Evaluating effectiveness of cadaveric arthroscopic training for orthopaedic residents: A comparison of joints and training levels.

Purpose: This study aimed to evaluate the effects and interactions of training level and different joints on the outcomes of cadaveric arthroscopic training courses for orthopaedic residents. Methods: This prospective study enrolled 16 orthopaedic residents who voluntarily participated in a cadaveric training programme involving the shoulder, elbow, wrist, knee and ankle joints. Outcomes were quantitatively assessed using task-specific checklists and the Arthroscopic Surgery Skill Evaluation Tool. Two-way analysis of variance (ANOVA) was conducted to determine the significance of the interactions between joint and years of training. Results: Resident scores significantly increased after the dedicated lectures in all five joints (p = 0.003 for the shoulder module, p < 0.001 for the other joints). Two-way ANOVA revealed that the progress made after the dedicated lectures was significantly impacted by the joint (p = 0.006) and training level × joint interaction (p = 0.005) but not by the training level (p = 0.47). The simple effect of the joint was examined using Sidak's multiple comparison test. Among junior residents, the dedicated lectures resulted in more substantial progress in elbow and wrist arthroscopy when compared to shoulder arthroscopy (p = 0.020 and p = 0.043, respectively). Conclusions: The results suggest that, in cadaveric arthroscopic training courses for orthopaedic residents, training outcomes are primarily impacted by the specific joint being trained rather than the training level. Specifically, junior residents demonstrated greater improvement with training in procedures that are less commonly encountered during on-the-job training, such as elbow and wrist arthroscopy. Clinical Relevance: These findings suggest the need to prioritise wrist and elbow arthroscopic training for junior residents to optimise educational outcomes. Level of Evidence: Level III.

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 including 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 the ultrasound examination was performed under a static condition. Providing dynamic information from shoulder muscle is important in clinical applications because the pains sometimes come from various positions of the 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 an 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 by volunteers as they are moving their arms. The experimental results show 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 a 3-D motor stage experimental setup. Human experiments show that the shear wave velocities (SWVs) were increased with the angles of shoulder abduction, and the average transverse and longitudinal SWVs were increased from 2.24 to 3.35 m/s and 2.95 to 5.95 m/s with abduction angle from 0° to 60°, respectively, which they are anisotropic-dependent. All the experimental results indicate that the proposed wearable ultrasound DDSWE can quantify the mechanical properties of shoulder muscles dynamically, thereby helping surgeons and physical therapists determine whether the intensity of rehabilitation shoulder be tuned down or escalated in the future.

Associations between femoral 3D curvature and sagittal imbalance of spine.

Background: The sagittal imbalance (SI) of spine triggers compensatory mechanisms (CMs) of lower extremity (LE) to restore trunk balance. These CMs can cause long-period stress on the femur and may possibly alter the femoral morphology. This cross-sectional observational study aimed to answer the following questions: (a) Do SI subjects exhibit greater femoral bowing compared to subjects with sagittal balance? (b) Are there associations between femoral bowing and CMs of LE in SI subjects? Methods: Subjects who underwent biplanar full body radiographs with the EOS imaging system between January 2016 and September 2021 were recruited. Sagittal parameters included T1-pelvic angle (TPA), pelvic incidence (PI), pelvic tilt (PT), sacral slope, lumbar lordosis (LL), PI-LL, and PT/PI ratio. LE parameters were femoral obliquity angle (FOA), knee flexion angle (KA), and ankle dorsiflexion angle. Femoral bowing was quantified as 3D radius of femoral curvature (RFC). Associations between 3D RFC and the radiographic parameters were analyzed. Results: A total of 105 subjects were included, classified into balance group (TPA < 14°, n = 40), SI group (TPA ≥ 14° and KA <5°, n = 30), and SI with knee flexion group (TPA ≥ 14° and KA ≥ 5°, n = 35). 3D RFC was significantly lower in SI with knee flexion group compared to the other two groups (both p < 0.001). Stepwise linear regression showed that age, SI and knee flexion, femoral length (FL), FOA, and KA were independent predictors for 3D RFC. Conclusion: Greater femoral bowing is observed in subjects with SI and knee flexion compared to the balanced population. CM parameters, including KA and FOA, are associated with 3D RFC. Further longitudinal study is needed to investigate the cause-and-effect relationship between SI, CMs of LE, and femoral bowing.

