Recombinant Human Parathyroid Hormone Biocomposite Promotes Bone-to-Tendon Interface Healing by Enhancing Tenogenesis, Chondrogenesis, and Osteogenesis in a Rabbit Model of Chronic Rotator Cuff Tears

PURPOSE

To investigate the effect of recombinant human parathyroid hormone (rhPTH) biocomposite on bone-to-tendon interface (BTI) healing for surgical repair of a chronic rotator cuff tear (RCT) model of rabbit, focusing on genetic, histologic, biomechanical and micro-computed tomography (CT) evaluations.

METHODS

Sixty-four rabbits were equally assigned to the 4 groups: saline injection (group A), nanofiber sheet alone (group B), rhPTH-soaked nanofiber sheet (nanofiber sheet was soaked with rhPTH, group C), and rhPTH biocomposite (rhPTH permeated the nanofiber sheet by coaxial electrospinning, group D). The release kinetics of rhPTH (groups C and D) was examined for 6 weeks in vitro. Nanofiber scaffolds were implanted on the surface of the repair site 6 weeks after the induction of chronic RCT. Genetic and histologic analyses were conducted 4 weeks after surgery. Furthermore, genetic, histologic, biomechanical, micro-CT, and serologic analyses were performed 12 weeks after surgery.

RESULTS

In vivo, group D showed the highest collagen type I alpha 1 (COL1A1), collagen type III alpha 1 (COL3A1), and bone morphogenetic protein 2 (BMP-2) messenger RNA (mRNA) expression levels (all P < .001) 4 weeks after surgery; however, there were no differences between groups at 12 weeks postsurgery. After 12 weeks postsurgery, group D showed better collagen fiber continuity and orientation, denser collagen fibers, more mature bone-to-tendon junction, and greater fibrocartilage layer formation compared with the other groups (all P < .05). Furthermore, group D showed the highest load-to-failure rate (28.9 ± 2.0 N/kg for group A, 30.1 ± 3.3 N/kg for group B, 39.7 ± 2.7 N/kg for group C, and 48.2 ± 4.5 N/kg for group D, P < .001) and micro-CT outcomes, including bone and tissue mineral density, and bone volume/total volume rate (all P < .001) at 12 weeks postsurgery.

CONCLUSIONS

In comparison to rhPTH-soaked nanofiber sheet and the other control groups, rhPTH biocomposite effectively accelerated BTI healing by enhancing the mRNA expression levels of COL1A1, COL3A1, and BMP-2 at an early stage and achieving tenogenesis, chondrogenesis, and osteogenesis at 12 weeks after surgical repair of a chronic RCT model of rabbit.

CLINICAL RELEVANCE

The present study might be a transitional study to demonstrate the efficacy of rhPTH biocomposites on BTI healing for surgical repair of chronic RCTs as an adaptable polymer biomaterial in humans.

The application of a dual-lead locking screw could enhance the reduction and fixation stability of the proximal humerus fractures: a biomechanical evaluation

Introduction

Bicortical screw fixation, which penetrates and fixes the near and far cortex of bone, has been conventionally used to achieve compressive fixation for fracture using screws. Open reduction and internal fixation using the locking plate are widely used for treating proximal humerus fractures. However, minimal contact between the bone and the locking plate can lead to an insufficient reduction. Theoretically, a dual-lead locking screw with different leads for the screw head and body could enhance the reduction and fixation stability of fragments in proximal humeral fractures without bicortical fixation, and achieve additional compression at the bone-plate-screw interface. This study assessed the insertion mechanics of the lead ratio of the dual-lead locking screw and its effect on the fixation stability of the proximal humerus fracture.

Methods

A Multi-Fix® locking plating system composed of ∅ 3.5 mm locking screws and a locking plate was used to make a locked plating for Sawbone bone blocks and fourth-generation composite humeri. Two different types of Sawbone bone blocks were used to simulate the osteoporotic (10 PCF) and normal cancellous (20 PCF) bones. The lead of the screw head thread (L head ) was 0.8 mm, and that of the screw body (L body ) was 0.8, 1.25, 1.6, 2.0, and 2.4 mm, whose lead ratios (R lead = L body / L head ) were 1.0, 1.56, 2.0, 2.5, and 3.0, respectively.

Results

The dual-lead locking screw elevated the compression between the locking plate and the bone. The elevation in the compression due to the dual-lead thread became weaker for the cancellous bone when the lead of the screw body was more than twice that of the screw head. The plate/humerus compression with strong bone quality withstood higher dual-lead-driven compression.

Discussion

A dual-lead locking screw of L body = 1.25 mm (R lead = 1.56 ) is recommended for maximum rotational stability for the locked humerus plating. The screws with over L body = 1.6 mm (R lead = 2 ) have no advantage in terms of the failure torque and maximum torsional deformation. Any locking dual-lead screw with a body thread lead of <1.6 mm (R lead = 2 ) can be used without the risk of bone crush when surgeons require additional compression to the locked cancellous bone plating.

Comparison between osteonecrosis of the humeral and femoral heads - epidemiological analysis of the surgical trend using the nationwide claims database of the republic of Korea

BACKGROUNDS

The humeral head is the second most common site of osteonecrosis, after the femoral head. However, compared to osteonecrosis of the femoral head (ONFH), epidemiological information on osteonecrosis of the humeral head (ONHH) is scarce. We hypothesised that different biomechanical properties of the shoulder from the hip joint might present different epidemiological characteristics of ONHH from those of the ONFH. To evaluate epidemiological differences, we compared trends in the surgical treatment of ONHH and ONFH using the nationwide medical claims database of the Republic of Korea (ROK).

METHODS

We analysed epidemiological data from the Health Insurance Review and Assessment (HIRA) database of the ROK between 2008 and 2018. HIRA database contains almost all medical information in an anonymised form, including demographics, diagnoses, and types of surgical procedures, generated through healthcare practices in ROK. The annual incidence rates of ONHH and ONFH were calculated based on the total number of the general population. Demographics, annual incidence, and the proportion of post-traumatic osteonecrosis and surgical procedures were compared according to the anatomical site and the affected year.

RESULTS

The total number of patients treated for ONHH and ONFH during the study period was 1,028 and 66,260, respectively. Although the incidence of ONHH increased, it is a relatively rare disease compared to ONFH. ONHH occurred more frequently in females, while ONFH occurred predominantly in male patients (p < 0.001). Surgical treatment for ONHH was most frequently performed in older patients (63.7%), whereas middle-aged patients had the largest proportion of ONFH (48.9%, p < 0.001). The proportion of post-traumatic osteonecrosis was significantly higher in the ONHH (5.1%) than in the ONFH (1.9%, p < 0.001). Arthroplasty was performed more frequently in the ONHH (96.0%) than in the ONFH (92.9%, p < 0.001).

CONCLUSION

Despite the anatomical similarities between the hip and shoulder joints, the different biomechanical properties, such as weight-bearing functions, might cause epidemiological differences between ONHH and ONFH.

The Effect of Combining Hyaluronic Acid and Human Dermal Fibroblasts on Tendon Healing

BACKGROUND

The incidence of rotator cuff tears is rapidly increasing, and operative techniques for rotator cuff repair have been developed. However, the rates of postoperative retear remain high.

PURPOSE/HYPOTHESIS

The purpose was to determine the effects of human dermal fibroblasts (HDFs) with hyaluronic acid (HA) on tendon-to-bone healing in a rabbit model of chronic rotator cuff tear injury. It was hypothesized that HA would enhance HDF proliferation and that a combination of HA and HDFs would produce a synergistic effect on the healing of repaired rotator cuff tendons of rabbits.

STUDY DESIGN

Controlled laboratory study.

METHODS

For in vitro study, HDFs were plated on a 24-well plate. After 1 day, 2 wells were designated as the test group and treated with 0.75% HA in phenol red-free Dulbecco's modified Eagle medium (DMEM). An other 2 wells served as control groups and were treated with the same volume of phenol red-free DMEM without HA. Each group was duplicated, resulting in a total of 4 wells, with 2 wells in each group for replication purposes. The cells were incubated for 24 hours, followed by 72-hour cultivation. Absorbance ratios at 96 and 24 hours were compared to evaluate cell proliferation. For the in vivo study, a total of 24 rabbits were randomly allocated to groups A, B, and C (n = 8 each). Supraspinatus tendons were detached bilaterally and left for 6 weeks to establish a chronic rotator tear model. Torn tendons were subsequently repaired using the following injections: group A, 0.5 × 106 HDFs with HA; group B, HA only; and group C, saline only. At 12 weeks after repair, biomechanical tests and histological evaluation were performed.

RESULTS

In vitro study showed that HDF proliferation significantly increased with HA (HDFs with HA vs HDFs without HA; 3.96 ± 0.09 vs 2.53 ± 0.15; P < .01). In vivo, group A showed significantly higher load-to-failure values than the other groups (53.8 ± 6.9 N/kg for group A, 30.6 ± 6.4 N/kg for group B, and 24.3 ± 7.6 N/kg for group C; P < .001). Histological evaluation confirmed that group A showed higher collagen fiber density and better collagen fiber continuity, tendon-to-bone interface maturation, and nuclear shape than the other groups (all P < .05).

CONCLUSION

This controlled laboratory study verified the potential of the combination of HDFs and HA in enhancing healing in a chronic rotator cuff tear rabbit model.

CLINICAL RELEVANCE

A potential synergistic effect on rotator cuff tendon healing may be expected from a combination of HDFs and HA.

Far-Infrared Radiation to Improve Clinical Outcomes after Arthroscopic Rotator Cuff Repair: A Prospective Randomized Comparative Clinical Study

Background

The efficacy of far-infrared radiation (FIR) after rotator cuff repair has not been demonstrated yet. The aim of this study was to evaluate the effects of postoperatively applied FIR with regard to early pain, range of motion (ROM), and tendon-to-bone healing after arthroscopic rotator cuff repair.

