Clinical Results and CT Analysis of ISA Stemless at a Minimum Follow-up of 2 Years.

INTRODUCTION: The utilization of stemless anatomic total shoulder arthroplasty is on the rise. Epiphyseal fixation leads to radiological bone remodeling, which has been reported to exceed 40% in certain studies series. The aim of this study was to present the clinical and radiological outcomes of a stemless implant with asymmetric central epiphyseal fixation at an average follow-up of 31 months. MATERIALS: This retrospective multicenter study examined prospective data of patients undergoing total anatomic arthroplasty with ISA Stemless implant and followed up at least 2 years. Clinical assessment included preoperative and final follow-up measurements of active range of motion (ROM), Constant score, and Subjective Shoulder Value (SSV). Anatomical epiphyseal reconstruction and bone remodeling at the 2-year follow-up were assessed by standardized Computed Tomography Scanner (CT scan). Statistical analysis employed unpaired Student's t-test or chi-squared test depending on the variable type, conducted using EasyMedStat software (version 3.22; www.easymedstat.com). RESULTS: Fifty patients (mean age 68 years, 62% females) were enrolled, with an average follow-up of 31 months (24-44). Primary osteoarthritis (68%) with type A glenoid (78%) was the prevailing indication. The mean Constant score and SSV improved significantly from 38 ± 11 to 76 ± 11 (p<0.001) and from 31% ± 16 to 88% ± 15 (p<0.001) respectively at the last follow-up. Forward elevation, external rotation and internal rotation ROM increased by 39° ± 42, 28° ± 21 and 3,2 ± 2,5 points respectively, surpassing the Minimally Clinically Important Difference (MCID) after total shoulder arthroplasty. No revisions were necessary. CT scans identified 30% osteolysis in the posterior-medial calcar region, devoid of clinical repercussions. No risk factors were associated with bone osteolysis. CONCLUSION: At an average follow-up of 31 months, ISA Stemless implant provided favorable clinical results. CT analysis revealed osteolysis-like remodeling in the posterior-medial zone of the calcar (30%), without decline in clinical outcomes and revisions. Long-term follow-up studies are mandated to evaluate whether osteolysis is associated with negative consequences.

Male sex, revision surgery, low volume of anterior cruciate ligament remnant, and significant instability are risk factors for Posterior Root Tear of the Lateral Meniscus in patients undergoing Anterior Cruciate Ligament Reconstruction.

PURPOSE: This multicenter study aimed to determine the incidence of lateral meniscus posterior root tears (LMPRTs) in patients undergoing ACL reconstruction and identify associated risk factors. METHODS: We conducted a retrospective, multicenter study using data from the Francophone Arthroscopic Society's registry. The study included all the patients in the registry who underwent ACL reconstruction surgery between June 2020 and June 2023, we excluded incomplete data. We compared delay from injury to surgery between LMPRTs group and No LMPRTs group. Variables investigated as potential risk factors for LMPRTs included age, sex, nature of surgery (primary or revision), pivot shift test result, side-to-side laxity under anesthesia, presence of ACL remnant, occurrence of medial meniscal tear, and presence of collateral ligament injury. Risk factors were analyzed using a logistic regression model. RESULTS: Among the 5359 patients analyzed, LMPRTs occurred in 7.0% (n=375) of cases during ACL reconstruction. Mean age at surgery was 29.3 +/- 10.3 years old [11-77]. Concerning delay to surgery, the mean time was 8.4 +/- 23.1 weeks [0.0-347.2] in the No LMPRTs group and 6.5 +/- 10.2 weeks [0.2-61.6] in the LMPRTs group (p = 0.109). Univariate analysis revealed that male sex (p < 0.001), revision surgery (p < 0.001), medial meniscal injury (p = 0.007), ACL remnant (0% vs > 70%, <10% vs > 70%, 10 to 30% vs > 70%, 30 to 50% vs > 70%, 50 to 70% vs > 70%; p < 0.001) and higher pivot shift grade (p = 0.011) were significantly associated with a presence of LMPRTs. Age, side-to-side laxity, and collateral ligament injury were not found to be significant risk factor In multivariate analysis : male sex, revision surgery, pivot shift test result and a low volume of ACL remnant remained significant. Side to side laxity was also a significant factor in multivariate analysis. CONCLUSION: This study identified male sex, revision surgery, low volume of ACL remnant, side to side laxity and higher grade of pivot shift as significant risk factors for LMPRTs during ACL reconstruction.

