Application of ChatGPT for Orthopedic Surgeries and Patient Care.

Artificial intelligence (AI) has rapidly transformed various aspects of life, and the launch of the chatbot "ChatGPT" by OpenAI in November 2022 has garnered significant attention and user appreciation. ChatGPT utilizes natural language processing based on a "generative pre-trained transfer" (GPT) model, specifically the transformer architecture, to generate human-like responses to a wide range of questions and topics. Equipped with approximately 57 billion words and 175 billion parameters from online data, ChatGPT has potential applications in medicine and orthopedics. One of its key strengths is its personalized, easy-to-understand, and adaptive response, which allows it to learn continuously through user interaction. This article discusses how AI, especially ChatGPT, presents numerous opportunities in orthopedics, ranging from preoperative planning and surgical techniques to patient education and medical support. Although ChatGPT's user-friendly responses and adaptive capabilities are laudable, its limitations, including biased responses and ethical concerns, necessitate its cautious and responsible use. Surgeons and healthcare providers should leverage the strengths of the ChatGPT while recognizing its current limitations and verifying critical information through independent research and expert opinions. As AI technology continues to evolve, ChatGPT may become a valuable tool in orthopedic education and patient care, leading to improved outcomes and efficiency in healthcare delivery. The integration of AI into orthopedics offers substantial benefits but requires careful consideration and continuous improvement.

Identification of plasma and urinary inflammatory markers in severe knee osteoarthritis: Relations with synovial fluid markers.

BACKGROUND: This study aimed to identify plasma and urinary cytokines as potential biomarkers for severe knee osteoarthritis (OA). It also investigated associations between these cytokines and cartilage markers, as well as their connections with synovial fluid (SF) markers. METHODS: Samples of plasma, urine, and SF were obtained from patients (n = 40) undergoing total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) due to severe knee OA. Control samples of plasma and urine were collected from non-OA individuals (n = 15). We used a Luminex immunoassay for the simultaneous measurement of 19 cytokines, MMP-1, and MMP-3 levels. COMP, CTX-II, and hyaluronan (HA) levels were quantified using enzyme-linked immunosorbent assay (ELISA) kits. Receiver operating characteristic (ROC) curves were utilized to analyze each biomarker's performance. Correlations among these biomarkers were evaluated via Spearman's correlation. RESULTS: The levels of plasma (p)CCL11, pCXCL16, pIL-8, pIL-15, pHA, urinary (u)CCL2, uCCL11, uCCL19, uCXCL16, uIL-1ß, uIL-6, uIL-8, uIL-12p70, uIL-15, uIL-33, uMMP-3, uHA, uCTX-II, and uCOMP were significantly elevated in individuals with severe knee OA. Notably, specific correlations were observed between the plasma/urine biomarkers and SF biomarkers: pCCL11 with sfHA (r = 0.56) and sfTNF-α (r = 0.58), pIL-15 with sfCCL19 (r = 0.43) and sfCCL20 (r = 0.44), and uCCL19 with sfCCL11 (r = 0.45) and sfIL-33 (r = 0.51). Positive correlations were also observed between uCCL11 and its corresponding sfCCL11(r = 0.49), as well as between sfCCL11 and other cytokines, namely sfCCL4, sfCCL19, sfCCL20, sfIL-33, and sfTNF-α (r = 0.46-0.63). CONCLUSION: This study provides an extensive profile of systemic inflammatory mediators in plasma of knee OA and identified four inflammatory markers (pCCL11, pIL-15, uCCL11, and uCCL19) reflecting joint inflammation.

Hypoxia-Inducible Factor and Oxidative Stress in Tendon Degeneration: A Molecular Perspective.

Tendinopathy is a debilitating condition marked by degenerative changes in the tendons. Its complex pathophysiology involves intrinsic, extrinsic, and physiological factors. While its intrinsic and extrinsic factors have been extensively studied, the role of physiological factors, such as hypoxia and oxidative stress, remains largely unexplored. This review article delves into the contribution of hypoxia-associated genes and oxidative-stress-related factors to tendon degeneration, offering insights into potential therapeutic strategies. The unique aspect of this study lies in its pathway-based evidence, which sheds light on how these factors can be targeted to enhance overall tendon health.

Computational Analysis of miR-140 and miR-135 as Potential Targets to Develop Combinatorial Therapeutics for Degenerative Tendinopathy.

