Effects of adipose-derived cell supplementation on tendon-bone healing in a rat model of chronic rotator cuff tear with suprascapular nerve injury

OBJECTIVE

To investigate the effect of adipose-derived cells (ADCs) on tendon-bone healing in a rat model of chronic rotator cuff tear (RCT) with suprascapular nerve (SN) injury.

METHODS

Adult rats underwent right shoulder surgery whereby the supraspinatus was detached, and SN injury was induced. ADCs were cultured from the animals' abdominal fat. At 6 weeks post-surgery, the animals underwent surgical tendon repair; the ADC (+ve) group (n = 18) received an ADC injection, and the ADC (-ve) group (n = 18) received a saline injection. Shoulders were harvested at 10, 14, and 18 weeks and underwent histological, fluorescent, and biomechanical analyses.

RESULTS

In the ADC (+ve) group, a firm enthesis, including dense mature fibrocartilage and well-aligned cells, were observed in the bone-tendon junction and fatty infiltration was less than in the ADC (-ve) group. Mean maximum stress and linear stiffness was greater in the ADC (+ve) compared with the ADC (-ve) group at 18 weeks.

CONCLUSION

ADC supplementation showed a positive effect on tendon-bone healing in a rat model of chronic RCT with accompanying SN injury. Therefore, ADC injection may possibly accelerate recovery in massive RCT injuries.

Does physiotherapy after rotator cuff repair require supervision by a physical therapist?: a meta-analysis

BACKGROUND

A supervised physiotherapy program (SPP) is a standard regimen after surgical rotator cuff repair (RCR); however, the effect of a home-based exercise program (HEP), as an alternative, on postoperative functional recovery remains unclear. Therefore, the purpose of this meta-analysis was to compare the functional effects of SPP and HEP after RCR.

METHODS

We searched electronic databases including Central, Medline, and Embase in April 2022. The primary outcomes included the Constant score, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and pain score. Secondary outcomes included range of motion, muscle strength, retear rate, and patient satisfaction rate. A meta-analysis using random-effects models was performed on the pooled results to determine the significance.

RESULTS

The initial database search yielded 848 records, five of which met our criteria. Variables at 3 months after surgery were successfully analyzed, including the Constant score (mean difference, -8.51 points; 95% confidence interval [CI], -32.72 to 15.69; P=0.49) and pain score (mean difference, 0.02 cm; 95% CI, -2.29 to 2.33; P=0.99). There were no significant differences between the SPP and HEP. Other variables were not analyzed owing to the lack of data.

CONCLUSIONS

Our data showed no significant differences between SSP and HEP with regard to the Constant and pain scores at 3 months after RCR. These results suggest that HEP may be an alternative regimen after RCR. Level of evidence: I.

Effect of suprascapular nerve injury on muscle and regenerated enthesis in a rat rotator cuff tear model

BACKGROUND

Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model.

METHODS

Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively.

RESULTS

SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups.

CONCLUSIONS

In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Basic research, controlled laboratory study.

Targeting FoxO transcription factors with HDAC inhibitors for the treatment of osteoarthritis

OBJECTIVES

Osteoarthritis (OA) features ageing-related defects in cellular homeostasis mechanisms in articular cartilage. These defects are associated with suppression of forkhead box O (FoxO) transcription factors. FoxO1 or FoxO3 deficient mice show early onset OA while FoxO1 protects against oxidative stress in chondrocytes and promotes expression of autophagy genes and the essential joint lubricant proteoglycan 4 (PRG4). The objective of this study was to identify small molecules that can increase FoxO1 expression.

METHODS

We constructed a reporter cell line with FoxO1 promoter sequences and performed high-throughput screening (HTS) of the Repurposing, Focused Rescue and Accelerated Medchem (ReFRAME) library . Hits from the HTS were validated and function was assessed in human chondrocytes, meniscus cells and synoviocytes and following administration to mice. The most promising hit, the histone deacetylase inhibitor (HDACI) panobinostat was tested in a murine OA model.

RESULTS

Among the top hits were HDACI and testing in human chondrocytes, meniscus cells and synoviocytes showed that panobinostat was the most promising compound as it increased the expression of autophagy genes and PRG4 while suppressing the basal and IL-1β induced expression of inflammatory mediators and extracellular matrix degrading enzymes. Intraperitoneal administration of panobinostat also suppressed the expression of mediators of OA pathogenesis induced by intra-articular injection of IL-1β. In a murine OA model, panobinostat reduced the severity of histological changes in cartilage, synovium and subchondral bone and improved pain behaviours.

CONCLUSION

Panobinostat has a clinically relevant activity profile and is a candidate for OA symptom and structure modification.

The mechanosensitive ion channel PIEZO1 is expressed in tendons and regulates physical performance

How mechanical stress affects physical performance via tendons is not fully understood. Piezo1 is a mechanosensitive ion channel, and E756del PIEZO1 was recently found as a gain-of-function variant that is common in individuals of African descent. We generated tendon-specific knock-in mice using R2482H Piezo1, a mouse gain-of-function variant, and found that they had higher jumping abilities and faster running speeds than wild-type or muscle-specific knock-in mice. These phenotypes were associated with enhanced tendon anabolism via an increase in tendon-specific transcription factors, Mohawk and Scleraxis, but there was no evidence of changes in muscle. Biomechanical analysis showed that the tendons of R2482H Piezo1 mice were more compliant and stored more elastic energy, consistent with the enhancement of jumping ability. These phenotypes were replicated in mice with tendon-specific R2482H Piezo1 replacement after tendon maturation, indicating that PIEZO1 could be a target for promoting physical performance by enhancing function in mature tendon. The frequency of E756del PIEZO1 was higher in sprinters than in population-matched nonathletic controls in a small Jamaican cohort, suggesting a similar function in humans. Together, this human and mouse genetic and physiological evidence revealed a critical function of tendons in physical performance, which is tightly and robustly regulated by PIEZO1 in tenocytes.