Methods

A total of 64 consecutive patients who underwent arthroscopic rotator cuff repair with small- to medium-sized tears were enrolled in this prospective comparative study and randomly divided into an FIR group (n = 31) and a control group (n = 33). In the FIR group, FIR using a radiator device (Aladdin-H) was applied for 30 minutes per session twice daily from the first postoperative day. This application lasted for 10 weeks during the postoperative period. Clinical outcomes were assessed using a visual analog scale for pain (pVAS) at 5 weeks and ROM at 3 and 6 months postoperatively. Functional scores were evaluated at 6 months postoperatively. Healing of the repaired rotator cuff was also evaluated using ultrasonography at 3 months and magnetic resonance imaging at 6 months postoperatively.

Results

In both groups, clinical and functional outcomes were improved up to 6 months compared with preoperative values. At 5 weeks and 3 months postoperatively, the average pVAS was significantly lower in the FIR group than in the control group (1.7 ± 1.0 vs. 2.8 ± 1.4; p = 0.002 at 5 weeks, 2.4 ± 1.3 vs. 3.2 ± 1.8; p = 0.041 at 3 months). However, there was no significant difference in ROM, functional score, or healing rate between two groups at each follow-up time point.

Conclusions

The application of FIR after arthroscopic rotator cuff repair could be a safe and effective procedure to decrease postoperative pain, especially in the early postoperative period. This effective application of FIR can be considered to facilitate painless rehabilitation in the postoperative period after arthroscopic rotator cuff repair.

What is the most predictive magnetic resonance imaging finding of rotator cuff tear concomitant with shoulder stiffness?

Background

Common magnetic resonance imaging (MRI) findings in adhesive capsulitis are not often evident in rotator cuff tear concomitant with shoulder stiffness. This study aimed to determine the most predictive MRI finding of rotator cuff tear with shoulder stiffness to differentiate from that without stiffness.

Materials and methods

The data of patients who underwent arthroscopic rotator cuff repair between January 2014 and October 2019 were retrospectively reviewed. Stiffness was defined as forward flexion <120°, external rotation at side <30°, and internal rotation at back 

Results

Anterior capsular thickness, glenoid capsular thickness in the axillary recess, and anterior and axillary capsular hyperintensities were significantly more dominant in the stiff group (all P < .05) than in the control group. Anterior capsular thickness and anterior capsular abnormal hyperintensity could be used to differentiate between the stiff and control groups (P < .05). Anterior capsular thickness showed high diagnostic performance with an area under the receiver operating characteristic curve of 0.993. The cut-off value for stiffness was 3.07 mm (sensitivity, 96.1%; specificity, 100%).

Conclusion

Anterior capsular thickening and abnormal hyperintensity were the most predictive MRI findings for stiffness in patients with rotator cuff tear and stiffness to differentiate from patients with rotator cuff tear without stiffness.

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Key Words

• Adhesive capsulitis
• Anterior capsular abnormal hyperintensity
• Anterior capsular thickness
• Magnetic resonance imaging
• Rotator cuff tear
• Stiff shoulder

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MESH Headings Collapse

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Affiliation(s)

Ji Young Yoon Department of Orthopaedic Surgery, National Police Hospital, Seoul, Republic of Korea
HeeSoo Han Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
Myoung Yeol Shin Department of Orthopaedic Surgery, National Police Hospital, Seoul, Republic of Korea
Hyeon Jang Jeong Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
Yusuhn Kang Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
Young Dae Jeon Department of Orthopaedic Surgery, Ulsan University College of Medicine, Ulsan University Hospital, Ulsan, Republic of Korea
Ji Un Kim Department of Orthopaedic Surgery, Korea University College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
Joo Han Oh Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea

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Arthroscopic transosseous anchorless rotator cuff repair reduces bone defects related to peri-implant cyst formation: a comparison with conventional suture anchors using propensity score matching

BACKGROUND

The transosseous anchorless repair (ToR) technique was recently introduced to avoid suture anchor-related problems. While favorable outcomes of the ToR technique have been reported, no previous studies on peri-implant cyst formation with the ToR technique exist. Therefore, this study compared the clinical outcomes and prevalence of peri-implant cyst formation between the ToR technique and the conventional transosseous equivalent technique using suture anchors (SA).

METHODS

Cases with arthroscopic rotator cuff repair (ARCR) between 2016 and 2018 treated with the double-row suture bridge technique were retrospectively reviewed. Patients were divided into ToR and SA groups. To compare clinical outcomes, 19 ToR and 57 SA cases without intraoperative implant failure were selected using propensity score matching (PSM). While intraoperative implant failure rate was analyzed before PSM, retear rate, peri-implant cyst formation rate, and functional outcomes were compared after PSM.

RESULTS

The intraoperative implant failure rate (ToR, 8% vs. SA, 15.3%) and retear rate (ToR, 5.3% vs. SA, 19.3%) did not differ between the two groups (all P>0.05). However, peri-implant cysts were not observed in the ToR group, while they were observed in 16.7% of the SA group (P=0.008). Postoperative functional outcomes were not significantly different between the two groups (all P>0.05).

CONCLUSIONS

The ToR technique produced comparable clinical outcomes to conventional techniques. Considering the prospect of potential additional surgeries, the absence of peri-implant cyst formation might be an advantage of ToR. Furthermore, ToR might reduce the medical costs related to suture anchors and, thereby, could be a useful option for ARCR. Level of evidence: III.

Subacromial notching after reverse total shoulder arthroplasty

BACKGROUND

Scapular notching is a well-known postoperative complication of reverse total shoulder arthroplasty (RTSA). However, subacromial notching (SaN), a subacromial erosion caused by repeated abduction impingement after RTSA, has not been previously reported in a clinical setting. Therefore, this study aimed to assess the risk factors and functional outcomes of SaN after RTSA.

METHODS

We retrospectively reviewed the medical records of 125 patients who underwent RTSA with the same design between March 2014 and May 2017 and had at least 2 years of follow-up. SaN was defined as subacromial erosion observed at the final follow-up but not on the X-ray 3 months after surgery. Radiologic parameters representing the patient's native anatomy and degrees of lateralization and/or distalization during surgery were evaluated using preoperative and 3 months postoperative X-rays. The visual analogue scale of pain, active range of motion, and American Shoulder and Elbow Surgeons score were assessed preoperatively and at the final follow-up to evaluate the functional outcomes of SaN.

RESULTS

SaN occurred in 12.8% (16/125) of enrolled patients during the study period. Preoperative center of rotation-acromion distance (P = .009) and postoperative humerus lateralization offset, which evaluated the degree of lateralization after RTSA (P = .003), were risk factors for SaN. The preoperative center of rotation-acromion distance and postoperative humerus lateralization cutoff values were 14.0 mm and 19.0 mm, respectively. The visual analogue scale of pain (P = .01) and American Shoulder and Elbow Surgeons score (P = .04) at the final follow-up were significantly worse in patients with SaN.

CONCLUSIONS

SaN might adversely affect postoperative clinical outcomes. As SaN correlated with patients' anatomical characteristics and degree of lateralization during RTSA, the implant's degree of lateralization should be adjusted according to the patient's own anatomical characteristics.

Can convertible metal-backed glenoid components replace cemented polyethylene glenoid components in anatomical total shoulder arthroplasty?

BACKGROUND

Anatomical total shoulder arthroplasty (aTSA) has been used to manage degenerative diseases such as primary osteoarthritis. An increase in the use of this procedure has led to several developments in humeral and glenoid components to improve patient outcomes. This study aimed to compare clinical and radiological outcomes of the newly-introduced convertible metal-backed glenoid components with cemented polyethylene glenoid components in aTSA, and to determine whether the new component would be comparable to a conventional one for reducing the burden of future revision or conversion surgeries.

METHODS

Medical records of fifty patients who underwent aTSA with at least two years of follow-up were retrospectively reviewed. Eighteen patients received convertible metal-backed glenoid components with vitamin E1-coated liner (MB group), while thirty-two patients received conventional cemented polyethylene glenoid components (PE group). Pre- and postoperative clinical and radiological outcomes (acromion-greater tuberosity angle [AGA] and humeral lateral offset [LO]) at final follow-up were assessed. Radiolucent lines (RLLs) and loosening around the humeral and glenoid components were also evaluated.

RESULTS

Clinical outcomes improved after surgery in both groups (all p < 0.001). The arc of rotation measured by AGA improved postoperatively in both groups (all p < 0.001), and AGA and LO were not different according to the type of glenoid components (all p > 0.05). Overall complication rates including RLLs of PE and MB groups were 43.8% (14/32) and 16.7% (3/18), respectively (p = 0.031). Although the PE group had more RLLs than did the MB group (p < 0.05), related symptoms and/or glenoid implant loosening were not observed in both groups. Subscapularis failure occurred in two patients in the PE group and in one in the MB group.

CONCLUSION

The convertible metal-backed glenoid implant with vitamin E1-coated liner may be a good alternative for considering the potential for an easier conversion to reverse total shoulder arthroplasty.

Bioactive Scaffold With Spatially Embedded Growth Factors Promotes Bone-to-Tendon Interface Healing of Chronic Rotator Cuff Tear in Rabbit Model

BACKGROUND

Functional restoration of the bone-to-tendon interface (BTI) after rotator cuff repair is a challenge. Therefore, numerous biocompatible biomaterials for promoting BTI healing have been investigated.

