Factors association with reparability of rotator cuff tears: A systematic review and meta-analysis.

PURPOSE: To identify and quantify the factors associated with the reparability of rotator cuff tears (RCTs). METHODS: PubMed, Scopus, and Web of Science databases were searched for clinical studies published in English focusing on RCT reparability by using the keywords "rotator cuff tear" and "reparability". A meta-analysis was conducted if ≥3 studies examined the same factor and provided enough data to assess RCT reparability. Quality assessment was completed using the QUADAS-2 tool. RESULTS: Eighteen studies (2700 patients) were enrolled, and 26 factors were included in the meta-analysis. The dichotomous variables associated with irreparability were Patte stage 3 (Odds ratio (OR): 8.0, 95% CI: 4.3-14.9), massive tear versus large tear (OR: 3.1, 95% CI: 1.3-7.2), Goutallier stage for each tendon, and tangent sign (OR: 11.1, 95% CI: 4.3-28.4). The continuous variables associated with irreparability were age (Mean difference (MD): 3.25, 95% CI: 1.4-5.1), mediolateral tear size (MD: 12.3, 95% CI: 5.8-18.9), anteroposterior tear size (MD: 10.4, 95% CI: 5.2-15.6), acromiohumeral distance on X-ray (MD: -2.3, 95% CI: -3.0 to -1.6) and magnetic resonance imaging (MD: -1.8, 95% CI: -2.8 to -0.9), and inferior glenohumeral distance on MRI (MD: 2.2, 95% CI: 1.4-3.0). CONCLUSION: This study revealed that older age, larger tear size, severe fatty infiltration, muscle atrophy, and advanced superior migration of the humeral head were strongly associated with irreparable RCTs. Conversely, clinical symptoms provided limited information for predicting reparability. Additionally, the tangent sign emerged as a powerful and simple tool for individual prediction, and several quantitative scoring systems also proved useful.

MicroRNA-146a gene transfer ameliorates senescence and senescence-associated secretory phenotypes in tendinopathic tenocytes.

OBJECTIVE: Tendinopathy is influenced by multiple factors, including chronic inflammation and aging. Senescent cells exhibit characteristics such as the secretion of matrix-degrading enzymes and pro-inflammatory cytokines, collectively known as senescence-associated secretory phenotypes (SASPs). Many of these SASP cytokines and enzymes are implicated in the pathogenesis of tendinopathy. MicroRNA-146a (miR-146a) blocks senescence by targeting interleukin-1ß (IL-1ß) receptor-associated kinase 4 (IRAK-4) and TNF receptor-associated factor 6 (TRAF6), thus inhibiting NF-κB activity. The aims of this study were to (1) investigate miR-146a expression in tendinopathic tendons and (2) evaluate the role of miR-146a in countering senescence and SASPs in tendinopathic tenocytes. METHODS: MiR-146a expression was assessed in human long head biceps (LHB) and rat tendinopathic tendons by in situ hybridization. MiR-146a over-expression in rat primary tendinopathic tenocytes was achieved by lentiviral vector-mediated precursor miR-146a transfer (LVmiR-146a). Expression of various senescence-related markers was analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunoblotting and immunofluorescence. MiR-146a expression showed a negative correlation with the severity of tendinopathy in human and rat tendinopathic tendons (p<0.001). RESULTS: Tendinopathic tenocyte transfectants overexpressing miR-146a exhibited downregulation of various senescence and SASP markers, as well as the target molecules IRAK-4 and TRAF6, and the inflammatory mediator phospho-NF-κB. Additionally, these cells showed enhanced nuclear staining of high mobility group box 1 (HMGB1) compared to LVmiR-scramble-transduced controls in response to IL-1ß stimulation. CONCLUSIONS: We demonstrate that miR-146a expression is negatively correlated with the progression of tendinopathy. Moreover, its overexpression protects tendinopathic tenocytes from SASPs and senescence through the IRAK-4/TRAF6/NF-kB pathway.

Suture Contamination During Arthroscopic Rotator Cuff Repair Is Associated With Significantly Higher Retear Rates in Magnetic Resonance Imaging: A Matched-Pair Analysis.

