Long-lasting decreased pain threshold negatively affects functional recovery after arthroscopic rotator cuff repair

PURPOSE

The relationship between sensitization and postoperative function in patients undergoing arthroscopic rotator cuff repair (ARCR). The purpose of this study was to evaluate the effect of pre-and postoperative reductions in the pressure pain threshold (PPT) on postoperative clinical outcomes in patients with ARCR and investigate changes in PPT and clinical outcomes resulting from postoperative administration of weak opioids activating the central inhibitory system.

METHODS

This retrospective study included patients who underwent primary ARCR, categorized into Group A (excellent/good Constant scores) and B (fair/poor Constant scores). In a complementary study, patients were randomized to the Control or Tramadol groups. Both studies evaluated the PPT, visual analog scale, active range of motion (ROM), Constant score, and retear rates pre-and postoperatively.

RESULTS

In the primary study with 158 patients, those with poor clinical outcomes exhibited significantly lower PPT at the affected shoulder preoperatively at 3 months postoperatively compared to those with good outcomes. The PPT of the affected side was lower than that of the uninvolved side not only at 1 and 3 months but also preoperatively and at 6 months in the poor outcome group. In the secondary study involving 96 patients, weak opioid administration was associated with increased PPT for 3 months, improved ROM at 3 months postoperatively, and reduced postoperative pain 1 year postoperatively.

CONCLUSION

Patients experiencing poor postoperative clinical outcomes exhibited prolonged lowered PPT. Lowered PPT due to sensitization may adversely affect functional recovery and pain perception. Elevating PPT using weak opioids improved clinical outcomes during the acute perioperative period after ARCR.

LEVEL OF EVIDENCE

III.

Older Age, Poor Preoperative Quadriceps Muscle Strength, and Residual Pain as Risk Factors for Poor Quadriceps Muscle Strength Recovery at 1 Year After ACL Reconstruction: A TMDU MAKS Study of 402 Patients

Background

Poor postoperative quadriceps muscle strength recovery after anterior cruciate ligament reconstruction (ACLR) leads to delayed return to sports and lower patient satisfaction.

Purpose/Hypothesis

The purpose of this study was to examine factors that affect quadriceps muscle strength 1 year after ACLR. It was hypothesized that older age, poor preoperative quadriceps muscle strength, and residual pain would be risk factors for poor quadriceps muscle strength recovery.

Study Design

Case-control study; Level of evidence, 3.

Methods

Included were patients from multiple institutions who underwent primary ACLR using autologous hamstring tendon grafts between August 1, 2013, and March 31, 2018, and who had at least 1 year of follow-up data. Patients with past ligamentous injuries in the affected knee, previous injuries or operations in the contralateral knee, accompanying ligament injuries of grade 2 or 3, or inflammatory or other types of osteoarthritis were excluded. Patients were categorized as having muscle strength ≥80% (good strength recovery) or <80% (poor strength recovery) compared with the contralateral leg at 1 year postoperatively. Multivariate logistic regression analysis was performed to investigate the factors influencing postoperative quadriceps muscle strength. In addition, a categorical analysis was conducted based on factors extracted by the multivariate logistic regression analysis.

Results

A total of 402 patients were included. Multivariate logistic regression analysis revealed that age at surgery (P = .020), preoperative quadriceps muscle strength (P = .006), and postoperative Knee injury and Osteoarthritis Outcome Score (KOOS)-Pain score (P = .002) were significantly associated with quadriceps muscle strength at 1 year postoperatively. The odds of poor muscle strength recovery according to categorical analysis were 5.0-fold higher for patients aged >40 versus ≤20 years, 4.2-fold higher for those with preoperative quadriceps muscle index <60% versus ≥80%, and 7.7-fold higher for those with a postoperative KOOS-Pain score of <85 versus 100.

Conclusion

Older age, poor preoperative quadriceps muscle strength, and low postoperative KOOS-Pain score were risk factors for poor quadriceps muscle strength 1 year after primary ACLR. Surgical indications, including age, preoperative active rehabilitation, and pain control, should be considered for optimization of postoperative quadriceps muscle strength recovery.

Anatomic restoration of the articular deep layer is a definitive factor for repair status in delaminated rotator cuff tear

BACKGROUND

Recent studies have focused on the deep layer in delaminated rotator cuff tears. However, no studies have discussed the relationship between repair success and the properties of the deep layer. Herein, we aimed to analyze the intraoperative repair tension of the deep layer with respect to clinical outcomes and repair integrity and to evaluate the clinical results of delaminated rotator cuff tears after dual layer-specific repair.