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.

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.

Administration of N-Acetylcysteine to Regress the Fibrogenic and Proinflammatory Effects of Oxidative Stress in Hypertrophic Ligamentum Flavum Cells.

Ligamentum flavum hypertrophy (LFH) is a major cause of lumbar spinal stenosis (LSS). In hypertrophic ligamentum flavum (LF) cells, oxidative stress activates intracellular signaling and induces the expression of inflammatory and fibrotic markers. This study explored whether healthy and hypertrophic LF cells respond differently to oxidative stress, via examining the levels of phosphorylated p38 (p-p38), inducible nitric oxide synthase (iNOS), and α-smooth muscle actin (α-SMA). Furthermore, the efficacy of N-acetylcysteine (NAC), an antioxidant, in reversing the fibrogenic and proinflammatory effects of oxidative stress in hypertrophic LF cells was investigated by assessing the expression levels of p-p38, p-p65, iNOS, TGF-ß, α-SMA, vimentin, and collagen I under H2O2 treatment with or without NAC. Under oxidative stress, p-p38 increased significantly in both hypertrophic and healthy LF cells, and iNOS was elevated in only the hypertrophic LF cells. This revealed that oxidative stress negatively affected both hypertrophic and healthy LF cells, with the hypertrophic LF cells exhibiting more active inflammation than did the healthy cells. After H2O2 treatment, p-p38, p-p65, iNOS, TGF-ß, vimentin, and collagen I increased significantly, and NAC administration reversed the effects of oxidative stress. These results can form the basis of a novel therapeutic treatment for LFH using antioxidants.

Photoaffinity labeling of benzophenone-containing salicylanilide compounds to give an insight into the mechanism in disrupting peptidoglycan formation.

A series of salicylanilide compounds was previously identified as antibacterial agents that inhibit the peptidoglycan formation. To find the exact binding mode, we synthesized a benzophenone-containing salicylanilide compound (1) and used it as a photoaffinity probe to label Acinetobacter baumannii penicillin-binding protein (PBP1b). After incubation and photo-irradiation, the labeled protein was subjected to trypsin digestion, dialysis enrichment, LC-ESI-MS/MS analysis, and Mascot search to reveal an octadecapeptide sequence 364RQLRTEYQESDLTNQGLR381 that was labeled at E372. Our molecular docking experiments suggest a hydrophobic pocket surrounded by R367 and E372 is the binding site of salicylanilide 1. The pocket lies in between the transglycosylase and transpeptidase domains, thus binding of salicylanilide 1 can block the propagation pathway to disrupt the growth of peptidoglycan chain.

The characteristics and influence of iatrogenic fracture comminution following antegrade interlocking nailing for simple femoral shaft fractures, a retrospective cohort study.

AIM: The incidence and characteristics of iatrogenic comminution (IC) are unknown, and the influence of IC on fracture union is unclear. This study was aimed to investigate the (1) incidence and characteristics of IC and (2) the outcomes of IC following antegrade interlocking nailing of simple femoral shaft fractures. METHODS: We retrospectively collected data on patients who experienced simple femoral shaft fractures and underwent antegrade interlocking nailing between February 2009 and December 2016. The incidence and characteristics of IC were examined. According to the presence of IC, patients were divided into two groups: an IC group and a non-IC (NIC) group. Demographic information and nonunion rates were compared between the two groups. Potential risk factors for IC (age, gender, body mass index (BMI), nail fit ratio, reduction technique, and greater trochanter nail entry) were analyzed using univariate and multivariate logistic regression. The aforementioned variables, along with IC occurrence, were also assessed as potential risk factors for nonunion at 12 and 24 months after operation using multivariate logistic regression. RESULTS: Of the 211 total patients, IC occurred in 20.9% (n = 44) of patients. Most ICs were found at the level of the isthmus, and involved the medial cortex. Compared with the NIC group, higher nonunion rates were observed in the IC group at 12 months (31.8% vs. 12.5%, p = 0.002) and 24 months (18% vs. 6.5%, p = 0.017) after surgery. Age older than 35 years old was related with the occurrence of IC in univariate analysis. Multivariate analysis found no risk factor associated with IC. Open reduction technique, IC occurrence and higher BMI were identified as the risk factors of nonunion at 12 months and 24 months after surgery in multivariate analysis. CONCLUSION: IC is a non-rare complication in antegrade interlocking nailing of simple femoral shaft fractures and was associated with higher nonunion rate. Age older than 35 years old showed a trend toward increasing risk of iatrogenic fracture comminution. In multivariate analysis, open reduction technique, IC occurrence and higher BMI significantly correlated with fracture nonunion. LEVEL OF EVIDENCE: Level IV.