Posterior decentering of the humeral head in patients with arthroscopic rotator cuff repair

Background: In some patients with rotator cuff tear (RCT), the axial view of magnetic resonance imaging (MRI) shows subtle posterior decentering (PD) of the humeral head from the glenoid fossa. This is considered to result from a loss of centralization that is typically produced by rotator cuff function. There are few reports on PD in RCT despite the common occurrence of posterior subluxation in degenerative joint disease. In this study, we investigated the effect of PD in arthroscopic rotator cuff repair (ARCR). Methods: We conducted a retrospective study of consecutive patients who underwent ARCR at our institute and were followed-up for at least 1 year. PD was identified as a 2 mm posterior shift of the humeral head relative to the glenoid fossa in the axial MRI view preoperatively. The tear size and fatty degeneration (FD, Goutallier classification) were also evaluated using preoperative MRI. Retears were evaluated through MRI at 1 year postoperatively. Results: We included 135 shoulders in this study. Ten instances of PD (including seven retears) were observed preoperatively. Fifteen retears (three and 12 retears in the small/medium and large/massive tear groups, respectively) were observed postoperatively. PD was significantly correlated with tear size, FD, and retear occurrence (p<0.01 each). The odds ratio for PD in retears was 33.8, which was greater than that for tear size ≥3 cm and FD grade ≥3. Conclusions: We concluded that large tear size and FD contribute to the occurrence of PD. Furthermore, PD could be a predictor of retear after ARCR.

Neurotropin protects rotator cuff tendon cells from lidocaine-induced cell death

Background

Local anesthetics often are used in rotator cuff tears as therapeutic tools, although some cases have reported that they have detrimental effects. Neurotropin (NTP) is used widely in Japan as a treatment for various chronic pain conditions and is shown to have protective effects on cartilage and nerve cells. In this study, we investigated the protective effect of NTP against lidocaine-induced cytotoxicity.

Methods

Tenocytes from rotator cuff tendons were incubated with lidocaine, NTP, lidocaine with NTP, and a control medium. Cell viability was evaluated using the WST-8 assay. Cell apoptosis was detected via annexin V staining using flow cytometry. The expression of BCL-2 and cytochrome c, which are involved in the intrinsic mitochondrial pathway of apoptosis, was evaluated via Western blotting and immunohistochemical staining.

Results

In the cell viability assay, lidocaine decreased cell viability in a dose-dependent manner, and NTP did not affect cell viability. Moreover, NTP significantly inhibited the cytotoxic effect of lidocaine. The flow cytometry analysis showed that lidocaine significantly induced apoptosis in tenocytes, and NTP considerably inhibited this lidocaine-induced apoptosis. Western blotting experiments showed that lidocaine decreased the protein expression of BCL-2, and that NTP conserved the expression of BCL-2, even when used with lidocaine. Immunohistochemical staining for cytochrome c showed that 0.1% lidocaine increased cytochrome c-positive cells, and NTP suppressed lidocaine-induced cytochrome c expression.

Conclusions

NTP suppresses lidocaine-induced apoptosis of tenocytes by inhibiting the mitochondrial apoptotic pathway. Intra-articular/ bursal injection of NTP with lidocaine could protect tenocytes in rotator cuff tendons against lidocaine-induced apoptosis.

Incidence of Re-Dislocation/Instability After Arthroscopic Bankart Repair: Analysis via Telephone Interviews

INTRODUCTION

Current advances in arthroscopic surgery have led to good outcomes for arthroscopic Bankart repair (ABR) for recurrent anterior shoulder dislocation. However, recent studies have reported recurrence rates of 4%-19% after ABR. In our survey conducted from February 2002 to December 2010, the post-ABR re-dislocation rate was 8.8%. In 2011, we began performing the ABR with open Bristow (B) procedure or Remplissage (R) procedure in patients with large glenoid or humeral head bone defects and in patients who play collision sports. Therefore, the present study is the second series evaluating the incidence of re-dislocation and instability after recurrent anterior shoulder dislocation.

METHOD

Surgery was performed for 84 cases of shoulder instability from January 2011 to August 2017. After excluding 7 open surgeries, 6 reoperations, and 2 patients with multidirectional instability, telephone interviews were conducted with 69 patients. The average follow-up duration was 46.9 months (range, 13-92 months).

RESULT

ABR alone was performed 61 patients; the B procedure was added for 3 patients, and the R procedure was added for 5 patients. Telephone interviews were conducted with 61 patients. There were no cases of re-dislocation or reoperation. Four patients who underwent only ABR experienced postoperative instability, but not to the extent that their daily lives were affected.

CONCLUSION

This study showed that the addition of R or B technique to ABR for recurrent anterior shoulder dislocation resulted in a 0% re-dislocation rate.

Clinical outcome in patients with hand lesions associated with complex regional pain syndrome after arthroscopic rotator cuff repair

Background

Complex regional pain syndrome (CRPS)-related hand lesions are one of the complications following arthroscopic rotator cuff repair (ARCR). This study aimed to investigate the clinical outcomes of patients with CRPS-related hand lesions following ARCR.

