Comparison of blood loss between intra-articular microporous polysaccharide hemospheres powder and tranexamic acid following primary total knee arthroplasty.

Total knee arthroplasty (TKA) is associated with substantial blood loss and tranexamic acid (TXA) effectively reduces postoperative bleeding. Although it is known that there is no difference between intravenous or intra-articular (IA) injection, the general interest is directed towards topical hemostatic agents regarding thromboembolic events in high-risk patients. This study aimed to compare the blood conservation effects of IA MPH powder and TXA in patients undergoing primary TKA. We retrospectively analyzed 103 patients who underwent primary TKA between June 2020 and December 2021. MPH powder was applied to the IA space before capsule closure (MPH group, n = 51). TXA (3 g) was injected via the drain after wound closure (TXA group, n = 52). All patients underwent drain clamping for three postoperative hours. The primary outcome was the drain output, and the secondary outcomes were the postoperative hemoglobin (Hb) levels during the hospitalization period and the perioperative blood transfusion rates. An independent Student's t-test was used to determine differences between the two groups. The drain output in the first 24 h after surgery was significantly higher in the MPH group than in the TXA group. The postoperative Hb levels were significantly lower in the MPH group than in the TXA group. In patients with simultaneous bilateral TKA, there was a significant difference in the blood transfusion volumes and the rates between groups. It is considered that IA MPH powder cannot replace IA TXA because of an inferior efficacy in reducing blood loss and maintaining postoperative Hb levels in the early postoperative period after primary TKA. Moreover, in the case of simultaneous bilateral TKA, we do not recommend the use of IA MPH powder because it was notably less effective in the field of transfusion volume and rate.

Spontaneous resolution of spinoglenoid ganglion cyst: a case series.

BACKGROUND: Spontaneous resolution of a spinoglenoid notch ganglion cyst (SGC) without surgical treatment has been rarely reported; however, we have encountered this phenomenon occasionally. Therefore, we aimed to describe a case series of consecutive patients with SGC in whom it spontaneously resolved without surgical treatment. METHODS: We retrospectively reviewed 12 patients with magnetic resonance imaging (MRI)-confirmed SGC in whom it resolved without surgical treatment between January 2011 and March 2023. We included patients without abnormally increased signal intensity or muscle atrophy due to denervation from suprascapular neuropathy on MRI. Resolution of the SGC was confirmed via MRI or ultrasound at the follow-up visit, and suprascapular neuropathy was assessed using electromyography and nerve conduction studies when needed. For functional assessments, the visual analog scale for pain and active range of motion of the shoulder were used to compare pre and postresolution follow-ups. RESULTS: Eleven men and 1 woman with a median age of 54.0 years (interquartile range [IQR] 37.0-65.3) were included in this study. The SGCs resolved spontaneously at a median of 13.2 months with an IQR of 8.2-23.0 after initial evaluation using MRI. The SGCs were multiloculated cysts with superior labrum anterior and posterior II-IX lesions, with a median diameter of 2.5 cm (IQR 2.0-2.8). The median visual analog scale for pain (pre-resolution 5.0 [IQR 4.0-7.0] vs postresolution 1.0 [IQR 0.0-1.0], P = .002) and internal rotation at the back (preresolution 8.0 [IQR 7.0-10.3] vs postresolution 7.5 [IQR 7.0-8.0], P = .034) were significantly improved after the resolution. CONCLUSIONS: Surgical treatment may not be necessary in all cases of SGC. Nonsurgical treatment may be a viable option in the absence of suprascapular nerve involvement or superior labrum anterior and posterior-related physical findings.

Automatic segmentation of inconstant fractured fragments for tibia/fibula from CT images using deep learning.

Orthopaedic surgeons need to correctly identify bone fragments using 2D/3D CT images before trauma surgery. Advances in deep learning technology provide good insights into trauma surgery over manual diagnosis. This study demonstrates the application of the DeepLab v3+ -based deep learning model for the automatic segmentation of fragments of the fractured tibia and fibula from CT images and the results of the evaluation of the performance of the automatic segmentation. The deep learning model, which was trained using over 11 million images, showed good performance with a global accuracy of 98.92%, a weighted intersection over the union of 0.9841, and a mean boundary F1 score of 0.8921. Moreover, deep learning performed 5-8 times faster than the experts' recognition performed manually, which is comparatively inefficient, with almost the same significance. This study will play an important role in preoperative surgical planning for trauma surgery with convenience and speed.

