Radiolunate Arthrodesis in the Rheumatoid Wrist: A Retrospective Clinical and Radiologic Long-Term Follow-up.

PURPOSE: This study aimed to determine the results of radiolunate arthrodesis for rheumatoid arthritis (RA) after a long-term follow-up period of up to 20 years under tight postoperative medical control of RA. We also compared the results between patients with and without degenerative changes in the midcarpal joints at follow-up. We determined the radiologic factors predictive of secondary degenerative changes in the midcarpal joint. METHODS: This was a long-term retrospective analysis of 16 wrists of 14 patients with RA treated with radiolunate arthrodesis first reported in 2013. The mean follow-up period was 14 years (range, 8-23 years; SD, 4.6 years). Ten wrists had a Larsen classification of grade III, whereas 6 wrists had grade IV. The range of motion was assessed, and clinical outcomes were graded using the Mayo Wrist Score and Stanley classification system. The Carpal Height Index, Ulnar Translation Index, and changes in the midcarpal joint contour were determined from radiographs. We categorized the changes in the midcarpal joint as unchanged or degenerative. RESULTS: At final follow-up, the clinical scores improved; however, the extension and flexion range of motion was significantly reduced compared with that before surgery. The Carpal Height Index and Ulnar Translation Index improved immediately after surgery and remained stable at final follow-up. The changes in the midcarpal joint were categorized as unchanged in 6 wrists and degenerative in 10 wrists. The clinical outcomes were similar between the groups. The mean preoperative Ulnar Translation Index was significantly higher in the degenerative group than in the unchanged group. CONCLUSIONS: Radiolunate arthrodesis in patients with RA maintained good clinical results and corrected alignment, even during long-term follow-up. Preoperative severe ulnar translation deformity was a risk factor for postoperative degeneration of the midcarpal joint, and pre-existing degenerative changes at the midcarpal joint might lead to loss of wrist range of motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Computed tomography revealed the correlation between radiolucency and alignment of all-polyethylene pegged glenoid component more than 10 years after total shoulder arthroplasty in the Japanese population.

BACKGROUND: Anatomical total shoulder arthroplasty (TSA) provides successful long-term outcomes but complications can occur after 10 years that require revision. Computed tomography (CT) is a useful tool for assessing radiolucent lines around the glenoid component of TSA; however, the merits of long-term post-TSA follow up with CT are unclear. The purpose of this study was to evaluate the long-term outcomes after TSA of Japanese population and to identify factors related to radiolucency around the glenoid component using CT. METHODS: A retrospective review was conducted of TSA patients who had completed at least 10 years of clinical follow up. Radiographs and CT images of the affected shoulder obtained at the last follow up were evaluated for radiolucent lines around the stem and each peg, superior inclination and retroversion of the glenoid component, subluxation index, and critical shoulder angle (CSA). Shoulder ROM, Constant-Murley score and UCLA score were compared between the preoperative and last follow up period. RESULTS: Eighteen shoulders in 16 patients met the inclusion criteria. Mean patient age was 61 years, mean follow up period was 137 months, and mean Yian CT score was 19%. CT score was significantly highest in pegs located inferiorly (p < 0.05). Mean glenoid superior inclination was 12.6°, retroversion was -0.3°, subluxation index was 46%, and CSA was 33.7°. Glenoid superior inclination was significantly lower (p = 0.007) in shoulders with possible loosening than in cases with no loosening (5.0° vs 15.6°). Mean Constant score and UCLA score improved significantly after TSA, from 25.8 to 10.7 points preoperatively to 70.1 and 28.9 points postoperatively, respectively. Mean shoulder flexion, internal rotation, and external rotation also showed improvement postoperatively. CONCLUSION: TSA provides good long-term outcomes. Radiolucency was present most frequently around the inferior pegs of the glenoid component. Glenoid superior inclination may affect the formation of radiolucent lines around glenoid pegs. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment study.

Correlation between carpal rotational alignment and postoperative wrist range of motion following total wrist arthroplasty.