Methods

Altogether, 103 patients with ARCR were included in this study (mean age, 63.6±8.2 years; 66 males and 37 females; follow-up period, preoperative to 12 months postoperative). Clinical assessment included the Japanese Orthopaedic Association (JOA) score, University of California, Los Angeles (UCLA) score, Constant score, 36-item short form health survey (SF-36) score, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score from preoperative to 12 months postoperatively. The patients were either assigned to the CRPS group or non-CRPS group depending on CRPS diagnosis until the final follow-up, and clinical outcomes were then compared between the groups.

Results

Of 103 patients, 20 (19.4%) had CRPS-related hand lesions that developed entirely within 2 months postoperatively. Both groups showed significant improvement in JOA, UCLA, and Constant scores preoperatively to 12 months postoperatively (p<0.001). Comparisons between the two groups were not significantly different, except for SF-36 “general health perception” (p<0.05) at 12 months postoperatively. At final follow-up, three patients had residual CRPS-related hand lesions with limited range of motion and finger edema.

Conclusions

CRPS-related hand lesions developed in 19.4% of patients following ARCR. Shoulder or upper-limb function improved in most cases at 12 months, with satisfactory SF-36 patient-based evaluation results. Patients with residual CRPS-related hand lesions at the last follow-up require long-term follow-up.

Preoperative hyaluronic acid injection modulates postoperative functional outcome in patients undergoing arthroscopic rotator cuff repair

Background

Arthroscopic rotator cuff repair (ARCR) generally yields acceptable clinical results. Hyaluronic acid (HA), a high-molecular-weight polysaccharide, is present in the extracellular matrix of soft connective tissue and synovial fluid, and its injection is known to significantly improve pain and clinical outcomes after rotator cuff injury. Some studies have described the role of HA injections as conservative therapy for rotator cuff tears. Since the subacromial bursa is believed to be the main source of shoulder pain in rotator cuff tears, subacromial injection is frequently used before surgery; however, its relationship with the clinical outcome after surgery remains unclarified. Therefore, we aimed to examine effects of preoperative subacromial HA injection on postoperative clinical outcome in patients with ARCR.

Methods

Ninety-eight patients were divided into a HA injection group and a non-injection group. The functional outcome measured was the University of California, Los Angeles (UCLA) score. Univariate analysis was performed to obtain variables with p values less than 0.1; we then used propensity score analysis, adjusting for pre- and post-operative confounding factors.

Results

The UCLA scores of all patients significantly improved 1 year postoperatively (PO) (p < 0.05). Subacromial HA injections were performed in patients with worse preoperative function. Univariate analysis showed significantly greater improvements in the injection group than in the non-injection group in terms of preoperative UCLA score, trauma, diabetes mellitus, UCLA score 3 months PO, abduction strength 4 months PO, and internal rotation (IR) strength 6 and 12 months PO. Propensity score analysis demonstrated that UCLA scores 3 months PO and IR strength 12 months PO in the injection group were significantly greater than those in the non-injection group. There were no significant differences in postoperative re-tear rates between the groups. In sub-analysis of the injection group, propensity scores showed that concurrent use of local anesthetics did not affect the data, suggesting that HA was effective.

Conclusion

Subacromial injection was administered to patients with worse function before ARCR. Propensity score analysis successfully demonstrated that functional outcome after surgery was improved in patients who were administered this injection compared with patients who were not administered this injection before surgery.

Effects of Estrogen-Deficient State on Rotator Cuff Healing

BACKGROUND

Rotator cuff retears after surgical repair are a concern, despite advances in operative techniques, but few studies have investigated the effects of the estrogen-deficient state on tendon-to-bone healing at the repair site.

PURPOSE

We evaluated the effect of the estrogen-deficient state on tendon-to-bone healing after rotator cuff repair in an ovariectomized rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Female Sprague Dawley rats underwent detachment and immediate repair of the supraspinatus tendon. Surgery was performed in 24 rats at 4.5 weeks of age 17 weeks after ovariectomy (OVX group) and in 24 age-matched control rats without ovariectomy (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks after surgery for biomechanical and histological evaluations of reattachment. Bone mineral density (BMD) at the insertion site and cancellous bone in the humeral head was assessed by micro-computed tomography.

RESULTS

BMD was significantly lower both at the insertion site and in cancellous area in the OVX group than in the control group at weeks 2 to 12. Ultimate load to failure, ultimate stress, linear stiffness, and the Young modulus were significantly lower in the OVX group than in the control group at 2 and 4 weeks, but the difference was no longer significant at 8 and 12 weeks. At 2 and 4 weeks, relatively immature granulation tissue was observed in the OVX group compared with the control group. At 8 and 12 weeks after surgery, there were differences in the tendon-bone interface in the 2 groups: Direct insertion with well-established chondroid tissue was seen in the control group, and indirect insertion without chondroid tissue was seen in the OVX group. Consistently, the amount of chondroid tissue was greater and collagen organization was better in the control group than in the OVX group. Cells expressing cathepsin K were significantly more numerous both at the insertion site and in cancellous bone in the OVX group than in the control group.

CONCLUSION

The estrogen-deficient state by ovariectomy, compared with control rats, led to decreased biomechanical properties and poor development of chondroid tissue that influenced the repair of the tendon insertion after surgery.

CLINICAL RELEVANCE

Agents that modulate bone metabolism might improve tendon-to-bone healing in patients with an estrogen-deficient state, such as postmenopausal women who undergo rotator cuff surgery.

Prognostic factors affecting clinical outcomes after arthroscopic rotator cuff repair: importance of functional recovery by 3 months after surgery

BACKGROUND

To examine important factors that affect clinical outcomes following arthroscopic rotator cuff repair (ARCR).