METHODS

A total of 202 patients with delaminated rotator cuff tears had undergone dual layer-specific suture bridge repair; the mean follow-up duration was 28.6 (24-72) months. Intraoperatively, the repair tension of the deep layer was measured using a tensiometer, and mobility was ranked as easy or tight. After repair of the deep layer, the superficial layer tension was measured and ranked in a similar fashion. Clinical outcomes were evaluated using the Constant score, American Shoulder and Elbow Surgeons score, and subjective shoulder values. The relationship between retear and intraoperative qualitative factors of tendons was investigated. Prognostic factors for retear were analyzed using multiple logistic regression analyses.

RESULTS

Postoperative retears occurred in 11 (5.4%) patients. With regard to the deep layer, the tight mobility group had greater tear size, tendon retraction, and fatty infiltration of the supraspinatus and infraspinatus than the easy mobility group. No intergroup difference in postoperative retear rate was observed between the tight and easy deep-layer groups. Logistic regression analysis showed that fatty infiltration of the infraspinatus (odds ratio, 3.1; 95% confidence interval, 1.3-7.7; P = .013) and mobility of the superficial layer after deep layer repair (odds ratio, 8.1; 95% confidence interval, 1.7-38.1; P = .008) were predictors of retear.

CONCLUSION

Intraoperative mobility in the deep layer was not directly related to postoperative retear. Conversely, the quality of the infraspinatus concomitant with mobility of the superficial layer after deep layer repair significantly influenced repair integrity. Good clinical results were obtained even in cases with high repair tension of the deep layer.

High diagnostic accuracy of magnetic resonance imaging in detecting subscapularis tendon tears by focusing on the most superior portion of the subscapularis tendon

PURPOSE

This study aimed to test the hypothesis that identifying the exact location of the most superior portion of the subscapularis tendon using magnetic resonance imaging (MRI) provides high diagnostic accuracy in detecting subscapularis tendon tears.

METHODS

This study included 157 patients who underwent primary arthroscopic rotator cuff repair between 2014 and 2017. All patients underwent conventional 1.5-T MRI in our hospital, within 3 months before surgery. We retrospectively compared the diagnosis of subscapularis tendon tears using MRI based on an anatomical concept focusing on the superior-most insertion point of the subscapularis tendon with intraoperative arthroscopic findings.

RESULTS

Subscapularis tendon tears were detected in 80 (51.0%) of the 157 patients during arthroscopic evaluation. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the MRI examination were 90, 83, 85, 89, and 87%, respectively. With a kappa score of 0.83, the concordance rate between the two raters was almost perfect (95% confidence interval, 0.75-0.92). The sensitivities of the oblique-sagittal and axial sequences were 84 and 79%, respectively.

CONCLUSIONS

Preoperative MRI evaluation focusing on the most superior portion of the subscapularis tendon demonstrated high diagnostic accuracy in detecting subscapularis tendon tears. To find the most superior portion of the subscapularis tendon tears, it was essential to check the slice at the level of the lesser tubercle tip and its adjacent slice. In addition, the combined observation of oblique-sagittal and axial sequences helped to detect subscapularis tendon tears with higher sensitivity.

Comparison of tissue pharmacokinetics of esflurbiprofen plaster with flurbiprofen tablets in patients with knee osteoarthritis: A multicenter randomized controlled trial

This open‐label, multicenter, prospective, randomized controlled trial aimed to determine the effectiveness of esflurbiprofen plaster (SFPP) and flurbiprofen tablets (FPTs) on knee osteoarthritis in patients scheduled for total knee arthroplasty by comparing the transfer of esflurbiprofen and flurbiprofen to tissues and fluids. Thirty‐eight patients were randomly assigned in a 1:1 ratio to receive SFPP or FPT. Both groups were then divided into four subgroups, according to whether they received the final dose of SFPP or FPT at 2, 7, 12, or 24 h before planned surgery. The primary endpoints were the esflurbiprofen concentrations in synovium, synovial fluid, and plasma. Areas under concentration–time curves (AUC_{0–24 h}) of esflurbiprofen were calculated for each group. Pain was assessed using a numeric rating scale (NRS) 7 days before and immediately before surgery. The AUC_{0–24 h} in the synovium were 4401.24 and 4862.70 ng·h/g in the SFPP and FPT groups, respectively. Maximum esflurbiprofen concentrations were observed in the synovium, synovial fluids, and plasma after SFPP application for 12 h. The NRS results indicated a long‐lasting effect of SFPP. The AUC of the synovial esflurbiprofen concentration of SFPP indicated that the SFPP is transferred to the synovium and synovial fluid in high concentration. The efficient deep‐tissue transfer of esflurbiprofen suggests that its pharmacokinetic characteristics differ from those of conventional topical NSAIDs. This study was prospectively registered in the Japan Registry of Clinical Trials (registration number: jRCTs031180228).