PURPOSE: To evaluate the correlation between suture contamination and rotator cuff tendon retear after arthroscopic rotator cuff repair. METHODS: Patients undergoing primary arthroscopic rotator cuff repair from April 1, 2020, to September 30, 2022, were enrolled. Those younger than 18 years, with a history of shoulder surgeries or shoulder infection episodes, or who declined participation were excluded. A 5-cm section of the first-cut suture, originating from the anchor eyelet ends, in each rotator cuff repair surgery was subjected to bacteria culture and polymerase chain reaction analysis. Patients with positive culture findings were matched 1:1 to those with negative culture reports based on age, sex, tear size as well as involved tendons, preoperative fatty infiltration grade (Goutallier grade), and preoperative muscle atrophy grade (Warner score). Postoperative rotator cuff tendon retear assessments were conducted at the 6-month mark using the Sugaya classification via magnetic resonance imaging. The Wilcoxon signed-rank test was used for matched-pair comparisons between the groups. RESULTS: A total of 141 patients (60 men and 81 women) with a mean age of 61.0 ± 8 years were finally enrolled. Twenty-six patients (18 men and 8 women) had a positive culture, while 115 patients (42 men and 73 women) had a negative culture. After the propensity score matching process, 24 culture-negative patients (16 men and 8 women) were selected as the culture-negative group. Age, fatty infiltration grade, and muscle atrophy grade were not significantly different between matched groups. The retear grade in the culture-positive group was significantly higher than that in the culture-negative group (P = .020) under the matched-pair comparison. Cutibacterium acnes was the most prevalent bacterial species responsible for suture contamination. CONCLUSIONS: The matched-pair analysis revealed that the presence of bacterial contamination on sutures was associated with a higher risk of retear on magnetic resonance imaging following arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Wearable Ultrasound Imaging Device for Dynamic Dual-Direction Shear Wave Elastography of Shoulder Muscle.

The shoulder is the most mobile joint in the human body, thus requiring intricate coordination of adjacent muscles. Patients suffered from rotator cuff muscle Injuries have several typical symptoms include shoulder pain and difficulty raising the arm, thus reducing work efficiency, and compromising the quality of life. Ultrasound has been used widely for shoulder soft tissue imaging as well as ultrasound elastography was introduced in shoulder examination for the dilemma of treating degenerative rotator cuff tears. However, most of ultrasound examination was performed under a static condition. Providing dynamic information from shoulder muscle are important in clinical applications because the pains sometime come from various positions of shoulder during moving. In this study, a customized wearable T-shaped ultrasound transducer (128+128 elements) was proposed for shoulder dual-direction shear wave elastography (DDSWE) which provides the SWE for both longitudinal (SW along the muscle fiber) and transverse (SW cross the muscle fiber) directions dynamically. An optical tracking system was synchronized with ultrasound imaging system to capture shoulder movements in 3-D space with their corresponding ultrasound images. The performance of DDSWE and the accuracy of optical tracking were verified by phantom experiments. Human studies were carried out from volunteers as they are moving their arms. Experimental results shows that the bias and precision for the proposed DDSWE in elastic phantom were about 6% and 1.2 % for both directions, respectively. A high accuracy of optical tracking was observed using 3-D motor stage experimental setup. Human experiments shows that the shear wave velocities (SWVs) were increased with the angles of shoulder abduction, the average transverse and longitudinal SWVs were increase from 2.24 m/s to 3.35 m/s and 2.95 m/s to 5.95 m/s with abduction angle from 0° to 60°, respectively, which they are anisotropic-dependent. All the experimental results indicates that the proposed wearable ultrasound DDSWE can quantify the mechanical properties of shoulder muscles dynamically, thereby may help surgeons and physical therapists determine whether the intensity of rehabilitation shoulder be tuned down or escalated in the future.

Association of the Coronal Lateral Collateral Ligament Sign in ACL-Deficient Knees With Greater Anterior Tibial Translation and Femorotibial Rotation in Adults and Adolescents.