Background: Degenerative tendinopathy, a condition causing movement restriction due to high pain, highly impacts productivity and quality of life. The healing process is a complex phenomenon and involves a series of intra-cellular and inter-cellular processes. Proliferation and differentiation of the tenocyte is a major and essential process to heal degenerative tendinopathy. The recent development in microRNA (miRNA)-mediated reprogramming of the cellular function through specific pathways opened door for the development of new regenerative therapeutics. Based on information about gene expression and regulation of tendon injury and healing, we attempted to evaluate the combinatorial effect of selected miRNAs for better healing of degenerative tendinopathy. Methods: The present study was designed to evaluate the combinatorial effect of two miRNAs (has-miR-140 and has-miR-135) in the healing process of the tendon. Publicly available information/data were retrieved from appropriate platforms such as PubMed. Only molecular data, directly associated with tendinopathies, including genes/proteins and miRNAs, were used in this study. The miRNAs involved in tendinopathy were analyzed by a Bioinformatics tools (e.g., TargetScan, miRDB, and the RNA22v2). Interactive involvement of the miRNAs with key proteins involved in tendinopathy was predicted by the Insilco approach. Results: Based on information available in the public domain, tendon healing-associated miRNAs were predicted to explore their therapeutic potentials. Based on computation analysis, focusing on the potential regulatory effect on tendon healing, the miR-135 and miR-140 were selected for this study. These miRNAs were found as key players in tendon healing through Rho-associated coiled-coil containing protein kinase 1 (ROCK1), IGF-1/PI3K/Akt, PIN, and Wnt signaling pathways. It was also predicted that these miRNAs may reprogram the cells to induce proliferation and differentiation activity. Many miRNAs are likely to regulate genes important for the tendinopathy healing process, and the result of this study allows an approach for miRNA-mediated regeneration of the tenocyte for tendon healing. Based on computational analysis, the role of these miRNAs in different pathways was established, and the results provided insights into the combinatorial approach of miRNA-mediated cell reprogramming. Conclusions: In this study, the association between miRNAs and the disease was evaluated to correlate the tendinopathy genes and the relevant role of different miRNAs in their regulation. Through this study, it was established that the synergistic effect of more than one miRNA on directed reprogramming of the cell could be helpful in the regeneration of damaged tissue. It is anticipated that this study will be helpful for the design of miRNA cocktails for the orchestration of cellular reprogramming events.

Comparison of Extracorporeal Shock Wave Therapy and Ultrasound-Guided Shoulder Injection Therapy in Patients with Supraspinatus Tendinitis.

Background: The present study compared the clinical effect of extracorporeal shock wave therapy (ESWT) with that of ultrasound (US)-guided shoulder steroid injection therapy in patients with supraspinatus tendinitis. We hypothesized that the two treatments would show comparable results. Methods: The inclusion criteria were age over 20 years and diagnosis of supraspinatus tendinitis using US. Ultimately, 26 patients were assigned using blocked randomization: 13 in the US-guided shoulder injection group and 13 in the ESWT group. Treatment outcomes were evaluated using the pain visual analog scale (pVAS), the American Shoulder and Elbow Society (ASES) score, and the Constant score at baseline and at 1 and 3 months after the procedure. Results: At 1 month after the intervention, pVAS, ASES, and constant score were significantly higher in the US-guided shoulder injection group than in the ESWT group, but not at 3 months after the intervention. Both groups showed clinically significant treatment effects at 3 months after the intervention compared to baseline. No significance was shown using equivalence testing. Conclusions: US-guided shoulder injection therapy was not superior to ESWT therapy. Considering the complications and rebound phenomenon of steroid injections, interventions using ESWT may be a good alternative to treat patients with supraspinatus tendinitis.

Quantitative Magnetic Resonance Imaging measurement of muscle atrophy and fatty degeneration after arthroscopic rotator cuff repair.