Risk factors and prevalence of ramp lesions in ACL ruptures: An analysis from the registry of the Francophone Arthroscopic Society.

PURPOSE: The study aimed to estimate the prevalence of ramp lesions among patients undergoing anterior cruciate ligament (ACL) reconstruction and identify risk factors associated with these lesions. METHODS: A retrospective, multicentre cohort study was conducted using data from the Francophone Arthroscopic Society's registry, including 5359 patients who underwent ACL reconstruction (ACLR) from June 2020 to June 2023. Potential risk factors for ramp lesion such as patient demographics, revision surgery, pivot shift, side-to-side anteroposterior laxity, medial collateral ligament (MCL) injury, lateral meniscal tear and the volume of ligament remnant were evaluated using multivariate regression analyses. BMI and delay to surgery were also assessed. RESULTS: Ramp lesions were identified in 822 patients (15.3%). Univariate analysis identified male sex, younger age, revision surgery, lateral meniscal injury, percentage of ACL remnant (all p < 0.0001) and pivot shift (p = 0.0103) as significant risk factors. MCL injury was associated with a lower risk (p < 0.0001). In multivariate analysis, male sex, younger age, revision surgery, lateral meniscal injury and percentage of ACL remnants remained significant risk factors, while MCL injury remained a protective factor. The anteroposterior laxity wasn't a significant predictor in either analysis. In subgroup analysis, there were no differences concerning body mass index (n.s) and the delay to surgery (n.s). CONCLUSION: The study identified male sex, younger age, revision surgery, lateral meniscal injury and pourcentage of ACL remnant as significant risk factors for ramp lesions, with MCL injury acting as a protective factor. This will help regarding the suspicion and identification of ramp lesions. LEVEL OF EVIDENCE: Level III.

The relevance of knee arthroscopy photographs in medicolegal proceedings.

PURPOSE: Whether photographs included in the operative report of knee arthroscopies can make the surgeon liable in the event of a legal investigation remains unknown. The main objective of this study was to establish inter-observer reliability in determining the presence or absence of lesions of the cartilage, meniscus and anterior cruciate ligament (ACL). Secondary objective was to assess the inter-observer reliability in classifying lesions. METHOD: A retrospective observational study was conducted in a continuous serie of 60 patients who underwent knee arthroscopy from the same operator. The photographs of each patient's operative report were presented separately to three experts, blinded to each other. Each expert had to decide on the presence or absence of injuries to the following structures: meniscal, cartilage and ACL and then, classify it. Primary and secondary endpoints were evaluated using the Fleiss' kappa index. RESULTS: Inter-observer reliability for lesion detection was between 0.4 and 0.61 for all structures with three exceptions: for cartilage, it was low (0.15) at the lateral tibial plateau and poor (-0.01) at the external condyle. On the contrary, the concordance was almost perfect (0.8) for the ACL. For classifying cartilaginous and meniscal lesions, inter-observer reliability was poor (from 0.03 to 0.14), except for at the lateral meniscus (0.65). CONCLUSION: Inter-observer reliability of arthroscopic knee diagnoses is poor when photographs alone are used. In the event of a legal investigation following knee arthroscopy, the photographs included in the operative report should not be used alone to hold the surgeon liable.

Enhancing Haloarene Coupling Reaction Efficiency on an Oxide Surface by Metal Atom Addition.