Biomechanical comparison between various screw fixation angles for Latarjet procedure: a cadaveric biomechanical study.

BACKGROUND: The Latarjet procedure is a reliable treatment for the management of anterior glenohumeral instability with glenoid bone loss. However, the biomechanical properties of different fixation angles between screw and glenoid surface (α angle) have rarely been studied. The aim of the study was to investigate and compare the fixation stability, failure load, and failure mechanism between different α angles for Latarjet procedures, which were performed on cadaver specimens. METHODS: Twenty-four shoulder specimens (8 in each of 3 groups) were dissected free of all soft tissue, and a 25% glenoid defect was created. The coracoid process was osteomized and fixed with 2 screws at 3 different α angles: 0° (group A), 15° (group B), and 30° (group C). Specimens were mounted to a testing apparatus, and cyclic loading (100 cycles at 1 Hz) was applied with a staircase protocol (50, 100, 150, and 200 N). Gross graft displacement and interface displacement were measured. The ultimate failure loads and failure mechanisms were recorded. RESULTS: There was no significant difference in gross displacement under any cyclic load between 3 groups. However, a significant larger interface displacement was noted in group C than in group A in 150-N cyclic loading (P = .017). Under failure strength testing, all 24 specimens failed because of screw cutout from the glenoid, and the ultimate failure load was similar among the three groups. CONCLUSION: Compared with the 0° α angle, the displacement after cyclic loading did not significantly increase when the α angle was increased to 15° but significantly increased at 30° for Latarjet procedures, which were performed on cadaver specimens. The results suggest that surgeons should apply the screws as parallel as possible to the glenoid surface when performing the Latarjet procedure. Although mild deviation may not reduce fixation stability, α angles greater than 30° should be avoided.

Association Between Medial Displacement of the Middle Glenohumeral Ligament and Subscapularis Tear Severity.

Background: The intraoperative invisible middle glenohumeral ligament (MGHL) test has been shown to be associated with a subscapularis tendon retraction. However, the preoperative location of the MGHL and its association with subscapularis tear severity has not been evaluated. Purpose: To determine (1) the interrater reliability for identification and position of the MGHL, (2) any association between the MGHL position and subscapularis tears, and (3) the cutoff point at which MGHL position can predict subscapularis tear severity. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The magnetic resonance imaging (MRI) scans and surgical records of 176 patients were retrospectively reviewed by 3 independent orthopaedists. MGHL's identification, level (its position on axial MRI), and medial retraction ratio (distance from the lesser tuberosity to the MGHL divided by the width of the glenoid) were documented, and the interobserver agreement of the 3 indices was assessed. We calculated the association between subscapularis tears and the MGHL level and medial retraction ratio. Receiver operating characteristic (ROC) curve analyses were conducted to establish the optimal threshold of the MGHL medial retraction ratio to predict subscapularis tear. Results: The MGHL was identified by at least 2 reviewers in 124 individuals (70.5%). The interobserver reliability was very good for MGHL identification (κ = 0.766), moderate for MGHL level (κ = 0.582), and excellent for MGHL medial retraction ratio (intraclass correlation coefficient = 0.848). A low, positive correlation between MGHL level and subscapularis tear severity was found (Somers d = 0.392, P < .001), as well as a significant association between the medial retraction ratio and Lafosse classification of subscapularis tear size (P < .001). A medial retraction ratio of ≥1.25 had a sensitivity of 0.70, a specificity of 0.83, and a positive likelihood ratio of 4.20, with excellent accuracy (area under the ROC curve = 0.820) to predict severe subscapularis tear. Conclusion: The MGHL was identified in 70.5% of shoulder MRIs. The location of the MGHL on preoperative MRI, as described by its level and the medial retraction ratio, was significantly associated with subscapularis tear severity, and a medial retraction ratio of ≥1.25 was predictive of a severe subscapularis tear.