What is the most predictive magnetic resonance imaging finding of rotator cuff tear concomitant with shoulder stiffness?

Background: Common magnetic resonance imaging (MRI) findings in adhesive capsulitis are not often evident in rotator cuff tear concomitant with shoulder stiffness. This study aimed to determine the most predictive MRI finding of rotator cuff tear with shoulder stiffness to differentiate from that without stiffness. Materials and methods: The data of patients who underwent arthroscopic rotator cuff repair between January 2014 and October 2019 were retrospectively reviewed. Stiffness was defined as forward flexion <120°, external rotation at side <30°, and internal rotation at back 

The correlation of the spinoglenoid ganglion cyst size with the electrophysiological alterations of suprascapular nerve and the rotator cuff muscle power.

BACKGROUND: Although various treatment options are available for spinoglenoid cyst, including conservative and surgical methods, there is no standard guideline for its surgical decompression. Thus, the purpose of the study was to correlate the size of the spinoglenoid notch ganglion cyst (GC) as revealed by magnetic resonance imaging (MRI) with electrophysiological alterations, muscle power, and pain severity, and to estimate a cut-off value of cyst size to perform a decompression. METHODS: Between January 2010 and January 2018, the patients with a GC at the spinoglenoid notch diagnosed on MRI, and who had a minimum follow-up of 2 years after the decompression were included. Maximum cyst diameter as measured on MRI was used for comparison. Electromyography (EMG) and nerve conduction velocity (NCV) studies were performed before the surgery. Peak torque deficit (PTD) percentage compared to opposite shoulder was calculated preoperatively and at 1 year after surgery. Pain severity was estimated using visual analogue scale (VAS) preoperatively. RESULTS: Ten (50%) of 20 patients with GC > 2.2 cm and 1 (5.9%) of 17 patients with GC < 2.2 cm showed EMG/NCV abnormalities (p = 0.019). There was a correlation between the cyst size and the positive EMG/NCV findings (Correlation coefficient (CC) = 0.535, p < 0.001). The preoperative peak torque deficit on the external rotation was correlated with the positive EMG/NCV findings (CC = 0.373, p = 0.021). The PTD was improved significantly at 1 year postoperatively in patients with a GC size >2.2 cm (p = 0.029). The cyst size was not related to the preoperative pain VAS and muscle power. CONCLUSIONS: The spinoglenoid cyst size >2.2 cm, but not pain severity or muscle power, correlates with the positive finding of EMG for compressive suprascapular neuropathy. The GC size >2.2 cm can be a reference to decide the need of decompression surgery. LEVEL OF EVIDENCE: IV, case series.

Long-term Clinical Outcomes After TightRope Versus Hook Plate Fixation for Acute Acromioclavicular Joint Dislocation.

Background: There is limited information regarding the long-term efficacy of techniques for surgical fixation after acromioclavicular (AC) joint dislocation. Purpose: To evaluate the efficacy of hook plate (HP) and TightRope (TR) fixation for acute AC joint dislocations by comparing the long-term clinical and radiological patient outcomes. Study Design: Cohort study, Level of evidence, 3. Methods: This study retrospectively analyzed data from 61 patients with acute AC joint dislocation between July 2011 and November 2015. The patients were grouped according to surgical procedure: HP (n = 36) and TR (n = 25). Clinical outcomes at final follow-up were evaluated using the visual analog scale (VAS) for pain; the American Shoulder and Elbow Surgery score; the Korean Shoulder Score; and the University of California, Los Angeles (UCLA) shoulder score. Side-to-side coracoclavicular (CC) distance on radiographs, postoperative complications, and the rate of subacromial erosion in the HP group were also assessed between procedures. Results: The mean follow-up period was 7.0 ± 1.0 years, and there were no significant differences in pain or outcome scores between the HP and TR groups (all P > .05). Forward flexion was better in the TR group (172.6° ± 5.6°) versus the HP group (166.0° ± 10.8°; P = .002). The percentages of patients with a difference in the side-to-side CC distance of <5 mm were 83.3% and 72.0% in the HP and TR groups, respectively (P = .288). Complications were found in 2 patients in the HP group and 1 in the TR group (P ≥ .999). Subacromial erosion was observed in 41.7% of patients after HP fixation, with no difference in VAS pain scores at the final follow-up in patients with versus without subacromial erosion (P = .719). Conclusion: When comparing HP with TR fixation for the treatment of acute AC joint dislocations, there were no significant differences in functional outcome scores, final CC distance, or complications. Slightly better forward flexion was seen after TR fixation. Subacromial erosion occurred in 40% of patients after HP fixation, but this did not affect long-term VAS pain scores. Both surgical techniques are effective treatment options for AC joint dislocation.