The bottom-up synthesis of carbon-based nanomaterials directly on semiconductor surfaces allows for the decoupling of their electronic and magnetic properties from the substrates. However, the typically reduced reactivity of such nonmetallic surfaces adversely affects the course of these reactions. Here, we achieve a high polymerization yield of halogenated polyphenyl molecular building blocks on the semiconducting TiO2(110) surface via concomitant surface decoration with cobalt atoms, which catalyze the Ullmann coupling reaction. Specifically, cobalt atoms trigger the debromination of 4,4″-dibromo-p-terphenyl molecules on TiO2(110) and mediate the formation of an intermediate organometallic phase already at room temperature (RT). As the debromination temperature is drastically reduced, homocoupling and polymerization readily proceed, preventing presursor desorption from the substrate and entailing a drastic increase of the poly-para-phenylene polymerization yield. The general efficacy of this mechanism is shown with an iodinated terphenyl derivative, which exhibits similar dehalogenation and reaction yield.

Arthroscopic Posterior Bankart Repair Using the Wilmington Portal to Facilitate Suture Anchor Implantation.

Posterior shoulder instability (PSI) accounts for 2% to 10% of all shoulder instability, with recurrent posterior subluxation being the most common type. One of the most important risk factors is the presence of an anterior humeral notch (so-called reverse Hill-Sachs lesion), and the most common lesion in PSI is a posterior labral lesion. When conservative treatment fails, surgery is recommended to provide long-term stability, manage pain, and enable a return to previous activity levels. Most posterior labral tears are treated by an arthroscopic posterior Bankart procedure. Visualization of the posterior aspect of the glenohumeral joint is technically challenging in this procedure. The instrumental portal is also a matter of concern because there is no rotator interval posteriorly for cannula placement. The purpose of this article is to propose a technique using a secondary posterolateral Wilmington instrumental portal to perform easy and reproducible placement of the posterior suture anchor at a 45° angle to the glenoid rim. We recommend implementing this technique in patients with painful PSI or with a type B2 lesion according to the Moroder classification.

Insufficient evidence to confirm benefit of adjuvant distal clavicle resection during rotator cuff repair: a systematic review and meta-analysis.

The aim of this study is to determine whether adjuvant Distal Clavicle Resection (DCR) improves outcomes of Rotator Cuff Repair (RCR) in terms of ROM, clinical scores as well as reducing complications and/or reoperations. This systematic review conforms to the PRISMA guidelines. Studies were included if they compared outcomes of RCR with and without adjuvant DCR and reported on postoperative ROM, clinical scores, complications, and/or reoperations. Seven studies that comprised 1572 shoulders which underwent RCR at a follow-up ranged 8-54 months: 398 with adjuvant DCR and 1174 without DCR. No significant differences were found between patients that had DCR versus those that did not have DCR, in terms of postoperative clinical scores (ASES, Constant, pVAS), postoperative ROM (AFE, external and internal rotation), retear rate and reoperation rate. There were no significant differences in ROM, clinical scores, or rates of retears and reoperations between patients that underwent RCR with or without adjuvant DCR. There is insufficient evidence to support routine DCR during RCR; the incidence of new or residual acromioclavicular joint (ACJ) pain after RCR with adjuvant DCR is higher than following isolated RCR, which could in fact induce iatrogenic morbidity and therefore does not justify the additional surgery time and costs of routine adjuvant DCR.

On-Surface Synthesis of Polyphenylene Wires Comprising Rigid Aliphatic Bicyclo[1.1.1]Pentane Isolator Units.

