Ligament augmentation repair is broadly applied across different orthopaedic subspecialities: an ISAKOS international survey of orthopaedic surgeons.

OBJECTIVES: To evaluate how ligament augmentation repair (LAR) techniques are currently used in different anatomic regions in orthopaedic sports medicine, and to identify the most common indications and limitations of LAR. METHODS: We sent survey invitations to 4,000 members of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine society. The survey consisted of 37 questions total, with members only receiving some branching questions specific to their area of specialisation. Data were analysed using descriptive statistics, and the significance between groups was evaluated using chi-square tests of independence. RESULTS: Of 515 surveys received, 502 were complete and included for the analysis (97% completion rate). 27% of respondents report from Europe, 26% South America, 23% Asia, 15% North America, 5.2% Oceania, and 3.4% Africa. 75% of all survey respondents report using LAR, most frequently using it for the anterior talofibular ligament ( 69%), acromioclavicular joint ( 58%), and the anterior cruciate ligament (51%). Surgeons in Asia report using LAR the most (80%), and surgeons in Africa the least (59%). LAR is most commonly indicated for additional stability (72%), poor tissue quality (54%), and more rapid return-to-play (47%). LAR users state their greatest limitation is cost (62%), while non-LAR users state their greatest reason not to use LAR is that patients do well without it (46%). We also find that the frequency of LAR use among surgeons may differ based on practice characteristics and training. For example, surgeons who treat athletes at the professional or Olympic level are significantly more likely to have a high annual use of LAR (20+ cases) compared to surgeons that treat only recreational athletes (45% and 25%, respectively, p â€‹= â€‹0.005). CONCLUSION: LAR is broadly applied in orthopaedics but its rate of use is not homogeneous. Outcomes and perceived benefits vary depending on factors such as surgeon specialty and treatment population. LEVEL OF EVIDENCE: Level V.

Publication trends in ligament augmentation techniques: current concepts.

IMPORTANCE: Ligament augmentation techniques (LATs) are surgical procedures, in which an anatomical ligament repair or reconstruction is strengthened with a synthetic material. During the last decade, LATs have increased in prevalence in clinical practice and academic literature. Observing the trends in LAT publications can be used to identify clusters of strong evidence for clinical practice and to highlight areas of the literature which need further development. OBJECTIVE: This article aims to define ligament augmentation as a technique category, observe anatomical, procedural, and temporal trends in LAT publication, and report on the state of current research in this field. EVIDENCE REVIEW: Primary literature in the English language, which describes ligament augmentation and reports on human, cadaveric, or biomechanical models, and published prior to May 24th, 2022, was targeted for analysis. PubMed, Embase, and Cochrane CENTRAL databases were explored using a focused keyword search strategy, and the resulting publications were reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were collected and analysed using descriptive statistics. FINDINGS: Two hundred eighty-three publications reporting ligament augmentation techniques, published from May 1989 to May 2022, were included for final analysis. A wide technical and anatomical variety of procedures are reported. 36.8% of LAT publications describe knee ligaments, among which the anterior cruciate ligamenthas the highest focus in ligament augmentation publications (31.8% of articles). LAT literature has recently expanded in anatomical scope, with many contemporary articles describing the usage of a LAT in the ankle syndesmosis and coracoclavicular ligaments. 60.4% of LAT literature has been published since 2017. There has been an 11% average increase in the rate of LAT publication reports since 2015. Novel fixation devices-suture buttons and suture anchors-have gained wide popularity in the literature. CONCLUSIONS AND RELEVANCE: In this review, we define LATs and quantitatively describe the expansion of LAT use reported in the literature. This data will provide physicians an overview of the history of these methods, as well as illustrate the broad range of applications available for the use of LATs.

Ion Mobility Spectrometry Characterization of the Intermediate Hydrogen-Containing Gold Cluster Au7(PPh3)7H52.

We employ ion mobility spectrometry and density functional theory to determine the structure of Au7(PPh3)7H52+ (PPh3 = triphenylphosphine), which was recently identified by high mass resolution mass spectrometry. Experimental ion-neutral collision cross sections represent the momentum transfer between the ionic clusters and gas molecules averaged over the relative thermal velocities of the colliding pair, thereby providing structural insights. Theoretical calculations indicate the geometry of Au7(PPh3)7H52+ is similar to Au7(PPh3)7+, with three hydrogen atoms bridging two gold atoms and two hydrogen atoms forming single Au-H bonds. Collision-induced dissociation products observed during IMS experiments reveal that smaller hydrogen-containing clusters may be produced through fragmentation of Au7(PPh3)7H52+. Our findings indicate that hydrogen-containing species like Au7(PPh3)7H52+ act as intermediates in the formation of larger phosphine ligated gold clusters. These results advance the understanding and ability to control the mechanisms of size-selective cluster formation, which is necessary for scalable synthesis of clusters with tailored properties.

ESI-MS Identification of the Cationic Phosphine-Ligated Gold Clusters Au1-22: Insight into the Gold-Ligand Ratio and Abundance of Larger Clusters.

Triphenylphosphine (PPh3)-ligated gold nanoclusters are valuable for a number of potential applications due to their relative ease of synthesis and usefulness in forming advanced cluster architectures. While previous studies have reported cationic PPh3-ligated gold clusters with core sizes of Au1-4, Au6-11, and Au13-14, there has not been definitive identification by mass spectrometry of many larger clusters in the Au12-25 range. Herein, we survey a polydisperse solution of cationic PPh3-ligated gold clusters using high-mass-resolution (M/ΔM = 60,000) electrospray ionization mass spectrometry (ESI-MS). To improve the sensitivity and mass resolution of larger clusters for unambiguous identification, we increased the number of scan averages and reduced the range of mass collection windows to 200 m/z, thereby mitigating potential mass and ion abundance bias resulting from smaller "building block" gold clusters that are present in much higher abundance in solution. In addition to the previously reported clusters, we identify several new species including Au5(PPh3)5+, Au12(PPh3)9HCl2+, Au15(PPh3)9Cl2+, Au16(PPh3)10Cl22+, Au17(PPh3)113+, Au18(PPh3)102+, Au19(PPh3)10Cl2+, Au20(PPh3)12H33+, Au21(PPh3)10Cl2+, and Au22(PPh3)10Cl22+, indicating that a full range of clusters between Au1-22 may be observed in a single polydisperse solution. Considering all of the clusters observed, our findings provide evidence that the Au12-14 size range is a critical transition point in cluster nucleation. While smaller clusters exhibit a 1:1 gold-to-ligand ratio, larger clusters (beginning Au12-14) feature additional gold atoms without an equal number of accompanying ligands. Our results support previous evidence in the literature indicating that the "magic number" icosahedral Au13 geometry is the smallest cluster size where a ligand-less central gold atom is coordinated by a complete shell of 12 surrounding ligated gold atoms, thereby creating a stable "one-shell" cluster. Furthermore, our findings reinforce growing evidence that ligands may be used to actively direct gold cluster size and abundance during synthesis. While for PPh3-ligated systems the most abundant species are Au6-9 clusters, we find that for related methyldiphenylphosphine (PPh2Me) and dimethylphenylphosphine (PPhMe2)-ligated systems the most abundant cluster sizes are Au10-11 and Au12-14, respectively. Together, we demonstrate that reducing the range of m/z collection windows and increasing the number of scan averages dramatically improves instrument sensitivity for cationic gold clusters, enabling thorough characterization of polydisperse solutions that is not possible using conventional techniques.