Relation between spine alignment and scapular position by plain radiograph examination.

Background: Both scapular dynamics and static scapular position are important in the treatment of shoulder dysfunction. This study aimed to create an index that can evaluate scapular position on plain radiographs and evaluate the relation between scapular position and posture accurately. Methods: Using four fresh frozen cadavers, we developed a glenoid angle grade based on the degree of overlap between the shadow of the coracoid inflection point and the upper edge of the scapula on frontal plain radiographs: grade 1, no overlap; grade 2, overlaps by less than half of the shadow; grade 3, overlaps by more than half. We then performed a retrospective cohort study that included 329 shoulders of 329 patients who underwent spine surgery. Spine alignment parameters (SPAPs), including cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence, pelvic tilt, sacral slope, and sagittal vertical axis were measured on standing lateral plain radiographs. Glenoid anterior tilt (GAT) and glenoid anteversion angle (GAVA) were calculated on frontal radiographs and three-dimensional computed tomography scans. Correlations between SPAPs and each angle were investigated, and independent influencing factors were sought in multivariate analysis. Individual factors, GAT, GAVA, and SPAPs were compared among the grades. Results: SPAPs associated with GAT were sagittal vertical axis (R = 0.14, P = .011), TK (R = 0.12, P = .026), and LL (R = -0.11, P = .046). Multivariate analysis identified TK and LL as independent influencing factors (TK, P = .001; LL, P = .008). SPAPs associated with GAVA were CL (R = 0.17, P = .002), TK (R = 0.29, P < .001), and LL (R = 0.25, P < .001). Multivariate analysis identified CL, TK, and LL as independent influencing factors (CL, P = .01; TK, P = .03; LL, P = .03). There were 183, 127, and 19 cases categorized as grades 1, 2, and 3. GAT (grade 1, 24.0 ± 7.8; 2, 32.4 ± 7.0; 3, 41.0 ± 7.8), GAVA (1, 29.3 ± 7.6; 2, 33.7 ± 9.5; 3, 31.5 ± 8.3), and TK (1, 30.6 ± 13.6; 2, 35.1 ± 14.2; 3, 43.1 ± 20.4) differed significantly according to grade. Conclusion: We identified factors that influence scapular position and demonstrated that scapular position can be estimated by a grading system using plain radiographs.

Reduction of perioperative blood loss and operating time for arthroscopic rotator cuff repair by intravenous administration of tranexamic acid.

Background: Tranexamic acid (TXA) is widely used in hip and knee arthroplasty to reduce perioperative bleeding. Recently, its use has been expanded to arthroscopic surgery. The purpose of this study was to evaluate the efficacy of preoperative use of TXA in arthroscopic rotator cuff repair (RCR). Methods: A cohort comprising 129 consecutive patients who underwent arthroscopic primary RCR at our institution was retrospectively investigated according to whether they received TXA (April 2018 to December 2020, TXA group, n = 64) or did not receive TXA (April 2016 to March 2018, non-TXA group, n = 65). TXA was administered at a dose of 1 g intravenously. Rotator cuff tears were repaired by the suture bridge technique. Videos of the arthroscopic procedures were reviewed and rated for visual clarity using a 10-point numeric rating scale. Arthroscopic procedures were divided into glenohumeral, resection of bursal tissue and acromioplasty, and RCR steps. Each step was rated separately. Age, sex, body mass index, hemoglobin level before and on days 1 and 7 after surgery, operating time, mean arterial pressure, tear size, and number of anchors used for cuff repair were compared between the two groups. Results: There were no statistically significant differences in the patient demographic data. The operating time was significantly shorter in the TXA group than in non-TXA group (97.8 ± 21.8 min vs 116.2 ± 26.0 min). The clarity of the visual field was similar between the two groups during the glenohumeral phase but was significantly higher in the TXA group during the resection of bursal tissue and acromioplasty and RCR phases. Hemoglobin level was not significantly different between the groups on postoperative day 1 but was significantly higher in the TXA group on day 7. Conclusion: Administration of a single intravenous dose of TXA improved visual clarity in arthroscopic RCR, decreased the total operating time, and reduced hemoglobin loss on postoperative day 7.

Influence of the glenoid baseplate position on the direction and length of the superior and inferior locking screws.