Background: The coronal lateral collateral ligament (LCL) sign (the entire LCL being seen in 1 coronal slice on a magnetic resonance imaging [MRI] scan), is a new secondary sign of anterior cruciate ligament (ACL) tear. Purpose: To (1) evaluate the coronal LCL sign in adults with ACL tears and (2) compare the magnitude of the MRI scan parameters between adolescent and adult ACL-deficient knees with positive coronal LCL signs. Study Design: Cross-sectional study; Level of evidence: 3. Methods: We retrospectively reviewed patients who underwent ACL reconstruction between February 1, 2013, and May 31, 2021, and divided them into adolescent (10-18 years) and adult (>18 years) groups. Tibial translation, femorotibial rotation, and presence of the coronal LCL sign were evaluated using MRI. The static femorotibial position parameters were also compared between positive and negative coronal LCL sign groups. Independent Student t tests were used to identify statistically significant differences for continuous variables, whereas the categorical variables were compared using the chi-square test. Results: A total of 65 adolescents and 300 adults with ACL tears were identified. The coronal LCL sign was present in a similar percentage of adolescents and adults with ACL tears (57% vs 58%; P = .873). The anterior tibial translation (ATT) in patients with positive coronal LCL signs (adolescents, 7.9 ± 3.4 mm; adults, 6.6 ± 3.5 mm) was significantly greater compared with those with negative signs (adolescents, 1.5 ± 2.6 mm, P < .001; adults, 2.3 ± 4.2 mm, P < .001). Femorotibial rotation was also statistically greater in positive coronal LCL sign groups (adolescents, 6.4°± 5.6°; adults, 7.0°± 5.0°) compared with negative sign groups (adolescents, 0.7°± 4.7°, P < .001; adults, 3.5°± 4.2°, P < .001). Conclusion: The occurrence of the coronal LCL sign on MRI scans was comparable between adolescents and adults with ACL-deficient knees. The presence of the LCL sign was associated with a greater ATT and femorotibial rotation in both adolescents and adults with ACL tears.

Biomechanical Comparison of Coracoclavicular Fixation Using Metallic Versus All-Suture Anchors.

Background: A coracoclavicular (CC) fixation technique using an all-suture anchor with the assistance of fluoroscopy can prevent iatrogenic anterior deltoid detachment from the clavicle; however, soft anchor pullout has been reported as a complication. Purpose: To compare the biomechanical properties of conventional metallic and all-suture anchors for CC suture fixation. Study Design: Controlled laboratory study. Methods: A total of 24 fresh-frozen cadaveric specimens were divided into 2 groups: metal anchor group (group M) and all-suture anchor group (group A). In group M, 5.0-mm metallic suture anchors were used for CC fixation, whereas 2.8-mm all-suture anchors were used in group A. The prepared specimens were mounted on a materials testing machine. After preconditioning at 0 to 20 N for 10 cycles, the specimens were subjected to cyclic loading from 20 to 70 N for 1000 cycles. Finally, all the specimens were loaded to failure. Cyclic elongation, linear stiffness, ultimate load, and failure modes were recorded, and the Mann-Whitney U test was used to compare nonparametric parameters between the 2 groups. Results: All of the specimens completed the cyclic loading test. The elongation after cyclic loading in group M (1.6 ± 0.6 mm) was significantly smaller compared with that in group A (2.5 ± 1.2 mm) (P = .02). No between-group differences were found in linear stiffness (42 ± 17 N/mm in group M and 41 ± 17 N/mm in group A). The ultimate failure load in group M (263 ± 66 N) was significantly greater than that in group A (177 ± 76 N) (P = .02). All specimens failed because of suture anchor pullout. Conclusion: The use of all-suture anchors in CC fixation resulted in significantly greater cyclic displacement and smaller ultimate failure load than that of metallic anchors. Clinical Relevance: Understanding the most biomechanically sound suture anchor may assist in lowering the risk of clinical failure in CC fixation and repair.

Predictors of in-hospital mortality in older patients undergoing distal femur fracture surgery: A case-control study.

INTRODUCTION: Geriatric fractures including distal femur and hip fractures are associated with high mortality rates. Currently, prognostic factors for in-hospital postoperative mortality are not identified. We aimed to evaluate overall in-hospital mortality and related potential risk factors in elderly patients who underwent distal femur fracture surgery. MATERIALS AND METHODS: A retrospective cohort study of patients older than 60 years, who underwent distal femur fracture surgery between January 01, 2003, and December 31, 2021, was conducted. A case-control study was conducted to compare two age-matched groups of elderly patients of equivalent ages at a 1:4 ratio. The in-hospital mortality rate was calculated and potential confounders were compared between groups. RESULTS: A total of 170 patients were enrolled; five died during hospital stay after undergoing surgery, yielding a 2.94% in-hospital mortality rate. Twenty patients who did not die were included in the control group. Patients' demographics were similar. The case-control comparison showed that the time from injury to surgery, preoperative hemoglobin level, estimated glomerular filtration rate (eGFR), and white blood cell count were significant factors correlated with in-hospital mortality. DISCUSSION: The overall in-hospital mortality rate was 2.94%. Significant risk factors for in-hospital mortality included a longer time from injury to surgery, lower preoperative hemoglobin level and eGFR, and higher preoperative white blood cell count. In conclusion, preoperative comprehensive geriatric assessment, including cognitive, nutritional, and frailty status, should also be considered in the elderly fracture care model.