Comparison of Biomechanical Failure Loads Between Tape-Type and Conventional Sutures in Internal Knotless Anchor-Based Constructs.

Background: Despite the increasing prevalence of tape-type sutures, whether internal knotless anchors can consistently affix tape-type sutures has not been thoroughly investigated. Purpose: To evaluate whether substituting tape-type sutures for conventional sutures influences the suture-holding strength of internal knotless anchors. Study Design: Controlled laboratory study. Level of evidence, 5. Methods: A total of 3 internal knotless anchors were tested: a spiral core clamping anchor (Footprint Ultra PK), a winged clamping anchor (PopLok), and a spooling anchor (ReelX STT). Four constructs were compared for each type of anchor, with the anchor double or quadruple loaded with tape-type sutures or conventional sutures. The testing protocol comprised preloading suture tension to 10 N; cyclic loading, in which tension increased in increments of 10 N from 10 to 90 N; and a load-to-failure stage set at a speed of 0.5 mm/s. The clinical failure load (CFL) was defined as suture slippage of ≥3 mm. Also, 1-way analysis of variance and power analysis were used to compare the CFLs of the constructs. Results: For the quadruple-loaded spiral core clamping anchors, a significant reduction in CFLs was seen with conventional sutures over tape-type sutures (138.10 ± 4.73 vs 80.00 ± 12.25 N, respectively; P < .001). This reduction was not observed under the double-loaded condition (conventional vs tape type: 76.00 ± 5.48 vs 80.00 ± 10.00 N, respectively). Substitution of the suture materials did not significantly reduce the CFLs for the winged clamping anchors (conventional vs tape type: 40.00 ± 10.00 vs 30.00 ± 7.07 N for double loaded, respectively, and 64.00 ± 13.41 vs 50.00 ± 10.00 N for quadruple loaded, respectively) or the spooling anchors (conventional vs tape type: 62.00 ± 19.23 vs 56.32 ± 20.20N for double loaded, respectively, and 72.00 ± 21.68 vs 84.00 ± 13.42 N for quadruple loaded, respectively). Conclusion: Substituting tape-type sutures for conventional sutures increased the CFLs of some internal knotless anchors. With specific suture-anchor combinations, quadruple-loaded conventional suture anchors had CFLs higher than those of double-loaded conventional suture anchors. Clinical Relevance: When multiple tape-type sutures are used in conjunction with a clamping anchor, clinicians should note a possible reduction in CFLs and resultant early suture slippage.

Knots Tied With High-Tensile Strength Tape Biomechanically Outperform Knots Tied With Round Suture.

BACKGROUND: Tape-type suture material is well-accepted in arthroscopy surgery. PURPOSE: To compare the knot security of a high-tensile strength round suture and high-tensile strength tape with commonly used arthroscopic knots. STUDY DESIGN: Controlled laboratory study. METHODS: We compared the performance of No. 2 braided nonabsorbable high-strength suture with that of 1.3-mm braided nonabsorbable high-strength tape. Five commonly used arthroscopic knots were investigated: the Roeder knot; the Western knot; the Samsung Medical Center (SMC) knot; the Tennessee knot; and a static surgeon's knot. Seven knots were tied for each combination of knots and suture types. Knots were tied on a 30-mm circumferential metal post, and the suture loops were transferred to a materials testing machine. After preloading to 5 N, all specimens were loaded to failure. The clinical failure load, defined as the maximal force to failure at 3 mm of crosshead displacement, yield load, and stiffness, were recorded. A 2-way analysis of variance was used to determine differences between the groups. RESULTS: Both suture type and knot type significantly affected the clinical failure load, yield load, and stiffness (P = .002). The high-strength tape resulted in a significantly greater clinical failure load than the high-strength suture in the case of the Roeder knot, Western knot, and SMC knot (P = .027, .005, and .016, respectively). When the high-strength round suture was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the Tennessee knot (P = .011, .003, and .035, respectively) and the static surgeon's knot (P < .001 for all). When the high-strength tape was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the static surgeon's knot (P = .001, .001, and .003, respectively). CONCLUSION: The results of this study indicated that arthroscopic knots tied using 1.3-mm high-strength tape biomechanically outperformed knots tied using a No. 2 high-strength suture. While the static surgeon's knot exhibited the best biomechanical properties, the Tennessee knot resulted in generally better biomechanical properties among the arthroscopic sliding knots. CLINICAL RELEVANCE: Elongation and loosening of tied knots possibly affects the clinical results of repaired constructs.