Myositis unrelated to the inoculation site after COVID-19 vaccination: a case report.

We describe the case of a 49-year-old right hand-dominant woman with myositis of the biceps brachii muscle unrelated to the inoculation site following Pfizer-BioNTech COVID-19 vaccination on the deltoid muscle of the left shoulder. Coronavirus disease 2019 (COVID-19) pandemic has involved global spread, and different vaccines including inactivated, protein, vectored, and nucleic acid vaccines have been developed and administered. Common side effects of COVID-19 vaccines include general manifestations such as headache, fever, and fatigue, and various musculoskeletal symptoms. Here, we present a case of myositis occurring in the biceps brachii muscle unrelated to the inoculation site, which has not been reported previously, accompanied by a literature review.

Deep Learning Model Based on You Only Look Once Algorithm for Detection and Visualization of Fracture Areas in Three-Dimensional Skeletal Images.

Utilizing "You only look once" (YOLO) v4 AI offers valuable support in fracture detection and diagnostic decision-making. The purpose of this study was to help doctors to detect and diagnose fractures more accurately and intuitively, with fewer errors. The data accepted into the backbone are diversified through CSPDarkNet-53. Feature maps are extracted using Spatial Pyramid Pooling and a Path Aggregation Network in the neck part. The head part aggregates and generates the final output. All bounding boxes by the YOLO v4 are mapped onto the 3D reconstructed bone images after being resized to match the same region as shown in the 2D CT images. The YOLO v4-based AI model was evaluated through precision-recall (PR) curves and the intersection over union (IoU). Our proposed system facilitated an intuitive display of the fractured area through a distinctive red mask overlaid on the 3D reconstructed bone images. The high average precision values (>0.60) were reported as 0.71 and 0.81 from the PR curves of the tibia and elbow, respectively. The IoU values were calculated as 0.6327 (tibia) and 0.6638 (elbow). When utilized by orthopedic surgeons in real clinical scenarios, this AI-powered 3D diagnosis support system could enable a quick and accurate trauma diagnosis.

Progression of Symptomatic Partial-Thickness Rotator Cuff Tears: Association With Initial Tear Involvement and Work Level.

Background: Partial-thickness rotator cuff tears (PTRCTs) often progress to full-thickness rotator cuff tears (FTRCTs). Thus, it is important to analyze the risk factors for tear progression to determine the proper timing of repair. Purpose: To identify the risk factors associated with progression of PTRCT. Study Design: Case-control study; Level of evidence, 3. Methods: Included were 89 patients diagnosed with PTRCT on magnetic resonance imaging (MRI) scans who underwent nonoperative treatment at the authors' institution between August 2012 and August 2019. Patient characteristics, shoulder stiffness (compared with the contralateral shoulder); work level (classified as high [heavy manual labor], medium [manual labor with less activity], and low [sedentary activity]); and radiological factors including initial tear size, acromion type (flat, curved, hooked, or heel-shaped), and initial tear involvement (as a percentage of the rotator cuff tendon footprint length) were analyzed to assess their association with tear progression, defined as >20% increase in tear involvement. Results: The mean MRI follow-up period was 22.3 ± 17.2 months (median, 16.1 months; range, 6.4-89.5 months), and tear progression was observed in 12 patients (13.5%). In these 12 patients, tear involvement increased by 60% of the rotator cuff footprint, while mediolateral (ML) and anteroposterior (AP) tear sizes progressed by 1.1 and 1.8 mm, respectively. Univariate regression analysis showed that shoulder stiffness (P = .031), work level (P = .001), initial tear involvement (P < .001), ML and AP tear sizes (P < .001 and P = .005, respectively), and acromion type (P = .003) were significantly associated with tear progression. Multivariate regression analysis showed that initial tear involvement (odds ratio [OR], 1.053; 95% CI, 1.006-1.102; P = .026) and high work level (OR, 15.831; 95% CI, 1.150-217.856; P = .039) were independent risk factors for tear progression. The cutoff value for initial tear involvement was 47.5% (sensitivity, 81.8%; specificity, 85.7%). Conclusion: Tear progression was observed in 14% of patients with PTRCT in this study. To predict tear progression, evaluating the tear involvement during initial MRI is essential. The risk of tear progression increased with initial tear involvement >47.5% and a heavy work level.