Definition of irreparable rotator cuff tear: a scoping review of prospective surgical therapeutic trials to evaluate current practice.

BACKGROUND: The definition of irreparable rotator cuff tear (IRCT) is controversial. This scoping review provides definitions used to describe IRCT in the literature. This scoping review (1) identified criteria used in the definition of IRCT and (2) investigated the current state of those criteria in prospective surgical therapeutic trials. METHODS: This scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. PubMed, Scopus, and Web of Science were searched in March 2023. Studies were screened against predetermined inclusion and exclusion criteria. Criteria regarding clinical symptoms, preoperative images, and intraoperative findings were captured respectively. RESULTS: A total of 41 prospective studies were eligible for inclusion, and 35 studies (85.4%) defined IRCT. IRCT was defined on the basis of the following main criteria: preoperative image findings (28/35), intraoperative findings (24/35), and symptoms (16/35). With regard to preoperative images, IRCT was mainly defined on the basis of retraction of the tendon in the coronal plane (22/28), the severity of fatty degeneration (19/28), and ruptured tendon number or width of the defect in the sagittal plane (17/28). CONCLUSION: This scoping review highlights the lack of a standardized definition for IRCT in clinical practice, with common predictive criteria including a duration of over 6 months, retraction beyond 5 cm, Goutallier grade 3 fatty infiltration, and the rupture of two or more tendons. However, surgeons should apply more than one criterion when examining preoperative images and confirm reparability during surgery. A more objective manner of evaluating intraoperative reparability is necessary.

Deficits in neuromuscular control of increasing force in patients with chronic lateral epicondylitis.

Objective: This study investigated the neuromuscular control of increasing and releasing force in patients with chronic lateral epicondylitis (CLE). Methods: Fifteen patients with CLE (10 males, 5 females, 46.5 ± 6.3 years) and fifteen healthy participants (9 males, 6 females, 45.3 ± 2.5 years) participated in this study. In addition to power grip and maximal voluntary contraction (MVC) of wrist extension, force fluctuation dynamics and characteristics of inter-spike intervals (ISI) of motor units (MUs) with various recruitment thresholds in the extensor carpi radialis brevis (ECRB) and extensor carpi radialis longus (ECRL) during a designated force-tracking task with a trapezoidal target (0%-75%-0% MVC) were assessed. Results: Besides a smaller MVC of wrist extension, the patients exhibited significantly greater task errors (p = 0.007) and force fluctuations (p = 0.001) during force increment than the healthy counterparts. Nevertheless, no force variables significantly differed between groups during force release (p > 0.05). During force increment, the amplitudes of the motor unit action potential of the ECRB and ECRL muscles of the patients were smaller than those of the heathy counterparts (p < 0.001). The patient group also exhibited a higher percentage of motor units (MU) with lower recruitment threshold (<5% MVC) in the ECRL/ECRB muscles and a lower percentage of MU with higher recruitment threshold (>40% MVC) in the ECRB muscle, compared to the healthy group. During force increment, the patient group exhibited a higher rate of decrease in inter-spike intervals (ISIs) of motor units with lower recruitment thresholds (<10% MVC) in the ECRB and ECRL muscles, compared to the control group (p < 0.005). Conclusion: The patients with CLE exhibited more pronounced impairment in increasing force than in releasing force. This impairment in increasing force is attributed to deficits in tendon structure and degenerative changes in the larger motor units of the wrist extensors. To compensate for the neuromuscular deficits, the rate of progressive increase in discharge rate of the remaining smaller motor units (MUs) is enhanced to generate force. Significance: The deficits in neuromuscular control observed in CLE with degenerative changes cannot be fully explained by the experimental pain model, which predicts pain-related inhibition on low-threshold motor units.

Modified arthroscopic intra-articular transtendinous looped biceps tenodesis leads to satisfactory functional outcomes and less frequent Popeye deformity compared to biceps tenotomy.