Bicyclo[1.1.1]pentane (BCP) motifs are of growing importance to the pharmaceutical industry as sp3 -rich bioisosteres of benzene rings and as molecular building blocks in materials science. Herein we explore the behavior of 1,3-disubstituted BCP moieties on metal surfaces by combining low-temperature scanning tunneling microscopy / non-contact atomic force microscopy studies with density functional theory modeling. We examine the configuration of individual BCP-containing precursors on Au(111), their supramolecular assembly and thermally activated dehalogenative coupling reactions, affording polymeric chains with incorporated electronically isolating units. Our studies not only provide the first sub-molecular insights of the BCP scaffold behavior on surfaces, but also extend the potential application of BCP derivatives towards integration in custom-designed surface architectures.

Early Ultrastructural Changes in Biopsies From Patients With Symptomatic CKD of Uncertain Etiology.

Introduction: Although the investigation of chronic kidney disease of uncertain etiology (CKDu) has identified many possible influencing factors in recent years, the exact pathomechanism of this disease remains unclear. Methods: In this study, we collected 13 renal biopsies from patients with symptomatic CKDu (Sym-CKDu) from Sri Lanka with well-documented clinical and socioeconomic factors. We performed light microscopy and electron microscopic evaluation for ultrastructural analysis, which was compared with 100 biopsies from German patients with 20 different kidney diseases. Results: Of the 13 Sri Lankan patients, 12 were men (92.3%), frequently employed in agriculture (50%), and experienced symptoms such as feeling feverish (83.3%), dysuria (83.3%), and arthralgia (66.6%). Light microscopic evaluation using activity and chronicity score revealed that cases represented early stages of CKDu except for 2 biopsies, which showed additional signs of diabetes. Most glomeruli showed only mild changes, such as podocyte foot process effacement on electron microscopy. We found a spectrum of early tubulointerstitial changes including partial loss of brush border in proximal tubules, detachment of tubular cells, enlarged vacuoles, and mitochondrial swelling associated with loss of cristae and dysmorphic lysosomes with electron-dense aggregates. None of these changes occurred exclusively in Sym-CKDu; however, they were significantly more frequent in these cases than in the control cohort. Conclusion: In conclusion, our findings confirm the predominant and early alterations of tubular structure in CKDu that can occur without significant glomerular changes. The ultrastructural changes do not provide concrete evidence of the cause of CKDu but were significantly more frequent in Sym-CKDu than in the controls.

The Minimal Clinically Important Difference, Patient Acceptable Symptom State, and Clinical Outcomes of Anterior Cruciate Ligament Repair Versus Reconstruction: A Matched-Pair Analysis From the SANTI Study Group.

BACKGROUND: There has been increasing interest in anterior cruciate ligament (ACL) repair because of theoretical advantages over ACL reconstruction; however, the contemporary literature has failed to provide high-quality evidence to demonstrate these advantages. PURPOSE: To compare the clinical and functional outcomes of ACL repair versus ACL reconstruction at a minimum follow-up of 2 years. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who underwent ACL repair were propensity matched (based on demographics, time between injury and surgery, knee laxity parameters, presence of meniscal lesions, preoperative activity level, and sport participation), in a 1:1 ratio, to those who underwent ACL reconstruction during the same period. Isokinetic testing was used to evaluate strength deficits at 6 months postoperatively. Knee laxity parameters were evaluated at 12 months. Complications, return to sport, and patient-reported outcome scores were recorded at final follow-up. RESULTS: In total, 75 matched pairs (150 patients) were evaluated. The repair group had significantly better mean hamstring muscle strength at 6 months compared with the reconstruction group (1.7% ± 12.2% vs -10.0% ± 12.8%, respectively; P < .0001). At a mean final follow-up of 30.0 ± 4.8 months, the repair group had a significantly better mean Forgotten Joint Score-12 (FJS-12) score compared with the reconstruction group (82.0 ± 15.1 vs 74.2 ± 21.7, respectively; P = .017). Noninferiority criteria were met for ACL repair, compared with ACL reconstruction, with respect to the subjective International Knee Documentation Committee score (86.8 ± 9.0 vs 86.7 ± 10.1, respectively; P < .0001) and side-to-side anteroposterior laxity difference (1.1 ± 1.4 vs 0.6 ± 1.0 mm, respectively; P < .0001). No significant differences were found for other functional outcomes or the pivot-shift grade. There were no significant differences in the rate of return to the preinjury level of sport (repair group: 74.7%; reconstruction group: 60.0%; P = .078). A significant difference was observed regarding the occurrence of ACL reruptures (repair group: 5.3%; reconstruction group: 0.0%; P = .045). Patients who experienced a failure of ACL repair were significantly younger than those who did not (26.8 vs 40.7 years, respectively; P = .013). There was no significant difference in rupture rates between the repair and reconstruction groups when only patients aged >21 years were considered (2.9% vs 0.0%, respectively; P = .157). The minimal clinically important difference and Patient Acceptable Symptom State (PASS) thresholds were defined for the ACL repair group. A significantly greater proportion of patients in the repair group achieved the PASS for the FJS-12 compared with their counterparts in the reconstruction group (77.3% vs 60.0%, respectively; P = .034). CONCLUSION: ACL repair was associated with some advantages over ACL reconstruction including superior hamstring muscle strength at 6 months and significantly better FJS-12 scores. However, the failure rate was significantly higher after ACL repair, and younger patients were particularly at risk.