Anatomical Repair of a Femoral-Sided Avulsion Fracture of the Anterior Cruciate Ligament: A Case Report

CASE

We report a rare case of femoral-sided avulsion fracture of both the anteromedial and posterolateral bundle attachments of the anterior cruciate ligament (ACL). We performed an arthroscopic double-bundle pull-out repair. At the 1-year follow-up, the patient had no deformity, laxity of the knee, and no limitations when engaging in various sports activities.

CONCLUSION

An avulsion fracture of both the anteromedial and posterolateral bundle attachments is a rare injury. Arthroscopically assisted reduction and fixation demonstrated successful achievement of both bone union and good ACL function.

POS0532 AveRAGE PREDNISOLONE DOSE OF ONLY 1 MG PER DAY WAS RISK FACTOR FOR CLINICAL FRACTURES IN PATIENTS WITH RHEUMATOID ARTHRITIS - NINE-YEAR FINDINGS OF THE TOMORROW STUDY

Background:

Previous cohort studies showed that the use of prednisolone (PSL) was a risk factor for clinical fractures in patients with rheumatoid arthritis (RA). However, there are few reports on relationship between PSL dose and clinical fractures.

Objectives:

The present study aimed to determine the effect of PSL dose on the incidence of clinical fractures in the RA patients treated with PSL.

Methods:

We evaluated anthropoetric parameters, bone mineral density (BMD), disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), RA medication (methotrexate (MTX) dose, use of biologic disease modified anti-rheumatic-drugs (bDMARDs), and PSL dose) and the incidence of clinical fractures during nine years in RA patients who participant the TOMORROW study (UMIN000003876), which is a 10-years prospective cohort study. Data on clinical fracture was self-reported on the questionnaires. In this analysis, the data of RA patients treated with PSL at least once during nine-year period were evaluated. We analyzed the average dose of PSL until the incidence of the clinical fractures. The risk factor for clinical fractures were analyzed by using Cox proportional hazard model with adjustment for age, sex, body mass index (BMI), and smoking history.

Results:

We analyzed the data of 67 RA patients treated with PSL. Among them, median age was 61.8 year, 56 patients (83.6%) were female, 47 patients (70.1%) were never smoker and median disease duration was 12.1 year. The number of patients treated with PSL at baseline was 48 (69.1%). During 9 years, 23 clinical fractures were observed in 67 patients, and the incidence of clinical fracture was 0.046/person-year. In 19 patients, who were not treated with PSL at baseline but treated with PSL at least once during 9 years, 5 clinical fractures were observed. In 67 RA patients, Cox proportional hazard analysis revealed that baseline disease activities, BMD at thoracic vertebrae and medication were not significant risk factors for clinical fractures. However, average PSL dose of more than only 1 mg/day was a significant risk factor for the incidence of clinical fracture (hazard ratio (HR): 2.80; p=0.03) (Table 1).

Table 1.

Adjusted hazard ratio for clinical fractures in patients with rheumatoid arthritis treated with PSL.

* Adjusted Hazard ratio95% Confidence intervalP valueCRP (mg/dL)1.290.88-1.910.19RF (IU/mL)0.990.99-1.000.07ACPA (U/mL)0.990.98-1.000.18DAS28-ESR0.990.71-1.390.97BMD at thoracic vertebrae (mg/cm2)0.020.00-1.000.05bDMARDs use0.550.23-1.320.18Bisphosphonate use2.330.95-5.710.07average dose of MTX (mg/week)1.020.92-1.120.74average score of DAS28-ESR1.150.76-1.750.52average dose of PSL more than 1mg/day2.81.09-7.240.03

*Hazard ratio was adjusted for age, sex, body mass index (BMI), and smoking history. RF, Rheumatoid factor; ACPA, Anti-cyclic citrullinated peptide antibody; DAS28-ESR, disease activity score 28-erythrocyte sedimentation rate; BMD, Bone mineral density; bDMARDs, biologic disease modified anti-rheumatic-drugs; MTX, methotrexate; PSL, prednisolone.

Conclusion:

In RA patients treated with PSL, average PSL dose of only 1mg/day significantly increased the risk for the incidence of clinical fractures. Even for established RA patients, continuous use or initiation of low PSL dose was apparently significant risk factor for clinical fractures.