BACKGROUND: Although total wrist arthroplasty (TWA) has become a common treatment option for wrists with damage due to rheumatoid arthritis (RA), the optimal implant axial alignment for TWA has been inadequately studied. This study was performed to investigate the relationships between implant alignment and carpal rotational alignment and the wrist range of motion (ROM) following TWA. METHODS: This study included 18 patients who underwent TWA using a DARTS® Total Wrist System (Teijin Nakashima Medical, Okayama, Japan) for wrist RA. Pre- and 6-month postoperative computed tomography scans were performed, including the radial volar line (Rv), capitohamate axis (CH), and Rv-CH angle in axial scans. The wrist ROM was also measured. The relationship between the Rv-CH angle and ROM was examined. RESULTS: The mean Rv-CH angle showed significant wrist pronation from 73.0° to 83.4° postoperatively. We observed a significant positive correlation (0.58) between the postoperative Rv-CH angle and extension and a significant negative correlation (- 0.56) between the postoperative Rv-CH angle and flexion. CONCLUSIONS: Implantation of the DARTS® TWA prosthesis resulted in pronation of the carpal axial alignment, which was correlated with postoperative wrist extension. The volar cortex of the distal radius can be a novel reference axis for adequate implant placement.

Patient characteristics affecting knowledge of the possibility of surgical reconstruction for rheumatoid hand and wrist deformities.

OBJECTIVES: We aimed to investigate patient characteristics affecting their knowledge of surgical reconstruction for rheumatoid hand and wrist deformities, and to investigate such characteristics affecting their hope of receiving hand surgery if patients with rheumatoid arthritis (RA) knew surgical reconstruction options. METHODS: We carried out a questionnaire survey for all patients with RA who came to our outpatient department of rheumatology. Multivariate logistic regression analysis was performed to examine significant characteristics associated with the knowledge of surgical reconstruction and patients' hope of receiving hand surgery. RESULTS: In total, 687 patients were evaluated in this study and 337 (49%) reported knowledge about surgical reconstruction. A multivariate logistic regression analysis showed that patients with good control of disease activity and with long-lasting hand and wrist deformities were significantly associated with having knowledge of surgical reconstruction. Among the 337 patients with knowledge, only 122 (36%) expressed a hope of receiving hand surgery. The statistical analysis showed that younger age and surgical history were significantly associated with the hope of receiving surgery. CONCLUSION: Surgeons and rheumatologists should enlighten patients about the importance of hand surgery to achieve functional remission in this new era of treatment for patients with RA.

Fibroma of tendon sheath of the hand in a 3-year-old boy: a case report.

BACKGROUND: Fibroma of tendon sheath (FTS) is a rare benign soft tissue tumor that often occurs in the upper extremities. It manifests as a slow-growing mass, often without tenderness or spontaneous pain. FTS occurs most commonly in people aged 20-40 years and is extremely rare in young children. Because FTS presents with atypical physical and imaging findings, it might be misdiagnosed as another soft tissue tumor such as a ganglion cyst or tenosynovial giant cell tumor (TSGCT). Although marginal resection is usually performed, a high rate of local recurrence is reported. CASE PRESENTATION: A boy aged 3 years and 1 month visited our outpatient clinic with a complaint of a mass of the left hand. An elastic hard mass approximately 20 mm in diameter could be palpated on the volar side of his left little finger. This mass was initially diagnosed as a ganglion cyst at another hospital. Ultrasonography revealed a well-circumscribed hypoechoic mass with internal heterogeneity on the flexor tendon. On magnetic resonance imaging (MRI), the mass showed iso signal intensity to muscle on T1-weighted images, and homogeneously low signal intensity to muscle on T2-weighted images. The mass was peripherally enhanced after contrast administration. FTS was initially suspected as the diagnosis on the basis of these imaging features. Because of the limited range of motion of his little finger, surgery was performed when he was 4 years old. Histopathological findings indicated the mass was well-circumscribed and contained scattered spindle cells embedded in a prominent collagenous matrix. The spindle cells contained elongated and cytologically bland nuclei with a fine chromatin pattern. Nuclear pleomorphism and multinucleated giant cells were not observed. On the basis of these findings, we made a diagnosis of FTS. One year after surgery, no signs of local recurrence were observed. CONCLUSIONS: We experienced an extremely rare case of FTS in the hand of a 3-year-old child. We especially recommend ultrasonography for hand tumors of young children to diagnose or eliminate ganglion cysts. MRI helped differentially diagnose FTS from TSGCT. Although marginal resection can be performed as a treatment, great care should be taken postoperatively because FTS has a high possibility of local recurrence.

