Relationship Between Achilles Tendon Stiffness Using Myoton PRO and Translation Using a Tensile Testing Machine: A Biomechanical Study of a Porcine Model.

Background Achilles tendinopathy is a common ankle disorder in both the general population and athletes. This condition can alter the mechanical characteristics of the Achilles tendon (AT) by decreasing tendon stiffness. Achilles tendinopathy is primarily treated conservatively; however, few monitoring tools exist for evaluating the condition of the AT. The Myoton PRO (Myoton AS, Tallinn, Estonia) device is a handheld tool used to evaluate tissue stiffness. However, no basic studies have examined the validity of Myoton PRO for assessing the AT. This study aimed to assess the validity of Myoton PRO using animal ATs and to examine its clinical applicability. Methods We used 28 fresh porcine ankles and evaluated AT stiffness at the calcaneus insertion site (AT0) and 2.0 cm above the calcaneus (AT2) using Myoton PRO. We also measured changes in the AT length using a tensile testing machine during the cyclic loading test. We investigated the correlation between dynamic stiffness and length change. Furthermore, we assessed the difference in stiffness between AT0 and AT2. Results The dynamic stiffness was 717.6 ± 183.1 N/m at AT0 and 467.4 ± 152.3 N/m at AT2. The change in length during the cyclic loading test was 1.8 ± 0.7 mm. The correlation between dynamic stiffness and length change was as follows: AT0, r=-0.61; AT2, r=-0.64 (P<0.001). The dynamic stiffness at AT0 was significantly greater than that at AT2 (P<0.001). Conclusions AT assessment using Myoton PRO has potential clinical utility as an indicator of tissue stiffness.

Clinical outcomes and cost-effectiveness of manipulation under brachial plexus block versus physiotherapy for refractory frozen shoulder: a prospective observational study.

Background: Frozen shoulder (FS) is a pathological condition that involves a painful and stiff shoulder joint, most commonly in people aged 40-60 years. Most literature supports treatment with physical therapy (PT), although some studies have demonstrated years of continuing pain and functional deficits. Manipulation under anesthesia is effective at eliminating the contracture of intra-articular lesions for refractory FS. This study aimed to compare whether manipulation under anesthesia or PT is a more effective treatment in refractory FS. Methods: This study was a prospective observational study. A total of 102 patients with refractory FS were enrolled in this study in the medical records, all of whom had severe and multidirectional loss of motion and thickening of the joint capsule and coracohumeral ligament on magnetic resonance imaging. Fifty-one patients were in the manipulation under brachial plexus block (MUB) group (34 females, median age: 57 years), and 51 patients were in the PT group (34 females, median age: 59 years). The MUB procedure consisted of the conventional method with additional adduction manipulation, in which one examiner initially abducted the shoulder joint as much as possible. We recorded the visual analog scale, shoulder range of motion, and American Shoulder and Elbow Surgeons and Constant Scores at the initial baseline visit and at the 1-, 3-, 6-, and 12-month follow-ups. The total cost was calculated from the medical records, and cost-effectiveness was evaluated using quality-adjusted life year and incremental cost-effectiveness ratio. Results: Visual analog scale (P < .001), range of motion (P < .001), and American Shoulder and Elbow Surgeons and Constant Scores (P < .001) in the MUB group were significantly superior to those in the PT group at 1, 3, 6, and 12 months after treatment. The median cost and total quality-adjusted life year in the MUB and PT groups were $1375 versus $2751 and 2.95 versus 2.68, respectively, and the cost-effectiveness ratio between the MUB and PT groups was calculated as -$560. Conclusions: The new MUB procedure provides a shorter treatment period, better clinical outcomes, and higher cost-effectiveness in patients with refractory FS compared to PT.

Morphological and histological evaluation of the tendon-bone junction in porcine shoulders to create a rotator cuff tear and repair model.