PURPOSE: The present study aimed to propose a modified intra-articular transtendinous looped biceps tenodesis (mTLBT) using a suture anchor and to compare the functional outcomes and incidence of Popeye deformities between biceps tenotomy and mTLBT. METHODS: Medical records of patients who underwent either tenotomy or mTLBT for the long head of the biceps tendon (LHBT) lesion between January 2016 and April 2021 were retrospectively reviewed. The inclusion criteria were patients aged 40-70 years with LHBT pathologies, such as superior labrum anterior to posterior (SLAP) lesions > type II, LHBT pulley system rupture with bicipital instability, and intra-articular LHBT tear. The exclusion criteria were full-thickness supraspinatus tears, frozen shoulder, shoulder fracture, and postoperative traumatic events that affected the operated shoulder. All patients were followed up for at least 1 year. Popeye deformity, bicipital cramping pain, visual analog scale (VAS) pain score, and functional outcome scores (University of California at Los Angeles [UCLA] and American Shoulder and Elbow Surgeons [ASES] scores) were recorded. Fisher's exact test and Chi-square test were used for categorical variables, whereas the Mann-Whitney U test was used for nonparametric variables. RESULTS: The mTLBT and tenotomy groups included 15 and 40 patients, respectively. The incidence of Popeye deformity and biceps cramping pain in the tenotomy group (52.5% and 50%, respectively) was significantly higher than that in the mTLBT group (13.3% and 20%, respectively) (p = 0.009 and p = 0.045, respectively). The postoperative VAS, UCLA, and ASES scores were not significantly different between the two groups. One patient in the tenodesis group experienced metallic-anchor pullout. CONCLUSION: mTLBT is an arthroscopic intra-articular top of the groove tenodesis that can be performed completely in the intra-articular space and is especially suitable for patients with an intact or partially torn rotator cuff. This technique is reliable for treating biceps pathologies as it results in similar functional outcome scores, lesser biceps cramping pain, and less frequent Popeye deformity compared to biceps tenotomy. LEVEL OF EVIDENCE: III.

Association of Coracoacromial Ligament Degeneration With Rotator Cuff Tear Patterns and Retear Rate.

Background: Coracoacromial ligament (CAL) degeneration is thought to be a factor in external impingement in bursal-sided rotator cuff tears, but CAL release is associated with adverse effects. Purpose: To investigate the association between CAL degeneration and the patterns of massive rotator cuff tears using multiple modalities and to assess the effect of CAL degeneration on supraspinatus tendon retear rates. Study Design: Cohort study; Level of evidence, 2. Methods: The authors prospectively recruited 44 patients who had undergone arthroscopic rotator cuff repair without acromioplasty or CAL release. Preoperative radiographs and magnetic resonance imaging (MRI) scans were reviewed to determine acromial morphology and CAL thickness, respectively. Rotator cuff tears were categorized as isolated supraspinatus or massive (involvement of ≥2 tendons), with massive tears categorized using the Collin classification. Acromial degeneration was analyzed using the Copeland-Levy classification. The CAL was biopsied intraoperatively and histologically analyzed using the Bonar score. At 6-month follow-up, the integrity of the repaired supraspinatus tendon was analyzed on MRI using the Sugaya classification. Finally, the associations among CAL degeneration, rotator cuff tear pattern, and arthroscopic grading were investigated. Results: Patients with Collin type B rotator cuff tear had significantly higher CAL Bonar scores than those with Collin type A or isolated supraspinatus tears (10.0 vs 6.8 and 3.4; P = .03 and P < .001, respectively). Patients with a degenerative acromial undersurface of Copeland-Levy stage 2 or 3 had CALs with significantly higher Bonar scores than those with an intact acromial undersurface (8.4 and 8.2 vs 3.5; P = .034 and P = .027, respectively). The CAL Bonar scores of patients with different stages of the 6-month postoperative Sugaya classification were comparable (6.5, 7.2, 8.0, and 7.8 for stages 1, 2, 3, and 4, respectively; P = .751). Conclusion: CAL degeneration was more severe in anterosuperior-type massive rotator cuff tears. Interestingly, even without acromioplasty, the severity of CAL degeneration did not affect the retear rate of the supraspinatus tendon.

Surgical treatment of inferior pole fractures of the patella: a systematic review.