BACKGROUND: It is unclear whether muscle atrophy (MA) and fatty degeneration (FD) have improved after arthroscopic rotator cuff repair (ARCR). Therefore, the objective of this study was to perform quantitative magnetic resonance imaging (MRI) measurement to evaluate MA and FD before and after surgery. Correlations of clinical outcome with changes in MA and FD were also analyzed. MATERIALS AND METHODS: From March 2013 to March 2017, 40 patients who had no re-tear up to 1 year after ARCR were enrolled. MA and FD of supraspinatus muscle before surgery, at 3 days after surgery, and at 1 year after surgery were measured quantitatively in conventional Y-view and supraspinatus origin-view (SOV). Measurement items were muscle area (mm2), occupation ratio (%), fatty infiltration (FI, %), and fatty degenerative area (mm2). Postoperative clinical outcomes were measured at 1 year after ARCR. Correlation between measure values and outcome scores were analyzed. RESULTS: Inter-measurement reliability was high (ICC = 0.933, Cronbach-α = 0.963). There was no significant change in MA in conventional Y-view at 1 year after surgery (Occupation ratio, p = 0.2770; MA, p = 0.3049) or in SOV (MA, p = 0.5953). FI and fat area measured with the conventional method on Y-view and showed significant differences (p = 0.0001). However, FI and fat area measured with the modified method on Y-view and SOV showed no significant difference (all p > 0.05). Postoperative clinical outcomes showed significant improvement compared to preoperative ones (p = 0.0001). However, there was no significant correlation between FD and FA (p = 0.653). CONCLUSION: Quantitative MRI measurement was shown to be a reliable and valid method. MA and FD do not improve after ARCR considering postoperative anatomical changes of supraspinatus at 1-year follow-up. FD of the supraspinatus in conventional Y-view, but not in SOV, showed a significant change at 1 year postoperatively. MA showed no significant improvement. There was no correlation between improvement in clinical scores and changes in FD and MA.

Clinical and Anatomical Outcomes of Arthroscopic Repair of Large Rotator Cuff Tears with Allograft Patch Augmentation: A Prospective, Single-Blinded, Randomized Controlled Trial with a Long-term Follow-up.

Background: Arthroscopic rotator cuff repair using human dermal matrix allograft augmentation has been widely used. We assessed the effect of acellular human dermal matrix augmentation after arthroscopic repair of large rotator cuff tears through a prospective, single-blinded, randomized controlled trial with a long-term follow-up. Methods: Sixty patients with large-sized rotator cuff tears were randomly assigned to two groups. Patients in the control group underwent arthroscopic rotator cuff repair. Allograft patch augmentation was additionally performed in the allograft group. All patients were subdivided into a complete coverage (CC) group or an incomplete coverage (IC) group according to footprint coverage after cuff repair. Constant and American Shoulder and Elbow Surgeons (ASES) scores were assessed preoperatively and at final follow-up. Magnetic resonance imaging was also performed at the same time to evaluate the anatomical results. Results: Forty-three patients were followed up for an average of 5.7 years. Clinical scores (Constant and ASES) increased significantly at the last follow-up in both groups. The increase in ASES score in the allograft group was statistically significantly greater than that in the control group. The degree of Constant score improvement did not differ significantly between the two groups. The retear rate was 9.1% in the allograft group, which was significantly lower than that in the control group (38.1%). In the control group, the CC subgroup had a statistically significantly lower retear rate (16.7%) than did the IC subgroup. There were no retear cases in the CC subgroup of the allograft group. Conclusions: Long-term follow-up of arthroscopic repair of large rotator cuff tears with allograft patch augmentation showed better clinical and anatomical results. Footprint coverage after rotator cuff repair was an important factor affecting the retear rate. If the footprint was not completely covered after rotator cuff repair, allograft patch augmentation may reduce the retear rate.

Clinical and Radiologic Outcomes of Small Glenoid Baseplate in Reverse Total Shoulder Arthroplasty: A Prospective Multicenter Study.