BACKGROUND: This study aimed to morphologically and histologically examine whether pig is useful as models for rotator cuff tear (RCT). METHODS: The morphology of the scapula and humerus bones was evaluated by taking X-ray and three-dimensional computed tomography (3D CT) scans of the right shoulders of five female pigs (age: 4 months). The rotator cuff (RC) footprint at the humeral insertion of these was observed and its shape was measured. Next, they underwent general anesthesia and an acute rotator cuff tear/rotator cuff repair (RCT/RCR) model was created using a deltoid split approach. Four weeks after surgery, the animals were euthanized, the shoulder joints were harvested, and the repaired RC was evaluated by hematoxylin and eosin staining and toluidine blue staining. RESULTS: The scapula of the pig had a vestigial acromion, in contrast to that in humans. The supraspinatus and infraspinatus tendons were connected so as to overlap each other and attached to the postero-superior part of the greater tuberosity. These tendons were located extra-articularly, separate from the joint capsule. The average antero-posterior length of the foot print was 17.4 ± 0.7 mm on the medial margin and 19.1 ± 2.2 mm on the lateral margin. The maximum medial-to-lateral width of it was 5.1 ± 0.5 mm. In all RCT/RCR models at 4 weeks after surgery, the repaired RC compound tendon was visually confirmed to be continuous with the footprint. Histologically, it was confirmed that regeneration of the four-layer structure of the bone-tendon junction had occurred. CONCLUSION: Porcine supraspinatus and infraspinatus attachment to the greater tuberosity have a structure similar to that of sheep and dogs, which is advantageous for creating the RCT/RCR model. It might be used for future in vivo studies of shoulder joint diseases. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Pigs could potentially serve as a viable model for rotator cuff tears.

Use of a preoperative 3D templating and proximal lateral tibial fitting patient-specific instrumentation in fixed valgus complex primary total knee arthroplasty for a patient with retaining hardware for internal fixation to treat Schatzker type V tibial plateau fracture: A case report.

A 72-year-old female patient with a fixed valgus knee deformity due to a Schatzker type V tibial plateau fracture treated with bilateral locking plates 8 years ago was admitted to our clinic with complaints of chronic pain and knee instability when walking. Radiographs revealed Kellgren-Lawrence Classification grade 4 knee osteoarthritis and 20.5° of valgus knee deformity. She was treated with three-dimensional templating and proximal lateral tibial fitting patient-specific instrumentation-assisted mechanically aligned posterior sacrificing total knee arthroplasty with minimal removal of the retained hardware for the internal fixation of the tibial plateau fracture via a lateral approach, resulting in a favorable clinical outcome. The use of proximal lateral tibial fitting patient-specific instrumentation in fixed valgus complex primary total knee arthroplasty for patients with retaining hardware for internal fixation to treat tibial plateau fractures is considered a treatment option to decrease surgical invasion.

Relationship between pain and range of motion in frozen shoulder.

Background: A frozen shoulder (FS) is characterized by pain and limited range of motion (ROM). Although physical assessment of ROM is important for diagnosing and staging FS, ROM cannot be accurately assessed in clinical practice because of pain and muscle contraction. This study aimed to measure changes in shoulder joint ROM before and after anesthesia (ΔROM) in patients with FS and investigate the factors affecting these changes. Methods: This study included 54 patients (age, 55.6 ± 9.4 years; 17 males; disease duration, 6.6 ± 3.4 months) with FS before manipulation under transmission anesthesia. FS was defined as having a ROM in external rotation (ER) that was less than 50% of that in the unaffected shoulder. Pain at night and during motion was assessed using a numerical rating scale. Before anesthesia, the passive ROM of forward flexion (FF), abduction (AD), and ER were measured in the supine position. After confirming that the anesthesia was effective, passive ROM was measured again. Results: The ROM in the FF, AD, and ER after anesthesia was significantly higher than that before anesthesia (P < .001). ΔROM in the FF, AD, and ER was significantly correlated with pain at night (r = 0.51, P < .001; r = 0.45, P < .001; and r = 0.39, P = .004, respectively). Furthermore, ΔROM in the ER was significantly correlated with pain during motion (r = 0.31, P = .023) and disease duration (r = -0.31, P = .021). Conclusion: The ROM of the FS is susceptible to pain and muscle contraction. Interventions, such as physical therapy, may be recommended after pain relief.