Disclosure of Interests:

Hitoshi Yoshimura: None declared, Tatsuya Koike Grant/research support from: Takeda Pharmaceutical, Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical, Eisai, Abbott Japan, Teijin Pharma, Banyu Pharmaceutical and Ono Pharmaceutical, Kenji Mamoto: None declared, Yuko Sugioka: None declared, Tadashi Okano: None declared, Masahiro Tada: None declared, Kentaro Inui Grant/research support from: Janssen Pharmaceutical K.K. and Astellas Pharma Inc, Hiroaki Nakamura: None declared

Primary Lymphangiosarcoma of the Urinary Bladder in a Dog

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

Osteointegration of a Biocomposite Suture Anchor After Arthroscopic Shoulder Labral Repair

PURPOSE

To evaluate osteoconductivity of a poly-L-lactide co-glycolide (PLG)-calcium sulfate (CS)-β-tricalcium phosphate (β-TCP) biocomposite suture anchor after arthroscopic shoulder labral repair.

METHODS

The subjects of this study were patients who participated in a clinical trial for acquisition of marketing approval of a PLG-CS-β-TCP biocomposite anchor in Japan. They underwent arthroscopic labral repair using the anchor, and computed tomographic (CT) images of the glenoid were obtained 2 years after surgery. Osteoconductivity at the anchor sites was evaluated with the CT images using the established ossification quality score. Shoulder function scores including the Rowe score and Japanese Shoulder Society shoulder instability score were also assessed 2 years after surgery.

RESULTS

CT images and functional scores were obtained from 37 patients, comprising 29 men and 8 women with a mean age of 29 years (range, 25-33 years) at surgery. A total of 148 anchors were implanted in the 37 shoulders. Osteoconductivity was seen in 133 of 148 anchor sites (90.0%) 2 years after implantation. No significant differences in osteoconductivity were found by anchor diameter or position. The Rowe score significantly improved from 39.9 points (95% confidence interval [CI], 33.8-45.9 points) preoperatively to 96.6 points (95% CI, 95.1-98.1 points) at 2 years postoperatively (P < .001). The Japanese Shoulder Society shoulder instability score also significantly improved, from 63.1 points (95% CI, 58.4-67.7 points) preoperatively to 96.3 points (95% CI, 94.7-97.8 points) at 2 years postoperatively (P < .001).

CONCLUSIONS

Biocomposite suture anchors made of PLG, CS, and β-TCP exhibited some osteoconductivity 2 years after arthroscopic labral repair, as well as good clinical outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Diffuse Pulmonary Meningotheliomatosis with Sarcomatous Transformation in a Shiba Dog

A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2-5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey-white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.

Degradation of Cylindrical Poly-Lactic Co-Glycolide/Beta-Tricalcium Phosphate Biocomposite Anchors After Arthroscopic Bankart Repair: A Prospective Study

The purpose of this study was to examine widening and ossification of anchor holes after arthroscopic Bankart repair with the use of cylindrical biocomposite anchors made of 70% poly-L-lactide-co-glycolide acid (PLGA) and 30% beta-tricalcium phosphate (ß-TCP). Twenty-two patients were enrolled in a clinical trial to acquire marketing approval of a PLGA/ß-TCP biocomposite suture anchor in Japan and underwent arthroscopic Bankart repairs with the anchors. Eleven of 22 patients had computed tomography scans after 2-year follow-up. Three surgeons independently evaluated width and ossification of anchor holes in 4 grades using computed tomography scans. When the evaluations disagreed, the final grade was determined based on the 3 surgeons' consensus. Seven men and 4 women were evaluated at a mean of 30 months (range, 28-32 months) after surgery, and a total of 47 anchors were implanted. Anchor holes were narrowed in 39 (83%) of 47 anchor sites and were almost or completely filled in (type 3 or 4) in 21 (45%) of 47 anchor sites. Ossification was seen in 46 (98%) of 47 anchor sites and was nearly complete or complete (type 3 or 4) in 16 (34%) of 47 anchor sites. There were no significant differences in both anchor hole width and ossification score on comparison of the anteroinferior (4- to 6-o'clock positions in the right shoulder) with other anchor sites. Cylindrical biocomposite anchors made of 70% PLGA/30% ß-TCP showed a low incidence of anchor hole widening and excellent ossification regardless of anchor site. [Orthopedics. 2018; 41(3):e348-e353.].