BACKGROUND: The purpose of this study was to evaluate the clinical and radiologic outcomes of reverse total shoulder arthroplasty (RTSA) using a small glenoid baseplate in patients with a small glenoid and to analyze the contributing factors to scapular notching. METHODS: A total of 71 RTSAs performed using a 25-mm baseplate were evaluated at a mean of 37.0 ± 3.3 months. Shoulder function was evaluated using American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS) for pain, Single Assessment Numeric Evaluation (SANE) for satisfaction, and active range of motion. Scapular neck angle (SNA), prosthesis-scapular neck angle (PSNA), peg glenoid rim distance (PGRD), and sphere bone overhang distance (SBOD) were measured to assess the effects on scapular notching. RESULTS: Shoulder function (ASES: 39.4 ± 13.8 preoperative vs. 76.2 ± 9.5 at last follow-up, p < 0.001), VAS for pain (6.1 ± 1.8 vs. 1.7 ± 1.4, p < 0.001), SANE for satisfaction (7.0 ± 11.8 vs. 83.4 ± 15.3, p < 0.001), and active forward flexion (115.6° ± 40.1° vs. 141.6° ± 17.2°, p < 0.001) were significantly improved. The mean diameter of the inferior glenoid circle was 26.0 ± 3.0 mm and the mean glenoid vault depth was 24.0 ± 4.5 mm. Scapular notching was found in 13 patients (18.3%) and acromial fracture in 2 patients (2.8%). There were no significant differences in preoperative SNA and PSNA at postoperative 3 years between patients with and without scapular notching (101.6° ± 10.5° and 110.8° ± 14.9° vs. 97.3° ± 13.3° and 104.9° ± 12.4°; p = 0.274 and p = 0.142, respectively). PGRD and SBOD were significantly different between patients with scapular notching and without scapular notching (24.8 ± 1.6 mm and 2.6 ± 0.5 mm vs. 21.9 ± 1.9 mm and 5.8 ± 1.9 mm; p < 0.001 and p < 0.001, respectively). CONCLUSIONS: RTSA using a 25-mm baseplate in a Korean population who had relatively small glenoids demonstrated low complication rates and significantly improved clinical outcomes. Scapular notching can be prevented by proper positioning of the baseplate and glenosphere overhang using size-matched glenoid baseplates.

Proteomic Classification and Identification of Proteins Related to Tissue Healing of Platelet-Rich Plasma.

BACKGROUND: Platelet-rich plasma (PRP) is a plasma component of autologous blood containing a high concentration of platelets. PRP is used to promote healing of damaged tissues. However, there are not many studies on the composition and expression patterns of active proteins in PRP. The purpose of this study was to identify unknown factors that contribute to tissue healing by proteomic analysis of proteins in PRP. METHODS: Three men in their 30s with no basal disease participated in this study. All identified proteins were classified for tissue healing-related functions on the basis of the gene ontology analysis of adhesion molecule with Ig-like domain 2 (AmiGO2). PRP was prepared by using the ACP kit and GPS III kit. RESULTS: We identified a total of 125 proteins related to wound healing, along with three proteins for angiogenesis involved in wound healing, two proteins for fibroblast migration, four proteins for collagen biosynthesis process, two proteins for glycosaminoglycan biosynthesis process, and 13 proteins for glycosaminoglycan binding. So, in addition to the growth factors that have been already known to be involved in tissue healing, 25 new proteins were identified. CONCLUSIONS: We identified the unknown proteins associated with tissue healing in PRP. Our findings may serve as a foundation for the establishment of basic medical evidence for PRP applications.

Prospective Clinical Research of the Efficacy of Platelet-rich Plasma in the Outpatient-based Treatment of Rotator Cuff Tendinopathy.

BACKGROUND: The purpose of this study is to compare the clinical outcomes of the control group and platelet-rich plasma (PRP) group among the patients who failed to respond to conservative treatment as outpatient-based therapy for rotator cuff tendinopathy, and to compare the clinical results of leukocyte-poor (LP) PRP and leukocyte-rich (LR) PRP. METHODS: Inclusion criteria are (1) over 18-year-old, (2) patients with rotator cuff tendinopathy, no rotator cuff tear by radiologic diagnosis (ultrasonography or magnetic resonance imaging) within the last 3 months, and (3) not effective to conservative treatment for more than 1 month. Of the final 60 subjects, 33 patients in the exercise treatment group and 27 patients in the PRP injection group (LP-PRP, 13; LR-PRP, 14) were included. Clinical evaluation was carried out by assessing the outcomes of treatment using the Numeric Rating Scale pain score, the American Shoulder and Elbow Society (ASES) score, and the Constant score at baseline and at 3 and 6 months after the procedure. RESULTS: There was a statistically significant difference in ΔASES3months (ASES3months-ASESfirst) score between the control and PRP groups (p=0.006). However, there was no statistical significance between LP-PRP and LR-PRP groups (p>0.05). CONCLUSIONS: This study showed that PRP injection was more effective than exercise therapy for the first 3 months. However, there was no difference between the LP-PRP group and the LR-PRP group. Regardless of the type of PRP, clinical application of PRP injection in patients with rotator cuff tendinopathy seems to be effective in early treatment.

Leukocyte-Poor Platelet-Rich Plasma-Derived Growth Factors Enhance Human Fibroblast Proliferation In Vitro.