Evaluation of muscle stiffness in adhesive capsulitis with Myoton PRO.

Background: Adhesive capsulitis (AC) is characterized by pain and limited range of motion, caused by stiffness of the joint capsule and coracohumeral ligament. On the other hand, there have been few reports on muscle stiffness in AC. The purpose of this study was to assess muscle stiffness in patients of AC with a portable and noninvasive device, Myoton PRO. We hypothesized that muscle stiffness around shoulder joint increases in AC. Methods: At first, we surveyed correlation between Myoton PRO and shear wave elastography with phantoms. Second, reproducibility and repeatability of healthy volunteers with Myoton PRO were evaluated. Finally, muscle stiffness was measured in 40 patients who were diagnosed with AC. Muscle stiffness was quantitatively measured with Myoton PRO. We compared the stiffness of the anterior deltoid (AD), pectoralis major, and latissimus dorsi (LD) in AC patients on both the affected and nonaffected sides. Results: Correlation coefficient in shear wave elastography and Myoton PRO was 0.99(P = .001). Reliability of intraoperator and interoperator with Myoton PRO was 0.9 or higher. Muscle stiffness values (N/m) of the AD, pectoralis major, and LD were 355 ± 61, 252 ± 54, 207 ± 51 in the affected sides and 328 ± 50, 252 ± 41, 186 ± 37 in the nonaffected sides, and the differences were significant in the AD and LD (P = .005, P = .002, respectively). Conclusions: We used Myoton PRO to evaluate muscle stiffness in AC. The AD and LD muscles of AC patients were significantly stiffer on the affected side compared to the nonaffected side.

Efficacy of fracture stem in reverse shoulder arthroplasty for 3- or 4-part proximal humerus fractures.

BACKGROUND: This study compared the clinical results of fracture stems and conventional stems using the same glenoid component in reverse shoulder arthroplasty for proximal humerus fractures in the elderly. METHODS: This retrospective study included 35 patients who underwent Grammont-type reverse shoulder arthroplasty for proximal humerus fractures from 2014 to 2020. The average age at surgery was 79.2 (range, 65-92) years, with 33 female shoulders. Fracture types per Neer classification were 3-part fracture, 4-part fracture, in 13 and 22 shoulders, respectively. The final follow-up period was 35 (range, 24-81) months. The Constant score, American Shoulder and Elbow Surgeons score, shoulder range of motion, and healing of greater tuberosities at the final follow-up of AEQUALIS™ REVERSED (Conventional stem group: n = 15) and AEQUALIS™ REVERSED FX (Fractured stem group: n = 20) were retrospectively investigated. RESULTS: There were no statistically significant differences in age at surgery, sex, body mass index, fracture type, waiting time from injury to surgery, or preoperative general condition between the groups. The Constant and American Shoulder and Elbow Surgeons scores of the fractured stem group were significantly higher than those of the conventional stem group (P = 0.038 and P = 0.023, respectively). The anterior elevation and external rotation at the side of the fractured stem group also showed significantly higher values than those of the conventional stem group (fractured stem group vs. conventional stem group: anterior elevation 127° ± 25° vs. 105° ± 35°, P = 0.041; external rotation 28° ± 13° vs. 13° ± 12°, P = 0.015). The greater tuberosity healing rate was 46.7% (7/15) in the conventional stem group and 85.0% (17/20) in the fractured stem group (P＝0.027). CONCLUSIONS: The findings suggest that use of a fracture-specific stem rather than a conventional stem in Grammont-type reverse shoulder arthroplasty for proximal humerus fractures improves tuberosity healing, postoperative range of motion, and clinical scores.

Isolated bursal-side infraspinatus tear diagnosed by computed tomography bursography: a case series.