Cutaneous Angiolymphoid Hyperplasia in a Dog

A 5-year-old male miniature dachshund was presented with a dermal nodule on the left forelimb that increased to 5 mm in diameter over a 2-month period. Grossly, the nodule was firm, and both the external and cut surfaces were homogeneously pale pink in colour. Microscopically, the nodule was comprised of mainly plump endothelial cells and inflammatory cells; among the latter, lymphocytes were predominant, with few scattered plasma cells, mast cells and macrophages. Lymphoid follicles with germinal centres were often observed. Mitotic figures were not observed amongst the endothelial cells. Immunohistochemically, the endothelial cells were positive for vimentin, factor VIII-related antigen and CD31, and the surrounding cells were positive for smooth muscle actin. Lymphocytes expressed CD3 or BLA36. These findings led to a diagnosis of cutaneous angiolymphoid hyperplasia. To the best of our knowledge, this is the first report of a cutaneous proliferative disorder comprising an admixture of proliferating vascular endothelial cells and lymphocytic infiltration with follicle formation in a dog.

An Insight into the Characteristics of a Nucleation Catalyst in CFC-Free Rigid Foam Systems

The establishment of CFC-free polyurethane foam systems, aimed at total CFC elimination by the year 1995, is of paramount importance in the present day polyurethane foam technology. Especially in rigid foam systems, the attempts to apply a variety of alternative blowing agents such as HCFC-22, -141b, and -142b, HFC-134a and -356, and hydrocarbons such as n-pentane, isopentane and cyclopentane, as well as all-water blown systems, are being examined.

In all cases of alternative blown systems, however, there exist differences in foaming behavior as well as inferior foam properties compared to traditional CFC-11 blown systems. Especially in HCFC-141b and cyclopentane blown systems, which have gained the greatest interest among the above-mentioned options, the following three subjects are of major concern. The requirements involved in achieving the resolution of these problems are dependent not only on the development of major raw materials but also on the selection of suitable auxiliary intermediates such as catalysts and foam stabilizers. (1) Thermal Conductivity; HCFC-141b, cyclopentane and carbon dioxide, which is generated from the reaction of water and isocyanate, have high thermal conductivity compared to CFC-11, thereby causing inferior insulation performance of the foam. Fine cell technology is now being examined in order to improve the thermal conductivity. For the achievement of the fine cell structure, the selection of suitable amine catalyst systems is important, although the effect of foaming stabilizers has an especially large contribution. (2) Dimensional Stability; not only in all-water blown systems, but also in HCFC-141b and cyclopentane blown systems which use water in high concentration, dimensional stability becomes a large problem due to the diffusion of carbon dioxide gas from the foam cell. For the improvement of dimensional stability, there exists the option to increase the foam strength; moreover, it is important to improve the isotropy of cell structure by adjusting amine catalyst systems. (3) Foam density; since 141b and cyclopentane have relatively higher boiling points and less blowing efficiency, lowering the foam density becomes rather difficult. Moreover, lower foam density normally provides poor dimensional stability. It can be said that the catalytic activity ratio in blowing/gelling of amine catalysts play an important role for the lowering of foam density with improved dimensional stability.

It is very difficult to improve these three factors simultaneously. In this report, however, the improvements of these subjects are discussed from a standpoint of amine catalysts; also special newly developed nucleation catalyst systems are introduced for cyclopentane and HCFC-141b blown systems.

Salivary Gland Epithelial-Myoepithelial Carcinoma with High-Grade Transformation in a Dog

An 8-year-old male neutered standard dachshund was presented with a slowly growing mass in the left submandibular salivary gland. Histopathological examination revealed a tumour that was composed of bilayered duct-like structures with an inner layer of ductal cells and an outer layer of clear cells. Both inner and outer cells in the greater part of the tumour exhibited low to moderate atypia and low mitotic activity. However, a focal area towards the periphery showed enhanced cellular atypia and mitotic activity in tumour cells. Immunohistochemically, the outer layer of clear cells expressed myoepithelial markers, while the inner layer cells were positive for a luminal epithelial marker. No local recurrence or lymph node or distant metastasis was observed 18 months following surgery. Based on the morphology and immunohistochemical findings, a final diagnosis of epithelial-myoepithelial carcinoma with high-grade transformation was made.

Characterization of Spontaneous Mammary Tumors in Domestic Djungarian Hamsters (Phodopus sungorus)