PURPOSE

To determine the efficacy of scaffolds with spatiotemporal delivery of growth factors (GFs) to accelerate BTI healing after rotator cuff repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

An advanced 3-dimensional printing technique was used to fabricate bioactive scaffolds with spatiotemporal delivery of multiple GFs targeting the tendon, fibrocartilage, and bone regions. In total, 50 rabbits were used: 2 nonoperated controls and 48 rabbits with induced chronic rotator cuff tears (RCTs). The animals with RCTs were divided into 3 groups: (A) saline injection, (B) scaffold without GF, and (C) scaffold with GF. To induce chronic models, RCTs were left unrepaired for 6 weeks; then, surgical repairs with or without bioactive scaffolds were performed. For groups B and C, each scaffold was implanted between the bony footprint and the supraspinatus tendon. Four weeks after repair, quantitative real-time polymerase chain reaction and immunofluorescence analyses were performed to evaluate early signs of regenerative healing. Histological, biomechanical, and micro-computed tomography analyses were performed 12 weeks after repair.

RESULTS

Group C had the highest mRNA expression of collagen type I alpha 1, collagen type III alpha 1, and aggrecan. Immunofluorescence analysis showed the formation of an aggrecan+/collagen II+ fibrocartilaginous matrix at the BTI when repaired with scaffold with GFs. Histologic analysis revealed greater collagen fiber continuity, denser collagen fibers, and a more mature tendon-to-bone junction in GF-embedded scaffolds than those in the other groups. Group C demonstrated the highest load-to-failure ratio, and modulus mapping showed that the distribution of the micromechanical properties of the BTI repaired with GF-embedded scaffolds was comparable with that of the native BTI. Micro-computed tomography analysis identified the highest bone mineral density and bone volume/total volume ratio in group C.

CONCLUSION

Bioactive scaffolds with spatially embedded GFs have significant potential to promote the BTI healing of chronic RCTs in a rabbit model.

CLINICAL RELEVANCE

The scaffolds with spatiotemporal delivery of GF may serve as an off-the-shelf biomaterial graft to promote the healing of RCTs.

The correlation of the spinoglenoid ganglion cyst size with the electrophysiological alterations of suprascapular nerve and the rotator cuff muscle power

BACKGROUND

Although various treatment options are available for spinoglenoid cyst, including conservative and surgical methods, there is no standard guideline for its surgical decompression. Thus, the purpose of the study was to correlate the size of the spinoglenoid notch ganglion cyst (GC) as revealed by magnetic resonance imaging (MRI) with electrophysiological alterations, muscle power, and pain severity, and to estimate a cut-off value of cyst size to perform a decompression.

METHODS

Between January 2010 and January 2018, the patients with a GC at the spinoglenoid notch diagnosed on MRI, and who had a minimum follow-up of 2 years after the decompression were included. Maximum cyst diameter as measured on MRI was used for comparison. Electromyography (EMG) and nerve conduction velocity (NCV) studies were performed before the surgery. Peak torque deficit (PTD) percentage compared to opposite shoulder was calculated preoperatively and at 1 year after surgery. Pain severity was estimated using visual analogue scale (VAS) preoperatively.

RESULTS

Ten (50%) of 20 patients with GC > 2.2 cm and 1 (5.9%) of 17 patients with GC < 2.2 cm showed EMG/NCV abnormalities (p = 0.019). There was a correlation between the cyst size and the positive EMG/NCV findings (Correlation coefficient (CC) = 0.535, p < 0.001). The preoperative peak torque deficit on the external rotation was correlated with the positive EMG/NCV findings (CC = 0.373, p = 0.021). The PTD was improved significantly at 1 year postoperatively in patients with a GC size >2.2 cm (p = 0.029). The cyst size was not related to the preoperative pain VAS and muscle power.

CONCLUSIONS

The spinoglenoid cyst size >2.2 cm, but not pain severity or muscle power, correlates with the positive finding of EMG for compressive suprascapular neuropathy. The GC size >2.2 cm can be a reference to decide the need of decompression surgery.

LEVEL OF EVIDENCE

IV, case series.

Posterior Rotator Cuff Tears: Is Extracorporeal Shockwave Therapy a Risk Factor?

Background

Negative effects of extracorporeal shock wave therapy (ESWT) on vulnerable tendon structures have been reported. Meanwhile, tears of the posterior rotator cuff tendon, which is thinner than the anterior, are not common, and the clinical features remain poorly understood. Therefore, we evaluated the relationship between ESWT and posterior rotator cuff tears (RCTs) by investigating the risk factors.

Methods

Of 294 patients who underwent rotator cuff repair between October 2020 and March 2021, a posterior RCT more than 1.5 cm from the biceps tendon or an isolated infraspinatus tear was identified in 24 (8.1%, group P). Sixty-two patients (21%) with an anterior RCT within 1.5 cm of the biceps tendon were analyzed as a control group (group A). Preoperative clinical characteristics were assessed to determine the risk factors of posterior RCTs.

Results

Calcific deposits were more frequently observed in group P (n = 7, 29.2%) than group A (n = 6, 9.7%, p = 0.024). Further, those in group P were more likely to undergo ESWT (n = 18, 75.0%) than those in group A (n = 15, 24.2%, p < 0.001). Of these, 7 patients experiencing calcific tendinitis from group P (29.2%) and 4 from group A (6.5%, p = 0.005) underwent ESWT for calcification removal. Furthermore, 11 patients experiencing tendinopathy from group P (45.8%), and 11 from group A (17.7%, p = 0.007) underwent ESWT for pain relief. The mean level of fatty infiltration of the supraspinatus was significantly higher in group A than group P (1.8 vs. 1.0, p < 0.001).

Conclusions

Since a high prevalence rate of posterior RCTs was related to ESWT, it should be carefully considered when treating calcific tendinitis or pain in patients experiencing tendinopathy.

Implant selection for successful reverse total shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) emerged as a new concept of arthroplasty that does not restore normal anatomy but does restore function. It enables the function of the torn rotator cuff to be performed by the deltoid and shows encouraging clinical outcomes. Since its introduction, various modifications have been designed to improve the outcome of the RTSA. From the original cemented baseplate with peg or keel, a cementless baseplate was designed that could be fixed with central and peripheral screws. In addition, a modular-type glenoid component enabled easier revision options. For the humeral component, the initial design was an inlay type of long stem with cemented fixation. However, loss of bone stock from the cemented stem hindered revision surgery. Therefore, a cementless design was introduced with a firm metaphyseal fixation. Furthermore, to prevent complications such as scapular notching, the concept of lateralization emerged. Lateralization helped to maintain normal shoulder contour and better rotator cuff function for improved external/internal rotation power, but excessive lateralization yielded problems such as subacromial notching. Therefore, for patients with pseudoparalysis or with risk of subacromial notching, a medial eccentric tray option can be used for distalization and reduced lateralization of the center of rotation. In summary, it is important that surgeons understand the characteristics of each implant in the various options for RTSA. Furthermore, through preoperative evaluation of patients, surgeons can choose the implant option that will lead to the best outcomes after RTSA.

Serum Vitamin D Level Correlations With Tissue Vitamin D Level and Muscle Performance Before and After Rotator Cuff Repair

BACKGROUND

There is a lack of studies about serum and tissue vitamin D levels of the rotator cuff muscle on muscle power, fatty degeneration, and healing failure after rotator cuff repair (RCR). Furthermore, no studies have evaluated vitamin D receptor proteins in the rotator cuff that show a close association with serum vitamin D levels.

PURPOSE

To evaluate the correlations between serum vitamin D and tissue vitamin D as well as perioperative variables of arthroscopic RCR.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From March 2017 to October 2017, a total of 36 patients who underwent RCR were prospectively enrolled, and supraspinatus muscle tissue was obtained during surgery to analyze tissue vitamin D levels. Serum vitamin D levels were checked preoperatively and at 6 months and 1 year postoperatively. Tissue vitamin D levels were assessed using liquid chromatography, and the vitamin D receptor was measured by western blotting. Isokinetic muscle performance test (IMPT; peak torque and torque deficiency compared with the opposite shoulder) results and fatty degeneration of the rotator cuff using the Goutallier classification were assessed preoperatively and at 1 year after surgery. The American Shoulder and Elbow Surgeons score and Constant score were collected at 2 years after surgery. Healing failure of the repaired rotator cuff was analyzed by magnetic resonance imaging at 1 year after surgery.

RESULTS

Overall, only three patients (8.3%) had serum vitamin D sufficiency (>20 ng/mL). Among 36 patients, 26 patients returned for their 1-year follow-up. Lower preoperative serum vitamin D levels resulted in lower serum vitamin D levels at 6 months and 1 year postoperatively (all P < .05). Lower preoperative and 1-year postoperative serum vitamin D levels resulted in more torque deficiency on the IMPT in abduction than higher preoperative and 1-year postoperative serum vitamin D levels (all P < .05). Tissue vitamin D levels had a strong correlation with preoperative serum vitamin D levels (P = .001). Lower tissue vitamin D levels were associated with lower peak torque on the IMPT in abduction (P = .043) and a tendency of lower peak torque on the IMPT in external rotation (P = .077) at 1 year postoperatively. There was no correlation between tissue and serum vitamin D levels and functional outcomes, fatty degeneration, and healing failure after surgery (all P > .05). The vitamin D receptor showed no correlation with any variables (all P > .05).

CONCLUSION

Lower preoperative serum vitamin D levels had a strong correlation with lower tissue vitamin D levels and lower serum vitamin D levels at 1 year after surgery. Furthermore, the patients with lower serum vitamin D levels showed more weakness of muscle power perioperatively. The results of this study emphasized the association between vitamin D levels and rotator cuff muscle power.

Clinical outcomes of reverse shoulder arthroplasty and rotator cuff repair in patients with massive rotator cuff tears without osteoarthritis: comparison using propensity score matching

BACKGROUND

The optimal management for massive rotator cuff tears (MRCTs) without osteoarthritis (OA) remains controversial. The purpose of this study was to evaluate and compare the clinical outcomes of reverse shoulder arthroplasty (RSA) vs. rotator cuff repair (RCR) in patients with MRCTs without OA.