Topographic Analysis of Lateral Versus Medial Femoral Condyle Donor Sites for Oblong Medial Femoral Condyle Lesions.

PURPOSE: To analyze the topographic matching of oblong osteochondral allografts to treat large oval medial femoral condyle (MFC) lesions using computer simulation models. The secondary objective was to determine whether lateral femoral condyle (LFC) grafts would have a similar surface matching when compared with MFC grafts in this setting. METHODS: Human femoral hemicondyles (10 MFCs, 7 LFCs) underwent 3-dimensional computed tomography. Models were created from computed tomography images and exported into point-cloud models. Donor-recipient matches with large condylar width mismatch were excluded. The remaining specimen were divided into 3 donor-recipient groups with 2 defect sizes (17 × 30 mm and 20 × 30 mm): 20 MFC donor (MFCd)-MFC recipient (MFCr), 27 ipsilateral LFC donor (LFCd)-MFCr, and 26 contralateral LFCd-MFCr. Grafts were optimally virtually aligned with the MFCr defect. Mismatch of the articular cartilage and subchondral bone surfaces between the graft and the defect and articular step-off were calculated. RESULTS: MFCd grafts resulted in articular cartilage surface mismatch and peripheral step of less than 0.5 mm for both defect sizes. The subchondral bone surface mismatch was significantly greater than the articular cartilage surface mismatch (P < .01) in both defect sizes). Conversely, the ipsilateral and contralateral LFCd grafts resulted in significantly greater articular cartilage surface mismatch and step-off for both defect sizes when compared to MFCd grafts (P < .01). CONCLUSIONS: Oblong MFC allografts provide acceptable topographic matching for large oval MFC lesions when condylar width differences are minimized. However, concern exists in using oblong LFC allografts for MFC defects, as this can result in increased peripheral step-off and surface mismatch. CLINICAL RELEVANCE: These data reinforce the ability to use oblong MFC osteochondral allograft for treating oval cartilage lesions of the MFC when condylar width is considered. Although other studies have demonstrated LFCs can be used to treat circular defects on the MFC, this may not be true for oblong grafts.

Topographic Matching of Osteochondral Allograft Transplantation Using Lateral Femoral Condyle for the Treatment of Medial Femoral Condyle Lesions: A Computer-Simulated Model Study.

PURPOSE: The purpose of this study was to determine whether lateral femoral condyle (LFC) osteochondral allografts (OCAs) would have a similar articular cartilage contour and resulting subchondral bone contour when compared with medial femoral condyle (MFC) allografts for the treatment of MFC chondral defects. METHODS: In this controlled laboratory study, human femoral hemi-condyles (10 MFCs and 8 LFCs) were divided into 4 groups: MFC recipient, MFC donor, ipsilateral LFC donor, and contralateral LFC donor. Computed tomography (CT) images were obtained for each, and 3D CT models were created and exported into point-cloud models. Three circular defect and graft models were created on each condyle at 3 locations (0°, 45° posterior, and 90° posterior regions). The graft model in each donor group was virtually placed on the MFC recipient defect model. The least distances of the articular cartilage surface between the graft and the defect models and the resulting mean least distance of the subchondral bone surface were calculated. RESULTS: The mean least distance of the articular cartilage surface was less than 0.5 mm in all donor-recipients, and there was no significant difference among donor groups. Although the mean least distance of the subchondral bone surface was significantly greater than the articular cartilage surface in all donor groups (P < .001), there was no significant difference among donor groups. CONCLUSION: Ipsilateral and contralateral LFC grafts provided similar articular cartilage surface and resulting subchondral bone surface matching with that of MFC grafts, suggesting that LFCs could be a potential source of OCA for the treatment of MFC lesions. CLINICAL RELEVANCE: Ipsilateral and contralateral LFCs can be suitable donor sites for the treatment of MFC lesions with OCAs.