PURPOSE: This study aimed to comprehensively review the existing evidence concerning surgical treatment of inferior pole fractures of the patella and to report the outcomes and complications of different fixation techniques. METHOD: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches of PubMed, Scopus, and Web of Science were conducted in March 2023. Studies were screened against predecided inclusion and exclusion criteria. The extracted data included fracture characteristics, surgical techniques, and radiographic and functional outcomes. The Methodological Index for Non-Randomized Studies (MINORS) quality assessment tool was used to assess the eligible literature. The primary outcome was postoperative range of motion of different surgical methods, and the secondary outcomes were other clinical results and complications. RESULTS: A total of 42 studies satisfied all the inclusion criteria and were deemed suitable for review. Fourteen case-control studies and 28 case series were selected, for a total of 1382 patients with a mean age of 51.0 years (range = 11-90). The follow-up period ranged from 6 to 300 months. The surgical techniques were categorized based on the device used as follows: (1) rigid fixation device; (2) tensile fixation device; (3) mixed device; and (4) extra-patella device. CONCLUSION: Regarding the outcomes following surgical treatment of inferior pole fractures of the patella, the postoperative range of motion (ROM) of each technique ranged from 120° to 135°, with the exception of that involving the patellotibial wire which had poorer outcomes. The lowest functional score was also found in those using the patellotibial wire. Complications after surgery are rare, but approximately half of the patients required additional surgery for implant removal, particularly those whose initial surgery involved rigid fixation devices. It's worth noting that bony fragment excision is no longer recommended, and the combined use of multiple surgical devices is now more common.

Is implant choice associated with fixation strength for displaced radial neck fracture: a network meta-analysis of biomechanical studies.

The multitude of fixation options for radial neck fractures, such as pins, screws, biodegradable pins and screws, locking plates, and blade plates, has led to a lack of consensus on the optimal implant choice and associated biomechanical properties. This study aims to evaluate the biomechanical strength of various fixation constructs in axial, sagittal, and torsional loading directions. We included biomechanical studies comparing different interventions, such as cross/parallel screws, nonlocking plates with or without augmented screws, fixed angle devices (T or anatomic locking plates or blade plates), and cross pins. A systematic search of MEDLINE (Ovid), Embase, Scopus, and CINAHL EBSCO databases was conducted on September 26th, 2022. Data extraction was carried out by one author and verified by another. A network meta-analysis (NMA) was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Primary outcomes encompassed axial, bending, and torsional stiffness, while the secondary outcome was bending load to failure. Effect sizes were calculated for continuous outcomes, and relative treatment ranking was measured using the surface under the cumulative ranking curve (SUCRA). Our analysis encompassed eight studies, incorporating 172 specimens. The findings indicated that fixed angle constructs, specifically the anatomic locking plate, demonstrated superior axial stiffness (mean difference [MD]: 23.59 N/mm; 95% CI 8.12-39.06) in comparison to the cross screw. Additionally, the blade plate construct excelled in bending stiffness (MD: 32.37 N/mm; 95% CI - 47.37 to 112.11) relative to the cross screw construct, while the cross-screw construct proved to be the most robust in terms of bending load failure. The parallel screw construct performed optimally in torsional stiffness (MD: 139.39 Nm/degree; 95% CI 0.79-277.98) when compared to the cross screw construct. Lastly, the nonlocking plate, locking T plate, and cross-pin constructs were found to be inferior in most respects to alternative interventions. The NMA indicated that fixed angle devices (blade plate and anatomic locking plate) and screw fixations may exhibit enhanced biomechanical strength in axial and bending directions, whereas cross screws demonstrated reduced torsional stability in comparison to parallel screws. It is imperative for clinicians to consider the application of these findings in constraining forces across various directions during early range of motion exercises, taking into account the distinct biomechanical properties of the respective implants.

Biomechanical comparison of different suture anchors used in rotator cuff repair surgery-all-suture anchors are equivalent to other suture anchors: a systematic review and network meta-analysis.