Role of open cerclage wiring in patients with comminuted fractures of the femoral shaft treated with intramedullary nails.

INTRODUCTION: The role of open cerclage wiring in comminuted femoral shaft fracture treatment with intramedullary nails remains unclear. Here, we analyzed the effect of open cerclage wiring and the risk factors for nonunion after interlocking nailing in comminuted femoral shaft fracture treatment. We hypothesized that open cerclage wiring can be applied in patients with severe comminuted femoral shaft fractures without affecting bone healing. PATIENTS AND METHODS: This retrospective cohort study used data from consecutive patients who underwent interlocking nail fixation of a comminuted femoral shaft fracture between January 1, 2009, and December 31, 2016. First, eligible patients were divided into the wire and no wire groups according to the surgical technique used, and their union rate was recorded. The patients were then divided into the union and nonunion groups, and their perioperative data were analyzed. RESULTS: In total, 71 comminuted femoral shaft fractures treated with interlocking nail fixation were included: 38 fractures (53.5%) augmented with the open wiring technique and 33 reduced with closed or mini-open techniques without wiring. The wire group demonstrated significant improvements in fracture reduction compared with the no wire group, whereas no significant difference was observed in the union rate between the wire and no wire groups (p = 0.180). Moreover, 46 (65%) of 71 fractures achieved union smoothly, and no significant difference was observed in any perioperative data between the union and nonunion groups. DISCUSSION: Augmentation with open cerclage wiring is indicated for comminuted femoral shaft fractures treated with intramedullary nails, even when the fragments are large or greatly displaced. Thus, open cerclage wiring can be used for fracture treatment without decreasing the union rate.

Assessment of sagittal spinopelvic parameters in a Taiwanese population with spondylolysis by the EOS imaging system: a retrospective radiological analysis.

BACKGROUND: The impact of sagittal spinopelvic alignment on spondylolysis is well established in Caucasian populations. However, prior studies suggest that people from different ethnological backgrounds showed divergence, and a few studies that focused on Asian populations reported conflicting results. The aim of this study is to use the EOS imaging system to evaluate the spinopelvic parameters of spondylolysis patients, and their relationship with spondylolisthesis, disc degeneration, and age in a Taiwanese population. METHODS: Radiographic sagittal spinopelvic parameters for 45 spondylolysis patients and 32 healthy people were evaluated, including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), and lumbar lordosis (LL). The spinopelvic parameters were compared between spondylolytic and control groups. These parameters were further compared between spondylolytic subjects with and without spondylolisthesis, with and without high-grade disc degeneration, and young (< 30 years old) and middle-aged. RESULTS: The PI and LL of the spondylolytic group (52.6°±12.0° and 41.3°±15.2°) were significantly higher than those of the healthy control group (47.16°±7.95° and 28.22°±10.65°). Further analysis of the spondylolytic patients revealed that those with high-grade disc degeneration were more prone to spondylolisthesis (92.3 %) compared to those without (50 %; p = 0.001). The middle-aged group had significantly higher rates of spondylolisthesis (80 %) and high-grade disc degeneration (52.4 %) compared with those for the young group (45 and 16.7 %, respectively; p = 0.017 and 0.047, respectively). No statistically significant difference in the sagittal spinopelvic parameters was found when spondylolytic patients were divided according to the occurrence of spondylolisthesis or high-grade disc degeneration. CONCLUSIONS: In a Taiwanese population, PI and LL were significantly larger in spondylolytic patients. Disc degeneration and age were associated with the occurrence of spondylolisthesis. Ethnological differences should thus be taken into account when making clinical decisions regarding spondylolysis in a Taiwanese population.

Fracture of the inferior pole of the patella: tension band wiring versus transosseous reattachment.