METHODS

We conducted a retrospective data analysis of 68 patients treated for MRCTs via RSA and 215 patients treated for MRCTs via arthroscopic RCR between January 2014 and April 2019. Through propensity score matching, patients were matched for sex, age, tear size, and global fatty degeneration index. Thirty-nine patients in each group were included, and all patients had completed minimal 2-year follow-up. Postoperative radiologic evaluations of healing failure were performed. The visual analog scale score for pain, range of motion, and functional outcome measures including the American Shoulder and Elbow Surgeons score, QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) score, Simple Shoulder Test score, and Constant score were assessed and compared between the 2 groups.

RESULTS

Healing failure was observed in 10 patients in the RCR group (32.3%). No statistically significant differences in preoperative range of motion and functional scores were found between the RCR and RSA groups. Both groups showed significant pain relief and functional improvement at final follow-up. Patients in the RCR group showed significantly greater forward elevation (156.4° ± 23.8° vs. 139.7° ± 22.4°, P < .001) and internal rotation (thoracic vertebra, T8.2 ± 1.2 vs. T9.7 ± 2.6, P = .001). The average American Shoulder and Elbow Surgeons score was 88.3 ± 12.2 in the RCR group and 81.8 ± 16.1 in the RSA group (P = .045). The QuickDASH score was significantly higher in the RCR group (P = .019). A significantly higher Simple Shoulder Test score (9.7 ± 2.8 vs. 8.1 ± 3.0, P = .01) and a significantly higher Constant score (67.2 ± 6.5 vs. 63.2 ± 7.1, P = .011) were seen in the RCR group.

CONCLUSION

Both RSA and RCR are effective and reliable treatment options for MRCTs without OA. However, the RCR group showed better shoulder function improvement than the RSA group. Considering the possible implications of RSA, RCR should be referred to as a first-line treatment option for patients with MRCTs without OA with proper indications.

Allogeneic Dermal Fibroblasts Improve Tendon-to-Bone Healing in a Rabbit Model of Chronic Rotator Cuff Tear Compared With Platelet-Rich Plasma

PURPOSE

To compare the effects of allogeneic dermal fibroblasts (ADFs) and platelet-rich plasma (PRP) on tendon-to-bone healing in a rabbit model of chronic rotator cuff tear.

METHODS

Thirty-two rabbits were divided into 4 groups (8 per group). In 2 groups, the supraspinatus tendon was detached and was left as such for 6 weeks. At 6 weeks after creating the tear model, we performed transosseous repair with 5 × 10⁶ ADFs plus fibrin injection in the left shoulder and PRP plus fibrin in the right shoulder. The relative expression of the COL1, COL3, BMP2, SCX, SOX9, and ACAN genes was assessed at 4 weeks (group A) and 12 weeks (group B) after repair. Histologic and biomechanical evaluations of tendon-to-bone healing at 12 weeks were performed with ADF injection in both shoulders in group C and PRP injection in group D.

RESULTS

At 4 weeks, COL1 and BMP2 messenger RNA expression was higher in ADF-injected shoulders (1.6 ± 0.8 and 1.0 ± 0.3, respectively) than in PRP-injected shoulders (1.0 ± 0.3 and 0.6 ± 0.3, respectively) (P = .019 and P = .013, respectively); there were no differences in all genes in ADF- and PRP-injected shoulders at 12 weeks (P > .05). Collagen continuity, orientation, and maturation of the tendon-to-bone interface were better in group C than in group D (P = .024, P = .012, and P = .013, respectively) at 12 weeks, and mean load to failure was 37.4 ± 6.2 N/kg and 24.4 ± 5.2 N/kg in group C and group D, respectively (P = .015).

CONCLUSIONS

ADFs caused higher COL1 and BMP2 expression than PRP at 4 weeks and showed better histologic and biomechanical findings at 12 weeks after rotator cuff repair of the rabbit model. ADFs enhanced healing better than PRP in the rabbit model.

CLINICAL RELEVANCE

This study could serve as a transitional study to show the effectiveness of ADFs in achieving tendon-to-bone healing after repair of chronic rotator cuff tears in humans.

Safety and Efficacy of Autologous Dermal Fibroblast Injection to Enhance Healing After Full-Thickness Rotator Cuff Repair: First-in-Human Pilot Study

Background:

There is growing interest in various biological supplements to improve tendon healing in patients after arthroscopic rotator cuff repair. The ideal biological supplement to strengthen rotator cuff remains unknown.

Purpose:

To assess the safety and efficacy of autologous cultured dermal fibroblast (ADF) injection on tendon-to-bone healing in patients after arthroscopic rotator cuff repair.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 6 patients who underwent arthroscopic rotator cuff repair between June 2018 and March 2020; all patients had a full-thickness rotator cuff tear (>2 cm) involving the supraspinatus and infraspinatus tendons. The patients were injected with ADF between the repaired tendon and footprint during arthroscopic rotator cuff repair using the suture bridge technique. The safety of ADFs and the procedure was evaluated at 5 weeks postoperatively, and the anatomical healing of the repaired tendon was accessed at 6 months postoperatively using magnetic resonance imaging and at 12 months using ultrasonography. Outcomes including shoulder range of motion (ROM), visual analog scale (VAS) for pain, and functional scores were measured at 6 and 12 months postoperatively.

Results:

Adverse reactions to ADF injection were not observed at 6 months after surgery. VAS and functional scores at 6 and 12 months postoperatively were significantly improved compared with preoperative scores (all P < .05). However, there was no significant difference on any ROM variable between preoperative and postoperative measurements at 6 and 12 months (all P > .05). No healing failure was found at 6 and 12 months postoperatively.

Conclusion:

There was no adverse reaction to ADF injection, and all patients had successful healing after rotator cuff repair. A simple and easily accessible ADF injection may be a novel treatment option for increasing the healing capacity of torn rotator cuff tendons. Further clinical research is needed to verify the study results.

Rotator Cuff Tendon Healing Using Human Dermal Fibroblasts: Histological and Biomechanical Analyses in a Rabbit Model of Chronic Rotator Cuff Tears

BACKGROUND

Tenocytes derived from tendons have been reported to be effective in the treatment of rotator cuff tears through the expression of extracellular matrix proteins. Human dermal fibroblasts, known to express collagen types I and III as tenocytes do, may likely be substitutes for tenocytes to enhance healing rotator cuff tears.

PURPOSE

To demonstrate the capability of human dermal fibroblasts to enhance healing of rotator cuff tears.

STUDY DESIGN

Controlled laboratory study.

METHODS

The cellular properties and expression profiles of growth factors were compared between human dermal fibroblasts and tenocytes. In both cell types, a series of extracellular matrix proteins were analyzed along with matrix metalloproteinases and tissue inhibitors of metalloproteinases involved in the collagenolytic system. A total of 35 rabbits were divided into 5 groups: normal (n = 2), saline control (n = 9), fibrin control (n = 9), low dose of human fibroblasts (HF-LD; n = 9), and high dose of human fibroblasts (HF-HD; n = 6). Cells were injected into the sutured lesions at 6 weeks after creation of bilateral rotator cuff tears, followed by histological and biomechanical analyses at 12 weeks.

RESULTS

Human dermal fibroblasts exhibited a protein expression pattern similar to that of tenocytes. More specifically, the expression levels of collagen types I and III were comparable between fibroblasts and tenocytes. The histological analysis of 30 surviving rabbits showed that collagen fibers were more continuous and better oriented with a more mature interface between the tendon and bone in the sutured lesions in the HF-LD and HF-HD groups. Most importantly, biomechanical strength, measured using the load to failure at the injection site, was 58.8 ± 8.9 N/kg in the HF-HD group, increasing by approximately 2-fold (P = .0003) over the saline control group.

CONCLUSION

Human dermal fibroblasts, showing cellular properties comparable with tenocytes, effectively enhanced healing of chronic rotator cuff tears in rabbits.

CLINICAL RELEVANCE

Human dermal fibroblasts can be used in place of tenocytes to enhance healing of rotator cuff tears.

Optimal insertion site of glenoid baseplate in reverse total shoulder arthroplasty: anatomical simulation using three dimensional image processing software

PURPOSE

Conventionally, the central structure of the baseplate is inserted through the point where the vertical and horizontal axes of the glenoid intersect (conventional insertion site (CIS)). However, there is scanty theoretical evidence that CIS has the optimal bone stock. We evaluated the optimal insertion site for the glenoid baseplate through the three-dimensional volumetric measurement of the glenoid bone stock.

METHODS

Pre-operative computed tomography (CT) images of 30 consecutive reverse total shoulder arthroplasty procedures were analyzed. Three-dimensional image processing software was used to reconstruct CT and volumetrically measure the glenoid bone stock according to the simulated central peg. A simulated central peg was inserted to the medial pole of the scapula from 49 points determined along with the intersect point of the vertical and horizontal axes of the glenoid CIS at 2-mm intervals. The overlapped volume between the simulated central peg and glenoid vault, representing the amount of glenoid bone stock along the passage of the central peg, was then automatically calculated.

RESULTS

The depth of the glenoid vault was 25.5 ± 3.0 mm (range, 19.3-31.5), and the mean overlapped volume between the simulated central peg and the glenoid vault was 623.0 ± 185.8 ml. The optimal insertion site for the bony purchase of the central peg was 2 mm inferior and posterior from the CIS (765.3 ± 157.5).

CONCLUSION

The optimal insertion site of the baseplate is located slightly inferiorly and posteriorly to the CIS. This anatomical information may be used as a reference to determine the optimal insertion site of the baseplate according to an implant of a surgeon's choice.

Trabecular Bone Score Could Not Predict the Bone Mineral Density of Proximal Humerus

Background

Osteoporosis is an important clinical factor for tendon healing after arthroscopic rotator cuff repair (ARCR). Conventional dual energy X-ray absorptiometry (DXA) of the hip and lumbar spine (LS) does not represent proximal humeral bone mineral density (BMD). Theoretically, direct measurement of the BMD of the proximal humerus is the best method; however, it is not popular and is non-standardized. Therefore, we evaluate whether the trabecular bone score (TBS) using LS DXA would represent proximal humeral BMD.