BACKGROUND: Leukocyte-poor platelet-rich plasma (LP-PRP) from peripheral blood is currently used as a concentrated source of growth factors to stimulate repair at sites of soft tissue injury. Fibroblasts are primary mediators of wound healing. Thus, we aimed to assess the positive effect of LP-PRP on human fibroblast proliferation in vitro. METHODS: LP-PRP was prepared from 49 donors. The fibroblasts were seeded, and at 24 hours after seeding, 1 × 107/10 µL LP-PRP was added once to each well. The cells were harvested 10 times during study period at our planned points, and we examined cell proliferation using the water-soluble tetrazolium salt-1 assay. We collected the supernatants and measured the amount of growth factors such as platelet-derived growth factor (PDGF)-AB/BB, insulin-like growth factor-1 (IGF-1), transforming growth factor-ß1 (TGF-ß1), and vascular endothelial growth factor (VEGF), which are known to be involved in wound healing processes, by multiplex assay. RESULTS: Human fibroblasts treated with LP-PRP showed a significant increase in proliferation when compared to untreated controls (p < 0.001 at days 4, 6, and 8). Multiplex cytokine assays revealed various secretion patterns. PDGF-AB/BB appeared at early time points and peaked before fibroblast proliferation. IGF-1 and TGF-ß1 secretion gradually increased and peaked on days 4 and 6 post-treatment. The early VEGF concentration was lower than the concentration of other growth factors but increased along with cell proliferation. CONCLUSIONS: Platelets in LP-PRP release growth factors such as PDGF, IGF-1, TGF-ß1 and VEGF, and these growth factors have a promoting effect for human fibroblast proliferation, one of the important mediators of wound healing. These results suggest that growth factors derived from LP-PRP enhance the proliferation of human fibroblast.

Can a Single Sagittal Magnetic Resonance Imaging Slice Represent Whole Fatty Infiltration in Chronic Rotator Cuff Tears at the Supraspinatus?

BACKGROUND: This study aimed to investigate whether fatty infiltration (FI) measured on a single sagittal magnetic resonance imaging (MRI) slice can represent FI of the whole supraspinatus muscle. METHODS: This study retrospectively reviewed the MRIs of 106 patients (age 50-79 years) divided into three rotator cuff tear-size groups: medium, large, and massive. Fat mass and muscle mass on all T1-weighted sagittal MRI scans (FA and MA) were measured. Of the total MRI scans, the Y-view was defined as the most lateral image of the junction of the scapular spine with the scapular body on the oblique sagittal T1-weighted image. Fat mass and muscle mass seen on this Y-view single slice were recorded as F1 and M1, respectively. Fat mass and muscle mass were also assessed on MRI scans lateral and medial to the Y-view. The means of fat mass and muscle mass on these three slices were recorded as F3 and M3, respectively. Average FI ratios (fat mass/muscle mass) of the three assessment methods (F1/M1, FA/MA, and F3/M3) were compared. Intraclass correlation coefficients (ICCs) were calculated for inter- and intraobserver reliability. RESULTS: ICCs showed higher reliability (> 0.8) for all measurements. F1/M1 values were not statistically different from FA/MA and F3/M3 values (p > 0.05), except in males with medium and large tears. F3/M3 and FA/MA were not statistically different. The difference between F1/M1 and FA/MA did not exceed 2%. CONCLUSIONS: A single sagittal MRI slice can represent the whole FI in chronic rotator cuff tears, except in some patient groups. We recommend measurement of FI using a single sagittal MRI slice, given the effort required for repeated measurements.

Enhanced Tendon-to-Bone Healing of Chronic Rotator Cuff Tears by Bone Marrow Aspirate Concentrate in a Rabbit Model.

BACKGROUND: To evaluate the influence of bone marrow aspirate concentrate (BMAC) on tendon-to-bone healing in a rabbit rotator cuff model and to characterize the composition of growth factors in BMAC. METHODS: In this in vivo study, 40 rabbits were allocated into five groups: control (C), repair + saline (RS), repair + platelet-rich plasma (PRP; RP), repair + BMAC (RB) and repair + PRP + BMAC (RPB). A tear model was created by supraspinatus tendon transection at the footprint. Six weeks after transection, the torn tendon was repaired along with BMAC or PRP administration. Six weeks after repair, shoulder samples were harvested for biomechanical and histological testing. Ten rabbits were used for processing PRP and BMAC, followed by analysis of blood cell composition and the levels of growth factors in vitro. RESULTS: The ultimate load-to-failure was significantly higher in RPB group compared to RS group (p = 0.025). BMAC-treated groups showed higher values of biomechanical properties than RS group. The histology of BMAC-treated samples showed better collagen fiber continuity and orientation than RS group. BMAC contained significantly higher levels of the several growth factors than PRP. CONCLUSIONS: Locally administered BMAC enhanced tendon-to-bone healing and has potential for clinical applications.