METHODS

Among 163 patients who underwent ARCR, we included 71 shoulders in 71 patients whose progress was monitored for > 2 years, postoperatively. We divided the patients into groups A (scores ≥ 83 points, 59 patients) and B (scores < 83 points, 12 patients) using the Japanese Orthopedic Association (JOA) score at 24 months. We then conducted univariate and multivariate analyses of pre- and postoperative (2 and 3 months, respectively) factors.

RESULTS

The mean JOA score for all patients significantly improved from 63.7 ± 11.5 points preoperatively to 90.3 ± 9.6 points at 24 months postoperatively (P < 0.05). However, there were no significant between-group differences in the preoperative scores. In addition, there were no significant differences in the postoperative re-tear rate. Univariate analysis revealed that the range of motion (preoperative abduction and postoperative elevation, abduction, internal rotation, and external rotation), muscle strength (external rotation 3 months postoperatively), postoperative pain level [visual analog scale (VAS) maximum score, 10 points], partial repair, Cofield classification, and preoperative width were significant factors (P < 0.05 for all factors). Multivariate and receiver operating characteristic curve analyses showed that VAS at 2 months postoperatively and elevation at 3 months postoperatively were significant factors.

CONCLUSIONS

To obtain a JOA score of ≥ 83 points at 24 months postoperatively, following ARCR, a postoperative VAS of < 5 points at 2 months and postoperative elevation of ≥ 110° at 3 months should be achieved.

Hand lesion after arthroscopic rotator cuff repair: Association with complex regional pain syndrome

BACKGROUND

It is known that complex regional pain syndrome (CRPS) occurs after arthroscopic rotator cuff repair (ARCR); however, few studies have investigated this complication. Therefore, the purpose of the present study was to evaluate CRPS after ARCR.

METHODS

A total of 182 patients who underwent ARCR were enrolled in this study. The average age of patients was 62.8 ± 10.0 years, with an average follow-up period of 21.5 ± 38.1 months. CRPS criteria outlined by the Ministry of Health, Labor, and Welfare study team for CRPS in Japan (MHLWJ) and International Association for the Study of Pain (IASP 2005) were utilized for diagnosis. There are two rating systems for the "clinical purpose" and "research purpose" in both criteria, respectively. Clinical outcomes, including Japanese Orthopedic Association (JOA) and University of California, Los Angeles scores, were evaluated using univariate and multivariate analysis.

RESULTS

CRPS exclusively occurred in the hand of the operated limb, developing within 3 months of surgery. Two or more of the following symptoms were noted in patients with the hand lesion associated with CRPS: edema (93.4%), restricted range of motion (83.4%), hyperalgesia (30.1%), paridrosis (20.4%), and atrophic change (12.2%). Under these conditions, the incidences of CRPS were 24.2% (44/182) when evaluated by the MHLWJ rating system for the "clinical purpose;" 11% (22/182) by the MHLWJ rating system for the "research purpose;" 6% (11/182) by the IASP 2005 for the "clinical purpose;" and 0.5% (1/182) by the IASP 2005 for the "research purpose." Results of multivariate analysis demonstrated that "Function" in the JOA score was a risk factor for the development of CRPS after ARCR, when evaluated by a system for the "clinical purpose" of the MHLWJ.

CONCLUSION

Following ARCR, CRPS-induced hand lesions occur more frequently than is generally believed, thereby suggesting that its impact on surgical outcomes should be clarified in the future.

Hyaluronic Acid Accelerates Tendon-to-Bone Healing After Rotator Cuff Repair

BACKGROUND

There is growing evidence that the subacromial injection of hyaluronic acid (HA) is effective for pain relief in rotator cuff tears; however, its effect on tendon-to-bone healing remains unknown.

PURPOSE

To examine the effect of HA on the chondrogenesis of mesenchymal stem cells (MSCs) in vitro and on tendon-to-bone healing in a rotator cuff repair model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Bilateral complete tears of the infraspinatus tendon were made in rabbits and subsequently repaired. Before closure, 1 mL HA was applied to the repaired site, and phosphate-buffered saline was used in the opposite side as a control. Biomechanical, histological, and immunohistochemical analyses were performed at 4, 8, and 12 weeks after surgery. After euthanizing each animal, the bone marrow was isolated from the femoral bone in the same rabbits. Then, MSCs were cultured in media for chondrogenic differentiation, and the chondral pellet production and cartilage-related gene expression levels in the cells were examined at various concentrations of HA.

RESULTS

At 4 and 8 weeks after surgery, ultimate load-to-failure was significantly greater in the HA group than in the control group (45.61 ± 9.0 N vs 32.42 ± 9.4 N at 4 weeks, 90.7 ± 16.0 N vs 66.97 ± 10.0 N at 8 weeks; both P < .05) but not at 12 weeks after surgery (109.6 ± 40.2 N vs 108.1 ± 42.6 N, P > .05). Linear stiffness was not significant throughout the time point evaluation. The chondroid formation area at the tendon-bone interface stained by safranin O (control vs HA group) was 0.33% ± 0.7% versus 13.5% ± 12.3% at 4 weeks after surgery ( P < .05) and 3.0% ± 5.9% versus 12.9% ± 12.9% at 8 weeks after surgery ( P < .05), but there was no significant difference at 12 weeks after surgery. Maturity of collagen at the repaired site stained by PicroSirius Red (control vs HA group) was 16.2 ± 10.6 versus 43.5 ± 21.3 at 4 weeks after surgery ( P < .05), but there were no significant differences at 8 and 12 weeks after surgery. MSCs were cultured in media for chondrogenic differentiation, and the chondral pellet production and cartilage-related gene expression levels in the cells were examined at various concentrations of HA. The number of CD44-positive cells (control vs HA group) was 8.3% ± 1.4% versus 26.2% ± 5.2% at 3 days after surgery ( P < .05), 1.8% ± 1.1% versus 26.6% ± 11.6% at 4 weeks after surgery ( P < .05), 0.6% ± 0.9% versus 0.5% ± 0.6% at 8 weeks after surgery ( P > .05), and 1.8% ± 4.0% versus 5.4% ± 4.2% at 12 weeks after surgery ( P > .05). Compared with the control group, HA significantly increased the volume of cartilaginous pellet produced by MSCs (0.0016 ± 0.0015 mm³ at 0 mg/mL of HA, 0.0041 ± 0.0023 mm³ at 1.0 mg/mL, and 0.0041 ± 0.0018 mm³ at 4.0 mg/mL), with increased mRNA expression (relative ratio to control) of type 2 collagen (1.34 ± 0.38), SOX9 (1.58 ± 0.31), and aggrecan (1.30 ± 0.22) genes in the pellet ( P < .01).