BACKGROUND: Partial-thickness rotator cuff tears are commonly found in the articular-side tendon of the supraspinatus; however, isolated lesions, except those occurring in the supraspinatus tendons, are rare. We report three cases of isolated bursal-side infraspinatus tears that were difficult to detect by magnetic resonance imaging but could be visualized by computed tomography bursography. CASE PRESENTATION: Three Asian patients (59-71 years old) with shoulder pain ranging from 1 month to 3 years in duration were each diagnosed with shoulder impingement syndrome. Magnetic resonance imaging studies failed to show a tear of the rotator cuff tendon complex. However, computed tomography bursography showed a longitudinal infraspinatus partial-thickness tear on the bursal side in each case. Arthroscopic decompression of the subacromial space and debridement of the infraspinatus tendon tear successfully alleviated the shoulder pain in two of the three patients; the third patient did not undergo surgery and remained symptomatic at follow-up. CONCLUSIONS: In patients with chronic shoulder pain but normal magnetic resonance imaging findings, computed tomography bursography should be considered, as bursal-side infraspinatus tears may be found in these patients. Furthermore, our findings provide a basis for larger studies to further establish the accuracy of computed tomography bursography for these lesions.

Reduction of abnormal blood flow in frozen shoulder after shoulder manipulation under ultrasound-guided cervical nerve root block: semiquantitative analysis using dynamic magnetic resonance imaging.

Background: We previously reported a characteristic dynamic magnetic resonance imaging (MRI) change in patients with frozen shoulder (FS) and named this abnormal blood flow pattern the "burning sign". In this study, a semiquantitative method was used to evaluate changes in this abnormal blood flow pattern on dynamic MRI after shoulder manipulation under ultrasound-guided cervical nerve root block (MUC) in patients with FS. Methods: Nineteen patients with FS underwent MUC, with dynamic MRI performed before and after. We used dynamic MRI to semiquantitatively assess changes in the burning sign at the axillary pouch (AP) and rotator interval (RI) by examining the enhancement rate in the signal intensity and the enhancement velocity. Functional assessments included a numeric rating scale score, the range of shoulder motion, the American Shoulder and Elbow Surgeons score, and the Constant score. Results: The burning sign in the AP and RI was observed with dynamic MRI in all patients before MUC. The average interval from MUC until dynamic MRI was 8.2 months (range, 6-12). Clinical results for all patients improved after MUC. The before and after MUC enhancement rates (%) were 217 ± 51 and 85 ± 36 in the AP and 233 ± 61 and 73 ± 40 in the RI, respectively (both P < .001). The before and after MUC enhancement velocities (ms/s) were 902 ± 335 and 203 ± 125 in the AP and 1249 ± 634 and 213 ± 146 in the RI, respectively (both P < .001). Conclusion: Dynamic MRI semiquantitatively demonstrated a reduction in abnormal blood flow and improvement in clinical results after MUC in patients with FS.

Prognostic factors of shoulder manipulation under ultrasound-guided cervical nerve root block for frozen shoulder for patient with diabetes mellitus: A retrospective cohort study.

INTRODUCTION: Shoulder manipulation under ultrasound-guided cervical nerve root block (MUC) gives good clinical results in patients with frozen shoulder 1 week after the procedure. However, some patients are refractory to MUC. The present study was performed to investigate the prognostic factors of MUC for frozen shoulder. METHODS: We evaluated 73 frozen shoulders (70 patients) to investigate the prognostic factors of MUC. The patients' mean age was 56.6 years, and 60% were female. The mean duration of symptoms before MUC was 8.6 months. We assessed pain using a numeric rating scale (NRS), range of motion (ROM), and the American Shoulder and Elbow Surgeons (ASES) score before and 1 year after MUC. We compared patients with an ASES score of <80 (defined as a poor clinical result) with those with an ASES score of ≥80 (good clinical result). To identify the risk factors for a poor clinical result, multiple logistic regression analysis was performed using the following variables: age, sex, duration of symptoms before MUC, diabetes mellitus (DM), initial NRS score, and initial ROM. RESULTS: The initial NRS score and the prevalence of DM were significantly greater in the poor clinical results group. Multiple logistic regression analysis revealed that DM was the only independent risk factor for a poor clinical result after MUC (odds ratio, 51; 95% confidence interval, 10.9-237; p = .01). CONCLUSIONS: DM is a negative prognostic factor of MUC for frozen shoulder, and patients with DM should be informed of this before they undergo treatment for frozen shoulder.