The SFA datalake platform and anterior cruciate ligament tear registry of the French Society of Arthroscopy (SFA): Rationale, statutes and plans.

SFA Datalake is the registry platform of the French Society of Arthroscopy (SFA). It was designed to collect and store data on arthroscopic orthopedic surgery and joint-sparing surgery in French-speaking countries. The anterior cruciate ligament (ACL) tear registry is the first registry to be set up based on SFA Datalake. Registries are intended to enable systematic standardized data collection, and provide information for surgeons to improve clinical practice and results. The ACL tear registry was designed in the light of guidelines, the literature and existing registries. Data are collected prospectively on a secure on-line application accessible via a computer or smartphone. Data collection is organized according to clinical examination results, preoperative findings, and follow-up data based on patient-administered subjective quality of life questionnaires. The pilot committee consists of 5 SFA board members, appointed for 2 years. LEVEL OF EVIDENCE: IV.

Consensus statement on data to be entered in the ACL tear registry: SFA-DataLake.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction is a frequent procedure, with room for improvement by rehabilitation measures and associated peripheral and meniscal surgeries that are currently under assessment, requiring follow-up. Outside France, there have been ACL registries for 20 years now. The French Arthroscopy Society (SFA) decided to set up an ACL tear registry within its SFA DataLake registry platform. MATERIAL AND METHOD: This article presents the methodology underlying the ACL Tear Registry: i.e., identification, definition and coding of essential and relevant data. A test phase comprised an initial assessment to improve data quality and overall coherence, to optimize data-entry time for patients and practitioners, who are the guarantors of the registry's use and efficacy. RESULTS: The SFA DataLake ACL Tear Registry was made available to SFA members in December 2021. It aims to enable a review of practices for surgeons, early detection of failure of procedures and implants, with rates of failure and abnormal complications, and identification of prognostic factors for outcome, especially regarding original items that do not figure in previous registries. CONCLUSION: SFA DataLake strikes a balance between "indispensable" and "original" items. The choice of contents and data quality is founded on a robust methodology with overall coherence, enabling analysis of large cohorts and comparisons with the literature and other registries. However, it remains to assess rates of data entry and item relevance as the Registry progresses. LEVEL OF EVIDENCE: IV.

Defining Minimal Clinically Important Difference and Patient Acceptable Symptom State After the Latarjet Procedure.