Difference in vascular patterns between transosseous-equivalent and transosseous rotator cuff repair.

BACKGROUND: Vascularity is the important factor of biologic healing of the repaired tissue. The purpose of this study was to clarify sequential vascular patterns of repaired rotator cuff by suture techniques. METHODS: We randomized 21 shoulders in 20 patients undergoing arthroscopic rotator cuff repair into 2 groups: transosseous-equivalent repair (TOE group, n = 10) and transosseous repair (TO group, n = 11). Blood flow in 4 regions inside the cuff (lateral articular, lateral bursal, medial articular, and medial bursal), in the knotless suture anchor in the TOE group, and in the bone tunnel in the TO group was measured using contrast-enhanced ultrasound at 1 month, 2 months, 3 months, and 6 months postoperatively. RESULTS: The sequential vascular pattern inside the repaired rotator cuff was different between groups. The blood flow in the lateral articular area at 1 month, 2 months, and 3 months (P = .002, .005, and .025) and that in the lateral bursal area at 2 months (P = .031) in the TO group were significantly greater than those in the TOE group postoperatively. Blood flow was significantly greater for the bone tunnels in the TO group than for the knotless suture anchor in the TOE group at 1 month and 2 months postoperatively (P = .041 and .009). CONCLUSION: This study clarified that the sequential vascular pattern inside the repaired rotator cuff depends on the suture technique used. Bone tunnels through the footprint may contribute to biologic healing by increasing blood flow in the repaired rotator cuff.

Predictive factors of long head of the biceps tendon disorders-the bicipital groove morphology and subscapularis tendon tear.

BACKGROUND: Disorders of the long head of the biceps (LHB) tendon contribute to anterior shoulder pain. Although LHB tendon disorders are associated with rotator cuff disease, distinguishing between biceps and rotator cuff pathology is difficult. The objective was to identify the predictors of LHB tendon disorders associated with a supraspinatus tear. METHODS: In 55 patients (average age, 65 years) undergoing arthroscopic rotator cuff repair, bicipital groove morphology were assessed using computed tomography, and subscapularis tear and bicipital groove effusion were assessed using magnetic resonance imaging, retrospectively. The LHB tendon was evaluated arthroscopically according to the Lafosse classification. Univariate and multivariate ordinal logistic regression analyses were conducted for injury grade with all covariates. RESULTS: The arthroscopic evaluation of the LHB tendon showed that there were 23 shoulders classified as grade 0, 15 as grade 1, and 17 as grade 2. Univariate logistic regression analysis showed that the width and depth, a medial spur of the bicipital groove, and a subscapularis tear were significantly associated with LHB tendon disorders. Multivariate ordinal logistic regression analysis identified a medial spur and subscapularis tear as significant predictors of LHB tendon disorders. CONCLUSIONS: The preoperative computed tomography and magnetic resonance images, notably the presence of a spur on the bicipital groove or a subscapularis tear, were useful for identifying LHB tendon disorders. When these are found in preoperative images, the clinician should evaluate the patient for the presence of an LHB tendon disorder as a pain generator.

Radial shortening osteotomy for Kienböck disease: minimum 10-year follow-up.

