) and shear motion (p < 0.001) were significantly increased at the low anterior column fracture line in the APCS group compared to the IAS group. CONCLUSIONS: Replacing the antegrade posterior column screw with an infraacetabular screw is not recommendable as it results in an increased interfragmentary motion, especially at the posterior hemitransverse component of an ACPHT fracture.

Increased ß2-adrenergic signaling promotes fracture healing through callus neovascularization in mice.

Traumatic brain injury (TBI) leads to skeletal changes, including bone loss in the unfractured skeleton, and paradoxically accelerates healing of bone fractures; however, the mechanisms remain unclear. TBI is associated with a hyperadrenergic state characterized by increased norepinephrine release. Here, we identified the ß2-adrenergic receptor (ADRB2) as a mediator of skeletal changes in response to increased norepinephrine. In a murine model of femoral osteotomy combined with cortical impact brain injury, TBI was associated with ADRB2-dependent enhanced fracture healing compared with osteotomy alone. In the unfractured 12-week-old mouse skeleton, ADRB2 was required for TBI-induced decrease in bone formation and increased bone resorption. Adult 30-week-old mice had higher bone concentrations of norepinephrine, and ADRB2 expression was associated with decreased bone volume in the unfractured skeleton and better fracture healing in the injured skeleton. Norepinephrine stimulated expression of vascular endothelial growth factor A and calcitonin gene-related peptide-α (αCGRP) in periosteal cells through ADRB2, promoting formation of osteogenic type-H vessels in the fracture callus. Both ADRB2 and αCGRP were required for the beneficial effect of TBI on bone repair. Adult mice deficient in ADRB2 without TBI developed fracture nonunion despite high bone formation in uninjured bone. Blocking ADRB2 with propranolol impaired fracture healing in mice, whereas the ADRB2 agonist formoterol promoted fracture healing by regulating callus neovascularization. A retrospective cohort analysis of 72 patients with long bone fractures indicated improved callus formation in 36 patients treated with intravenous norepinephrine. These findings suggest that ADRB2 is a potential therapeutic target for promoting bone healing.

The paediatric polytrauma CT-indication (PePCI)-score-Development of a prognostic model to reduce unnecessary CT scans in paediatric trauma patients.

BACKGROUND: Whole-Body CT (WBCT) is frequently used in emergency situations for promptly diagnosing paediatric polytrauma patients, given the challenges associated with obtaining precise details about the mechanism and progression of trauma. However, WBCT does not lead to reduced mortality in paediatric patients, but is associated with high radiation exposure. We therefore wanted to develop a screening tool for CT demand-driven emergency room (ER)-trauma diagnostic to reduce radiation exposure in paediatric patients. METHODS: A retrospective study in a Level I trauma centre in Germany was performed. Data from 344 paediatric emergency patients with critical mechanism of injury who were pre-announced by the ambulance for the trauma room were collected. Patients' symptoms, clinical examination, extended Focused Assessment with Sonography for Trauma (eFAST), routinely, laboratory tests and blood gas and - when obtained - WBCT images were analysed. To identify potential predictors of severe injuries (ISS > 23), 300 of the 344 cases with complete data were subjected to regression analyses model. RESULTS: Multiple regression analysis identified cGCS, base excess (BE), medically abnormal results from eFAST screening, initial unconsciousness, and injuries involving three or more body regions as significant predictors for a screening tool for decision-making to perform WBCT or selective CT. The developed Paediatric polytrauma CT-Indication (PePCI)-Score was divided into three risk categories and achieved a sensitivity of 87 % and a specificity of 71 % when comparing the low and medium risk groups with the high risk group. Comparing only the low-risk group with the high-risk group for the decision to perform WBCT, 32/35 (91 %) of patients with an ISS >23 were correctly identified, as were 124/137 (91 %) with lower ISS scores. CONCLUSION: With the newly developed PePCI-Score, the frequency of WBCT in a paediatric emergency patients collective can be significantly reduced according to our data. After prospective validation, the initial assessment of paediatric trauma patients in the future could be made not only by the mechanism of injury, but also by the new PePCI-Score, deriving on clinical findings after thorough clinical assessment and the discretion of the trauma team.

Impact of the medial displacement calcaneal osteotomy on foot biomechanics: a systematic literature review.

INTRODUCTION: Progressive collapsing foot deformity (PCFD), formally known as "adult-acquired flatfoot deformity" (AAFFD), is a complex foot deformity consisting of multiple components. If surgery is required, joint-preserving procedures, such as a medial displacement calcaneal osteotomy (MDCO), are frequently performed. The aim of this systematic review is to provide a summary of the evidence on the impact of MDCO on foot biomechanics. MATERIALS AND METHODS: A systematic literature search across two major sources (PubMed and Scopus) without time limitation was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria. Only original research studies reporting on biomechanical changes following a MDCO were included. Exclusion criteria consisted of review articles, case studies, and studies not written in English. 27 studies were included and the methodologic quality graded according to the QUACS scale and the modified Coleman score. RESULTS: The 27 included studies consisted of 18 cadaveric, 7 studies based on biomechanical models, and 2 clinical studies. The impact of MDCO on the following five major parameters were assessed: plantar fascia (n = 6), medial longitudinal arch (n = 9), hind- and midfoot joint pressures (n = 10), Achilles tendon (n = 5), and gait pattern parameters (n = 3). The quality of the studies was moderate to good with a pooled mean QUACS score of 65% (range 46-92%) for in-vitro and a pooled mean Coleman score of 58 (range 56-65) points for clinical studies. CONCLUSION: A thorough knowledge of how MDCO impacts foot function is key in properly understanding the postoperative effects of this commonly performed procedure. According to the evidence, MDCO impacts the function of the plantar fascia and Achilles tendon, the integrity of the medial longitudinal arch, hind- and midfoot joint pressures, and consequently specific gait pattern parameters.

