Periostin Is a Biomarker for Anterior Shoulder Instability: Proteomic Analysis of Synovial Fluid

BACKGROUND

The incremental biological changes in the synovial microenvironment of the shoulder in acute and chronic instability that may contribute to joint degeneration are poorly understood. Proteomic analysis of synovial fluid in patients with shoulder instability may improve our understanding of proteins that are shed into shoulder synovial fluid after an injury.

HYPOTHESIS

Injury-specific factors such as the direction of instability and the severity of glenoid and humeral bone loss are associated with the proteome of synovial fluid in patients with shoulder instability.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Synovial fluid lavage samples were compared between patients with anterior (n = 12) and posterior (n = 8) instability and those without instability (n = 5). Synovial proteins were identified with liquid chromatography-tandem mass spectrometry. Orthogonal validation of protein targets found to be significant on tandem mass spectrometry was performed in a separate set of prospective patients with Western blotting. Data were processed and analyzed, and P values were adjusted with the Benjamini-Hochberg method for multiple comparisons.

RESULTS

A total of 25 patients were included. Tandem mass spectrometry identified 720 protein groups in synovial fluid of patients with shoulder instability. There were 4 synovial proteins that were significantly expressed in patients with anterior instability relative to posterior instability: periostin (POSTN) (adjusted P value = .03; log fold change [logFc] = 4.7), transforming growth factor beta-induced protein ig-h3 (adjusted P value = .05; logFc = 1.7), collagen type VI alpha-3 chain (adjusted P value = .04; logFc = 2.6), and coagulation factor V (adjusted P value = .04; logFc = -3.3). Among these targets, POSTN showed a moderate correlation with the Hill-Sachs lesion size (r = 0.7). Prospective validation with Western blotting confirmed a significantly higher level of POSTN in synovial fluid of patients with anterior instability (P = .00025; logFc = 5.1).

CONCLUSION

Proteomic analysis enriched our understanding of proteins that were secreted into shoulder synovial fluid of patients with shoulder instability. The identification of POSTN, a proinflammatory catabolic protein involved with tissue remodeling and repair, as a significant target in anterior shoulder instability is a novel finding. Therefore, further study is warranted to determine the role that POSTN may play in the progression of bone loss and posttraumatic osteoarthritis.

CLINICAL RELEVANCE

Proteomic analysis of synovial fluid in patients with shoulder instability improved our understanding of this abnormality after an injury.

Buffering Mitigates Chondrocyte Oxidative Stress, Metabolic Dysfunction, and Death Induced by Normal Saline: Formulation of a Novel Arthroscopic Irrigant

For decades, surgeons have utilized 0.9% normal saline (NS) for joint irrigation to improve visualization during arthroscopic procedures. This continues despite mounting evidence that NS exposure impairs chondrocyte metabolism and compromises articular cartilage function. We hypothesized that chondrocyte oxidative stress induced by low pH is the dominant factor driving NS toxicity, and that buffering NS to increase its pH would mitigate these effects. Effects on chondrocyte viability, reactive oxygen species (ROS) production, and overall metabolic function were assessed. Even brief exposure to NS caused cell death, ROS overproduction, and disruption of glycolysis, pentose phosphate, and tricarboxylic acid (TCA) cycle pathways. NS also stimulated ROS overproduction in synovial cells that could adversely alter the synovial function and subsequently the entire joint health. Buffering NS with 25 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) significantly increased chondrocyte viability, reduced ROS production, and returned metabolite levels to near control levels while also reducing ROS production in synovial cells. These results confirm that chondrocytes and synoviocytes are vulnerable to insult from the acidic pH of NS and demonstrate that adding a buffering agent to NS averts many of its most harmful effects.

Ulnar Variance in Athletes: A Scoping Review

CONTEXT

Ulnar variance (UV) is a measurement of the relative locations of the radius and ulna that may become perturbed in athletic populations. Positive UV can be associated with wrist pathologies often treated conservatively or surgically and may result in interruption of sports participation.

OBJECTIVE

This scoping review aims to summarize diagnostic measures of UV in athletes, describe its relation to separate wrist conditions, and present treatment strategies for symptomatic UV.

DATA SOURCES

A systematic search was created and modified for PubMed, CINAHL, Embase, and SPORTDiscus including articles from inception until February 2, 2022.