PURPOSE: To clarify long-term clinical and radiological results more than 10 years after radial shortening osteotomy for Kienböck disease. METHODS: Eleven wrists of 10 patients that had been classified as Lichtman stages 3A (2 wrists), 3B (8 wrists), and 4 (1 wrist) underwent radial shortening for Kienböck disease. The mean follow-up period was 14.3 years (range, 10-21 y). Clinical outcomes were quantified using the Japanese version of the Disabilities of the Arm, Shoulder, and Hand questionnaire and the modified Mayo wrist score. Radiographic and magnetic resonance imaging studies were performed for 9 of the 10 patients preoperatively and all 10 patients at follow-up. RESULTS: At follow-up, 6 wrists were asymptomatic and the remaining 5 had mild occasional pain. The mean range of extension and grip strength significantly improved. The mean modified Mayo wrist score and Disabilities of the Arm, Shoulder, and Hand scores were 92 (range, 80-100) and 5 (range, 0-18), respectively. At follow-up, no progression of the Lichtman stage was found in any patient. There was no significant progressive lunate collapse in any patient. The magnetic resonance imaging in 7 wrists showed increased signal intensity of the lunate; the remaining 3 wrists had no alteration in signal intensity of the bone. CONCLUSIONS: Our study demonstrated satisfactory clinical results after 10 or more years in patients who underwent radial shortening for Kienböck disease. Although we found no improvement in signal intensity of the lunate in 3 wrists, unloading of the diseased lunate after radial shortening gives long-lasting symptom relief and may prevent lunate collapse. TYPE OF STUDY/LEVEL OF DISEASE: Therapeutic IV.

Interruption of glycosphingolipid synthesis enhances osteoarthritis development in mice.

OBJECTIVE: Glycosphingolipids (GSLs) are ubiquitous membrane components that modulate transmembrane signaling and mediate cell-to-cell and cell-to-matrix interactions. GSL expression is decreased in the articular cartilage of humans with osteoarthritis (OA). This study was undertaken to determine the functional role of GSLs in cartilage metabolism related to OA pathogenesis in mice. METHODS: We generated mice with knockout of the chondrocyte-specific Ugcg gene, which encodes an initial enzyme of major GSL synthesis, using the Cre/loxP system (Col2-Ugcg(-/-) mice). In vivo OA and in vitro cartilage degradation models were used to evaluate the effect of GSLs on the cartilage degradation process. RESULTS: Although Col2-Ugcg(-/-) mice developed and grew normally, OA changes in these mice were dramatically enhanced with aging, through the overexpression of matrix metalloproteinase 13 and chondrocyte apoptosis, compared to their wild-type (WT) littermates. Col2-Ugcg(-/-) mice showed more severe instability-induced pathologic OA in vivo and interleukin-1α (IL-1α)-induced cartilage degradation in vitro. IL-1α stimulation of chondrocytes from WT mice significantly increased Ugcg messenger RNA expression and up-regulated GSL metabolism. CONCLUSION: Our results indicate that GSL deficiency in mouse chondrocytes enhances the development of OA. However, this deficiency does not affect the development and organization of cartilage tissue in mice at a young age. These findings indicate that GSLs maintain cartilage molecular metabolism and prevent disease progression, although GSLs are not essential for chondrogenesis of progenitor and stem cells and cartilage development in young mice. GSL metabolism in the cartilage is a potential target for developing a novel treatment for OA.

Effect of low-intensity pulsed ultrasound on bone healing at osteotomy sites after forearm bone shortening.

PURPOSE: To test the hypothesis that low-intensity pulsed ultrasound (LIPUS) may accelerate healing at osteotomy sites after forearm bone shortening osteotomies. METHODS: In this prospective study, we enrolled 27 patients who underwent ulnar shortening osteotomy for ulnar impaction syndrome or radial shortening osteotomy for Kienböck disease. We randomized limbs to be treated with LIPUS (14 osteotomies, LIPUS group) or without LIPUS (13 osteotomies, control group). At 1 week postoperatively, patients in the LIPUS group received once-daily 20-minute LIPUS treatments that continued until at least 12 weeks postoperatively. At 2, 4, 6, 8, 12, 16, and 24 weeks postoperatively, we assessed union of the osteotomy site to determine the time to union using 4 projections of x-rays. RESULTS: In this study, all osteotomies achieved complete union. The mean times to complete cortical union were 57 days in the LIPUS group and 76 days in the control group. Regarding endosteal union, the mean times were 121 days in the LIPUS group and 148 days in the control group. The LIPUS group had significantly reduced times for both types of union. CONCLUSIONS: Application of LIPUS shortened the time to cortical union by 27%, and to endosteal union by 18%. Our results indicate that LIPUS accelerated bone healing after we performed forearm bone shortening osteotomies. This may provide earlier return to activity and work for patients undergoing forearm osteotomies.