Methods

Conventional hip and LS DXA and proximal humeral BMD were measured in 212 consecutive ARCR patients, and TBS was calculated using LS DXA. Comparative analysis between the affected and contralateral asymptomatic shoulders was done; moreover, correlation analysis was conducted to evaluate the representativity of TBS for proximal humeral BMD. Regression analysis was performed to elucidate the risk factor of intraoperative suture anchor failure (ISAF).

Results

BMDs of the affected shoulder were significantly lower than those of the contralateral side (all P<0.05). TBS failed to present a strong correlation with proximal humeral BMD (correlation coefficients 0.155–0.506, all P<0.05), and the BMD of the greater tuberosity (GT) of the proximal humerus was revealed to be a sole risk factor for ISAF (odds ratio, 0.01, P=0.020).

Conclusions

TBS and conventional hip and LS DXA did not represent proximal humeral BMD. Furthermore, among the various radiological measurements, the BMD of the GT was a sole risk factor of ISAF. Therefore, further research for the direct measurement of proximal humeral BMD is mandatory to predict proximal humeral focal osteoporosis.

Efficacy of Intraoperative Platelet-Rich Plasma Augmentation and Postoperative Platelet-Rich Plasma Booster Injection for Rotator Cuff Healing: A Randomized Controlled Clinical Trial

Background:

Platelet-rich plasma (PRP) has been applied as an adjuvant treatment for arthroscopic rotator cuff repair (ARCR) to enhance rotator cuff healing. However, it remains debatable whether PRP enhances tendon-to-bone healing.

Purpose:

To assess the efficacy of intraoperative augmentation and postoperative injection of PRP that was prepared using the double-spin method and calcium activation without thrombin in patients with ARCR.

Study Design:

Randomized controlled trial; Level of evidence, 1; and cohort study; Level of evidence, 3.

Methods:

A total of 58 patients underwent ARCR using intraoperative PRP augmentation. Half of the patients were randomly assigned to receive an additional ultrasound-guided PRP injection at the repair site at 2 weeks postoperatively (PRP-booster group); the other half did not receive the booster injection (PRP-only group). A control group that did not receive any PRP treatment was retrospectively matched using propensity score matching. Structural integrity was assessed using magnetic resonance imaging at 1 year postoperatively, and healing rates were compared between patients with tear sizes ≤2 cm versus >2 cm. Functional outcomes were assessed using the visual analog scale (VAS) for pain; VAS for satisfaction; shoulder range of motion; and Constant, American Shoulder and Elbow Surgeons, and Simple Shoulder Test scores at minimum 2-year follow-up.

Results:

In patients with tears >2 cm, the rate of healing failure at 1-year follow-up was significantly less in the overall PRP group than in the control group (12.9% vs 35.7%, respectively; P = .040), however, the PRP-booster group did not present a better healing rate than did the PRP-only group. The overall PRP group had lower VAS for pain scores compared with the control group (0.5 ± 1.1 vs 1.3 ± 1.8, respectively; P = .016) and higher VAS for satisfaction scores (9.2 ± 1.2 vs 8.6 ± 1.7; P = .023) at the final follow-up, whereas no statistical difference was found between the PRP-only and PRP-booster groups in functional outcomes.

Conclusion:

Intraoperative PRP augmentation during ARCR demonstrated superior anatomic healing results in patients with rotator cuff tears >2 cm as well as reduced pain and increased subjective satisfaction. PRP booster injection provided no additional benefit to tendon integrity or functional recovery.

New quantified measurement of fatty infiltration of the rotator cuff muscles using magnetic resonance imaging

BACKGROUND

The degree of fatty infiltration of the rotator cuff muscle is typically evaluated using the Goutallier-Fuchs grading system, but its consistency remains controversial. This study aimed to evaluate a new quantified measurement of fatty infiltration based on three-dimensionally reconstructed volumetric data obtained from magnetic resonance images of non-pathologic shoulders using open-source software.

METHODS

Fourteen shoulder 3-T magnetic resonance images (8 men, 6 women) without lesions obtained between 2010 and 2017 were analysed. Slicer version 4.6.2 was used to semi-automatically reconstruct the three-dimensional volumetric data from T2 sagittal oblique images and to differentiate fat tissue from rotator cuff muscle using the difference in signal intensity.

RESULTS

The cutoff value for dividing muscle and fat was 508.9. The inter-class and intra-class correlations of each rotator cuff muscle and fat tissue were >0.9 (all P < 0.001). The mean muscle volume of the supraspinatus, infraspinatus, teres minor, and subscapularis were 15.2, 20.9, 13.3, and 29.7 mL, respectively. The muscle volume of the men was greater than that of the women (all P < 0.001), and the fat infiltration ratio was positively correlated with body mass index (all P < 0.05).

CONCLUSIONS

The semi-automated quantified measurement of fatty infiltration of the rotator cuff muscles using magnetic resonance imaging and Slicer software presented excellent consistency. This technique could be an alternative measurement to complement the weak consistency of the Goutallier-Fuchs grading system. However, to reduce the error of measurement, this study evaluated non-pathologic shoulders. Therefore, further study using magnetic resonance imaging of pathologic shoulders is necessary for actual clinical application.

LEVEL OF EVIDENCE

Level IV, case series, diagnostic study.

Vitamin D level in the rotator cuff muscle and serum correlates with postoperative muscle performance at 1 year after rotator cuff repair

Objectives:

Previously, we reported that tissue vitamin D (tVD) in the rotator cuff muscle had strong correlation with pre-operative serum vitamin D (sVD). Furthermore, tVD reflected more on the preoperative muscle power. This study was a follow-up study to evaluate correlations of tVD, vitamin D receptor (VDR), and postoperative sVD with rotator cuff muscle performance, fatty degeneration, healing failure, and functional outcomes at 1 year after rotator cuff repair (RCR).

Methods:

Between March and October in 2017, 36 patients who underwent RCR were prospectively enrolled and 26 patients were followed at 1 year postoperatively and analyzed. tVD was assessed using liquid chromatography, and the VDR was measured by western blotting. sVD was checked preoperatively, 6 months, and 1 year post-operatively. At 1 year after surgery, isokinetic muscle performance test (IMPT), ASES score and Constant score were evaluated, and MRI was used to analyze fatty degeneration and the healing failure.

Results:

The mean level of sVD at 1 year post-operatively was 20.5 ± 9.2 ng/ml. Only six patients had normal level of sVD (> 20 ng/ml, 23.1%), while 19 patients had insufficiency (10 - 20 ng/ml, 73.0%), and one patient had defi-ciency (< 10 ng/ml, 3.8%). Lower sVD at pre-operatively had lower sVD at 6 months and 1 year post-operatively (all p < 0.05). Higher pre-operative and 1 year post-operative sVD had less deficiency of IMPT in abduction (pre-operative, post-operative; CC; Abduction, -0.324, -0.395, p = 0.047, 0.041, respectively) How-ever, no correlation was found in deficiency of IMPT in ER, IR (pre-operative, post-operative; CC; ER, IR; 0.025, -0.042; p = 0.926, 0.874, respectively; post-operative; CC; ER, IR; -0.250, -0.157; p = 0.333, 0.548, re-spectively). Although, there was no correlation was found between torque of muscle power at 1 year post-operatively with pre- and post-operative sVD (all p > 0.05), higher tVD had higher torque of abduction (CC: 0.440, p = 0.043), and showed tendency of higher torque of external rotation (ER) (CC: 0.335, p = 0.077). There was no correlation of tVD and sVD with functional outcomes, fatty degeneration and re-tear rate (all p > 0.05). VDR showed no correlation with any variables (all p > 0.05).

Conclusions:

tVD and sVD showed positive correlation with rotator cuff muscle performance at 1 year after RCR. Regarding lower sVD at pre-operatively had lower sVD at 1 year post-operatively, and considering lower sVD had higher deficiency of muscle power, supplementation of vitamin D to these patients with low sVD would enhance rota-tor cuff muscle performance postoperatively.

Comparing Clinical Outcomes After Subacromial Spacer Insertion Versus Other Reconstruction Methods in the Treatment of Irreparable Massive Rotator Cuff Tears

Background:

Previous studies on subacromial spacer (SAS) insertion have been limited to case series that did not compare the effectiveness of this technique with other techniques.

Hypothesis:

Outcomes after SAS insertion for the treatment of irreparable massive rotator cuff tears (IMRCTs) will be similar to those of other techniques.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This retrospective study was based on data collected from patients who underwent correction of IMRCTs between January 2010 and October 2017. Group 1 patients (n = 17) received SAS insertion with or without partial repair; group 2 patients (n = 36) were treated with other techniques (isolated partial repairs or bridging grafts). Preoperative tear size and global fatty degeneration index values were evaluated. Range of motion, visual analog scale for pain, American Shoulder and Elbow Surgeons (ASES) score, Constant score, Simple Shoulder Test (SST), Disabilities of the Arm, Shoulder and Hand score, and acromiohumeral distance (AHD) were assessed preoperatively and at final follow-up at least 2 years after the surgery (range, 24-60 months). In both groups, ultrasonographic examination was performed at 3 and 6 months postoperatively, and magnetic resonance imaging (MRI) was performed at 1 year.

Results:

Tear size and preoperative global fatty degeneration index were not significantly different between the groups (all P > .05). There were no differences in functional scores between the groups at final follow-up (all P > .05). AHD was maintained at final follow-up in group 1 (mean ± SD: 6.2 ± 2.1 mm [postoperatively] vs 6.7 ± 2.3 mm [final follow-up]; P = .678), and there was no difference compared with group 2 (7.2 ± 3.2 mm; P = .244). Patients with retears in group 2 (23 of 36, 63.9%) had lower ASES (P = .041) and SST (P = .027) scores at final follow-up when compared with patients in group 1. Six patients (35.3%) in group 1 had partial repairs; these patients had better external rotation at 90° (P = .047), better SST scores (P = .036), and higher AHDs at final follow-up (P = .046) than those in group 1 who had no repair. Three patients (50%) showed retears of partially repaired tendons on MRI. Of 13 patients (76.5%) in group 1 with postoperative MRI, 12 (92.3%) showed fibrotic tissue in the subacromial space not seen preoperatively.