Introduction : Superior screw insertion in reverse shoulder arthroplasty (RSA) carries the potential risk of suprascapular injury. The purpose of this study was to evaluate how the baseplate position affects the superior screw position and length in RSA. Methods : Three-dimensional (3D) computer simulation models of RSA were established using computed tomography data of baseplates with superior and inferior screws and 3D scapular models from 10 fresh cadavers. Superior screw position, the distance from the superior screw hole to the suprascapular notch, and the screw lengths were measured and compared among various baseplate positions with two inferior tilts (0 and 10 degrees) and three rotational patterns (11-5, 12-6, and 1-7 o'clock in the right shoulder). Results : For the 1-7 o'clock / inferior tilt 0 degrees baseplate, the superior screw located anterior to the SS notch in all shoulders, the distance to the SS notch was the longest (12.8 mm), and the inferior screw length was the shortest (23.1 mm). Conclusion : Although there is a concern of a short inferior screw length, initial fixation using a baseplate with 1-7 o'clock rotation and an inferior tilt of 0 degrees appears preferable for SS nerve injury prevention during superior screw insertion. J. Med. Invest. 69 : 185-190, August, 2022.

Characteristics of gene expression in frozen shoulder.

BACKGROUND: Severe frozen shoulder (FS) is often resistant to treatment and can thus result in long-term functional impairment. However, its etiology remains unknown. We hypothesized that gene expression of FS would vary by synovial location. METHODS: The synovial tissues of patients with FS were collected prospectively and analyzed for the expression of 19 genes. Synovial tissues from patients with rotator cuff tear (RCT) or shoulder instability (SI) were also analyzed as controls. A total of 10 samples were analyzed from each group. The specimens were arthroscopically taken from three different locations: rotator interval (RI), axillary recess (AX), and subacromial bursa (SAB). Total RNA was extracted from the collected tissues and was analyzed by real-time polymerase chain reaction for the following genes: matrix metalloproteinases (MMPs); tissue inhibitors of metalloproteinases (TIMPs); inflammatory cytokines (IL1B, TNF, and IL6); type I and II procollagen (COL1A1 and COL2A1); growth factors (IGF1 and TGFB1); neural factors (NGF and NGFR); SOX9; and ACTA2. RESULTS: Site-specific analysis showed that MMP13, IL-6, SOX9, and COL1A1 were increased in all three sites. Four genes (MMP3, MMP9, COL2A1, and NGFR) were increased in the AX, MMP3 in the RI, and NGFR in the SAB were increased in the FS group than in the RCT and SI groups. In the FS group, there was a correlation between the expression of genes related to chondrogenesis (MMP2, IGF1, SOX9, COL2A1, NGF, and NGFR) or fibrosis (MMP9, TGFB1, and COL1A1). CONCLUSION: The expression levels of numerous MMPs, pro-inflammatory cytokines, and collagen-related genes were increased in the FS group, suggesting that catabolic and anabolic changes have simultaneously occurred. In addition, genes related to chondrogenesis or fibrosis were highly expressed in the FS group, which might have affected the range of motion limitation of the shoulder. Compared to RI and SAB, the AX was the most common site of increased expression in FS. Analyzing the lower region of the shoulder joint may lead to the elucidation of the pathogenesis of FS.

Partial thickness tear of the supraspinatus at the musculotendinous junction in a softball catcher.

We report a rare case of a partial thickness tear of the supraspinatus at the musculotendinous junction in a softball catcher. Preoperative magnetic resonance images of the shoulder showed high signal intensity areas at the musculotendinous junction, along with discontinuity of the articular side of the supraspinatus. Arthroscopic examination revealed articular-side partial tear at the musculotendinous junction. The patient was able to return to playing softball 20 weeks after arthroscopic side-to-side repair. J. Med. Invest. 68 : 386-388, August, 2021.

Optimal baseplate position in reverse shoulder arthroplasty in small-stature Japanese women†:†a cadaveric study.

The purpose of this study was to determine the optimal position of the baseplate on the small glenoid of female Japanese. Two sets of 3D scapular models were made according to the CT data of 7 female cadavers. We set two scenarios of the baseplate placement : A and B. In scenario A, the baseplate was placed on the glenoid face centrally in the anteroposterior direction. In scenario B, the baseplate was implanted at the point where the baseplate post was contained within the glenoid vault. Whether or not the baseplate post perforated the scapular neck was recorded. In scenario A, the central post penetrated the scapular neck posteriorly in 5 scapulae. In scenario B, the average distances from the guide pin position to the anterior glenoid rim was 9.7 ±â€…1.7 mm and the optimal position of the guide pin was 1.9 ±â€…1.7 mm anterior from the glenoid center. The central post was contained within the scapula without breakage of the cortex. This study demonstrated that shifting the center of the baseplate slightly anterior to the anatomic center is necessary to avoid perforation of the scapular neck in small female Japanese. J. Med. Invest. 68 : 175-180, February, 2021.