Characteristics of dynamic magnetic resonance imaging for shoulder stiffness in postoperative breast cancer patients: A preliminary case series.

INTRODUCTION AND IMPORTANCE: Shoulder stiffness in postoperative breast cancer causes a decrease in their quality of life. However, the underlying pathology is not fully understood, and no study has investigated the dynamic magnetic resonance imaging (MRI) findings in these patients. Therefore, the current preliminary study aimed to investigate the dynamic MRI findings in patients with shoulder stiffness occurring after breast cancer surgery. METHODS: We retrospectively analyzed the electronic medical records of postoperative breast cancer patients with shoulder stiffness, dated from January 2015 to December 2020. The baseline characteristics, breast cancer treatment methods, range of active shoulder motion, and location of the abnormal enhancement on dynamic MRI were assessed. RESULTS: The mean age of the patients was 57.8 ± 6.1 years (range, 47-63 years) and the mean duration of shoulder symptoms was 5.6 ± 3.6 months (range, 2-12 months). An abnormal enhancement of the rotator interval and axillary pouch was observed on dynamic MRI of all the included patients. CONCLUSION: This study presents the first case reports of the dynamic MRI findings in postoperative breast cancer patients with shoulder stiffness. All patients had abnormal enhancement of the rotator interval and axillary pouch.

Clinical results of reverse shoulder arthroplasty for comminuted proximal humerus fractures in elderly patients: a comparison between nonporous stems versus trabecular metal stems.

BACKGROUND: This study compared the clinical results for nonporous stems vs. trabecular metal (TM) stems used in reverse shoulder arthroplasty (RSA) for comminuted proximal humeral fractures (CPHFs) in elderly patients. METHODS: In this retrospective study, a total of 41 shoulders (39 women) of patients with CPHF aged >70 years who underwent RSA were investigated. The minimum follow-up period was 2 years. A total of 15 shoulders were treated with Grammont-style RSA using nonporous stems (the G-RSA group), and 26 shoulders were treated with RSA combining TM stems (the FR-RSA group). The American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score, shoulder joint range of motion (ROM), and radiographic findings were compared between the 2 groups. RESULTS: ASES scores and Constant scores were significantly higher in the FR-RSA group than in the G-RSA group. External rotation at the side in the FR-RSA group was significantly higher than that in the G-RSA group. In the FR-RSA and G-RSA groups, the union rates at the greater tuberosity (GT) were 88.5% and 46.7%, respectively, and scapular notching rates were 20% and 7.7%, respectively. Based on a subanalysis, the age was lower, body mass index was higher, and ASES scores, Constant scores, and external rotation ROM were higher in the GT union group than in the GT nonunion group. CONCLUSION: GT bone union rates were high, and external rotation ROM of the shoulder joint were more improved for RSA using TM stems than those for RSA using nonporous stems in elderly patients with CPHF.

Characteristics of dynamic magnetic resonance imaging of symptomatic chronic calcifying tendinitis: preliminary case reports.

BACKGROUND: The symptoms of chronic calcifying tendinitis consist of shoulder contracture and impingement sign. However, there have been no reports about the use of imaging studies to differentiate these 2 clinical symptoms. A "burning sign" caused by abnormal blood flow was previously reported in the shoulder joint in patients with frozen shoulder by dynamic magnetic resonance imaging. This burning sign was related to pain. The purpose of this study was to investigate the dynamic magnetic resonance imaging findings in patients with symptomatic chronic calcifying tendinitis and to examine the relationship between the location of the burning sign and the physical findings. METHODS: We retrospectively analyzed data for 6 patients with symptomatic chronic calcifying tendinitis (mean age, 55.5 ± 9.3 years; 4 women). The range of shoulder motion, impingement sign, and location of the burning sign were assessed. RESULTS: Four patients had an impingement sign without shoulder contracture, and the other 2 patients had shoulder contracture. All the patients with an impingement sign also had a burning sign around the calcium deposit and no enhancement in the rotator interval and axillary pouch. Conversely, all the patients with contracture had a burning sign in the rotator interval and axillary pouch and no enhancement around the calcium deposit. CONCLUSIONS: Dynamic magnetic resonance imaging identified 2 types of findings in patients with symptomatic chronic calcifying tendinitis: a burning sign in the rotator interval and axillary pouch or around the calcium deposit. The former pattern may be related to shoulder contracture, whereas the latter may be related to impingement sign.