STUDY SELECTION

Articles including UV characterization, imaging modality style, and an athletic population were searched across multiple databases.

STUDY DESIGN

A scoping review was designed to identify the methods for imaging UV in athletic populations following the PRISMA Extension for Scoping Reviews (PRISMA-ScR).

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

The specific athletic population, imaging modality, measurement style, wrist pathology association, and surgical management of UV were extracted.

RESULTS

A total of 4321 records were screened independently for eligibility: 22 met inclusion criteria. Eight sports comprised the analysis. All studies referenced conventional radiography to diagnose UV; 50% specified the posteroanterior, 18.2% anteroposterior, and 13.6% pronated, gripping radiographs. Hafner's method (7×), Palmer's technique (2×), and the method of perpendiculars (3×) were used to measure UV. Athletes displayed more positive UV than nonathletes and UV became more positive over time in longitudinal studies. Triangular fibrocartilage complex tears, focal lunate necrosis, and ulnar abutment were associated with positive UV. Ulnar shortening osteotomy was the most performed operation for positive UV.

CONCLUSION

Conventional radiography is the gold standard for imaging UV in athletes. Hafner's method is the most commonly used radiograph measurement technique. Wrist pathology in athletic populations may indicate positive UV in need for operative management.

Early Versus Delayed Surgery for Midshaft Clavicle Fractures: A Systematic Review

Background

Orthopaedic surgeons debate the timing of and necessity for surgical intervention when treating displaced midshaft clavicle fractures (MCFs). This systematic review evaluates the available literature regarding functional outcomes, complication rates, nonunion, and reoperation rates between patients undergoing early versus delayed surgical management of MCFs.

Methods

Search strategies were applied in PubMed (Medline), CINAHL (EBSCO), Embase (Elsevier), Sport Discus (EBSCO), and Cochrane Central Register of Controlled Trials (Wiley). Following an initial screening and full-text review, demographic and study outcome data was extracted for comparison between the early fixation and delayed fixation studies.

Results

Twenty-one studies were identified for inclusion. This resulted in 1158 patients in the early group and 44 in the delayed. Demographics were similar between groups except for a higher percentage of males in the early group (81.6% vs. 61.4%) and longer time to surgery in the delayed group (4.6 days vs. 14.5 months). Disability of the arm, shoulder, and hand scores (3.6 vs. 13.0) and Constant-Murley scores (94.0 vs. 86.0) were better in the early group. Percentages of initial surgeries resulting in complication (33.8% vs. 63.6%), nonunion (1.2% vs. 11.4%), and nonroutine reoperation (15.8% vs. 34.1%) were higher in the delayed group.

Conclusion

Outcomes of nonunion, reoperation, complications, DASH scores, and CM scores favor early surgery over delayed surgery for MCFs. However, given the small cohort of delayed patients who still achieved moderate outcomes, we recommend a shared decision-making style for treatment recommendations regarding individual patients with MCFs. Level of Evidence: II.

Objective evaluation of chondrocyte density & cloning after joint injury using convolutional neural networks

Variations in chondrocyte density and organization in cartilage histology sections are associated with osteoarthritis progression. Rapid, accurate quantification of these two features can facilitate the evaluation of cartilage health and advance the understanding of their significance. The goal of this work was to adapt deep-learning-based methods to detect articular chondrocytes and chondrocyte clones from safranin-O-stained cartilage to evaluate chondrocyte cellularity and organization. The U-net and "you-only-look-once" (YOLO) models were trained and validated for identifying chondrocytes and chondrocyte clones, respectively. Validated models were then used to quantify chondrocyte and clone density in talar cartilage from Yucatan minipigs sacrificed 1 week, 3, 6, and 12 months after fixation of an intra-articular fracture of the hock joint. There was excellent/good agreement between expert researchers and the developed models in identifying chondrocytes/clones (U-net: R²  = 0.93, y = 0.90x-0.69; median F1 score: 0.87/YOLO: R²  = 0.79, y = 0.95x; median F1 score: 0.67). Average chondrocyte density increased 1 week after fracture (from 774 to 856 cells/mm² ), decreased substantially 3 months after fracture (610 cells/mm² ), and slowly increased 6 and 12 months after fracture (638 and 683 cells/mm² , respectively). Average detected clone density 3, 6, and 12 months after fracture (11, 11, 9 clones/mm² ) was higher than the 4-5 clones/mm² detected in normal tissue or 1 week after fracture and show local increases in clone density that varied across the joint surface with time. The accurate evaluation of cartilage cellularity and organization provided by this deep learning approach will increase objectivity of cartilage injury and regeneration assessments.