Two Cases of Spontaneous Recurrent Hemarthrosis of the Shoulder with Acromial Erosion Associated with Impingement Syndrome.

Spontaneous recurrent hemarthrosis of the shoulder is rare. Most previously reported cases were associated with massive rotator cuff tear and degenerative glenohumeral arthritis. We described two cases of recurrent hemarthrosis without osteoarthritis of the shoulder. Both cases had bony erosion of the acromion, which was confirmed arthroscopically as the origin of bleeding. Arthroscopic coagulation, acromioplasty, and drainage were successful and there was no recurrence of hemorrhage.

Bilateral Osteochondritis Dissecans of the Capitellum in Fraternal Twins: A Case Report.

CASE: We report the cases of 15-year-old male fraternal twins with bilateral osteochondritis dissecans (OCD) of the capitellum in the absence of syndromic features. At the time of presentation, they had been actively engaged in competitive rhythmic gymnastics for 3 years. Both patients had chronic symptoms in the right elbow, and both underwent arthroscopic evaluation and management. CONCLUSION: The cases of these 2 patients provide evidence to support the theory that the etiology of OCD may have a genetic background.

Pediatric isthmic spondylolisthesis showing radiologic evidence of slippage after physis injury.

The pathogenesis of slippage in pediatric spondylolisthesis is still unclear, although epiphyseal injury may account for many cases based on preclinical studies. However, no reports have described a pediatric case of isthmic spondylolisthesis showing radiologic evidence of epiphyseal injury. We report such evidence in a 13-year-old boy with low-back pain. Radiography revealed rounding of the S1 surface, a fracture line below the S1 endplate surface, and a bone marrow lesion in addition to slippage. Slippage and the rounding deformity were partially reversed (from 20 to 14% and from 42 to 27%, respectively) with conservative treatment and natural bone remodeling.

Outcome of an elbow check-up system for child and adolescent baseball players.

PURPOSE: Our aim was to examine the outcome of an elbow check-up system for youth baseball players. In particular, we investigated the nature of elbow injuries in youth baseball players with elbow pain and ultrasonographic findings of the capitellum. MATERIALS AND METHODS: A total of 1605 players participating in the regional summer championship in July 2013 underwent a questionnaire survey, physical examination, ultrasound imaging, and radiographic examination. RESULTS: A total of 499 (31.1%) players reported episodes of elbow pain, of whom 320 (64.1%) had abnormal findings on physical examination, and 115 (35.9%) agreed to undergo radiography. Among them, 98 (85.2%) exhibited radiographic abnormalities. On the initial ultrasonography screening, 60 (3.7%) players had an abnormal finding and 55 (91.7%) agreed to undergo radiography. Among them, 26 (47.3%) were found to have osteochondritis dissecans (OCD) of the capitellum on radiographs. CONCLUSIONS: About 30% of youth baseball players had episodes of elbow pain, and 64.1% of players with elbow pain had abnormal findings on physical examination. Furthermore, 85.2% of subjects who underwent radiographic examination exhibited radiographic abnormalities. About 4% of young baseball players had an abnormal finding on initial ultrasonography screening, and nearly 50% of them had OCD of the capitellum on radiographs. J. Med. Invest. 63: 171-174, August, 2016.

Subchondral Insufficiency Fracture of the Femoral Head Caused by Excessive Lateralization of the Acetabular Rim.

We present a case of a 53-year-old woman with subchondral insufficiency fracture (SIF) of the femoral head without history of severe osteoporosis or overexertion. Plain radiographs showed acetabular overcoverage with excessive lateralization of the acetabular rim. A diagnosis of SIF was made by typical MRI findings of SIF. The lesion occurred at the antipodes of the extended rim. Increased mechanical stress over the femoral head due to impingement against the excess bone was suspected as a cause of SIF. The distinct femoral head deformity is consistent with this hypothesis. This is the first report of SIF associated with acetabular overcoverage.

Stress fracture of the thoracic spine in an elite rhythmic gymnast: A case report.