Involvement of synovial matrix degradation and angiogenesis in oxidative stress-exposed degenerative rotator cuff tears with osteoarthritis.

BACKGROUND: Shoulder osteoarthritis is a gradual wearing of the articular cartilage concomitant with degenerative rotator cuff tears (RCTs). This pathologic disorder is related to inflammation, oxidative stress, and angiogenesis. Degenerative alterations may prompt production of cytokines and angiogenesis-related proteins, evoking rotator cuff diseases. This study tested the hypothesis that oxidative stress-responsive mediators can influence joint inflammation of patients with RCT. METHODS: Twelve healthy RCT patients not suffering shoulder osteoarthritis were categorized as the control group, and 24 patients were allocated to 2 RCT groups (RCTP1 and RCTP2), according to severity of RCT and glenohumeral arthritis. Cytokines, growth factors, and angiogenic biomarkers in synovial fluids, blood, platelet-rich plasma (PRP), and tendon tissues were analyzed with enzyme-linked immunosorbent assay, immunoblotting, and collagen zymography. RESULTS: Induction of interleukin 8, tumor necrosis factor α, and interleukin 1ß was considerably elevated in synovial fluids of RCTP groups (P = .0398, P = .0428, P = .0828, respectively). The joint inflammation highly enhanced insulin-like growth factor 1 and transforming growth factor ß1 (TGF-ß1) in the synovial fluids and serum. Angiogenesis-related angiopoietin (Ang) 1 and 2, Tie-2, and hypoxia-inducible factor 1α were upregulated in reactive oxygen species-exposed RCTP synovium (P < .05). The production of matrix metalloproteinase 1 markedly increased in synovial fluids of the RCTP group (P = .043), whereas tissue collagen type I expression diminished with reduction of connective tissue growth factor expression (P = .032). Although the secretion of platelet-derived growth factor AB and vascular endothelial growth factor was marginal in the circulation (P = .714, P = .335), platelet-derived growth factor AB, TGF-ß1, Ang-1, and matrix metalloproteinase 1 were enriched in PRP of the RCTP group (P < .001, P = .002, P = .0389, respectively). CONCLUSIONS: Synovial matrix degradation and oxidative stress-triggered angiogenesis may be involved in inducing RCT with joint inflammation. TGF-ß1, Ang-1, and Ang-2 are the major components to repair RCT and to alleviate joint inflammation in PRP therapy.

Functional and Radiographic Outcomes After Arthroscopic Transosseous Suture Repair of Medium Sized Rotator Cuff Tears.

PURPOSE: To evaluate the functional and anatomical outcomes after arthroscopic transosseous suture (TOS) repair of 2 to 4 cm sized rotator cuff tears and to identify preoperative factors influencing repair failure. METHODS: From May 2013 to August 2014, patients with symptomatic 2 to 4 cm full-thickness tears underwent arthroscopic TOS repair, and those who could be followed up for a minimum of 2 years were included in this retrospective study. Functional and anatomical outcomes were analyzed up to 2 years postoperatively. Factors affecting cuff repair failure were evaluated, using both univariate and multivariate analyses. RESULTS: Twenty-seven patients were included. On preoperative magnetic resonance imaging data, the mean anteroposterior dimension tear size was 27.0 ± 3.3 mm and mean retraction was 30.7 ± 3.1 mm. Anatomic failure (Sugaya III, IV, and V) rate was 33% with arthroscopic TOS repair; however, significant improvements were found regardless of cuff healing. Mean American Shoulder and Elbow Surgeons score (range, 0-100) improved from 48.8 ± 16.6 preoperatively to 80.1 ± 11.1 postoperatively (P < .001), mean Constant score (range, 0-100) improved from 54.5 ± 11.8 to 73.7 ± 8.5 (P < .001), and mean pain visual analog scale score (range, 0-10) improved from 3.9 ± 1.7 to 2.0 ± 1.1 (P < .001). These changes reached each minimal clinically important difference previously reported. Greater tear size in anteroposterior dimension (P = .034), decreased acromiohumeral distance (P = .022), and higher fatty infiltration of supraspinatus (P = .011) were independent preoperative factors associated with repair failure. Twelve patients (44%) experienced intraoperative bone laceration. CONCLUSIONS: Arthroscopic TOS repair was a reliable technique for patients with 2 to 4 cm size rotator cuff tear. Preoperative factors associated with cuff repair failure were greater tear size in anteroposterior dimension, decreased acromiohumeral distance, and higher fatty infiltration of supraspinatus. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Which Is Better for Arthroscopic Tenodesis of the Long Head of the Biceps: Soft Tissue or Bony Interference Fixation?