Conclusion:

There was no difference in outcomes between SAS and the other reconstruction methods for treating IMRCTs. However, given the high retear rate associated with other techniques and poor functional outcomes after retear, SAS insertion could be a viable option for treating IMRCTs.

Rationale for Small Glenoid Baseplate: Position of Central Cage within Glenoid Vault (Exactech® Equinoxe® Reverse System)

Background

Glenoid baseplate location is important to good clinical outcomes of reverse total shoulder arthroplasty (RTSA). The glenoid vault is the determining factor for glenoid baseplate location, but, to date, there are no reports on the effect of central cage location within the glenoid vault on RTSA outcomes when using the Exactech^® Equinoxe^® Reverse System. The purpose of this study was to determine the appropriate cage location in relation to the glenoid vault and monitor for vault and/or cortex penetration by the cage.

Methods

Data were retrospectively collected from the Samsung Medical Center (SMC) and Seoul National University Bundang Hospital (SNUBH). Patients who underwent RTSA between November 2016 and February 2018 were enrolled. Glenoid vault depth, central cage location within the vault were examined. Inferior glenoid rim–center distance, inferior glenoid rim–cage distance, and center–cage center distances were collected.

Results

Twenty-two patients were enrolled. Three SNUBH patients had inappropriate central cage fixation (33.3%) versus 4 SMC patients (30.8%). All cage exposures were superior and posterior to the glenoid vault. Mean center–cage distance was 5.0 mm in the SNUBH group and 5.21 mm in the SMC group. Center–prosthesis distance was significantly longer in the inappropriate fixation group than in the appropriate fixation group (p<0.024).

Conclusions

To ensure appropriate glenoid baseplate fixation within the glenoid vault, especially in a small glenoid, the surgeon should place the cage lower than usually targeted, and it should overhang the inferior glenoid rim.

Abstract P3-03-05: Not presented

This abstract was not presented at the conference.

Citation Format: Jung S-Y, Han JH, Park SJ, Lee E-G, Lee MH, Lee ES, Kang H-S, Lee KS, Park IH, Sim SH, Jeong HJ, Kwon Y, Lee D-E, Joo J, Kim S-K, Lee S. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-05.

Hemodynamic change and affecting factors after shoulder arthroplasty in the Asian population

BACKGROUND

This retrospective study was designed to compare the hemodynamics among the types of shoulder arthroplasty and to evaluate predictors of transfusion in the Asian population.

METHODS

A total of 212 shoulder arthroplasties (26 fracture hemiarthroplasty (fHA), 49 anatomical total shoulder arthroplasty (aTSA), 132 reverse total shoulder arthroplasty (rTSA), and 5 revision surgery) from August 2004 to January 2016 were retrospectively reviewed. Demographics, surgical factors, and perioperative hemodynamic factors among the types of arthroplasty were compared. Multivariate analysis was conducted to determine predictors of transfusion.

RESULTS

Preoperative hemoglobin and hematocrit levels were lower in the fracture hemiarthroplasty group (p < 0.001, 0.001). The overall transfusion rate of shoulder arthroplasties in Asian population was 11.3%, and transfusion rate was significantly different among the types of arthroplasty (fHA 30.8%, aTSA 10.2%, rTSA 7.6%, revision 20.0%; p = 0.010). The predictors of transfusion were preoperative hemoglobin levels <12.15 g/dL (OR = 7.404, 95% C.I. 2.420-22.653, p < 0.001) and <10.0 g/dL at postoperative day 1 (OR = 5.499, 95% C.I. 1.929-15.671, p = 0.001).

CONCLUSION

The best predictors of transfusion were hemoglobin levels of perioperative periods, furthermore, total amount of drainage could not represent the quantity of perioperative hemorrhage. Therefore, careful monitoring of hemoglobin level is more crucial than monitoring the amount of drainage. Hemodynamics according to the type of arthroplasty should be considered in shoulder arthroplasty.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Relationship Between Coronal Alignment and Rotational Profile of Lower Extremity in Patients With Knee Osteoarthritis

BACKGROUND

We aimed at determining whether the coronal alignment of lower extremity was related to rotational geometry of distal femur, femoral anteversion, and tibial torsion in patients with knee osteoarthritis.

METHODS

A total of 422 lower extremities were divided into 3 groups according to the coronal alignment: valgus (n = 31), neutral (n = 78), and varus group (n = 313). Condylar twisting angle was measured to determine rotational geometry of distal femur as the angle between the clinical transepicondylar axis and the posterior condylar line. Femoral anteversion was assessed using the angle between a line intersecting the femoral neck and the posterior condylar line (pFeAV) and the angle between the same line and transepicondylar axis that is not affected by posterior condylar variations (tFeAV). Tibial torsion was evaluated by measuring the angle between the posterior condyles of the proximal tibia and the transmalleolar axis.

RESULTS

As the coronal alignment changed from varus to valgus, the condylar twisting angle increased (r = 0.253, P < .001; 6.6° in varus, 7.4° in neutral, and 10.2° in valgus group). Although the pFeAV also increased (r = 0.145, P = .003), the tFeAV did not change significantly (P = .218). Mean tFeAV was 4.3° in varus, 4.7° in neutral, and 6.5° in valgus group. In contrast, as the coronal alignment changed from varus to valgus, the external tibial torsion increased (r = 0.374, P < .001; 22.6° in varus, 26.3° in neutral, and 32.6° in valgus group).

CONCLUSION

The change patterns of the rotational profiles of the lower extremity according to the coronal alignment should be considered in order to obtain satisfactory rotational alignment after TKA.

Pullout Strength of All-Suture Anchors: Effect of the Insertion and Traction Angle-A Biomechanical Study

PURPOSE

To evaluate the pullout strength of the all-suture anchor (ASA), based on the angles of anchor insertion and traction.

METHODS

Synthetic saw bones of 2 densities (0.16 and 0.32 g/cm³) with 3 mm thick cortical bone models were used. ASAs were inserted at 45°, 60°, 75°, or 90° and pulled at 2 angles from the surface: 45° (simulating the physiological pull of the supraspinatus) and 90° (simulating pulling out during knot tying). Five consecutive pullout tests for each insertion and traction angle combination per saw bone were conducted to evaluate the ultimate load to failure and mode of failure (80 tests total). Thereafter, 9 matched pairs of human cadaveric humeri with 2 ASA types were used (insertion angles, 45°, 75°, 90°; traction angle, 90°). Nine consecutive tests were conducted for each insertion angle and anchor type (54 tests total).

RESULTS

The pullout strength was significantly higher for high density- than for low-density saw bones (all P < .05). The pullout strength was higher at the 45°than at the 90° traction angle (all P < .05) and was significantly higher at the 90° and 75° than at the 45° insertion angle in both high-density saw bones and cadaveric humeri (all P < .05). However, the pullout strength was not significantly different by ASA type (all P > .05).

CONCLUSIONS

ASA showed stronger pullout strength in higher density bones. Furthermore, it presented stronger pullout strength in the physiological traction direction of supraspinatus rather than in the knot-tying direction, consistent with the deadman theory. However, stronger pullout strength was observed in the vertically directed insertion angle, not 45°. Therefore, implanting the ASA vertically may be clinically more beneficial not only when performing knot tying during surgery, but also when the supraspinatus tendon loads the ASA postoperatively.

CLINICAL RELEVANCE

The study provides biomechanical evidence that the optimal insertion angle for an ASA is more vertical than the 45°.

The Clinical Outcomes and Their Associated Factors in Staged Bilateral Arthroscopic Rotator Cuff Repair

PURPOSE

To compare perioperative characteristics and postoperative outcomes of both shoulders in patients who underwent arthroscopic bilateral rotator cuff repair sequentially and to assess the associated factors that would affect the anatomic healing in staged bilateral rotator cuff repair.

METHODS

The study enrolled 64 patients who underwent bilateral rotator cuff repair with follow-up imaging at least 12 months postoperatively. We allocated the shoulders operated on first to the surgery I group and those operated on second to the surgery II group. Visual analog scale (VAS) pain and satisfaction scores, range of motion, the American Shoulder and Elbow Surgeons score, the Simple Shoulder Test score, and healing failure were evaluated.

RESULTS

Range of motion improved with no significant between-group differences (all P > .05). In the surgery II group, VAS pain and VAS satisfaction scores were significantly worse at 6 months postoperatively (P = .048 and P = .041, respectively) but were comparable at final follow-up (P = .598 and P = .065, respectively). American Shoulder and Elbow Surgeons and Simple Shoulder Test scores at 6 months were worse in the surgery II group (P = .038 and P = .048, respectively) but similar at final follow-up (P = .786 and P = .087, respectively). Tear size was similar between the 2 surgical procedures (κ = 0.537, P < .001). Of the 11 patients with nonhealing in the surgery I group, 7 (63.6%) had subsequent failure in the other shoulder, and if one shoulder had healing failure, the other shoulder had a high possibility of healing failure as well (κ = 0.373, P = .004).

CONCLUSIONS

Bilateral arthroscopic rotator cuff repair showed good outcomes at final follow-up on both sides. Tear size was closely related in both shoulders, and healing failure after the first rotator cuff repair was an associated factor with healing failure after the second operation.

LEVEL OF EVIDENCE

Level IV, case series.