Spondylolysis, a defect or stress fracture of the vertebral pars interarticularis, occurs most frequently in the lower lumbar spine and occasionally in the cervical spine, but is extremely rare in the thoracic spine. We report the case of a 17 year-old girl, an elite rhythmic gymnast, who reported with early-stage thoracic spondylolysis at T10 and T11 levels. Physicians should be aware that performance of unusual athletic movements, such as those by gymnasts, may lead to spondylolysis in rare locations.

Arthroscopic excision of unstable os acromiale associated with impingement syndrome: a case report.

Os acromiale is a rare anatomical variant that is caused by failure of fusion of the acromial apophysis and is usually asymptomatic. We report a case of impingement syndrome of the left shoulder secondary to unstable os acromiale, which was initially overlooked and confirmed only during arthroscopic examination. Arthroscopic excision of the unstable fragment was successful without residual dysfunction of the deltoid muscle.

Clinical Significance of High-intensity Zone for Discogenic Low Back Pain: A Review.

High-intensity zone (HIZ) was originally described as a high-intensity signal on T2-weighted magnetic resonance (MR) images, located in the posterior annulus fibrosus, clearly separated from the nucleus pulposus. Among symptomatic patients with low back pain, HIZ is present in 28-59% of cases. In morphologically abnormal discs, high sensitivity and specificity of 81% and 79%, respectively, were reported for HIZs and concordant pain during discography. In contrast, another report indicated low rates. Although most papers reported high sensitivity and specificity for this relationship, it remains controversial. Regarding the pathology of HIZs, inflammatory granulation tissues are found at sites showing HIZs. Such inflammatory tissues produce pro-inflammatory cytokines and mediators, which sensitize the nociceptors within the disc and cause pain. An effective treatment for this condition is yet to be established. Recently, minimally invasive surgery using percutaneous endoscopic discectomy (PED) under local anesthesia was introduced. After removal of the degenerated disc material, the HIZ is identified with the endoscope and then coagulated and modulated with a bipolar radio pulse. This technique is called thermal annuloplasty. In conclusion, HIZs is an important sign of painful intervertebral disc disruption, if identified precisely based on factors such as location and intensity.

Optimizing baseplate position in reverse total shoulder arthroplasty in small-sized Japanese females: technical notes and literature review.

The management of cuff tear arthropathy (CTA) has always been a challenge for shoulder surgeons. Introduction of reverse total shoulder arthroplasty (RTSA) helped in providing pain relief and improved shoulder function in patients with CTA. In this study, we aimed to evaluate the short-term clinical results and some clinical details regarding the types of available prosthesis, positioning, and size of the components for RTSA in a population of short-stature female Japanese. In our seven cases, the average glenoid size was 23.9 mm in width and 34.2 mm in height. The average width was smaller than the size of all available baseplates. We implanted reverse shoulder prostheses with baseplate that measured 28 mm in diameter and two locking screws. The center of the baseplate was shifted to allow slight anterior overhang relative to the anatomical center to avoid breakage of the posterior cortex and to achieve firm fixation. One case of humeral shaft fracture occurred while inserting the humeral stem and required encircling wiring. In our experience, the short term clinical results of RTSA were excellent, but a new prosthesis that is designed to fit the short stature of Asians with smaller glenoid and humerus should be considered.

Tendon retraction with rotator cuff tear causes a decrease in cross-sectional area of the supraspinatus muscle on magnetic resonance imaging.

BACKGROUND: Muscle atrophy and fatty degeneration of the rotator cuff muscles have been reported as negative prognostic indicators after rotator cuff repair. Although the Y-shaped view is widely used for measuring the cross-sectional area of the supraspinatus muscle, the contribution of retraction of the torn tendon as well as muscle atrophy must be considered. The purpose of this study was to clarify the relationship between cross-sectional area and tendon retraction or size of the tear. METHODS: This study included 76 shoulders that were evaluated arthroscopically for the presence and size of tears. Cross-sectional areas of rotator cuff muscles were measured from the Y-shaped view to 3 more medial slices. The occupation ratio and tangent sign were evaluated on the Y-shaped view. The retraction of torn tendon was also measured on the oblique coronal images. RESULTS: On the Y-shaped view, the cross-sectional area of the supraspinatus and the occupation ratio decreased in conjunction with the increase in tear size. A significant decrease in cross-sectional area was noted only in large and massive tears on more medial slices from the Y-shaped view. Significant decreases in the cross-sectional area of the infraspinatus were observed in large and massive tears on all images. A negative correlation was found between tendon retraction and cross-sectional area, which was strongest on the Y-shaped view. CONCLUSIONS: To avoid the influence of retraction of the supraspinatus tendon, sufficient medial slices from the musculotendinous junction should be used for evaluation of muscle atrophy.