PURPOSE: To compare the outcome between arthroscopic soft tissue tenodesis (STT) at the rotator interval and bony interference fixation tenodesis (BIFT) at the distal bicipital groove for the long head of the biceps (LHB). METHODS: Twenty-five shoulders that underwent arthroscopic STT of the LHB were compared with 28 shoulders that underwent arthroscopic BIFT using a 5.5-mm Bio-Tenodesis screw (Arthrex, Naples, FL). American Shoulder and Elbow Surgeons scores, Constant score, and elbow flexion strength index (EFSI) were checked preoperatively, postoperative 1 year and 2 years. Ultrasound imaging evaluation took place at 1 year and 2 years postoperatively as well. RESULTS: The overall functional outcomes improved after surgery in both groups. The BIFT group showed a significant increase in EFSI (preop: 0.54, postoperative 2 years: 0.94) compared with that of the STT group (preop: 0.52, postoperative 2 years: 0.74) at postoperative 2 years (P = .006). However, no significant difference was seen in the increase of American Shoulder and Elbow Surgeons scores and Constant scores between the two groups. At postoperative 2 years, ultrasound showed seven empty grooves in the STT group, but only two empty grooves in the BIFT group (P = .046). CONCLUSIONS: Arthroscopic BIFT for the LHB showed better improvement in EFSI than arthroscopic STT. In addition, the STT group showed a higher failure rate than the BIFT group. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Dynamic function of coracoclavicular ligament at different shoulder abduction angles: a study using a 3-dimensional finite element model.

PURPOSE: The aim of this study was to determine the acromioclavicular (AC) motion and change in length and tension of the coracoclavicular ligament during different positions of shoulder abduction using a 3-dimensional finite element model based on computed tomography images from normal human shoulders. METHODS: The right shoulders of 10 living subjects were scanned with a high-resolution computed tomography scanner at 0°, 60°, 120°, and 180° of shoulder abduction. Several modeling programs were used to simulate AC motion. Finite element models of the conoid and trapezoid ligaments were constructed based on each footprint. The tension and length changes of each ligament during shoulder abduction were assessed. RESULTS: The distal clavicle exhibited internal rotation with respect to the medial acromion at 0°, 60°, 120°, and full abduction (3.2° ± 2.9°, 23.2° ± 10.8°, 20.6° ± 3.7°, and 37.1° ± 3.4°, respectively). With horizontal motion, the clavicle translated posteriorly at 60° of abduction (4.4 ± 3.4 mm) and then translated anteriorly at 120° and full abduction (0.4 ± 1.6 mm and 1.9 ± 0.4 mm, respectively). The lengths of the conoid ligament gradually increased at 60° to 180° of shoulder abduction whereas those of the trapezoid ligament remained relatively consistent at 60° to 120° of abduction compared with 0° of abduction. CONCLUSIONS: The distal clavicle had a wide range of motion during shoulder abduction, which did not support the concept of synchronous motion with the scapula. The conoid and trapezoid ligaments functioned reciprocally during shoulder abduction. With increasing shoulder abduction, the length of the conoid ligament gradually increased; meanwhile, the trapezoid ligament was relatively consistent and then lax at full abduction. In particular, the conoid ligament may act as a key restraint to prevent excessive retraction of the scapula during shoulder abduction. CLINICAL RELEVANCE: The data in this study have the potential to suggest that conoid and trapezoid ligaments should be reconstructed separately, and rigid AC fixation in patients with AC separation is not recommended based on the findings of this study.

Targeting inflammatory kinase as an adjuvant treatment for osteosarcomas.