Clinical and radiological results of radiolunate arthrodesis for rheumatoid arthritis: 22 wrists followed for an average of 7 years.

PURPOSE: To evaluate the clinical and radiological results of radiolunate (RL) arthrodesis for rheumatoid arthritis (RA) patients treated with disease-modifying antirheumatic drugs and/or biologicals with an average of 7 years of follow-up. In addition, we compared the results in advanced stages with those in less advanced stages in patients with comparatively low disease activity of RA. METHODS: This study included RL arthrodesis for 22 wrists in 19 patients with comparatively low disease activity of RA. The mean follow-up period was 7 years (range, 2-16 y). Fourteen wrists with Larsen classification grade III and 8 wrists with grade IV were included in this study. The range of motion was calculated, and clinical scores were graded using the Mayo wrist score and the Stanley classification. The carpal height ratio (CHR) and ulnar translation (UT) were determined from the radiographs. RESULTS: All wrists achieved radiographic fusion. Clinical scores were markedly improved, although there was a decrease in flexion. The Larsen grade did not deteriorate during follow-up. CHR and UT improved immediately after operation and remained good through the final follow-up. Although the flexion/extension range of motion of the grade IV wrists was smaller than that of the grade III wrists at follow-up, both groups obtained good clinical results. CONCLUSIONS: Our results for RL arthrodesis were clinically and radiologically better than those of previous reports. Control of the disease activity of RA could theoretically be a factor in obtaining good long-term clinical and radiographic outcomes. RL arthrodesis is our recommended procedure for the RA wrist even in the advanced stage. LEVEL OF EVIDENCE: Therapeutic IV.

Alterations of high-mannose type N-glycosylation in human and mouse osteoarthritis cartilage.

OBJECTIVE: The process of N-glycosylation is involved in the pathogenesis of various diseases. However, little is known about the contribution of changes in N-glycans in osteoarthritis (OA). The aim of this study was to identify the alterations in N-glycans in human OA cartilage, to characterize the messenger RNA (mRNA) expression of N-glycan biosynthesis enzyme genes (N-glycogenes) in mouse articular chondrocytes during cartilage degradation, and to analyze the relationship between altered N-glycan patterns and mechanisms of cartilage degradation. METHODS: Alterations in N-glycans were analyzed in human OA cartilage and degraded mouse cartilage by high-performance liquid chromatography and mass spectrometry. N-glycogene mRNA expression in mouse chondrocytes was measured using reverse transcription-polymerase chain reaction. To assess the relationship between the altered N-glycans and degradation of mouse cartilage, experiments involving either knockdown or overexpression of N-glycogenes were performed in mouse articular chondrocytes. RESULTS: Alterations in high-mannose type N-glycans were observed in both human OA cartilage and degraded mouse cartilage. The expression of ß1,2N-acetylglucosaminyltransferase I (GlcNAc-TI) mRNA, which converts high-mannose type N-glycans, was significantly increased in degraded mouse cartilage. Mouse chondrocytes with suppressed GlcNAc-TI expression had reduced levels of matrix metalloproteinase 13 (MMP-13) and ADAMTS-5 (aggrecanase 2) mRNA following stimulation with interleukin-1α (IL-1α). In contrast, mouse chondrocytes overexpressing GlcNAc-TI had increased levels of MMP-13 and ADAMTS-5 mRNA following stimulation with IL-1α. CONCLUSION: These findings indicate that alterations in high-mannose type N-glycans and N-glycogenes in chondrocytes correlate with the release of MMP-13 and ADAMTS-5 during cartilage degradation. These findings suggest that N-glycans play a crucial role in the initiation and progression of OA.