Menstrual hormone-induced cyclic thumb CMC instability and degeneration in women: a systematic review

Background

Relaxin is a hormone which peaks during the luteal phase of the menstrual cycle, and a known collagenolytic promoter that has been shown to avidly bind tissues supporting the trapeziometacarpal (TMC) joint in women. We hypothesize a causal linkage between cyclic binding of relaxin to the supporting tissues of the female TMC joint; and to the earlier onset of more severe TMC osteoarthritis (OA) commonly seen in women.

Methods

A systematic literature review was performed per PRISMA guidelines, qualitatively and quantitatively assessing papers regarding relaxin–TMC joint stability interactions. The primary outcome variable was TMC joint degeneration/loss of function; the “late stage” consequences of relaxin-induced instability. The secondary outcome variable was presence of early signs of relaxin-induced instability; specifically asymptomatic TMC joint laxity in young women.

Results

In healthy young women, menstrual cycle relaxin peaks corresponded with asymptomatic TMC joint instability. Immunohistochemical studies of TMC arthroplasty patients showed avidly increased relaxin binding to supporting tissues around the TMC joint in women but not men. Demographic analysis of patients from the TMC arthroplasty studies show a predominantly female cohort, who were on average significantly younger than the male surgical patients.

Conclusions

Each relaxin peak during the menstrual cycle can target receptors on the soft tissues supporting the TMC joint, including—critically—the main stabilizing ligament: the anterior oblique. The cyclic instability is typically asymptomatic for years after menarche, but causes cumulative chondral microtrauma. This likely causes the early-onset, high severity TMC joint OA clinically pervasive among female patients at orthopedic hand clinics. Further research is indicated to develop risk assessment strategies and potential interventional options before and after the onset of hormonal laxity-induced OA.

It is widely recognized among hand surgeons that female patients present at a younger age for basal thumb osteoarthritis, with more severe degeneration.

The little-known menstrual hormone relaxin, which peaks every ovulatory cycle, may be responsible for the female predominance of this pathology.

The soft tissue support structures for the thumb are known to express relaxin receptors which, when activated, trigger lysis of collagen and other extracellular matrix components.

Laxity in soft tissues supporting the thumb, such as the deep anterior oblique ligament, would result in joint instability and microtrauma.

If women cyclically experience thumb instability and cumulative cartilage microtrauma from menarche through menopause, the female propensity to develop TMC arthritis is aptly justified.

The Rurality of Lower Extremity Firearm Injuries

BACKGROUND

To highlight the unique spectrum of lower extremity firearm injuries seen at a rural, Midwestern level 1 trauma center to provide insight into prevalence, mechanism of injury, and identify modifiable factors that contribute to firearm injuries of the lower extremity. It is our belief that the creation of our database will help future trauma and firearm databases improve documentation and understand the relationship between anatomic location of injury and outcomes.

METHODS

A retrospective review of lower extremity firearm injuries from a rural, Midwestern level 1 trauma center was collected from January 2011 to December 2019. Data acquired included injury description; demographics, injury mechanism/ description/ location, firearm used, toxicology, and information regarding hospitalization. Data was analyzed using Chi-squared analysis and Fisher's exact test for categorical data and the Wilcoxon rank sum test for continuous data.

RESULTS

69 patients with lower extremity firearm injuries were identified. Average age was 30.14 years, 89.86% were males, and one fatality were identified. 47.83% (33) of these injuries were assaults, followed by unintentional injuries at 42.03% (29). Law enforcement-related and self-inflicted injuries contributed minimally. Handguns were the most common type of firearm, used in 72.5% of cases. Nearly 1/3 of the unintentional firearm injuries occurred during November or December, the active deer hunting months in the community of study.