The Prevalence of Vitamin D Deficiency in Patients Undergoing Total Knee Arthroplasty: A Propensity Score Matching Analysis.

PURPOSE: We investigated and compared the serum 25-OH vitamin D [25(OH)D] level and prevalence of vitamin D deficiency (VDD) between patients who underwent total knee arthroplasty (TKA) and healthy participants through a matched analysis. METHODS: The unmatched case group consisted of 824 patients who underwent TKA and the unmatched control group 2,794 healthy participants examined at our institution. The control group was matched on the various characteristics-sex, age, weight, body mass index (BMI), blood chemistry, and season of sampling-through propensity score matching (PSM). After PSM, 501 and 721 patients were matched in the case and control group, respectively. Levels of blood chemistry including 25(OH)D were examined and VDD was defined as < 20 ng/mL. RESULTS: The average serum 25(OH)D level was significantly lower in the OA group (15.3 ng/mL) than that in the control group (19.9 ng/mL, p < 0.001). When categorized using a 20 ng/mL cutoff, the VDD prevalence was 75.0% in the OA group and 59.4% in the control group. The prevalence of vitamin D insufficiency was 18.4% in the OA group and 24.5% in the control group. The prevalence of vitamin D sufficiency was 6.8% in the OA group and 15.9% in the control group (p < 0.001). CONCLUSIONS: The patients who underwent TKA had lower serum 25(OH)D level and higher VDD prevalence compared to the healthy participants who matched using PSM. There were no differences in VDD rates by sex or obesity and the VDD prevalence was more than 70% during all season. Therefore, in patients undergoing TKA, general attention to VDD is required regardless of sex, obesity, and season. Serum 25-OH vitamin D [25(OH)D] level and vitamin D deficiency (VDD) prevalence were compared between patients undergoing total knee arthroplasty and healthy individuals. The differences in serum 25(OH)D level and VDD prevalence were significant between the two groups after propensity score matching.

Quantitative magnetic resonance imaging assessment of the infraspinatus and teres minor in massive rotator cuff tear and its significance in clinical outcome after rotator cuff repair.

BACKGROUND: Teres minor (TM) muscle hypertrophy in large to massive rotator cuff tears (RCTs) has been considered a compensatory change to atrophy of the infraspinatus (ISP). However, few reports have assessed its relation to the prognosis after rotator cuff repair. METHODS: A total of 139 patients who underwent arthroscopic repair of large to massive RCTs involving the ISP between January 2013 and December 2015 were retrospectively investigated. Occupational ratios of the ISP (OR_ISP) and TM (OR_TM) were measured by sagittal magnetic resonance imaging (MRI). Rotator cuff healing was evaluated by MRI 1 year postoperatively, and functional outcomes using the Simple Shoulder Test (SST) and Constant score and external rotator (ER) strength by isokinetic muscle performance test (IMPT) were measured. RESULTS: A total of 116 patients completed the MRI and IMPT at 1 year postoperatively, and functional scores were measured at least 2 years postoperatively. Of these, the repaired tendon had not healed in 34 patients (29%). There was a highly negative correlation between OR_ISP and OR_TM both pre- and postoperatively (Pearson correlation = -0.52 and -0.54, respectively). Preoperative OR_ISP was significantly higher in the healed than in the healing failure group (0.47 ± 0.10 vs. 0.41 ± 0.12, P = .02); however, postoperative OR_ISP and pre- and postoperative OR_TM were not. The preoperative OR_ISP cutoff value for healing was 0.46. For functional outcomes, only postoperative OR_ISP showed a statistical correlation with SST, Constant score (P = .04 and .03, respectively), and ER strength (P = .02). CONCLUSION: TM muscle hypertrophy in large to massive RCT appears to be a compensatory change in the progression of atrophy of the ISP muscle and was not a significant indicator of either better healing of the repaired rotator cuff tendon or better function. Only preoperative OR_ISP was an independent prognostic factor affecting rotator cuff healing after repair of large to massive RCTs.