Simultaneous Bilateral Proximal Humerus Fractures Treated with Single-Stage Bilateral Reverse Shoulder Arthroplasty.

Introduction: Simultaneous bilateral fractures of the proximal humerus are infrequent, and simultaneous bilateral three- or four-part fractures are even rarer. Reverse shoulder arthroplasty (RSA) is being used increasingly for the treatment of three- and four-part fractures of the proximal humerus. However, treatment of simultaneous bilateral fractures of the proximal humerus is difficult because of concern about postoperative immobilization and rehabilitation. Case Presentation. A 75-year-old woman presented with bilateral shoulder pain subsequent to a fall on the street. Physical examination and radiographs showed simultaneous bilateral fractures of the proximal humerus. The right side fracture was classified as a four-part fracture and the left side fracture as a three-part fracture, according to Neer's classification. The right shoulder had a risk of avascular necrosis of the humeral head. For the left shoulder, the fracture type had caused ischemia of the humeral head. Single-stage bilateral RSA was performed 9 days after the injury. An abduction pillow was applied for 5 weeks postoperatively. Passive motion exercises were permitted starting at 4 weeks postoperatively, and active range of motion exercises were permitted at 6 weeks postoperatively. At the patient's most recent follow-up 30 months after surgery, the patient reported no restriction of the activities of daily living. Radiographs revealed no lucent line on the humerus and glenoid components, although bone resorption and superior retraction of the tuberosities on both sides were observed. Conclusions: Single-stage bilateral RSA improved shoulder function, but healing of the greater tuberosity can affect the improvement in external rotation after the operation. Although a long-term follow-up is needed, single-stage bilateral RSA appears to be a viable treatment option.

Implications of navigation system use for glenoid component placement in reverse shoulder arthroplasty.

Recently, three-dimensional (3D) planning, patient-specific instruments, and navigation system have been developed to improve the accuracy of baseplate placement in reverse shoulder arthroplasty (RSA). The purpose of this study was to evaluate baseplate placement using the navigation system. Sixty-four shoulders in 63 patients who underwent RSA for rotator cuff tear arthropathy or irreparable rotator cuff tears were enrolled. Conventional RSA was performed in 31 shoulders and navigated RSA using pre-operative planning software was performed in 33 shoulders. The use of augmented baseplates, the version and inclination of the baseplate, and screw length were compared between conventional RSA and navigated RSA. Augmented baseplates were used more frequently in navigated RSA than in conventional RSA (20 vs 9 shoulders, p = 0.014). Baseplate alignment was 1.0° (SD 5.1) of retroversion and 2.4° (SD 6.8) of superior inclination in conventional RSA and 0.2° (SD 1.9) of anteversion and 0.3° (SD 1.7) of superior inclination in navigated RSA. Compared with conventional RSA, precision of baseplate version and inclination were higher in navigated RSA (both p < 0.001). Superior, inferior, and posteroinferior screws were significantly longer in navigated RSA than in conventional RSA (p = 0.021, 0.001 and < 0.001, respectively). Precision of superior and inferior screw lengths was significantly higher in navigated RSA than in conventional RSA (both p = 0.001). Our results suggest that adoption of pre-operative planning software increased augmented baseplate use to minimize the glenoid reaming. The navigation system allows placement of the baseplate accurately, according to the pre-operative plan. Furthermore, the navigation system enables monitoring of screw length and direction in real time.

Diagnostic Utility of Superb Microvascular Imaging and Power Doppler Ultrasonography for Visualizing Enriched Microvascular Flow in Patients With Carpal Tunnel Syndrome.