CONCLUSION

The lower extremity is uniquely vulnerable to both assaults and unintentional injury in our rural environment, differing from what we have previously published regarding the upper extremity. Lower extremity gunshot wounds increased during the winter months, offering a correlation to deer hunting season. Our findings display that not all firearm injuries are created equal, and that there is a need to improve documentation of and additional study in order to optimally tailor firearm prevention measures based on the ruralityurbanicity spectrum. Level of Evidence: III.

Efficiency Benefits of Live Fluoroscopy in Hand Clinics

Background

Postoperative imaging protocols for common hand procedures typically consist of 2-3 plain radiographs at defined intervals dependent on the surgery. Radiographs typically verify reduction, hardware position, and/or evaluate for complications, but also generate costs and alterations in clinic flow. We hypothesize the use of mini-fluoroscopic images will provide comparable clinical data with less cost and improved clinic flow. The objectives of the study were to determine if clinic-based fluoroscopic imaging is feasible for post-operative hand patients and if fluoroscopic imaging results in improved clinic flow (less waiting and more time with provider) and theoretical cost savings using mini-fluoroscopy instead of traditional radiographs.

Methods

With institutional review board exemption, the prospective use of mini-fluoroscopic evaluation of post-operative hand surgery patients was compared to traditional radiographs using time-based cohort analysis. Patients who underwent percutaneous pinning of phalanges/metacarpals, ORIF (open reduction and internal fixation) of phalanges/metacarpals or ORIF of distal radius fractures were included to evaluate common hand surgery patients. Each cohort consisted of a 3-month data collection period with prospective measures of clinic flow (wait times, appointment times, time with provider) and estimated cost compared between the groups.

Results

24 patients met inclusion criteria for data analysis; 11 patients in the mini-fluoroscopy group and 13 patients in the traditional radiograph group. Appointments using mini-fluoroscopy were 24 minutes shorter (53 vs 77 minutes) from patient check-in to check out time. Check-in time to rooming was 10 minutes quicker (9 vs. 19 minutes) using mini-fluoroscopy. Traditional hand radiographs have a face-value of $734 per appointment/series for a total theoretical savings of $9540 (n=13).

Conclusion

The use of mini-fluoroscopy during orthopedic hand surgery post-operative visits provides a feasible, quick, cost effective way to evaluate patients postoperatively, ultimately, resulting in quicker patient appointments and greater time spent with providers. Level of Evidence: III.

Migrating Progenitor Cells Derived From Injured Cartilage Surface Respond to Damage-Associated Molecular Patterns

OBJECTIVE

To delineate the response of migrating chondrogenic progenitor cells (CPCs) that arose from the surface of mechanically injured articular cartilage to proinflammatory damage-associated-molecular-patterns (DAMPs).

DESIGN

Bovine CPCs and non-CPC chondrocytes isolated from either impacted or scratched articular cartilage were studied. Those 2 types of cells were treated with mitochondrial DAMPs (MTDs; 10 nM fMLF and 10 µg/mL CpG DNA), or 10 nM HMGB1, or 10 ng/mL IL-1b for 24 hours. At the end of experiments, conditioned media and cell lysates were collected for analysis of expression levels of matrix metalloproteinases (MMPs), chemokines, and cytokines that are associated with cartilage degeneration with Western blotting and quantitative polymerase chain reaction. The difference of expression levels was compared by Welch's t-test.

RESULTS

Our data indicated that HMGB1 and MTDs remarkably upregulated pro-MMP-13 expression in CPCs. Compared with non-CPCs, CPCs expressed significantly more baseline mRNAs of MMP-13, CXCL12, and IL-6. MTDs greatly increased the expression of MMP-13 and IL-6 in CPCs by over 100-fold (P < 0.001). MTDs also significantly increased IL-8 expression in CPCs to a similar extent (P < 0.001). However, when IL-1b was present, CPCs expressed less MMP-3 and active MMP-13 proteins as well as less CCL2 and IL-6 than did non-CPCs.

CONCLUSIONS

We concluded that CPCs were more sensitive than non-CPCs in response to DAMPs, especially MTDs. The proinflammatory nature of CPCs implied their critical role in the early phase of posttraumatic osteoarthritis development.