BACKGROUND: The Latarjet procedure is one of the most well-established treatment options for anterior shoulder instability. However, meaningful clinical outcomes after this surgery have not been defined. PURPOSE: This study aimed to establish the minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) for commonly used outcome measures in patients undergoing the Latarjet procedure and determine correlations between preoperative patient characteristics and achievement of MCID or PASS. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A multicenter retrospective review at 4 institutions was performed to identify patients undergoing primary open Latarjet procedure with minimum 2-year follow-up. Data collected included patient characteristics (age, sex, sports participation), radiological parameters (glenoid bone loss, off-track Hill-Sachs lesion), and 4 patient-reported outcome measures (collected preoperatively and 2 years postoperatively): the American Shoulder and Elbow Surgeons (ASES) score, the Single Assessment Numeric Evaluation (SANE), the visual analog scale (VAS) for pain, and the Western Ontario Shoulder Instability Index (WOSI). The MCID and PASS for each outcome measure were calculated, and Pearson and Spearman coefficient analyses were used to identify correlations between MCID or PASS and preoperative variables (age, sex, sports participation, glenoid bone loss, off-track Hill-Sachs lesion). RESULTS: A total of 156 patients were included in the study. The MCID values for ASES, SANE, VAS pain, and WOSI were calculated to be 9.6, 12.4, 1.7, and 254.9, respectively. The PASS values for ASES, SANE, VAS pain, and WOSI were 86.0, 82.5, 2.5, and 571.0, respectively. The rates of patients achieving MCID were 61.1% for VAS pain, 71.6% for ASES, 74.1% for SANE, and 84.2% for WOSI. The rates of achieving PASS ranged from 78.4% for WOSI to 84.0% for VAS pain. There was no correlation between any of the studied preoperative variables and the likelihood of achieving MCID or PASS. CONCLUSION: This study defined MCID and PASS values for 4 commonly used outcome measures in patients undergoing the Latarjet procedure. These findings are essential for incorporating patient perspectives into the clinical effectiveness of the Latarjet procedure and provide valuable parameters for the design and interpretation of future clinical trials.

Remplissage Yields Similar 2-Year Outcomes, Fewer Complications, and Low Recurrence Compared to Latarjet Across a Wide Range of Preoperative Glenoid Bone Loss.

PURPOSE: The purpose of this study was to compare functional outcome, return to sport, satisfaction, postoperative recurrence, and complications in patients undergoing primary arthroscopic Bankart repair with remplissage (ABR) to primary Latarjet. METHODS: A multicenter retrospective study was performed on patients undergoing primary ABR or open Latarjet between 2013 and 2019 who had a minimum 2-year follow-up. Baseline and two-year range of motion (ROM), patient-reported outcomes (PROs: Western Ontario Shoulder Instability Index [WOSI], Single Assessment Numeric Evaluation [SANE], and visual analog scale [VAS] for pain) recurrence, return to sport, satisfaction, and complications were reviewed. RESULTS: This study included 258 patients, including 70 ABRs and 188 Latarjet procedures. Baseline demographics, ROM, and PROs were similar. Mean preop glenoid bone loss (GBL) (12.3% ± 10.9% vs 7.6% ± 9%; P < .001) and off-track lesions (23% vs 13%; P = .046) were higher in the ABR group, while preoperative GBL range was similar (0-42% vs 0-47%). Changes in the VAS (1.9 vs 0.9; P = .019) and WOSI (1096 vs 805; P < .001) were improved in ABR. The percentage of patients who achieved a minimal clinically important difference was improved in WOSI for ABR and PASS for ABR in SANE, VAS, and WOSI scores. The ABR cohort reported worse changes in external rotation (ER) (-4° vs +19°; P < .001). Return to sport among overhead and contact athletes favored ABR (91.5% vs 72.7%; P = .007). Satisfaction and recurrent dislocation were similar. Surgical complications were observed in 0% of ABR cases, compared to 5.9% in the Latarjet group. CONCLUSION: Primary ABR resulted in 2-year functional outcomes that were as good or superior to primary Latarjet, with higher return to sport for overhead and contact activities, fewer complications, and comparably low recurrence rates, even despite greater bipolar bone loss in the ABR cohort. However, this comes at the expense of decreased external rotation, which may be considered in individual patients. LEVEL OF EVIDENCE: III, retrospective comparative study.