BACKGROUND: The optimal surgical technique for the fixation of inferior pole patellar fracture remains controversial. The aims of this study were (1) to compare clinical and radiological outcomes following fixation of inferior pole patellar fracture by using tension band wire (TBW) and transosseous reattachment (TOR) without excision of the bony fragment and (2) to determine the risk factors for postoperative radiological loss of reduction. METHODS: For this retrospective cohort study, consecutive patients with inferior pole patellar fracture between January 2010 and December 2017 were recruited. The patients were grouped according to their fixation method (TBW or TOR), and demographic data, clinical outcomes, and postoperative Insall-Salvati (IS) ratio were analyzed. Then, the patients were grouped according to radiological loss of reduction, the possible risk factors for loss of reduction were identified, and odds ratios were calculated. RESULT: This study included 55 patients with inferior pole patellar fracture; 30 patients were treated using TBW and 25 were treated using TOR. Clinical failure occurred in two patients in the TBW group (7%) and three in the TOR group (12%). The rate of radiological loss of reduction was significant higher in the TOR group, whereas removal of implants was significantly more common in the TBW group. Patella baja was noted immediately after surgery in the TOR group, but the IS ratios of the two groups were similar after 3 months. Fracture displacement of more than 30 mm was the only independent risk factor for postoperative radiological loss of reduction. CONCLUSION: For treating inferior pole patellar fracture, both TWB and TOR were effective and had a low clinical failure rate. In 60% of patients undergoing TBW fixation, however, additional surgery was required to remove the implants. Patella baja occurred immediately following TOR, but the patellar height was similar to that in the TBW group after 3 months. Surgeons should be aware of the high risk of postoperative radiological loss of reduction, especially when the fracture displacement is more than 30 mm.

Radiographic greater tuberosity spurs and narrow acromiohumeral intervals are associated with advanced retraction of the supraspinatus tendon in patients with symptomatic rotator cuff tears.

BACKGROUND: Degenerative signs on shoulder radiographs, including spur formation and narrow acromiohumeral intervals (AHIs), have been recognized as indicative of atrophic and fat-infiltrated rotator cuff muscles. Past studies have demonstrated that patients with poor quality muscles are prone to retraction of the supraspinatus tendon and failure to repair. However, the association between radiographic signs and tendon retraction has never been elucidated in previous literature. The present study aimed to investigate the association between the degenerative signs on shoulder radiographs and the severity of supraspinatus retraction. METHODS: Images of 67 individuals, who had undergone an arthroscopic rotator cuff repair, were retrospectively reviewed. The greater tuberosity (GT) morphology, subacromial spur, AHI, and acromial thickness were evaluated on the radiographs, whereas the retraction of the supraspinatus tendon was assessed via an MRI in accordance with the Patte classification. Simple regression analyses between the radiographic signs and Patte stages were performed, and factors reaching statistical significance were then included in the multiple ordinal logistic regression. Statistically significant predictors from the multiple regression analysis were constructed into combinations, for which the sensitivity and specificity were calculated. RESULTS: The GT morphology (P = .004), AHI (P = .083), subacromial spur (P = .008), and age (P = .004) were associated with supraspinatus retraction in the simple regression analyses. These four parameters were incorporated into the multiple ordinal logistic regression, where the GT spur (adjusted odds ratio 8.63, 95% confidence interval 2.16-34.53, P = .002) and AHI (AOR 0.79, 95% CI 0.63-0.98, P = .032) were demonstrated to be predictive of the Patte stage of supraspinatus retraction. The acromial spur implied a higher risk of severe retraction although this finding was not statistically significant (AOR 2.89, 95% CI 0.90-9.29, P = .075). The presence of concurrent GT spur and narrow AHI was highly specific (sensitivity 27.3% / specificity 91.1%) for advanced supraspinatus retraction. CONCLUSION: The presence of a radiographic GT spur, narrow AHI, and subacromial spur indicated advanced retraction of the supraspinatus tendon. When patients with clinical suspicion of rotator cuff tear present with combinations of these radiographic signs, a prompt MRI examination and a referral to a shoulder specialist are recommended.

Oxidative stress mediates age-related hypertrophy of ligamentum flavum by inducing inflammation, fibrosis, and apoptosis through activating Akt and MAPK pathways.