Clinical Outcomes of Revision Arthroscopic Capsulolabral Repair for Recurrent Anterior Shoulder Instability With Moderate Glenoid Bone Defects: A Comparison With Primary Surgery.

BACKGROUND: The optimal revision surgery for failed primary arthroscopic capsulolabral repair (ACR) has yet to be determined. Revision ACR has shown promising results. PURPOSE: To compare the functional, strength, and radiological outcomes of revision ACR and primary ACR for anterior shoulder instability. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between March 2007 and April 2017, a total of 85 patients underwent ACR (revision: n = 23; primary: n = 62). Functional outcome scores and positive apprehension signs were evaluated preoperatively, at 1 year, and then annually. Isokinetic internal and external rotation strengths were evaluated preoperatively and at 1 year after surgery. RESULTS: The mean follow-up was 36.5 ± 10.2 months (range, 24-105 months). There was no significant difference between the revision and primary groups in the glenoid bone defect size at the time of surgery (17.3% ± 4.8% vs 15.4% ± 5.1%, respectively; P = .197). At the final follow-up, no significant differences were found in the American Shoulder and Elbow Surgeons score (97.6 ± 3.1 vs 98.0 ± 6.2, respectively; P = .573), Western Ontario Shoulder Instability Index score (636.7 ± 278.1 vs 551.1 ± 305.4, respectively; P = .584), or patients with a positive apprehension sign (17.4% [4/23] vs 11.3% [7/62], respectively; P = .479) between the revision and primary groups. There was no significant difference between the revision and primary groups for returning to sports at the same preoperative level (65.2% vs 80.6%, respectively; P = .136) and anatomic healing failure at 1 year after surgery (13.0% vs 3.2%, respectively; P = .120). Both groups recovered external rotation strength at 1 year after surgery (vs before surgery), although the strength was weaker than in the uninvolved shoulder. In the revision group, a larger glenoid bone defect was significantly related to a positive apprehension sign (22.0% ± 3.8%) vs a negative apprehension sign (16.0% ± 3.2%; cutoff = 20.5%; P = .003). CONCLUSION: In patients with moderate glenoid bone defect sizes (10%-25%), clinical outcomes after revision ACR were comparable to those after primary ACR. However, significant glenoid bone loss was related to a positive remaining apprehension sign in the revision group. Surgeons should consider these findings when selecting their revision strategy for patients with failed anterior shoulder stabilization.

Multimodal nerve injection provides noninferior analgesic efficacy compared with interscalene nerve block after arthroscopic rotator cuff repair.

PURPOSE: This randomized noninferiority trial aimed to evaluate whether combined suprascapular, axillary nerve, and the articular branch of lateral pectoral nerve block (3NB) is noninferior to interscalene nerve block (ISB) for pain control after arthroscopic rotator cuff repair (ASRCR). MATERIALS AND METHODS: Eighty-five patients undergoing ASRCR were randomized to either 3NB (n = 43) or ISB (n = 42) group. We used 5 and 15 ml of 0.2% ropivacaine for each nerve in the 3NB and ISB groups, respectively. The primary outcome was the visual analog scale (VAS) pain score at 4 h postoperatively measured assessed on an 11-point scale (ranging from 0 = no pain to 10 = worst pain) that was analyzed using noninferiority testing. The secondary outcome was VAS pain scores in the recovery room and at 8, 12, 24, 36, 48, and 72 h postoperatively. Rebound pain, IV-PCA usage during 48 h, dyspnea, muscle weakness, and satisfaction were evaluated. RESULTS: Regarding the primary outcome, the mean difference in VAS pain scores between the 3NB (2.5 ± 1.6) and ISB (2.2 ± 2.3) groups at 4 h postoperatively was 0.3, with a 95% confidence interval (CI) of -0.56 to 1.11. The upper limit of 95% CI is lower than the noninferiority margin of 1.3 (p < 0.001). At all other time points, except in the recovery room, 3NB showed noninferior to ISB. Rebound pain, IV-PCA usage during the second 24 h, and muscle weakness were lower in the 3NB group (all p < 0.005). The satisfaction was similar in both groups (p = 0.815). CONCLUSION: Combined 3NB is noninferior to ISB in terms of pain control after ASRCR; and is associated with low levels of rebound pain, IV-PCA usage, and muscle weakness. LEVEL OF EVIDENCE: Randomized controlled trial, Level I.