PURPOSE: Suture anchors are commonly used to repair rotator cuff tendons in arthroscopy surgery, and several anchor materials have been created to maximize pull-out strength and minimize iatrogenic damage. We hypothesized that all-suture anchors have biomechanical properties equivalent to those of conventional anchors. Our purpose is to compare the biomechanical properties of different anchors used for rotator cuff repair. METHODS: The Embase, PubMed, Cochrane, and Scopus databases were searched for biomechanical studies on various suture anchors. The search keywords included rotator cuff tears and suture anchors, and two authors conducted study a selection, risk of bias assessment, and data extraction. The failure load, stiffness, and displacement were calculated using the mean differences with 95% confidence intervals (CIs). Failure modes were estimated using summary odds ratios with 95% CIs. The surface under the cumulative ranking curve was used for the relative ranking probabilities. A sensitivity analysis was performed by excluding studies using synthetic bones. RESULTS: The polyetheretherketone (PEEK) (p < 0.001) and all-suture anchors (p < 0.001) had higher failure loads than the biocomposite anchors, whereas no significant difference was observed in stiffness among the anchors. The all-suture (p = 0.006) and biocomposite anchors (p < 0.001) had displacements higher than the metal anchors. The relative ranking of the included anchors in failure loads and displacement changed in sensitivity analysis. The meta-analysis did not find significant differences, but the relative ranking probabilities suggested that all-suture anchor had a higher rate of anchor pull-out and a lower rate of eyelet or suture breakage. In contrast, the metal anchors were associated with a higher number of eyelet breakage episodes. CONCLUSIONS: All-suture anchors showed significantly higher failure loads than the biocomposite anchors and similar cyclic displacements to the biocomposite and PEEK anchors. There were no significant differences in stiffness between all-suture and conventional suture anchors. The relative ranking of biomechanical properties changed in sensitivity analysis, suggesting the potential effect of bone marrow density. LEVEL OF EVIDENCE: Level IV.

Modified Double-Pulley And Rip-Stop Suture Bridge Technique In Arthroscopic Rotator Cuff Repair.

Numerous techniques have been formulated for increasing the tendon-bone contact area and for providing a better healing environment for the tendon in cases of rotator cuff tear. An ideal rotator cuff repair maximizes the tendon-bone interface and provides the rotator cuff with sufficient biomechanical strength for it to withstand a high load. In this article, we propose a technique with the advantages of both the double-pulley and the rip-stop suture-bridge techniques, which increases the pressurized contact area along the medial row, achieves higher failure loads than non-rip-stop techniques, and reduces tendon cut-through.

Merged Lateral Row Modification of the Suture Bridge Technique for Simultaneous Supraspinatus and Subscapularis Repair.

Concomitate supraspinatus and subscapularis tear is not rare, and the suture bridge technique is one of the most effective methods for rotator cuff repair. However, some limitations exist in the use of such a technique for simultaneous supraspinatus and subscapularis repair. We introduce the technique of a merged lateral row for suture bridge rotator cuff repair, in which the lateral suture of the supraspinatus and subscapularis is placed in the greater tuberosity. We believe that this technique can reduce both the duration and cost of surgery and decrease soft-tissue damage. It can also allow the "comma tissue," to be simultaneously repaired.

Jigless Knotless Internal Brace Versus Other Minimal Invasive Achilles Tendon Repair Techniques in Biomechanical Testing Simulating the Progressive Rehabilitation Protocol.

The jigless knotless internal brace surgery (JKIB), an alternative method for minimal invasive surgery (MIS) repair of acute Achilles tendon rupture, has advantages of preventing sural-nerve injury in MIS and superficial wound infection in open surgery, as previous clinical research demonstrates. However, no comparative study on the biomechanical performance between JKIB and other MIS techniques has been reported until now. In this study, 50 fresh porcine Achilles tendons were used to compare the JKIB with open surgery (two-stranded Krachow suture) with other MIS techniques, including Percutaneus Achilles Repair System (PARS), Speedbridge (SB), and Achillon Achilles Tendon Suture System (ACH), using a biomechanical testing with cyclic loading at 1 Hz. This test was used to simulate a progressive rehabilitation protocol where 20 to 100 N was applied in the first 250 cycles, followed by 20 to 190 N in the second 250 cycles, and then 20 to 369 N in the third 250 cycles. The cyclic displacement after 10, 100 and 250 cycles were recorded. The survived cycles were defined as a sudden drop in measured load. In survived cycles, the JKIB group (552.3 ± 72.8) had significantly higher cycles than the open, PARS, and ACH groups (204.3 ± 33.3, 395.9 ± 96.0, and 397.1 ± 80.9, respectively, p < .01) as analyzed by post hoc analysis, but no significant difference as compared with the SB group (641.6 ± 48.7). In cyclic displacement after 250 cyclic loadings, the JKIB group (11.29 ± 1.29) showed no significant difference as compared with PARS, SB, and ACH groups (12.21 ± 1.18, 9.80 ± 0.80, and 11.57 ± 1.10 mm, respectively) and significant less displacement than the open group (14.50 ± 1.85, p < .01). These findings suggest that JKIB could be an option for acute Achilles tendon repair in the MIS fashion due to no larger cyclic elongation compared with other MIS techniques.