Inclusion of Olecranon Osteotomy With the Posterior Approach for Fixation of Distal Humerus Fractures (OTA/AO 13) Does Not Increase Surgical Complications

OBJECTIVES

To determine if inclusion of an olecranon osteotomy to the posterior paratricipital approach for operative fixation of distal humerus fractures significantly affects surgical complication rates (OTA/AO 13).

DESIGN

Retrospective comparative cohort study.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

Three hundred four patients underwent open reduction internal fixation of a distal humerus fracture between 2007 and 2017. Of those, 134 met inclusion criteria (≥15 years, OTA/AO fracture type 13A, B, or C, and posterior surgical approach) for the study (n = 64 with olecranon osteotomy; n = 70 without olecranon osteotomy).

INTERVENTION

Open reduction internal fixation of distal humerus fractures performed using a posterior paratricipital approach with or without olecranon osteotomy.

MAIN OUTCOME MEASURE

Ulnar neuropathy (UN), fracture site bony nonunion, and surgical site infection (SSI).

RESULTS

Thirty-one (33.3%) who underwent the paratricipital approach without olecranon osteotomy, and 15 patients (26.8%) who underwent olecranon osteotomy reported postoperative UN with no significant difference between approaches (P = 0.438). There was no significant difference in rates of SSI (P = 0.418) or fracture site nonunion (P = 0.263) when comparing the approaches. Subjects with Charlson comorbidity index ≥2 were more likely to not undergo an olecranon osteotomy (P = 0.01), whereas subjects with more complex fractures by OTA/AO classification were more likely to have an olecranon osteotomy approach (P = 0.001).

CONCLUSIONS

Addition of an olecranon osteotomy with the paratricipital approach for fixation of distal humerus fractures does not result in higher rates of UN, fracture site nonunion, or SSI.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Rurality of Upper Extremity Firearm Injuries

BACKGROUND

To highlight the unique spectrum of hand and upper extremity firearm injuries seen at a rural, Midwestern level 1 trauma center and identify modifiable factors that contribute to firearm injuries of the hand and upper extremity.

METHODS

A retrospective review of upper extremity firearm injuries from a rural, Midwestern level 1 trauma center was collected from January 2002 to December 2019. Data acquired included injury description, demographics, injury mechanism/description/location, firearm used, toxicology, and information regarding hospitalization. Data was analyzed using Chi-squared analysis and Fisher's exact test for categorical data and the Wilcoxon rank sum test for continuous data.

RESULTS

55 patients with upper extremity firearm injuries were identified. Average age was 33.3 ± 13.0 years, 81.8% were males, and zero fatalities were identified. 58% (38) of these injuries were unintentional firearm injuries, followed by assaults at 34.6% (19). Law enforcement-related and self-inflicted injuries contributed minimally. Handguns were the most common type of firearm, used in 43.6% of cases. 7.3% (4) of injuries occurred while hunting, with 21.8% (12) total during November or December, the active deer hunting months. 92.7% (51) of all firearm injuries presented with fracture, among which 92.2% (47) met a Gustilo-Anderson classification score of at least 3A. Alcohol was detected in 20% (11) of the patients, while other drugs of abuse were detected in 36.4% (20).

CONCLUSION

Our data suggests that upper extremity firearm injuries in a rural population are unique from urban injuries in that they are predominately unintentional, isolated, and non-fatal. We identify a distinct rural cohort that may benefit from better directed interventions to prevent firearm injuries and ultimately guide firearm education and public policy.Level of Evidence: III.

Supermicrosurgery in fingertip defects-split tibial flap of the second toe to reconstruct multiple fingertip defects: A case report

BACKGROUND

Injuries to multiple fingertips pose a significant treatment dilemma. Numerous reconstructive options exist, all with the ultimate goal of restoring function and sensibility to the injured fingertips.

CASE SUMMARY

A 24-year-old male suffered injury to multiple fingertips of the right hand, resulting in exposed distal phalanges of the middle, ring, and small fingers. The amputated distal stumps were not possible for replantation. Free flap coverage was selected in order to achieve better functional outcome. The fingertip defects were covered by performing a right second toe split tibial flap using local anesthesia at the harvest site and brachial plexus nerve block for the right upper extremity. At 6-month follow-up, all three of the reconstructed fingertips had some preserved nail growth, Semmes-Weinstein Monofilaments testing was equal to the contralateral side and the Static Two-Point Discrimination were comparable to the contralateral side.