BACKGROUND: A subset of patients with aggressive osteosarcomas responds poorly to conventional cytotoxic chemotherapy. Recent evidence from studies involving the liver, skin, stomach, and colon suggests that carcinogenesis is associated with inflammation. Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2 (ERK1/2) has diverse roles in cancer and inflammation. The hypothesis of the present study is that targeted ERK1/2 inhibition will demonstrate anti-cancer effects in osteosarcoma both in vitro and in vivo. METHODS: The therapeutic effect of PD98059, a MAPK/ERK pathway inhibitor, was examined with respect to cell death, survival, and anti-apoptotic protein expression by means of flow cytometry and immunoblotting in vitro. Additionally, we transplanted green fluorescent protein and luciferase-tagged 143B osteosarcoma cells into the proximal part of the tibia of nude mice. Mice were randomly assigned to treatment with doxorubicin, PD98059, or both. Vehicle-treated mice served as controls. Treatment outcome was assessed by measuring bioluminescence and by monitoring survival. RESULTS: In vitro, ERK1/2 blockage increased the expression of pro-apoptotic proteins and increased cell death in 143B osteosarcoma cells. Doxorubicin treatment increased the expression of Bcl-2, an anti-apoptotic protein, but this upregulation was blocked by combined treatment with PD98059, suggesting a role for ERK1/2 in conferring drug resistance. In osteosarcoma-bearing mice, targeting ERK1/2 with PD98059 resulted in prolonged survival in comparison with vehicle-treated control mice (median survival time, sixty-seven days compared with seventy-four days; p = 0.0272; survival ratio = 0.9122; 95% confidence interval = 0.4354 to 1.389). Standalone doxorubicin treatment yielded similar animal morbidity (median survival time, sixty-seven days compared with seventy-six days; p = 0.0170; survival ratio = 0.8882; 95% confidence interval = 0.4181 to 1.358). Combined PD98059 and doxorubicin treatment further prolonged survival (median survival time, sixty-seven days compared with eighty-two days; p = 0.0023; survival ratio = 0.8232; 95% confidence interval = 0.3606 to 1.286). CONCLUSIONS: Inhibiting ERK1/2 signaling resulted in osteosarcoma cell death by upregulating pro-apoptotic genes and inhibiting the Bcl-2-mediated resistance to doxorubicin. In osteosarcoma-bearing mice, ERK1/2 targeting alone or in combination with doxorubicin prolonged survival as compared with untreated mice.

Trans-tendon arthroscopic repair for partial-thickness articular side tears of the rotator cuff.

PURPOSE: The purpose of this study was to describe a modified trans-tendon method of repairing partial articular surface lesions, which restored the footprint of the rotator cuff anatomically. METHODS: The 24 consecutive patients with modified trans-tendon method which allowed a wider pressurized contact area by use of additional knotless anchor were included in this study. All patients were evaluated with ASES score and visual analog scale (VAS) preoperatively, postoperative 3 and 12 months. The strength was measured using Isobex digital strength analyzer preoperatively and postoperative 12 months. RESULTS: The ASES scores significantly improved from preoperative 38 ± 13 to 63 ± 5 at 3 months, and 89 ± 5 at 12 months postoperatively. The VAS scores also significantly improved from preoperative 6.6 ± 1.1 to 2 ± 0.7 at 3 months, 0.6 ± 0.7 at 12 months. The strengths significantly increased postoperatively, and there were no significant differences between affected and unaffected shoulders at 12 months postoperatively (P > 0.05). The 22 of 24 patients were either satisfied or very satisfied with postoperative result at 12 months postoperatively. CONCLUSION: This arthroscopic-modified trans-tendon suture bridge technique for partial-thickness articular side tears of the rotator cuff has shown excellent functional results and very high satisfaction rate of patient during the 12-month follow-up period. LEVEL OF EVIDENCE: Evidence therapeutic study, Level IV.

Arthroscopically assisted anatomical coracoclavicular ligament reconstruction using tendon graft.

We describe a method of arthroscopically assisted, mini-open, anatomical reconstruction of the coracoclavicular ligament. This method restores both components of the native ligament with the aim of achieving maximum stability with minimal disruption of the normal anatomy. Using the same principles of ligament reconstruction that are employed in other joints, transosseous tunnels are created following the native footprints of the conoid and trapezoid ligaments and an autologous graft is fixed using a PEEK screw. Adequate healing of the ligament occurs within the bone, to prevent stress risers with an appropriate working length. This procedure is unique, as it replaces the torn ligament with a natural substitute, in the appropriate location, through a minimally invasive procedure. This technique would be suitable for treatment of patients with either grade III or V acute acromioclavicular dislocations. Clinical outcomes for the first 13 consecutive patients treated with this procedure are reported, revealing excellent satisfaction rates with a Constant score of 96.6 at final follow-up.