CONCLUSION

HA accelerated tendon-to-bone healing in the rotator cuff repair model, enhancing the biomechanical strength and increasing chondroid formation and tendon maturity at the tendon-bone interface. Based on the data of in vitro experiments, HA-activated MSCs may play a crucial role in the acceleration of tendon-to-bone healing.

CLINICAL RELEVANCE

The data suggest the relevance of clinical application of HA to accelerate tendon-to-bone healing. It may decrease the number of retears after surgery.

Effect of Preoperative Fatty Degeneration of the Rotator Cuff Muscles on the Clinical Outcome of Patients With Intact Tendons After Arthroscopic Rotator Cuff Repair of Large/Massive Cuff Tears

BACKGROUND

Fatty degeneration of the rotator cuff muscles is associated not only with postoperative retear but also with postoperative muscle weakness; therefore, fatty changes in the muscles may affect the clinical outcome even in patients with these tears who have intact tendons after arthroscopic rotator cuff repair (ARCR).

PURPOSE

To evaluate the effect of fatty infiltration on the clinical outcome in patients with intact tendons after arthroscopic repair of large/massive cuff tears.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

One hundred fifty-five consecutive patients with large/massive rotator cuff tears underwent ARCR. Of these, 55 patients (mean ± SD age, 64.4 ± 9.1 years) in whom intact tendons after surgery were confirmed with magnetic resonance imaging at final follow-up (mean ± SD, 2.5 ± 1.4 years) were included in this study. Depending on their University of California Los Angeles (UCLA) score at the final follow-up, they were assigned to either the unsatisfactory group (score ≤27; n = 12) or the satisfactory group (score >27; n = 43). Various clinical parameters affecting the clinical outcome were examined through univariate and multivariate analyses.

RESULTS

The UCLA score of all patients significantly improved from 18.1 ± 4.4 points preoperatively to 29.8 ± 4.5 points postoperatively ( P < .0001). The mean preoperative UCLA scores were not significantly different between the satisfactory and unsatisfactory groups ( P = .39). Multivariate analysis showed that the preoperative Goutallier stages of the infraspinatus (odds ratio [OR], 8.87; 95% confidence interval [CI], 1.51-52.0; P = .016) and/or subscapularis (OR, 7.53; 95% CI, 1.58-35.9; P = .011) were significantly associated with outcome. Receiver operating characteristic curve analysis revealed a cutoff value of Goutallier stage 1 in both muscles, with area under the curve values of 0.79 (sensitivity 91% and specificity 51%) and 0.84 (sensitivity 100% and specificity 54%) in the infraspinatus and subscapularis, respectively.

CONCLUSION

Preoperative fatty degeneration of the infraspinatus and/or subscapularis with Goutallier stage 2 or higher was significantly associated with worse outcome in patients with large/massive tears who had intact tendons after ARCR.

Factors Affecting Clinical Outcome in Patients With Structural Failure After Arthroscopic Rotator Cuff Repair

PURPOSE

(1) To compare clinical outcomes between patients with large or massive rotator cuff tears who have healed cuffs and patients with postoperative structural failure (retear after complete or partial repair) and (2) to identify factors associated with clinical outcomes in patients with postoperative structural failure.

METHODS

We conducted a retrospective study of consecutive patients with large or massive cuff tears who underwent arthroscopic repair at our institution between 2005 and 2012. On the basis of intraoperative findings and magnetic resonance imaging at final follow-up, the patients were divided into 3 groups: healed group, retear group (after complete repair), and partial-repair group. The outcome measures comprised the Japanese Orthopaedic Association (JOA) and University of California, Los Angeles (UCLA) scores; muscle strength; and range of motion. The tear length, tear width, muscle atrophy, and fatty degeneration were evaluated by preoperative and postoperative magnetic resonance imaging. The extent of tendon reattachment to the superior, middle, and inferior facets and the lesser tuberosity was examined on magnetic resonance images at final follow-up.

RESULTS

In total, 74 patients (healed, 41; retear, 19; and partial repair, 14) were included in this study. The mean age was 63.8 ± 8.5 years, with a mean follow-up period of 3.6 ± 1.4 years. The postoperative JOA and UCLA scores significantly improved in all 3 groups, but the differences were not significant. In the retear and partial-repair groups, postoperative tendon preservation at the middle facet significantly affected the JOA and UCLA scores (P = .003 and P = .014, respectively).

CONCLUSIONS

The JOA and UCLA scores were significantly improved in patients with structural failure. Under these conditions, the only clinical factor that affected patient outcome was tendon healing at the middle facet. Thus tendon preservation at the middle facet was a predictor of good clinical outcomes in patients who underwent arthroscopic rotator cuff repair of large or massive tears and had postoperative structural failure.