Recent studies suggest that blood flow changes in the median nerve may help confirm a diagnosis of carpal tunnel syndrome (CTS). Herein, we examined the utility of superb microvascular imaging (SMI), a new ultrasonographic (US) technique for visualizing microvascular flow, for detecting blood flow differences between CTS patients and healthy controls. We performed a retrospective analysis of 28 hands with suspected CTS. Patients received both nerve conduction and US examinations. Ten healthy volunteers were enrolled as the control group. The nerve compression ratio and the blood flow signal area were quantified using color Doppler US (CDUS), power Doppler US (PDUS), and SMI. Correlation analyses between the blood flow signal area, the compound muscle action potential of the thenar muscle, and the nerve compression ratio were performed. As a result, the mean nerve compression ratio was found to be significantly higher in the CTS group. There were no differences in the blood flow signal area between the groups using CDUS, while PDUS and SMI showed higher blood flow signals in the CTS group. The blood flow signal area measured by SMI had stronger correlations with the compound muscle action potential amplitude and the nerve compression ratio than those for PDUS. The diagnostic utility of SMI was equivalent to PDUS, but superior to conventional CDUS. Nevertheless, the blood flow signal by SMI was more strongly correlated with the electrophysiological severity and compression ratio than for PDUS. Use of SMI in future studies may help clarify the underlying mechanisms of blood flow changes in CTS.

Intra-articular osteoid osteoma at the elbow mimicking arthritis: a case report.

Osteoid osteomas are benign, typically intracortical lesions most often affecting the diaphysis of long bones. Nocturnal pain and characteristic symptoms that are relieved by administration of non-steroidal anti-inflammatory drugs (NSAIDs) are present and can help in the diagnosis of osteoid osteoma. We report a case of 18-year-old boy with an osteoid osteoma in the olecranon fossa with an atypical clinical manifestation. The initial manifestation was arthritis-like symptoms such as local heat, motion pain rather than pain at rest, and limited range-of-motion. Notably, NSAIDs were not effective at all for relieving his symptoms. Magnetic resonance imaging showed bone marrow edema around the elbow joint. The symptoms were resistant to conservative treatments, and thus, surgical resection was required. Histopathological examination showed that the lesion consisted of woven bones and osteoid tissues that anastomosed with each other. Combined with a tumor size that was less than 2 cm, clinicopathologically, the tumor was diagnosed as an osteoid osteoma. The pain was immediately relieved after the operation, and range-of-motion recovered at 2 months postoperatively. At 1 year after the surgery, the patient did not exhibit recurrence of the tumor or exacerbation of elbow pain and had a full range of elbow motion. Osteoid osteoma should be considered for the differential diagnosis of arthritis of the elbow in patients who are adolescents and young adults, which is the peak age of onset for osteoid osteoma.

Stress distribution pattern in the distal radioulnar joint before and after ulnar shortening osteotomy in patients with ulnar impaction syndrome.

Ulnar shortening osteotomy (USO) for ulnar impaction syndrome potentially leads to degenerative changes of the distal radioulnar joint (DRUJ). This study was performed to evaluate the effect of the sigmoid notch morphology on the stress distribution pattern of the DRUJ using computed tomography (CT) osteoabsorptiometry (CT-OAM). We reviewed the pre- and postoperative transverse CT images of 15 wrists that had undergone USO. The examined wrists were classified into two groups based on the sigmoid notch morphology: the linear-type notch (type L) and the curved-type notch (type C). We calculated and statistically compared the percentage of the high-density area (%HDA) in each divided region of the sigmoid notch. In type L, %HDA was significantly larger in the distal-dorsal region of the sigmoid notch before USO. Postoperatively, in type L, no specific regions showed a significantly different %HDA. In type C, %HDA was significantly larger in the distal-volar region of the sigmoid notch before USO. Postoperatively, %HDA of type C was significantly larger in the proximal-volar region. Our results suggest that in patients with ulnar impaction syndrome, morphological evaluation of the sigmoid notch can serve as a predictor of osteoarthritis in the DRUJ with or without USO.