Extended skin cleaning on the shoulder with chlorhexidine reduces the cutaneous bacterial load but fails to decrease suture contamination in patients undergoing arthroscopy rotator cuff repair.

BACKGROUND: It remains unclear whether preoperative skin cleaning of the chin, neck, and chest with chlorhexidine soap can reduce suture contamination by Cutibacterium acnes in patients undergoing arthroscopic rotator cuff repair. METHODS: This study included patients who underwent primary arthroscopic rotator cuff repair. Exclusion criteria included age <18 years, previous shoulder surgery, history of shoulder infection, and allergy to chlorhexidine. Patients were randomized into 3 groups. Patients in the control group cleaned their skin with soap and water, as usual. Patients in the shoulder group cleaned their shoulders with chlorhexidine soap 3 days before surgery, whereas patients in the extended shoulder group additionally cleaned their chest, back, neck, and face with chlorhexidine soap. On the day of surgery, skin swab samples were obtained from the shoulder after surgical draping. After rotator cuff repair, sutures were cut from the anchor ends. Both traditional culture methods and polymerase chain reaction (PCR) were used. RESULTS: Ninety patients were enrolled (32 in the control group, 29 in the shoulder group, and 29 in the extended shoulder group) in the present study. The culture-positive rate from the posterior shoulder skin samples in the extended shoulder group (17.2%) was significantly lower than that in the control (40.6%) and shoulder (48.3%) groups (P = .036), whereas the culture-positive rates were not different among the 3 groups in other skin samples as well as the suture samples. The detection rates of C acnes in suture samples were 12.5%, 13.8%, and 17.2% in the control, shoulder, and extended shoulder groups, respectively (P = .603). CONCLUSION: Extensive skin cleaning of the shoulder region with chlorhexidine helps reduce the shoulder cutaneous bacterial load, but the detection of C acnes suture contamination in patients undergoing arthroscopic rotator cuff repair remained untouched regardless of the use of chlorhexidine soap in skin cleaning on the preoperative days.

A Study on the Structure and Biomedical Application Characteristics of Phosphate Coatings on ZKX500 Magnesium Alloys.

Magnesium-matrix implants can be detected by X-ray, making post-operative monitoring easier. Since the density and mechanical properties of Mg alloys are similar to those of human bones, the stress-shielding effect can be avoided, accelerating the recovery and regeneration of bone tissues. Additionally, Mg biodegradability shields patients from the infection risk and medical financial burden of needing another surgery. However, the major challenge for magnesium-matrix implants is the rapid degradation rate, which necessitates surface treatment. In this study, the ZKX500 Mg alloy was used, and a non-toxic and eco-friendly anodic oxidation method was adopted to improve corrosion resistance. The results indicate that the anodic coating mainly consisted of magnesium phosphate. After anodic oxidation, the specimen surface developed a coating and an ion-exchanged layer that could slow down the degradation and help maintain the mechanical properties. The results of the tensile and impact tests reveal that after being immersed in SBF for 28 days, the anodic oxidation-treated specimens maintained good strength, ductility, and toughness. Anodic coating provides an excellent surface for cell attachment and growth. In the animal experiment, the anodic oxidation-treated magnesium bone screw used had no adverse effect and could support the injured part for at least 3 months.

Young Children with a Bucket-Handle Tear to the Discoid Lateral Meniscus Successfully Treated Using Arthroscopic Saucerization and Repair: Two Case Reports.

Observations of a symptomatic discoid lateral meniscus in young children are infrequent. The objective of this report was to demonstrate the use of arthroscopic saucerization and repair for treating a bucket-handle tear of a lateral discoid meniscus in two young children. Two young children (a 28-month-old girl and a 5-year-old boy) presented with a bucket-handle tear of the complete type lateral discoid meniscus. Both patients received arthroscopic saucerization and repair. A full knee extension under a long leg cast was applied for one month after surgery. The two patients were able to achieve a full range of motion of their operated knees without limping or presenting an antalgic gait at the third month after surgery. Both patients and their parents felt satisfied with the treatment at the 2- and 3-year follow-ups, respectively. Our results demonstrated that arthroscopic saucerization and repair seems to be an effective treatment for bucket-handle tears of the lateral discoid meniscus in young children-even those younger than 3 years old. We reported the youngest case (a 28-month-old girl) in comparison with the findings from a literature review.