LEVEL OF EVIDENCE

Level III, case-control study.

Effects of corticosteroids and hyaluronic acid on torn rotator cuff tendons in vitro and in rats

Corticosteroids (CS) or hyaluronic acid (HA) is used in subacromial injection for the conservative treatment of rotator cuff tears (RCT); this study addresses the question of how CS and HA affect the tendon tissue and fibroblasts in vitro and in rats. Cell proliferation assays were performed in human tendon fibroblasts from RCT. Rats underwent surgery to create RCT, and the surgical sites were injected with CS or HA. The rotator cuff tendons were subjected to biomechanical testing, microscopic and immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), and ultrastructural analysis. Cell proliferation was significantly decreased with CS in vitro (p < 0.05). Maximal load of CS-treated tendons was significantly decreased compared with that of HA-treated tendons (p < 0.05), as well as PCNA(+) cells at 2 weeks (p < 0.05). Ultrastructural observations of the CS-treated rats detected apoptosis of tendon fibroblasts 24 h after surgery. Histological and biomechanical data 4 weeks after surgery were not significant among the three groups. Unlike HA, CS caused cell death, and inhibition of the proliferation of tendon fibroblasts, leading to a delay of tendon healing involved and a subsequent decrease of biomechanical strength at the surgical site.

Isolated fracture of the lesser tuberosity of the humerus: a case report

Fracture of the lesser tuberosity of the humerus often occurs concomitant with posterior shoulder dislocation or proximal humeral fracture, while isolated fractures are extremely rare. We report a case in which an isolated fracture of the lesser tuberosity of the humerus occurred due to a distinctive pathogenic mechanism. A 43-year-old male had his right shoulder forced into internal-rotation (i.e. back reach position) when he fell into a ditch approximately 70 cm wide and 1.5 m deep. Subcutaneous bleeding and tenderness were detected anteriorly in the shoulder, with restricted range of motion. Radiographs indicated a fracture of the lesser tuberosity of the humerus. Three-dimensional computed tomography (CT) confirmed an isolated fracture of the lesser tuberosity, which was displaced anteromedially by more than 5 mm from its previous anatomical position. During operation, the fractured fragment of the lesser tuberosity was reduced easily and fixed by a cancellous bone screw. At postoperative 2 years, the patient has recovered full range of motion with sufficient muscle strength, and has returned to work. The pathogenic mechanisms in this case were unique, differing from those that have been previously reported.

Teratogenicity of Aino virus in the chick embryo

Aino virus (JaNAr 28 strain), a possible agent of a congenital anomaly of calves, was inoculated into the yolk sac of chick embryos at a dose of 10(2), 10(3), 10(4) or 10(5) TCID50 0.2 ml-1 at four, six or eight days of incubation. At 21 days of incubation all the unhatched embryos or hatched chickens in the experimental and control groups were sacrificed for pathological examination. The incidence of hydranencephaly, cerebellar hypoplasia or agenesis and arthrogryposis or scoliosis was highest (85 per cent in the chicks inoculated with 10(3) TCID50 0.2 ml-1 at eight days of incubation. The lesions were very similar to those found in congenital abnormalities in calves suspected of a natural infection with Aino virus.

99Tcm tetrofosmin uptake in mediastinal tumours

We present our experience in visualizing mediastinal tumours using 99Tcm tetrofosmin. Three patients with thymic tumours and two patients with a mediastinal tumour (seminoma and small cell carcinoma) were found to have anterior mediastinal masses on chest radiographs, and subsequently underwent computed tomography and magnetic resonance imaging. In addition, the patients underwent single photon emission computed tomography (SPECT) with 99Tcm tetrofosmin and 201Tl. Intense uptake was seen on early 99Tcm tetrofosmin images in three patients with thymoma, invasive thymoma and mediastinal tumour (small cell carcinoma). In the remaining two patients with thymic carcinoma and mediastinal seminoma, there was intense 99Tcm tetrofosmin uptake on early images which reduced on delayed images. 201Tl uptake was intense on both early and delayed images. These findings suggest that different 99Tcm tetrofosmin uptake in early and delayed imaging may offer new information on these mediastinal tumours.

Hydranencephaly, cerebellar hypoplasia, and myopathy in chick embryos infected with aino virus

Pathogenesis of Aino virus (AIV), a suspected causative agent of congenital abnormalities of calves, has not yet been established by experimental infection of dams. To investigate the pathogenesis, 10(3) median tissue culture infective doses per 0.2 ml of AIV strain JaNAr 28 was inoculated into the yolk sac of 8-day-old chick embryos. At 4, 7, 10, and 13 days post-inoculation (PI) 20 eggs were opened and macro- and microscopic studies combined with virus recovery and immunohistochemical detection of the virus antigen were performed. At 7 to 13 days PI chick embryos manifested marked hydranencephaly, cerebellar hypoplasia, arthrogryposis, and scoliosis, with the highest incidences of 86.7%, 73.3%, 80.0%, and 20.0%, respectively. At 4 days PI the viral antigen was found in nerve cells, gitter cells in mild necrotic foci of the central nervous system (CNS), degenerative myotubules, and macrophages in the interstitium, which was associated with the early phase of AIV-induced encephalitis and polymyositis, with occasional accompanying hemorrhage and clumping of myotubular fragments. From 7 to 10 days PI, AIV antigen increased markedly in the liquefactive necrosis and in both degenerative and normal-looking myotubules in conjunction with developing hydranencephaly and arthrogryposis. The encephalitis and myositis had a tendency to mitigate by 10 days PI, coincident with a slight decrease in amount of AIV antigen. At 13 days PI there was almost no detectable AIV antigen in CNS and skeletal muscles, probably due to depletion of cells having affinity to AIV.