Epidemiology of shoulder and elbow pain in youth baseball players.

OBJECTIVES: There are relatively few published epidemiological studies examining the differences in the risk of shoulder and elbow pain in young baseball players. The purpose of this study was to investigate risk factors for shoulder and elbow pain in child and adolescent baseball players. METHODS: A total of 1563 players aged 7 to 12 years participated in this investigation. Subjects were asked whether they had experienced episodes of shoulder or elbow pain. We investigated the following risk factors for shoulder and elbow pain: age, position, years of baseball experience, and training hours per week. Data from the groups with and without shoulder and elbow pain were analyzed using multivariate logistic regression models. RESULTS: Among the 1563 participants, 15.9% and 29.2% reported episodes of shoulder and elbow pain, respectively. Multivariate analysis showed that shoulder pain was associated with age 10, 11, and 12 years, and that elbow pain was associated with age 10, 11, and 12 years, playing catcher, and >2 years of baseball experience. Training hours per week were not associated with either shoulder or elbow pain. CONCLUSION: In over 1000 baseball players aged 7 to 12 years, 15.9% reported episodes of shoulder pain, while 29.2% reported elbow pain in the throwing arm. The associated risk factors were different for each type of pain. Shoulder pain was associated with increased age while elbow pain was associated with increased age, increased years of baseball experience, and playing catcher.

Comparison of morphological features in the femur between femoral neck fractures and femoral intertrochanteric fractures.

PURPOSE: The purpose of this study is to make proximal femur fracture types more predictable by considering morphological features of an acetabulum as well as of a proximal femur in the Japanese population. METHODS: A retrospective review of radiographs of the proximal femoral fractures was conducted in patients registered from 2010 to 2012, dividing into patients with femoral neck fractures; Group Neck (n = 101), and patients with femoral intertrochanteric fractures; Group IT (n = 99). Intergroup comparison was conducted: age, sex, height, weight, the ratios of femoral intertrochanteric length (IT Length), femoral neck length (Neck Length), femoral neck width (Neck Width), lateral offset length (Offset) to femoral head diameter, neck-shaft angle (N-S angle), and center-edge angle of the acetabulum (C-E angle), adjusting for age. Multiple logistic regression analysis was conducted among these parameters. RESULTS: The Group IT showed significantly older age than the Group Neck. Greater C-E angle in Group IT was observed in the patients in their 80s and 90s years of age. The Group Neck showed greater N-S angle only in the patients in their 80s years of age. In multiple logistic regression analysis, the impact of the age and the C-E angle on the fracture types was similar (odds ratio 1.08, 1.09, respectively, p < 0.01 both). CONCLUSIONS: Age, N-S angle, and C-E angle could be independent predictors for determining the proximal femur fracture types.

Postoperative discal cyst: An unusual complication after microendoscopic discectomy in teenagers.

Various complications after microendoscopic discectomy (MED) are well known, but postoperative discal cyst is a unique and relatively unknown complication. Here, we report on two teenage patients who presented with postoperative discal cyst after MED for herniated nucleus pulposus (HNP), which resolved after conservative treatment. The patients were diagnosed with HNP at L4-5 and L5-S1 based on MRI and then treated by MED. Postoperative discal cyst was diagnosed on MRI after recurrence of symptoms. Both patients were managed conservatively. T2-weighted MRI demonstrated hyperintense collections adjacent to the operated intervertebral disc level, which were communicating with the corresponding disc annulus. Because the clinical symptoms were relatively mild, the patients were managed conservatively; both made a complete clinical recovery with radiological evidence of improvement. Postoperative discal cyst is a relatively unknown complication after MED for HNP. Surgeons should be aware of this postoperative complication when operating on young individuals with HNP.

Hysterical conversion paralysis in an adolescent boy with lumbar spondylolysis.

We describe a case of recurrent hysterical paralysis triggered by low back pain because of lumbar spondylolysis. A 16-year-old male soccer player was referred to our institution with five previous episodes of acute paralysis triggered by severe low back pain. We performed direct surgical repair of the terminal-stage bilateral spondylolysis at L4 using a hook-rod system. His chronic low back pain was completely resolved, and no further episodes of hysterical paralysis have occurred after surgery. Spine surgeons should be aware of possible hysterical conversion paralysis when there is discrepancy between radiological and neurological findings.