Arthroscopic rotator cuff repair: Is healing enough?

HYPOTHESIS/BACKGROUND: Arthroscopic rotator cuff repair most commonly results in good clinical outcomes, however understanding of predictive factors influencing the final clinical outcome is limited. AIM: The purpose of our study was to evaluate clinical outcomes of patients with healed supraspinatus tendon after arthroscopic rotator cuff repair and to identify its pre- and peri-operative predictive factors of good clinical results. METHODS: A multi-center prospective study followed up 188 patients, who had a healed tendon after an arthroscopic repair of isolated supraspinatus tear. Inclusion criteria were: age under 70 years old, isolated supraspinatus tear, stage 0 or I of fatty infiltration, healed supraspinatus tendon at one year postoperatively and the same arthroscopic double row rotator cuff repair used in all patients. Clinical assessment used Constant Murley Score (CMS) and Subjective Shoulder Value (SSV) preoperatively and at one year postoperatively. Ultrasound (US) control checked tendon repair quality based on Sugaya classification. Types I-II-III were considered as healed. RESULTS: The average age of our cohort was 57.57 (range; 41 to 70) years and the female to male ratio was 1.14 (range; 100 to 87). The average preoperative CMS was 53.75±13.50 (mean±SD; range; 16 to 83). At final follow up, the average postoperative CMS was 79.95±12.05 (mean±SD; range; 28 to 100). 12.22% (23/188) of patients, who had a CMS score below 70, had a clinically significant difference compared to the average CMS, due to the fact that the minimal clinically significant difference (MCID) in CMS is 10. A statistical analysis has shown that in patients with lower scores there was only a significant dominance of females (p-value=0.001). No difference was found in regards to age, preoperative CMS, fatty degeneration and other factors. CONCLUSION: Our study showed that despite all patients had a healed repair of supraspinatus, not all of them experienced a good final clinical outcome. The only factor negatively influencing the final clinical outcome was a female gender. No other structural factors seemed to influence the final clinical results. Futures studies should focus more on analyzing which personality traits and other psychosocial factors play an important role in determining the final outcome after arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: III; retrospective cohort study.

Superior capsular reconstruction for irreparable rotator cuff tears: Autografts versus allografts.

AIMS: Superior capsular reconstruction (SCR) is a treatment option for patients with massive irreparable rotator cuff tears. Different types of grafts from various donor sites have been described. There are no clinical studies comparing the different grafts available. The aim of this study is to compare the early clinical outcomes of patients who have undergone arthroscopic SCR with different types of grafts (allograft vs. autograft). MATERIAL AND METHODS: This study is a retrospective analysis of data collected prospectively, from patients who underwent arthroscopic SCR with either a long head of biceps autograft (LHB) (n=40) or an acellular dermal allograft (n=40), between March 2015 and April 2018. The pre- and postoperative clinical data were compared between the 2 groups, as well as the incidence and type of complications. RESULTS: All patients were monitored with a minimum follow-up of one year. Three patients (7.5%) in the autograft group, and 14 (35%) in the allograft group (p=0.005) had a complication, of which 2 (5%) and 5 (12.5%) respectively, required revision surgery (p=0.432). Linear regression ruled out any significant difference between the 2 groups, with respect to clinical scores. However, patients with a history of prior rotator cuff surgery had poorer results with regard to active elevation (ß, -29.3; p=0.020), internal rotation (ß, -3.4; p=0.003) and Subjective Shoulder Value (SSV) (ß, -17.2; p=0.023). Older patients, as well as men, are associated with poorer postoperative internal rotation (ß, -0.1; p=0.003 and ß, -1.9; p=0.039 respectively), and type D lesions are associated with poorer external rotation and postoperative SSV (ß, -11.3; p=0.012 and ß, -12.4; p=0.048 respectively), compared to type C lesions. Postoperative graft integrity was improved in the autograft group compared to the allograft group. (Grade 1: 65.8% vs. 2.9%; Grade 5: 5.3% vs. 28.6%; p<0.001). CONCLUSIONS: In both groups, clinical scores improved after SCR in patients with irreparable rotator cuff tears. Fewer complications and revisions were observed with the autograft compared to the allograft. If the LHB was still in place during surgery, its use appears valid, given the reasonable cost and low rate of complications associated with it. If absent, an allograft is also an option, considering the potential clinical improvement. LEVEL OF EVIDENCE: III; Case-control study.