Mammary tumors that spontaneously occurred in domestic Djungarian hamsters ( Phodopus sungorus) were histologically examined. Forty-five mammary tumors included 14 adenomas, 18 adenocarcinomas, 1 lipid-rich carcinoma, 2 adenoacanthomas, 2 malignant adenomyoepitheliomas, 1 benign mixed tumor, and 7 “balloon cell” carcinosarcomas. The latter 4 types were newly recognized neoplasms in Djungarian hamsters. The relatively high incidence of spontaneous mammary carcinosarcomas in domestic Djungarian hamsters is intriguing. Carcinosarcomas exhibited anomalous histological features made up of a mixture of glandular cells, polygonal cells (including “balloon cells”), and sarcomatous spindle cells in varying proportions. Transitional features from glandular cells to polygonal cells and subsequently to sarcomatous spindle cells were observed. Using immunohistochemistry, we observed that glandular cells exhibited an epithelial phenotype (cytokeratin(+)/vimentin(–)), spindle cells exhibited a mesenchymal phenotype (cytokeratin(–)/vimentin(+)), and polygonal cells exhibited an intermediate phenotype (cytokeratin(+)/vimentin(+)). Reduction or loss of β-catenin expression and gain of S100A4 expression were observed in polygonal and spindle cells. The polygonal cell population included a varying number of characteristic cells that were expanded by large intracytoplasmic vacuoles. Electron microscopy revealed that these “balloon cells” had large cytoplasmic lumens lined by microvilli. These observations suggest that epithelial-mesenchymal transition may account for the pathogenesis of mammary carcinosarcomas in Djungarian hamsters.

Neuroendocrine carcinoma of the mammary gland in a dog

A 10-year-old female border collie was presented with a mass (2 cm diameter) in the fifth mammary gland. The mass was located in the subcutis and the cut surface was grey-white in colour. Microscopically, the mass was composed of tumour cells arranged in nests of various sizes separated by delicate fibrovascular stroma. The tumour cells had small, round hypochromatic nuclei and abundant cytoplasm. Metastases were observed in the inguinal lymph node. Immunohistochemically, most tumour cells expressed cytokeratin (CK) 20, chromogranin A, neuron-specific enolase, synaptophysin and oestrogen receptor-β, but not low molecular weight CK (CAM5.2), p63 and insulin. Ultrastructurally, the tumour cells contained a large number of electron-dense granules corresponding to neuroendocrine granules. Based on these findings, this case was diagnosed as a neuroendocrine carcinoma of the mammary gland.

The anatomy of the coracohumeral ligament and its relation to the subscapularis muscle

BACKGROUND

Only a few reports describe the extension of the coracohumeral ligament to the subscapularis muscle. The purposes of this study were to histo-anatomically examine the structure between the ligament and subscapularis and to discuss the function of the ligament.

METHODS

Nineteen intact embalmed shoulders were used. In 9 shoulders, the expansion of the ligament was anatomically observed, and in 6 of these 9, the muscular tissue of the supraspinatus and subscapularis was removed to carefully examine the attachments to the tendons of these muscles. Five shoulders were frozen and sagittally sectioned into 3-mm-thick slices. After observation, histologic analysis was performed on 3 of these shoulders. In the remaining 5 shoulders, the coracoid process was harvested to investigate the ligament origin.

RESULTS

The coracohumeral ligament originated from the horizontal limb and base of the coracoid process and enveloped the cranial part of the subscapularis muscle. The superficial layer of the ligament covered a broad area of the anterior surface of the muscle. Laterally, it protruded between the long head of the biceps tendon and subscapularis and attached to the tendinous floor, which extended from the subscapularis insertion. Histologically, the ligament consisted of irregular and sparse fibers abundant in type III collagen.

CONCLUSION

The coracohumeral ligament envelops the whole subscapularis muscle and insertion and seems to function as a kind of holder for the subscapularis and supraspinatus muscles. The ligament is composed of irregular and sparse fibers and contains relatively rich type III collagen, which would suggest flexibility.

Locking versus non-locking neutralization plates for treatment of lateral malleolar fractures: a randomized controlled trial

PURPOSE

The reduction of periosteal compression through the use of a locking plate may minimize disturbances of bone blood supply and may improve the rate of bone union. A single-centre, assessor blinded randomized controlled trial was conducted to compare the clinical effectiveness of a locking plate and a non-locking plate.

METHODS

A total of 52 patients with AO/OTA 44B lateral malleolar fractures were included in this study. All patients underwent surgical fixation using a lag screw and neutralization plate. An identical treatment protocol was used in all patients, with exception of plate selection. The rate of radiographic bone union, defined as the complete disappearance of fracture lines confirmed through anteroposterior, lateral, and internal oblique views was compared at three, six, and 12 months following surgery. In addition, the Medical Outcomes 36-Item Short-Form Health Survey (SF-36) score, the time required for resolution of tenderness at the fracture site and the complication rate were evaluated.

RESULTS

Twenty-three patients were randomly assigned to undergo fixation using a locking plate, and 29 patients were assigned to undergo fixation using a non-locking plate. Intention-to-treat analysis showed no difference in the radiographic bone union rate of fibula, SF-36 score, the time for resolution of tenderness at the fracture site and complication rates.