Changes in Shoulder Rotator Strength After Arthroscopic Capsulolabral Reconstruction in Patients With Anterior Shoulder Instability.

BACKGROUND: The correlation between isokinetic internal and external rotation (IR and ER) strength and functional outcomes in patients with anterior shoulder instability treated by arthroscopic capsulolabral reconstruction (ACR) has not been studied. PURPOSE: To analyze isokinetic IR and ER strength and their correlation with clinical outcomes in patients with anterior shoulder instability treated by ACR. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between January 2004 and June 2015, a total of 104 patients who underwent ACR for anterior shoulder instability were analyzed. The mean peak torque (PT) in IR (IRPT) and ER (ERPT), PT deficit (PTD; %) relative to the opposite healthy shoulder, and PT ratio (PTR; ERPT/IRPT) were calculated before and 1 year after surgery. Functional scores were evaluated before surgery and at every follow-up visit. Recurrence and postoperative apprehension during ER at 90° of arm abduction were evaluated at 1 year and the final follow-up (76.6 ± 64.4 months). RESULTS: IR and ER strength were measured for 68 of 104 patients at 1 year after surgery. ERPT and IRPT were less on the involved side than on the uninvolved side before surgery (0.29 ± 0.10 vs 0.33 ± 0.10 N·m/kg, respectively, for ERPT [P = .002]; 0.36 ± 0.14 vs 0.41 ± 0.16 N·m/kg, respectively; for IRPT [P = .01]). At 1 year after surgery, IRPT on the involved side recovered (0.40 ± 0.20 N·m/kg), whereas ERPT remained weak (0.30 ± 0.13 N·m/kg) relative to the baseline value. PTD in IR (PTDIR) improved to 2.2% ± 24.4% (P = .012), whereas PTD in ER (PTDER) showed no improvement (13.5% ± 13.8%; P = .569). PTR on the involved side improved from 1.07 ± 1.71 to 0.86 ± 0.23 at 1 year (P < .001). All functional scores improved significantly at the final follow-up. At 1 year, 9 of 68 (13.2%) patients showed positive apprehension. PTDIR and PTDER on the involved side were worse in patients with positive apprehension than in those with negative apprehension (P = .039 and .014, respectively). PTDER was worse than PTDIR in patients with positive apprehension at 1 year (P = .022). CONCLUSION: For those with anterior shoulder instability, preoperative IR and ER strength of the involved shoulder were lower than those of the uninvolved shoulder. IRPT recovered, whereas ERPT remained weak after ACR. To prevent positive apprehension after surgery, IR and ER strengthening exercises are important, with more emphasis on exercises for ER.

Significance of the acromiohumeral distance on stress radiography for predicting healing and function after arthroscopic repair of massive rotator cuff tears.