Association of Remaining Anterior Knee Laxity With Inferior Outcomes After Revision ACL Reconstruction.

Background: The relationship between remaining anterior knee laxity and poorer clinical outcomes after anterior cruciate ligament reconstruction (ACLR) may be underrated, and the criteria for failure of revision ACLR have not been defined. Purpose/Hypothesis: To evaluate a possible association between remaining knee laxity and functional scores in patients after revision ACLR. We hypothesized that a postoperative side-to-side-difference (SSD) in knee laxity of ≥6 mm will be an objective parameter for failure. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 200 patients (77 women and 123 men; mean age, 30.8 ± 11 years; range, 18-61 years) who underwent revision ACLR between 2016 and 2019 were evaluated; The mean follow-up period was 30.2 ± 9 months (range, 24-67 months). Patients were divided into 3 groups according to postoperative SSD (<3 mm, 3-5 mm, or ≥6 mm). Preoperative and postoperative outcome measures (Lachman, pivot shift, visual analog scale [VAS] for pain, Tegner, Lysholm, International Knee Documentation Committee, and Knee injury and Osteoarthritis Outcome Score) were compared between the groups. Results: Of the 200 patients, 74% (n = 148) had a postoperative SSD of <3 mm at the latest follow-up, 19.5% (n = 39) had a postoperative SSD of 3 to 5 mm, and 6.5% (n = 13) had a postoperative SSD of ≥6 mm. Patients in all groups saw significant pre- to postoperative reductions in positive Lachman and pivot-shift tests as well as significant improvements in VAS pain, Lysholm, and Tegner scores (P < .001 for all). All postoperative functional scores of the patients with SSDs of <3 mm and 3-5 mm were significantly increased compared with those of patients with an SSD of ≥6 mm (P≤ .01 for all). Conclusion: In patients following revision ACLR, anterior and rotational knee laxity were successfully reduced while increasing postoperative functional outcomes. A remaining postoperative SSD of ≥6 mm was associated with inferior patient outcomes compared with an SSD <6 mm. An SSD of ≥6 mm represents an objective parameter in the definition of failure of revision ACLR.

Transcript-dependent effects of the CALCA gene on the progression of post-traumatic osteoarthritis in mice.

Osteoarthritis represents a chronic degenerative joint disease with exceptional clinical relevance. Polymorphisms of the CALCA gene, giving rise to either a procalcitonin/calcitonin (PCT/CT) or a calcitonin gene-related peptide alpha (αCGRP) transcript by alternative splicing, were reported to be associated with the development of osteoarthritis. The objective of this study was to investigate the role of both PCT/CT and αCGRP transcripts in a mouse model of post-traumatic osteoarthritis (ptOA). WT, αCGRP-/- and CALCA-/- mice were subjected to anterior cruciate ligament transection (ACLT) to induce ptOA of the knee. Mice were sacrificed 4 and 8 weeks post-surgery, followed by micro-CT and histological evaluation. Here we show that the expression of both PCT/CT and αCGRP transcripts is induced in ptOA knees. CALCA-/- mice show increased cartilage degeneration and subchondral bone loss with elevated osteoclast numbers compared to αCGRP-/- and WT mice. Osteophyte formation is reduced to the same extent in CALCA-/- and αCGRP-/- mice compared to WT controls, while a reduced synovitis score is noticed exclusively in mice lacking CALCA. Our data show that expression of the PCT/CT transcript protects from the progression of ptOA, while αCGRP promotes osteophyte formation, suggesting that CALCA-encoded peptides may represent novel targets for the treatment of ptOA.

Tranexamic Acid Attenuates the Progression of Posttraumatic Osteoarthritis in Mice.

BACKGROUND: Posttraumatic osteoarthritis (OA) is a common disorder associated with a high socioeconomic burden, particularly in young, physically active, and working patients. Tranexamic acid (TXA) is commonly used in orthopaedic trauma surgery as an antifibrinolytic agent to control excessive bleeding. Previous studies have reported that TXA modulates inflammation and bone cell function, both of which are dysregulated during posttraumatic OA disease progression. PURPOSE: To evaluate the therapeutic effects of systemic and topical TXA treatment on the progression of posttraumatic OA in the knee of mice. STUDY DESIGN: Controlled laboratory study. METHODS: OA was induced via anterior cruciate ligament (ACL) transection on the right knee of female mice. Mice were treated with TXA or vehicle intraperitoneally daily or intra-articularly weekly for 4 weeks, starting on the day of surgery. Articular cartilage degeneration, synovitis, bone erosion, and osteophyte formation were scored histologically. Micro-computed tomography evaluation was conducted to measure the subchondral bone microstructure and osteophyte volume. Cartilage thickness and bone remodeling were assessed histomorphometrically. RESULTS: Both systemic and topical TXA treatment significantly reduced cartilage degeneration, synovitis, and bone erosion scores and increased the ratio of hyaline to calcified cartilage thickness in posttraumatic OA. Systemic TXA reversed ACL transection-induced subchondral bone loss and osteophyte formation, whereas topical treatment had no effect. Systemic TXA decreased the number and surface area of osteoclasts, whereas those of osteoblasts were not affected. No effect of topical TXA on osteoblast or osteoclast parameters was observed. CONCLUSION: Both systemic and topical TXA exerted protective effects on the progression of posttraumatic OA. Drug repurposing of TXA may, therefore, be useful for the prevention or treatment of posttraumatic OA, particularly after ACL surgery. CLINICAL RELEVANCE: TXA might be beneficial in patients with posttraumatic OA of the knee.