CONCLUSION

No differences were observed in patients with AO/OTA 44B lateral malleolar fractures undergoing fixation with a locking versus non-locking neutralization plate.

Cellular Sources of Tenascin-C in Canine Mammary Carcinomas

Tenascin-C (Tn-C) is an extracellular matrix glycoprotein implicated in the progression of several human cancers. In canine mammary carcinomas, accumulation of Tn-C has been recognized in 3 different areas: regions of proliferating myoepithelial cells in complex carcinoma, basement membrane zone in low-grade simple carcinoma, and reactive stroma in high-grade simple carcinoma. To identify the Tn-C synthesizing cells in these areas, we utilized double-labeling immunohistochemistry, branched DNA in situ hybridization, and in situ hybridization–immunohistochemistry double-labeling techniques. In complex carcinomas, Tn-C was generated by proliferating myoepithelial cells. Tn-C in low-grade simple carcinomas was also derived from myoepithelial cells existing as a basal monolayer. However, stromal Tn-C in high-grade carcinomas was mainly synthesized by fibroblasts/myofibroblasts, similar to human breast cancer. Thus, the origin of Tn-C in canine mammary carcinomas differs between low- and high-grade malignancies. The role of myoepithelial cell-generated Tn-C is not yet understood.

Differences in Indicators of Malignancy Between Luminal Epithelial Cell Type and Myoepithelial Cell Type of Simple Solid Carcinoma in the Canine Mammary Gland

Routinely diagnosed simple solid carcinoma (SSC) of the canine mammary gland comprises a heterogeneous group of tumors. Seventy-two cases that had been diagnosed as SSC based on hematoxylin and eosin–stained tissue sections were reclassified immunohistochemically on the basis of myoepithelial markers p63 and α-smooth muscle actin, as well as a luminal epithelial marker cytokeratin 8. Only 23 cases (32%) were true SSC, composed only of luminal epithelial cells, whereas 11 cases (15%) were malignant myoepithelioma (MM), composed predominantly of myoepithelial cells, and 38 cases (53%) were biphasic carcinoma (BC), characterized by biphasic proliferation of luminal epithelial and basal/myoepithelial components. As the pathological parameters were compared between the reclassified tumor types, infiltrative potential, vascular/lymphatic invasion, lymph node metastasis, and Ki-67 labeling index were higher in true SSC compared with MM and BC, suggesting that the former may exhibit a poorer prognosis compared with the latter two.

Enhanced selective lymphatic delivery of cyclosporin a by solubilizers and intensified immunosuppressive activity against mice skin allograft

The absorption and lymphatic delivery of a new immunosuppressive drug, cyclosporin A (CsA), were studied in rats by administering CsA orally after solubilization with HCO-60 (polyoxyethylated hydrogenated castor oil), sugar ester, and oils. After the administration of solubilized CsA (7 mg/kg) to rats with thoracic lymph duct cannulas, both plasma and lymph CsA levels were measured over 6 hr. The lymph CsA levels were strongly affected by the solubilizers. The rank order of the solubilizers in enhancing lymph absorption was HCO-60 (57 µg/ml) > sugar ester (46 µg/ml) > sesame oil (3.5 µg/ml) > linoleic acid (0.4 µg/ml), where the parentheses show the maximum lymph CsA levels. Plasma CsA levels were below 2 µg/ml in each group of animals and were barely altered by the solubilizers. These results support the selective lymphatic delivery of CsA with solubilizers such as HCO-60 and sugar ester. The immunosuppressive activity of CsA (1 mg/kg) solubilized with HCO-60 was nearly equivalent to the sesame oil solution with 7 to 15 mg/kg CsA in the skin-allograft mice model.

Proliferative lesions of intra-epidermal cytokeratin CAM5.2-positive cells in canine nipples

Non-keratinocyte cells with clear or vacuolated cytoplasm are frequently observed in the epidermis of canine nipples. Most of these cells express cytokeratin (CK) CAM5.2, a marker of luminal epithelial cells. The morphological and immunohistochemical characteristics of these clear cells were investigated. Nipple tissue from 36 dogs of both sexes was collected and labelled immunohistochemically for CAM5.2, CK7, CK14, CK18, CK20, α-smooth muscle actin, p63, melan-A, E-cadherin, epidermal growth factor receptor and oestrogen receptor (OR). The intra-epidermal CAM5.2(+) clear cells were present singly or as small clusters, mostly within the basal layer, in 22 dogs (61%). These cells also expressed CK7, CK18, E-cadherin and OR. Electron microscopy revealed that some of these cells had surface microvilli. Multifocal proliferative lesions consisting of these cells were observed in the nipples of four dogs. In these lesions, proliferating cells formed bilayered tubules with CAM5.2(+) inner and CK14/p63(+) outer cells. This is the first report describing intra-epidermal CAM5.2(+) clear cells, distinct from melanocytes and Merkel cells in dog nipples. These cells might arise from the luminal epithelium of the papillary duct.