BACKGROUND: A decreased acromiohumeral distance (AHD) is commonly detected in patients with massive rotator cuff tears (mRCTs). Most studies evaluating fixed humeral elevation have used preoperative or postoperative standardized radiography and not stress radiography. This study aimed to evaluate the predictive role of the preoperative AHD measured using stress radiography (AHD_stress) in rotator cuff healing and function after arthroscopic repair of mRCTs. METHODS: The data of 113 patients who underwent arthroscopic repair of mRCTs were analyzed. Postoperative cuff integrity was evaluated using magnetic resonance imaging at 1 year, and shoulder function was evaluated at a mean of 34.9 ± 17.8 months (range, 24-92 months) postoperatively. Forty-seven patients showed healing failure. Propensity score matching (1-1) was performed between the healed group and healing failure group. Thirty-eight patients in each group were matched in the final analysis. The AHD and AHD_stress were defined as the shortest distances from the inferior acromion to the superior humerus on standard anteroposterior radiography and stress radiography (5.4-kg weight applied inferiorly in a neutral position), respectively. The AHD difference (AHD_diff) was defined as the difference between the AHD and AHD_stress values. Receiver operating characteristic curve analysis was performed to determine cutoff values for significant variables. RESULTS: No difference in the mean preoperative AHD was found between the healed group (7.5 ± 2.0 mm) and healing failure group (6.9 ± 2.2 mm, P = .234). The AHD_diff value was significantly higher in the healed group (4.4 ± 2.1 mm) than in the healing failure group (3.0 ± 2.0 mm, P = .002; cutoff, 3.2 mm). Patients with an AHD_diff value ≥ 3.2 mm showed a lower healing failure rate (28.9% vs. 71.1%, P < .001) and higher functional scores than patients with an AHD_diff value < 3.2 mm. The AHD_diff value was higher in patients with an American Shoulder and Elbow Surgeons (ASES) score ≥ 80 (4.9 ± 1.9 mm) than in those with an ASES score < 80 (3.1 ± 2.1 mm, P = .024). Among patients with healing failure, only the postoperative AHD showed a significant difference between those with an ASES score ≥ 80 (7.0 ± 2.5 mm) and those with an ASES score < 80 (4.8 ± 2.1 mm, P = .009; cutoff, 4.8 mm). CONCLUSION: A reducible AHD, which increased by ≥ 3.2 mm under stress radiography, can be a favorable predictor of rotator cuff healing and function after arthroscopic repair of mRCTs. Our findings suggest that this new and simple radiologic parameter should be considered preoperatively and would be helpful to determine appropriate treatment strategies.

Arthroscopic Treatment of Septic Arthritis of the Shoulder: Technical Pearls to Reduce the Rate of Reoperation.

BACKGROUND: The aim of this study was to evaluate clinical experience with arthroscopic debridement for septic arthritis of the shoulder joint and to report on our patient outcomes. METHODS: The retrospective analysis included 36 shoulders (male:female, 15:21), contributed by 35 patients (mean age, 63.8 years) treated by arthroscopy for septic arthritis of the shoulder between November 2003 and February 2016. The mean follow-up period was 14.3 months (range, 12-33 months). An additional posterolateral portal and a 70º arthroscope was used to access the posteroinferior glenohumeral (GH) joint and posteroinferior subacromial (SA) space, respectively. Irrigation was performed with a large volume of fluid (25.1±8.1 L). Multiple suction drains (average, 3.3 drains) were inserted into the GH joint and SA space and removed 8.9±4.3 days after surgery. Intravenous antibiotics were administered for 3.9±1.8 weeks after surgery, followed by oral antibiotic treatment for another 3.6±1.9 weeks. RESULTS: Among the 36 shoulders, reoperation was required in two cases (5.6%). The average range of motion achieved was 150.0º for forward flexion and T9 for internal rotation. The mean simple shoulder test score was 7.9±3.6 points. Nineteen shoulders (52.8%) had acupuncture or injection history prior to the infection. Pathogens were identified in 15 shoulders, with Staphylococcus aureus being the most commonly identified pathogen (10/15). Both the GH joint and the SA space were involved in 21 shoulders, while 14 cases involved only the GH joint and one case involved only the SA space. CONCLUSIONS: Complete debridement using an additional posterolateral portal and 70º arthroscope, a large volume of irrigation with >20 L of saline, and multiple suction drains may reduce the reoperation rate.

A preliminary study on surgical navigation for epiduroscopic laser neural decompression.

Epiduroscopic laser neural decompression is an emerging therapeutic modality to treat lumbar spine pathologies including chronic low back pain, spinal stenosis, and disk herniation via catheter insertion followed by laser ablation of the lesion. Despite the efficacy of epiduroscopic laser neural decompression, excessive radiation doses due to fluoroscopy during epiduroscopic laser neural decompression have limited its widespread application. To address the issue, we propose a surgical navigation system to assist in epiduroscopic laser neural decompression procedures using radiation-free image guidance. An electromagnetic tracking system was used as the basic modality to track the internal location of the surgical instrument with respect to the patient body. Patient-to-image registration was carried out using the point-based registration method to determine the transformation between the coordinate system of the patient and that of the medical images. We applied the proposed system in epiduroscopic laser neural decompression procedures to assess its effectiveness, and the outcomes confirmed its clinical feasibility. To the best of our knowledge, this is a report on the first surgical navigation applied for epiduroscopic laser neural decompression procedure.