Satisfaction With Elbow Function and Return Status After Autologous Osteochondral Transplant for Capitellar Osteochondritis Dissecans in High School Baseball Players.

BACKGROUND: Osteochondral autograft transplant (OAT), a surgical treatment for capitellar osteochondritis dissecans (OCD), has favorable rates of elbow recovery and return to sports in adolescents. However, few reports have investigated how long patients continue to play baseball after OAT and their satisfaction with their treatment outcome. PURPOSE: To evaluate the rate of boys who played baseball and received OAT for OCD in junior high school or earlier (age <15 years) and continued to play baseball in high school and the players' satisfaction with their elbow function during play. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 32 elbows of boys who played baseball and received OAT at age ≤15 years (mean, 14.1 years) were examined and divided into pitcher (n = 11) and nonpitcher (n = 21) groups according to their player position before surgery. The clinical Timmerman-Andrews score at the end of their high school baseball, participation percentage of players who continued to play baseball, and satisfaction level during play (on a scale of 0-10 during pitching and batting and in a 4-choice format) were compared between the 2 groups. RESULTS: The Timmerman-Andrews scores significantly improved after surgery in both groups, with no significant difference between the groups. Of the 32 players, 30 (93.8%) continued to play baseball throughout high school, including all players in the pitcher group and 19 (90.5%) of those in the nonpitcher group. The percentage of players who continued to pitch was 55.6% (6/11) in the pitcher group. Satisfaction with elbow joint function at the time of pitching was significantly lower in the pitcher group. Further, 5 players reported being "a little unsatisfied" because of elbow pain during pitching. All of the players indicated satisfaction with elbow function during batting. CONCLUSION: The percentage of players who received OAT for OCD in junior high school and continued to play baseball in high school was favorable. However, satisfaction with elbow function during throwing was lower in pitchers than in nonpitchers. CLINICAL RELEVANCE: Before surgery, consent should be obtained from patients who are pitchers after it is explained that satisfaction with elbow joint function during pitching could be decreased after OAT.

The course and clinical impact of articular magnetic resonance imaging findings 6 months after shoulder manipulation under ultrasound-guided cervical nerve root block for frozen shoulder.

BACKGROUND: In our previous study, iatrogenic capsular tears, bone bruises of the humeral head, and labral tears were detected on magnetic resonance imaging (MRI) performed 1 week after manipulation following ultrasound-guided cervical nerve root block in patients with frozen shoulder 6 months after manipulation. METHODS: We studied 25 patients with frozen shoulder. MRI was performed before, 1 week after, and 6 months after manipulation. On the basis of the course of MRI findings over a period of 6 months, the patients were divided into 2 groups: those with MRI findings of bone bruises, capsular tears, and/or labral tears (19 patients) and those with no MRI findings (6 patients). The clinical outcomes of the 2 groups at 6 months after manipulation were compared using the Wilcoxon matched-pairs test, the Mann-Whitney test, and the Fisher exact probability test for statistical analysis. RESULTS: At 1 week after manipulation, 96% of patients had capsular tears, 40% had bone bruises, and 20% had labral tears; these percentages had decreased at 6 months after manipulation to 4%, 20%, and 8%, respectively. No significant differences in clinical outcomes were noted between patients with residual MRI findings 6 months after manipulation and those without any MRI findings. CONCLUSION: Most of the iatrogenic capsular tears, bone bruises, and labral tears detected 1 week after manipulation had disappeared 6 months later. Residual MRI findings 6 months after manipulation had no significant correlation with clinical symptoms.