Upper limb amputation due to a brachial arterial embolism associated with a superior mesenteric arterial embolism: a case report

Background

Acute mesenteric ischemia due to an embolism of the superior mesenteric artery is associated with a high mortality rate. Over 20 percent of acute mesenteric embolism cases consist of multiple emboli, and the long-term prognosis depends on the incidence of subsequent embolic events at other sites. The incidence of emboli in the upper extremity associated with a superior mesenteric arterial embolism has rarely been described. The signs and symptoms of ischemic change in the upper limb can be masked by other circumstances, such as postoperative conditions or complications. In these cases, a late presentation or delayed diagnosis and treatment can result in limb loss.

Case presentation

We present a rare case of a 67-year-old Japanese woman with atrial fibrillation who developed an embolic occlusion of the brachial artery associated with a superior mesenteric arterial embolism. She developed gangrene in her right hand, which had progressed to the point that amputation was necessary by the time the gastrointestinal surgeon had consulted the Department of Orthopedic Surgery. The brachial arterial embolism diagnosis was delayed by the severe abdominal symptoms and shock conditions that followed the emergency enterectomy, resulting in amputation of the upper limb despite anticoagulation therapy. In this case, multiple infarctions of the spleen were also observed, indicating a shower embolism.

Conclusions

When treating a superior mesenteric arterial embolism in a patient with atrial fibrillation, the possibility of recurrent or multiple arterial thromboembolic events should be considered, even after the procedure is completed.

Multimodal cross-talk of olfactory and gustatory information in the endopiriform nucleus in rats

The endopiriform nucleus (EPN) is a large group of multipolar cells located in the depth of the piriform cortex (PC). Although many studies have suggested that the EPN plays a role in temporal lobe epilepsy, the normal function of the EPN remains to be elucidated. By using optical imaging of coronal brain slice preparations with voltage-sensitive dye, we found signal propagation from the PC or gustatory cortex (GC) to the EPN in normal medium. In our previous research, we failed to elicit a reliable signal reproducibly in the EPN by single stimulation either to the PC or GC. In our current research, we found that a double-pulse stimulation to either the PC or GC (interpulse interval: 20-100 ms) induced robust signal propagation to the EPN through excitation in the agranular division of the insular cortex (AI), with further extension to the claustrum. Finally, double site paired-pulse stimulation to the PC and GC also evoked excitation in the AI, claustrum, and EPN. These results suggest that the EPN has dual roles: 1) further processing of modality-specific olfactory and gustatory information from the PC and GC, respectively and 2) synergistic integration of PC-derived olfactory information and GC-derived gustatory information.

Increased presence of stromal myofibroblasts and tenascin-C with malignant progression in canine mammary tumors

The aims of this study were to determine whether the appearance of stromal myofibroblasts and the expression of tenascin-C (Tn-C) correlate with the grade of malignancy in canine mammary tumors and to determine the main cellular source of Tn-C in these tumors. Single or double immunostaining using antibodies against α-smooth muscle actin (α-SMA) and Tn-C was performed on serial sections of normal canine mammary glands as well as those with lobular hyperplasia, simple adenoma, and simple carcinoma. Thirty-nine of 42 simple carcinomas (93%) exhibited stromal α-SMA-positive myofibroblasts and Tn-C expression. Only 6 of 11 cases of simple adenoma (55%) showed these changes, whereas no changes were observed in normal mammary gland tissue or cases of lobular hyperplasia. The distribution of stromal Tn-C correlated with the presence of myofibroblasts. However, Tn-C immunoreactivity was also occasionally observed in the basement membrane zone surrounding the myoepithelial layer in normal tissue, benign lesions, and tubulopapillary carcinomas. This pattern of staining was not related to the presence of myofibroblasts. The appearance of stromal myofibroblasts and expression of Tn-C were significantly correlated with higher histological grades of malignancy and vascular/lymphatic invasion in simple carcinomas. Stromal myofibroblasts appear to be a major cellular source of Tn-C and play an important role in the development of canine mammary tumors. The Tn-C expressed in the basement membrane zone of normal, hyperplastic, and neoplastic mammary tissue, which is likely produced by neighboring myoepithelial cells, may differ functionally from the Tn-C produced by myofibroblasts.