The role of oxidative stress in ligamentum flavum (LF) hypertrophy has not been elucidated. We hypothesize that oxidative stress induces inflammatory responses and the subsequent fibrotic processes in LF, via activation of the Akt and MAPK pathways. Specimens of LFs were collected during surgeries for lumbar disc herniation (LDH) or lumbar spinal stenosis (LSS). Part of the LF specimens underwent analyses for ROS, fibrotic markers, and inflammatory mediators, with the remainder minced for cell cultures. The cell cultures were treated with H2O2, after which the cells were lysed and analyzed via western blotting. The specimens of the LSS patients showed increased infiltration of inflammatory cells and were stained positively for MMP-3, MMP-9, vimentin, and fibronectin. The LF of the LSS patients had increased oxidative stress and inflammation compared to that of the LDH patients. In vitro analyses demonstrated that oxidative stress rapidly activated the Akt and MAPK pathways. Inflammatory mediators, iNOS and NF-κB, and fibrotic markers, including TGF-ß, ß-catenin, α-SMA and vimentin, were significantly upregulated after induction of oxidative stress. Oxidative stress activated the intrinsic apoptotic pathway. These findings revealed that oxidative stress is one of the etiological factors of LF hypertrophy, which might provide new insights into treatment approaches.

Does using high-tensile strength tape improve the fixation strength in tendon graft fixation with needleless suture wrapping techniques compared to a suture?

PURPOSE: To compare the biomechanical properties of a high-tensile strength suture and high-tensile strength tape in tendon graft fixation using two needleless suture wrapping techniques, the modified Prusik knot and modified rolling hitch. METHODS: Two needleless suture wrapping techniques, the modified rolling hitch (MR) and modified Prusik knot (MP), were utilized. Meanwhile, two kinds of suture materials, a No. 2 braided nonabsorbable high-strength suture (S) and a 1.3 mm high-tensile strength tape (T), were used. A total of 40 porcine tendons were used, which were randomly divided into four groups. Each group was assigned to one of the following groups: MRS, MRT, MPS, and MPT. Each specimen was pretensioned to 100 N for three cycles, cyclically loaded from 50 to 200 N for 200 cycles, and finally loaded to failure. RESULTS: The MRT group (34.1 ± 3.5%) had a significantly higher value compared with the MRS (29.7 ± 2.3%), MPS (27.1 ± 3.6%) and MPT (29.5 ± 4.0%) groups in term of elongation after cyclic loadings (p = 0.002). In terms of ultimate failure load, there were no significant differences in the MRS (401 ± 27 N), MRT (380 ± 27 N), MPS (398 ± 44 N) and MPT (406 ± 49 N) values (p = 0.539). All specimens failed due to suture breakage at the knots. CONCLUSION: Compared with the high-tensile strength suture, using the high-tensile strength tape lead to greater elongation after cyclic loading when the modified rolling hitch was used. No differences in terms of elongation after cyclic loading and load to failure were found between the high-tensile strength suture and tape using the modified Prusik knot.

The radiographic morphology of the greater tuberosity is associated with muscle degeneration in patients with symptomatic rotator cuff tears.

BACKGROUND: Atrophy and fatty infiltration of the rotator cuff muscles portend poor findings in terms of postoperative function and the probability of retears. We assumed that sclerosis and spurs of the greater tuberosity (GT) on radiographs are associated with this rotator cuff muscle degeneration. METHODS: We retrospectively reviewed the preoperative radiographs and magnetic resonance (MR) images of 91 shoulders (average age of patients, 59.7 years; age range, 36-79 years) arthroscopically repaired between 2012 and 2016. The radiographic morphology of the GT was defined as normal, sclerotic, or spurring. Atrophy and fatty infiltration of the rotator cuff muscles were evaluated using the occupation ratio and Goutallier classification, respectively, via the MR images. Diagnoses of rotator cuff tears were made during arthroscopic shoulder surgery. RESULTS: Significant associations between the radiographic GT morphology and the severity of both supraspinatus muscle atrophy (P = .002) and infraspinatus muscle atrophy (P = .047) were found. The mean occupation ratios of both the sclerotic GT group and the spurring GT group were significantly reduced compared with the mean occupation ratio of the normal GT group. Patients with GT spurs were found to be prone to severe supraspinatus fatty degeneration (P = .020). CONCLUSIONS: For patients with rotator cuff tears, the presence of GT spurs or sclerosis on radiographs predicted the occurrence of supraspinatus and infraspinatus muscle atrophy, as well as supraspinatus fatty infiltration, based on MR images. The clinical relevance is that MR imaging is suggested for patients with radiographic GT sclerosis or spurs to detect advanced rotator cuff lesions.