Actinide Coordination Chemistry on Surfaces: Synthesis, Manipulation, and Properties of Thorium Bis(porphyrinato) Complexes.

Actinide-based metal-organic complexes and coordination architectures encompass intriguing properties and functionalities but are still largely unexplored on surfaces. We introduce the in situ synthesis of actinide tetrapyrrole complexes under ultrahigh-vacuum conditions, on both a metallic support and a 2D material. Specifically, exposure of a tetraphenylporphyrin (TPP) multilayer to an elemental beam of thorium followed by a temperature-programmed reaction and desorption of surplus molecules yields bis(porphyrinato)thorium (Th(TPP)2) assemblies on Ag(111) and hexagonal boron nitride/Cu(111). A multimethod characterization including X-ray photoelectron spectroscopy, scanning tunneling microscopy, temperature-programmed desorption, and complementary density functional theory modeling provides insights into conformational and electronic properties. Supramolecular assemblies of Th(TPP)2 as well as individual double-deckers are addressed with submolecular precision, e.g., demonstrating the reversible rotation of the top porphyrin in Th(TPP)2 by molecular manipulation. Our findings thus demonstrate prospects for actinide-based functional nanoarchitectures.

Lateral acromioplasty cannot sufficiently reduce the critical shoulder angle if preoperatively measured over 40°.

PURPOSE: To investigate whether arthroscopic lateral acromion resection can sufficiently reduce the critical shoulder angle (CSA) without damaging deltoid muscle insertion. METHODS: Ninety patients who underwent arthroscopic rotator cuff (RC) repair were retrospectively analysed. According to the preoperative CSA, patients were categorized as Group I (CSA < 35°) and Group II (CSA ≥ 35°). Additional arthroscopic lateral acromion resection was performed in Group II. The CSA was measured 1 week postoperatively, while RC integrity and the deltoid attachment were assessed at 3, 6 and 12 months via ultrasound. Deltoid function was evaluated using the Akimbo test, in which patients place their hands on the iliac crest with abduction in the coronal plane and internal rotation of the shoulder joint while simultaneously flexing the elbow joint and pronating the forearm. RESULTS: Large and massive RC tears were more prevalent in Group II (p = 0.017). In both groups, the CSA reduction was statistically significant (Group I = 1°: range 0°-3°, Group II = 3.7°: range 1°-8°; p < 0.001). When the preoperative CSA was > 40°, the respective postoperative CSA remained > 35° in 83.3% of cases (p < 0.001). Final shoulder strength was correlated with the amount of CSA reduction (rho = 0.41, p = 0.002). The postoperative CSA was higher, but not significantly different (n.s.), in patients with re-torn (36°, range 32°-40°) than with healed RC (33°, range 26°-38°). No clinical detachment or hypotrophy of the deltoid was observed with the Akimbo test and ultrasound evaluation. CONCLUSIONS: Arthroscopic lateral acromion resection is a safe procedure without affecting deltoid muscle origin or function, and it is effective in significantly reducing the CSA. However, the CSA cannot always be reduced to < 35°, especially in patients with preoperative CSA values > 40°. LEVEL OF EVIDENCE: III.