Clinical Significance of Macrophage Polarization in Antibody-Mediated Rejection of Renal Allograft

BACKGROUND

The significance of proinflammatory M1 (classically activated) and profibrotic M2 (alternatively activated) macrophages in antibody-mediated rejection (ABMR) after kidney transplantation has not been investigated.

METHODS

Fifty-five biopsy-confirmed ABMR samples were stained with MRP 8/14 (a marker of M1 macrophages) and CD163 (a marker of M2 macrophages), and positive cells were counted in glomeruli and the tubulointerstitium, respectively. Patients were classified into M1 and M2 polarization groups according to the glomerular and tubulointerstitial M1:M2 ratio, and the results were compared with Banff scores, serum creatinine level, estimated glomerular filtration rate (eGFR), and graft survival.

RESULTS

The glomerular M2 polarization group showed significantly higher chronic glomerulopathy scores, serum creatinine levels, and lower eGFR at the time of biopsy (P = .019 and P = .015, respectively) and 3-month postbiopsy (P = .016 and P = .032, respectively) than the M1 polarization group. The tubulointerstitial M2 polarization group had significantly lower glomerulitis, arteritis, peritubular capillaritis, and glomerulitis + peritubular capillaritis scores than the M1 polarization group, but there was no significant difference in renal function. Long-term graft survival was not associated with macrophage polarization.

CONCLUSION

Glomerular M2 polarization in ABMR biopsy samples is associated with chronic glomerular injury and poorer graft function, but without graft survival.

Postoperative New-Onset Pseudoparalysis: A Retrospective Analysis of 430 Consecutive Arthroscopic Repairs for Large to Massive Rotator Cuff Tears

BACKGROUND

The authors have sometimes encountered postoperative new-onset pseudoparalysis (PONP) after arthroscopic repair for large to massive rotator cuff tear (ARCR). As there are insufficient data regarding PONP, the authors aimed to determine whether such a condition is characterized by obvious risk factors, as well as to assess the conditions under which it can be reversed.

PURPOSE

To evaluate the predictors of PONP development after ARCR and its reversal and to integrate these predictors into a scoring system that can be applied in clinical practice.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The authors retrospectively analyzed 430 consecutive ARCRs performed between March 2010 and May 2016. Patients were stratified according to the occurrence of PONP. To determine the risk factors of PONP, the authors compared the PONP and control groups (patients who did not experience PONP) in terms of demographic, clinical, and operative characteristics. Results were expressed in terms of odds ratios (ORs).

RESULTS

The incidence of PONP was 6.0% (26 of 430). Predictors of PONP included torn subscapularis (OR, 7.875; 95% CI, 1.780-34.956; P = .007), ≥30-mm retraction of the torn supraspinatus (OR, 4.657; 95% CI, 1.537-14.203; P = .007), age ≥65 years (OR, 3.865; 95% CI, 1.465-10.040; P = .006), and preoperative stiffness (OR, 2.954; 95% CI, 1.212-7.159; P = .017). The reversal rate of PONP was 65.4% (17 of 26), and the mean time to PONP reversal was 10 months. The occurrence and reversal of PONP were not related to retear. Fatty infiltration of the supraspinatus lower than Goutallier grade 3 was the sole predictor of reversal (OR, 22.000; 95% CI, 1.857-260.648; P = .014).

CONCLUSION

Although the incidence of PONP after ARCR was low (6.0%), the risk of PONP was higher in patients with a torn subscapularis, larger supraspinatus tear size, older age, and preoperative stiffness. The mean time from PONP onset to reversal was 10 months, and PONP reversal was affected solely by fatty infiltration of the supraspinatus. Therefore, surgeons should consider the risk for PONP and attempt to identify high-risk patients before rotator cuff repair.

Subacromial Local Anesthetics Do Not Interfere With Rotator Cuff Healing After Arthroscopic Repair

BACKGROUND

Subacromial pain pumps are used for analgesia after arthroscopic rotator cuff surgery. However, there is controversy about myotoxic or tendinotoxic effects of local anesthetics.

HYPOTHESIS

Ropivacaine administered via a subacromial pain pump would have no adverse effect on rotator cuff tendon healing, fatty degeneration, strength, or functional outcomes after arthroscopic repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study continues follow-up of patients enrolled in the authors' 3 published prospective studies regarding pain control after arthroscopic rotator cuff repair. In total, 118 patients who underwent rotator cuff repair and returned for evaluation at least 1 year postoperatively were divided into 3 groups: patients who received continuous subacromial ropivacaine infusion (group 1, n = 33), those who received patient-controlled subacromial ropivacaine infusion (group 2, n = 30), and those who received other pain control modalities (intravenous patient-controlled analgesia and/or interscalene block; group 3, n = 55). At least 1 year postoperatively, tendon healing and changes in global fatty degeneration index (GFDI) were estimated through computed tomographic arthrography, magnetic resonance imaging, or ultrasonography. Changes in isokinetic muscle performance test (IMPT) were calculated and functional outcomes evaluated, including visual analog scales (VASs) for pain and satisfaction, American Shoulder and Elbow Surgeons score, and Constant score.

RESULTS

At final follow-up, there were no differences in pain VAS (group 1, 1.1 ± 2.3; group 2, 1.3 ± 1.9; group 3, 0.9 ± 1.7; P = .88), satisfaction VAS (group 1, 8.3 ± 2.4; group 2, 8.7 ± 1.5; group 3, 8.0 ± 2.1; P = .64), American Shoulder and Elbow Surgeons score (group 1, 79.5 ± 10.5; group 2, 81.1 ± 6.9; group 3, 75.7 ± 7.6; P = .34), or Constant score (group 1, 81.8 ± 8.7; group 2, 77.6 ± 9.3; group 3, 78.2 ± 8.4; P = .31). Among the 3 groups, there were no significant differences in healing rates (group 1, 72.7%; group 2, 73.3%; group 3, 70.9%; P = .83) and no differences in changes of GFDI (group 1, 0.45; group 2, 0.62; group 3, 0.41; P = .79), and IMPT (abduction: group 1, 113.0%; group 2, 121.5%; group 3, 120.1%; P = .73; external rotation: group 1, 112.1%; group 2, 121.6%; group 3, 111.7%; P = .71; internal rotation: group 1, 118.2%; group 2, 118.0%; group 3, 118.1%; P = .95). When data were reanalyzed with 2 groups (group 1 + 2 vs group 3), there were no significant differences in functional scores, healing rates, or changes in GFDI and IMPT ( P > .05).

CONCLUSION

Current data suggest that myotoxicity of subacromial ropivacaine administered via pain pump may be reversible or may not be so severe as to interfere with tendon healing and cause muscle degeneration and thus may not affect postoperative function.

Long-Term Outcomes of Patients with Stent Tips Embedded into Internal Carotid Artery Branches during Aneurysm Coiling

BACKGROUND AND PURPOSE

During stent-assisted coiling of ICA aneurysms, stent tips are sometimes unintentionally embedded into ICA branches. Stent tips can be visualized because they have radiopaque markers. Concerns regarding stent tip misplacement include risks of artery perforation and occlusion. The aim of this study was to evaluate the long-term outcomes of ICA branches with embedded stent tips.

MATERIALS AND METHODS

ICA branches with embedded stent tips were identified among 35 patients with unruptured ICA aneurysms treated with stent-assisted coiling between November 2003 and November 2014. Patient clinical and angiographic outcomes associated with the embedded stent tip were analyzed.

RESULTS

Most of the 35 studied aneurysms were paraclinoid ICA aneurysms (n = 30). The most commonly involved ICA branch was the posterior communicating artery (26 patients, 74.3%), followed by the anterior choroidal artery (8 patients, 22.9%) and ophthalmic artery (1 patient, 2.9%). During the follow-up period (38.6 ± 17.9 months), no new neurologic deficits developed. Neither hemorrhagic nor thromboembolic events occurred. Angiography was performed during the final follow-up evaluation at a mean of 32.7 ± 18.0 months, and all ICA branches with embedded stent tips showed patent blood flow without severe luminal narrowing.

CONCLUSIONS

In our experience, placement of a stent tip into ICA branches during stent-assisted coiling was not associated with any major adverse events.

Rapid Progressive Osteonecrosis of the Humeral Head After Arthroscopic Rotator Cuff Surgery

PURPOSE

To verify the clinical features and the risk factors of rapid progressive osteonecrosis of the humeral head after arthroscopic rotator cuff surgery (ARCS).

METHODS

Data and medical records of 24 patients who had rapid progressive collapse of the humeral head after ARCS performed from October 2012 to March 2016 were retrospectively analyzed. Among them, 8 patients demonstrated no evidence of osteonecrosis of the humeral head preoperatively yet developed rapid progressive collapse of the humeral head within 12 months after ARCS.

RESULTS

All patients were women with a mean age of 64.0 years (range, 52-74 years), and all of them had surgery on their dominant side. Sudden pain developed at a mean 4 months (range, 0-6 months) after index surgery. The rapid progressive collapse of the humeral head occurred within 12 months after index surgery. No clear risk factor or evidence supporting an association between ARCS and humeral head osteonecrosis was found.

CONCLUSIONS

Although the cause of the rapid progressive humeral head osteonecrosis after ARCS still needs to be established, surgeons should be aware of the possible development of humeral head osteonecrosis after ARCS, especially in older women with dominant arm involvement.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

Concurrent Post-Transplantation Diabetes Mellitus in Renal Allograft Recipients With Immunoglobulin A Nephropathy

BACKGROUND

The prevalence of post-transplantation immunoglobulin A nephropathy (PTIgAN) and diabetes mellitus (PTDM) increases with time after transplantation, and recognition and management of these conditions is becoming more important in renal allograft recipients as graft survival increases.

METHODS

We explored the influence of concurrent PTDM on renal allograft histology and function in 111 cases with PTIgAN diagnosed from 2000 to 2010 at our institution.