99mTc tetrofosmin uptake in lung cancer. A case report

This case report describes a 71-year-old man with a lung tumor in the posterior inferior segment of the right lung, detected on a screening chest radiograph. The patient underwent myocardial imaging with 99mTc tetrofosmin and 201Tl, using single photon emission CT (SPECT), and the tumor showed intense focal uptake of the radiotracer. This observation supports the recent suggestion that 99mTc tetrofosmin may be useful for oncologic imaging of lung carcinoma, and further studies may be warranted.

[Visual analysis of hepatic function by a scoring system using 99mTc-GSA]

To establish a simple hepatic function test, a five-point scoring system using 99mTc-galactosyl-human serum albumin (GSA) was applied to seventy-six patients with or suspected with hepatic dysfunction. Dynamic data at rest were obtained immediately and 30 minutes after intravenous bolus injection of 99mTc-GSA (185 MBq). Regions of interest (ROIs) were superimposed over the images of the liver and the entire heart. A visual analysis using a image taken 5 to 6 minutes after radiotracer injection was performed by the three observers blinded to the clinical information to assess their agreement or disagreement on the grading score. kappa-Test was used to evaluate the goodness of agreement. Three pairs in the first reading showed excellent interobserver agreement (0.92 mean kappa-value). Three pairs in the first and second reading also showed excellent intraobserver agreement (0.89 mean kappa-value). Data were also analyzed for correlations with heart/liver count ratio, ICG R15, LHL15, Alb, TB, PT, HPT and ZTT. There were good correlations between visual grading score and ICG R15 (Rs = 0.619, p < 0.0001) and between grading score and heart/liver count ratio (Rs = 0.866, p < 0.0001). Grading score was also correlated with LHL15, Alb, TB, PT, HPT and ZTT (Rs = -0.770; -0.580; 0.593; -0.544; -0.622; 0.518, p < 0.0001 for each). There was a significant difference between heart/liver count ratio and LHL15 in the Grade 4 and Grade 5 groups. In conclusion, the present data suggest that a five-point scoring system based on visual analysis using 99mTc-GSA uptake is a useful indicator for hepatic dysfunction in a clinical setting.

Proliferation and teratogenicity of Aino virus in chick embryos

Aino virus (AIV; JaNAr 28 strain) 10(3) TCID50/0.2 ml was inoculated in the yolk sac of 8-day-old chick embryos. Recovery and titration of the virus from various organs including the central nervous system (CNS) and skeletal muscle were performed at 2, 4, 7, 10 and 13 days after inoculation (PI). AIV was systematically disseminated and proliferated even 2 days PI. The titers of the recovered virus from the CNS and from skeletal muscle was the highest at 4 days PI and declined with time, whereas hydranencephaly, arthrogryposis and cerebellar hypoplasia developed at 7 days PI and gradually progressed until 13 days PI.

[MR diagnosis for metastasis or non-metastasis of mediastinal and hilar lymph nodes in cases of primary lung cancer: detectability, signal intensity, and MR-pathologic correlation]

The detectability and signal intensity on MR imaging of mediastinal and hilar lymph nodes were studied in cases of lung cancer. Additionally, short inversion time inversion recovery (STIR) images and pathologic findings were compared. In the detection of resected metastatic mediastinal and hilar lymph nodes (n = 146), the STIR image (82%) was superior to the T1-weighted image (71%) and the T2-weighted image (60%). On STIR imaging, 212 (60%) of 412 resected non-metastatic mediastinal nodes and 38 (33%) of 116 resected non-metastatic hilar lymph nodes were detected. Characteristics of signal intensities of metastatic nodes were mainly low on T1-weighted images, high on T2-weighted images, and very high on STIR images. The rate of these characteristics of signal intensity of metastatic nodes was 59%. However, the rate of very high signal intensity of metastatic nodes on STIR imaging was 81%. Pathologically, lymph nodes with high or very high signal intensities on STIR images were metastatic, reactive and hyperplastic, or non-metastatic. Lymph nodes with slightly high signal intensity or high intensity with a low focus on STIR images were anthracotic, anthrasilicotic, caseous necrotic, calcified, or fibrotic. Thus, when the signal intensity of a lymph node was decreased on the STIR image, there was no definite evidence of metastasis excluding micro-metastasis or coagulation necrosis of a metastatic tumor. We conclude that the signal characteristics on STIR imaging are useful for distinguishing between macro-metastatic and non-metastatic lymph nodes when enlarged nodes are detected by various other types of medical imaging.

Transcatheter hepatic arterial chemoembolization using epirubicin-lipiodol: experimental and pharmacological evaluation

The experimental and pharmacological characteristics of various formulations of an anticancer agent (epirubicin, EPI) and lipiodol were evaluated in vitro and in vivo. Three forms of EPI-lipiodol, i.e., an oil-in-water type of emulsion (O/W type), a water-in-oil type of emulsion (W/O type), and a suspension (S type), were prepared and investigated for their stability. An O/W-type emulsion using a stock solution of Iopamidol as the solvent for EPI was the most stable form in the stationary state in vitro. In 16 patients with malignant liver tumors (14 hepatocellular carcinomas and 2 liver metastases), the three forms of EPI-lipiodol were injected into the proper hepatic artery. The plasma EPI level was monitored periodically and analyzed pharmacokinetically. No significant difference in the pharmacokinetics of EPI was detected among the O/W, W/O, and S types.