RESULTS

Sixteen patients (14.4%) had PTDM at the time of diagnosis of PTIgAN, which increased to 28 patients (25.2%) at the last follow-up (10.4 years after transplantation). Donor ages were younger in PTIgAN patients with concurrent PTDM. However, other clinical and demographic data were not significantly different between PTIgAN patients with and without PTDM. Histologically, Banff "mm" scores were higher and "M1" of the Oxford classification was more frequent in PTIgAN patients with concurrent PTDM than in patients without PTDM, but the difference did not reach statistical significance. Serum creatinine levels and proteinuria at the time of biopsy and overall graft survival did not vary according to the presence of PTDM both at biopsy and at the last follow-up.

CONCLUSIONS

Concurrent PTDM does not significantly influence graft function or outcome for 10 years after transplantation in PTIgAN patients.

Piriformis ganglion: An uncommon cause of sciatica

Sciatica can occur due to a spinal lesion, intrapelvic tumor, diabetic neuropathy, and rarely piriformis syndrome. The causes of piriformis syndrome vary by a space-occupying lesion. A ganglionic cyst can occur in various lesions in the body but seldom around the hip joint. In addition, sciatica due to a ganglionic cyst around the hip joint has been reported in one patient in Korea who underwent surgical treatment. We experienced two cases of sciatica from a piriformis ganglionic cyst and we report the clinical characterics and progress after non-operative treatment by ultrasonography-guided aspiration. The two cases were diagnosed by magnetic resonance imaging and were treated by ultrasonography-guided aspiration. We followed the patients for more than 6months. The symptoms of piriformis syndrome from the ganglion improved following aspiration and this conservative treatment is a treatment method that can be used without extensive incision or cyst excision.

LEVEL OF EVIDENCE

Level IV historical case.

Spinal actions of ω-conotoxins, CVID, MVIIA and related peptides in a rat neuropathic pain model

BACKGROUND AND PURPOSE

Antagonists of the N-type voltage gated calcium channel (VGCC), Cav 2.2, have a potentially important role in the treatment of chronic neuropathic pain. ω-conotoxins, such MVIIA and CVID are effective in neuropathic pain models. CVID is reported to have a greater therapeutic index than MVIIA in neuropathic pain models, and it has been suggested that this is due to faster reversibility of binding, but it is not known whether this can be improved further.

EXPERIMENTAL APPROACH

We examined the potency of CVID, MVIIA and two intermediate hybrids ([K10R]CVID and [R10K]MVIIA) to reverse signs of neuropathic pain in a rat nerve ligation model in parallel with production of side effects. We also examined the potency and reversibility to inhibit primary afferent synaptic neurotransmission in rat spinal cord slices.

KEY RESULTS

All ω-conotoxins produced dose-dependent reduction in mechanical allodynia. They also produced side effects on the rotarod test and in a visual side-effect score. CVID displayed a marginally better therapeutic index than MVIIA. The hybrids had a lesser effect in the rotarod test than either of their parent peptides. Finally, the conotoxins all presynaptically inhibited excitatory synaptic neurotransmission into the dorsal horn and displayed recovery that was largely dependent upon the magnitude of inhibition and not the conotoxin type.

CONCLUSIONS AND IMPLICATIONS

These findings indicate that CVID provides only a marginal improvement over MVIIA in a preclinical model of neuropathic pain, which appears to be unrelated to reversibility from binding. Hybrids of these conotoxins might provide viable alternative treatments.

Cholesterol Removal from Whole Egg by Crosslinked β-Cyclodextrin

This study was carried out to optimize cholesterol removal in whole egg using crosslinked β-cyclodextrin (β-CD) and to recycle the β-CD. Various factors for optimizing conditions were concentration of the β-CD, mixing temperature, mixing time, mixing speed and centrifugal speed. In the result of this study, the optimum conditions of cholesterol removal were 25% crosslinked β-CD, 40°C mixing temperature, 30 min mixing time, 1,200 rpm mixing speed and 2,810×g centrifugal speed. The recycling was repeated five times. The cholesterol removal was 92.76% when treated with the optimum conditions. After determining the optimum conditions, the recyclable yields of the crosslinked β-CD ranged from 86.66% to 87.60% in the recycling and the percentage of cholesterol removal was over 80% until third recycling. However, the cholesterol removal efficiency was decreased when the number of repeated recycling was increased. Based on the result of this study, it was concluded that the crosslinked β-CD was efficient for cholesterol removal in whole egg, and recycling is possible for only limited repeating times due to the interaction of the β-CD and egg protein.

The impact of time-zero biopsy on early graft outcomes after living donor kidney transplantation

BACKGROUND

In contrast with deceased donor transplantation, the clinical significance of pathologic findings in time-zero biopsies after living donor kidney transplantation are rarely reported, due to the expectation that histologic findings and renal function are normal. The aim of this study was to identify subclinical pathologic findings in living donors and examine the effect on early graft renal function.

METHODS

Between December 2006 and July 2011, 146 living-donor kidney transplant recipients were enrolled in this study. We retrospectively analyzed donor and recipient-related clinical parameters, and post-transplant 6 months and 1 year estimated glomerular filtration rate (eGFR) as early graft renal function. Time-zero biopsies were evaluated using the 2007 Banff criteria.

RESULTS

Most abnormal histologic findings were of mild degree as determined by Banff scores. Global glomerulosclerosis (GS, 35.6%), tubular atrophy (CT, 36.3%), interstitial fibrosis (CI, 20.5%), vascular fibrous intimal thickening (CV, 4.1%), arteriolar hyaline thickening (AH, 14.4%), interstitial inflammation (I, 3.4%) were pathologic findings in time-zero biopsies. The univariate analysis revealed that donor age and gender were significantly associated with eGFR at post-transplant 6 months and at 1 year (P < .05). Furthermore, GS and CT were significantly associated with early graft renal function (P < .05). However, multivariate linear regression analysis showed only donor age was significantly associated with early graft renal function (P = .001).

CONCLUSION

A mild degree of subclinical, pathologic findings on time-zero biopsy did not affect early graft renal function in living-donor kidney transplantation.

Hyaluronidase treatment of acute lymphedema in a mouse tail model

The purpose of this study was to investigate the impact of hyaluronidase (HAase) on lymphedema using an acute mouse tail lymphedema model. Six-week-old mice served to produce acute lymphedema and were then either treated with HAase injection or used as operative controls. An additional group of unmanipulated normal mice was used for comparison. Tail volumes were measured for 23 days and histological changes examined. Western blot analysis was conducted to quantify lymphatic vessel endothelial hyaluronan receptor (LYVE)-1, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, podoplanin, CD 44, and vascular endothelial growth factor receptor3 (VEGFR3) expression levels. The operative control group showed an increase in thickness of the dermis and subdermis, microlymphatic dilatation, and an increase in neutrophils. In contrast, the HAase treated group exhibited alleviation of inflammation evidenced by a decline in microlymphatic dilatation and neutrophils and an overall increase in microlymphatic vessels. Western blot analysis demonstrated that TNF-alpha and TGF-beta1 expression declined but CD44 expression increased in the HAase treated group. Levels of LYVE1, podoplanin, and VEGFR3 also increased significantly in the HAase group. Our results indicate that HAase treatment in the acute mouse tail model reduced lymphedema volume possibly through degradation of HA trafficking, which reduced inflammation and fibrosis in tissues and stimulated lymphangiogenesis.

Osteosarcoma and chondrosarcoma of the shoulder: site-specific comparative analysis

Osteosarcoma and chondrosarcoma compose most of the primary malignancies of the shoulder. The literature lacks site-specific comparative analyses of these 2 major shoulder sarcomas. The purposes of this study were to describe the different characteristics of the 2 major sarcomas near the glenohumeral joint, examine differences in treatment outcomes, and evaluate the functional outcomes of limb salvage surgery. Thirty-two patients with osteosarcoma or chondrosarcoma who underwent a wide resection including the glenohumeral joint were enrolled in this study. The characteristics of tumor development and treatment, oncologic and functional outcomes, and factors affecting outcomes were compared between groups and with the literature. The results showed shoulder osteosarcoma developing similarly to the literature reports, whereas chondrosarcoma tended to be of a high histologic grade. Nonetheless, the osteosarcoma group had a poorer overall 5-year survival rate (53.0%) than the chondrosarcoma group (85.7%) or those in previous reports. The osteosarcoma group had a tendency toward a worse 5-year metastasis-free survival rate than the chondrosarcoma group (35.4% vs 75.0%, respectively), although the 5-year local recurrence-free survival rate was not significantly different between the 2 groups (75.0% vs 87.5%, respectively). Histologic grade, surgical stage, and chemotherapy affected the oncologic outcomes in univariate analysis, although not a single factor was independent in multivariate analysis. The functional outcomes were not significantly affected by clinical characteristics or surgical methods in patients who had undergone a wide resection including the glenohumeral joint.

Activation of hypoxia-inducible factor-1 regulates human histidine decarboxylase expression

Histidine decarboxylase (HDC) catalyzes the formation of histamine from histidine. Histamine has various effects in physiological and pathological reactions, such as inflammation, cell growth, and neuro-transmission. We investigated the role of hypoxia-inducible factor (HIF)-1 on hypoxia-induced HDC expression in human mast cell line, HMC-1 cells and mouse bone marrow-derived mast cells (BMMCs). Hypoxia significantly increased histamine production. HDC expression and activity were induced by hypoxia. Additionally, when cells were transfected with a native form of HIF-1alpha, hypoxia could induce higher HDC expression than in the nontransfected cell. HIF-1 binding activity for HDC 5' flanking region (HFR) was similar to that for the hypoxia-responsive element. Using HDC promoter deletion analysis, we also demonstrated that HFR was regulated by HIF-1 activation. In addition, depletion of HIF-1alpha prevents hypoxic induction of HDC in BMMCs. In conclusion, these results demonstrate that hypoxia induces HDC expression by transcriptional mechanisms dependent upon HIF-1.