[Bronchial atresia of additive anomalous bronchus]

A case of bronchial atresia of additive anomalous bronchus in right middle lobe was reported. A mass and emphysematous lung were found on the chest roentgenogram. CT, and MRI, and it is not difficult to diagnose.

[Diagnosis of acute gastrointestinal bleeding using scintigraphy with 99mTc-labeled red blood cells]

To evaluate the usefulness and clinical significance of scintigraphy using 99mTc-RBC in urgent abdominal bleeding, we performed abdominal bleeding scintigraphy in 20 patients with melena. These patients were admitted to the critical care center. Nine of 20 patients showed positive images with bleeding scintigraphy. Five of 20 patients were referred because of small intestinal bleeding. Four of these 5 patients revealed positive images. Seven of 9 patients who had positive image and four of 11 patients who were negative had open-surgery performed. While angiography was done in 8 patients, only 3 of the 8 patients were proven to have bleeding. These 3 patients also revealed positive images by bleeding scintigraphy. This technique facilitates the screening of bleeding in the ileum, where endoscopic techniques may prove difficult to detect the site of bleeding. We emphasize that abdominal scintigraphy should be performed on patients with G.I. bleeding since this is a more accurate examination than angiography.

Ruptured abdominal aortic aneurysm: factors influencing operative mortality

Of fifty-eight consecutive patients surgically treated for aneurysm of the abdominal aorta, twenty were emergency cases following the rupture. Associated diseases were found in 85 per cent of patients; hypertension being the most common. Fifty per cent of patients were in shock on admission. The duration between rupture and operation was three hrs to two weeks with the average of 115.5 hrs. In six patients, the diagnosis of abdominal aortic aneurysm was known for over six months. The operative mortality rate in case of ruptured abdominal aortic aneurysm was 45 per cent. The most important determinants of survival were the incidence of shock on admission, the incidence of associated disease, the known duration of the aneurysm, and the time interval from rupture to admission. The intraoperative factors most influencing survival were the type of rupture, intraoperative hypotension, and total blood loss. Comparison of the mortality rate in elective surgery of abdominal aortic aneurysms (5.3 per cent) with that in ruptured aneurysms (45.0 per cent) suggests the necessity for early elective operations whenever abdominal aortic aneurysms are diagnosed.

[Acute and chronic experimental tricuspid valvular stenosis in dogs]

Acute and chronic experimental tricuspid valve stenosis was produced in 20 dogs. Clinical and hemodynamic alterations that resulted from severe anatomic tricuspid valve narrowing were surprisingly mild. In the acute stenosis studies, the normal tricuspid valve area of 8.2 +/- 0.3 sq cm was narrowed to less than 1.0 +/- 0.1 sq cm with a resulting right auricle-right ventricle diastolic gradient of 3.7 +/- 0.7 mm Hg. In chronic studies, a decrease in tricuspid valve area from 7.6 sq cm to 1.6 +/- 0.3 sq cm produced a diastolic gradient of 1.8 +/- 0.2 mm Hg. After 60 days, overt signs of right-sided failure (pleural effusions and ascites) were absent, and histological evidence of passive congestion (liver and spleen) was not recognized. The splanchnic vascular beds appear to act as excellent buffers against increases in right-sided cardiac pressure. We conclude that isolated narrowing of the tricuspid valve must be very severe to cause notable clinical and hemodynamic changes.

[A comparative study of experimental models for cardiac preservation through orthotopic transplantation]

Various kinds of models for canine heart preservation were evaluated through orthotopic transplantation. Following warm ischemic (WIT) and preservation times (PT), donor hearts were orthotopically transplanted to recipients and observed for 2 hours. The study was divided into four groups. A heart-lung preparation (Group A) was preserved by coronary perfusion with diluted blood for an hour following 15-minute WIT in A-1 (n = 33), and 2 hours following 30-minute WIT in A-2 (n = 19). Following 30-minute WIT, the heart (Group B) was preserved for an hour by coronary perfusion with diluted blood in B-1 (n = 20), a modified Krebs solution in B-2 (n = 14), and a EL-solution in B-2 (n = 14). Following 30-minute WIT, the heart (Group C) was preserved for 2 hours by a Langendorff's model with coronary perfusion using perfluorochemical in C-1 (n = 5) and Hydroxyethyl starch in C-2 (n = 1). In Group D, electromechanical arrest of the heart and coronary vascular washout were performed in D-1 (n = 8) with K+ cardioplegia, D-2 (n = 8) with K+-verapamil cardioplegia, and D-3 (n = 5) with Collins M-verapamil cardioplegia. The heart was then removed and suspended in the same solution. The graft was preserved at 4 degrees C for 6 hours in D-1 and D-2, and 24 hours in D-3. Fourty-eight % in A-1 and 26% in A-2 were successfully transplanted.(ABSTRACT TRUNCATED AT 250 WORDS)

Cystic partially differentiated nephroblastoma and multilocular cyst of the kidney. Report of two cases of so-called multilocular cyst of the kidney

Two cases of so-called multilocular cyst of the kidney are presented. Although both cases satisfied all of the criteria which characterize the multilocular cyst of the kidney, one had cystic lesions and neoplastic lesions (nephroblastoma-like lesions) and the other had only cystic lesions and was complicated with hamartoma. We prefer the term "cystic partially differentiated nephroblastoma" as the diagnostic term for the former and "multilocular cyst of the kidney" for the latter. A study of 40 reported cases of multilocular cystic lesions of the kidney revealed that cases having only cystic lesions were distributed in all ages from 4.5 months to 71 years and that cases having neoplastic lesions were seen in infants from 4 months to 2 years.