CONCLUSION

This report provides a novel reconstructive option for the management of multiple fingertip injuries and demonstrates the utility of supermicrosurgery in management of these injuries.

Long-Term Clinical and Radiographic Follow-Up of Preaxial Polydactyly Reconstruction

PURPOSE

The purpose of the study was to determine the long-term results of preaxial polydactyly reconstruction through evaluating strength, range of motion, pain, arthritis, and functional outcomes.

METHODS

Patients having preaxial polydactyly reconstruction 15 to 60 years ago completed the Disabilities of the Arm, Shoulder, and Hand (DASH) and the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE) Computer Adaptive Test (CAT). Aggregate scores were compared with those of the general population. Patients completed a clinical evaluation comprising grip strength, pinch strength, side pinch strength, and range of motion. Mean strength and range of motion were compared with the contralateral extremity. Patients had radiographs of the reconstructed thumb to evaluate for arthritis.

RESULTS

Twenty-five patients, comprising 27 surgical reconstructions, completed patient-reported outcomes questionnaires, and 13 reconstructions underwent clinical and radiographic evaluation. The median follow-up was 36 years. The most common Flatt-Wassel classification was type IV. The mean DASH score was 3.7, similar to the general population mean of 10.1 (SD, 14.5). The mean PROMIS UE CAT score was 51.5, similar to the general population mean of 50 (SD, 10.0). The mean pinch strength, side pinch strength, and grip strength did not differ significantly from the contralateral extremity. There was significantly decreased range of motion at the interphalangeal joint. No patient had pain in the thumb or hand on clinical evaluation. A minority of patients developed radiographic evidence of interphalangeal joint arthritis (15.4%). Nearly half of patients, 46.2%, had angular deformity.

CONCLUSIONS

Preaxial polydactyly reconstruction patients have functional outcomes similar to the general population, despite decreased range of motion at the interphalangeal joint. Patients have maintained pinch strength, side pinch strength, and grip strength. Radiographic findings of arthritis were seen in 15% of patients at follow-up but none of these patients had associated pain. Late angular deformity developed in nearly half of patients, and this highlights the importance of close follow-up until skeletal maturity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Descriptive Epidemiology and Return to Sport After Hand Fractures in NCAA Athletes

BACKGROUND

Metacarpal and phalanx fractures are common among professional athletes. There is a paucity of data to guide team physicians on expected return to play after hand fractures. The purpose of this study was to examine the epidemiology and return to play times after hand fractures in NCAA athletes. We hypothesized that surgical management of fractures may expedite return to play times.

METHODS

The NCAA Injury Surveillance Program database was queried for metacarpal and phalanx fractures during the 2009-2014 seasons in all sports. Injury rates per 100,000 athleteexposures (AEs) were calculated. Student's t-test, Wilcoxon Rank sum tests, Chi-Squared tests, and Fisher Exact Test were used. Statistical significance was set to p<0.05.

RESULTS

Sports with the highest rates of phalanx and metacarpal fractures included Men's Football, Men's Ice Hockey, Men's Wrestling, and Women's Field Hockey. Multiple sports had participants with no hand fractures over the study period. Male student-athletes with metacarpal fractures treated operatively returned to play at a mean of 31.8±29.4 days versus 13.8±23.6 days for those treated non-operatively. 92% of male student-athletes were able to return to sport in the same season without operative management versus 67% with operative management. Female student-athletes had a cohort too small for statistical analysis. Return to play times for male student-athletes with phalanx fractures were not significantly different between operative and non-operative groups (16.1±21.5 days versus 7.1±13.3 days).

CONCLUSIONS

Hand fractures are relatively common among NCAA student-athletes participating in contact sports. Student-athletes with metacarpal fractures returned to play at an average of 2-4 weeks after injury; those with phalanx fractures returned at an average of 1-2 weeks. The return to play times illustrated within this study can be used to counsel athletes, athletic trainers, and coaches.Level of evidence: IV.

Postoperative care via smartphone following carpal tunnel release

INTRODUCTION

This study explores a novel smartphone application for postoperative care following carpal tunnel release (CTR). We hypothesized that a software-based 'virtual visit' for CTR could be safe, effective and convenient for the patient.

METHODS

Our group developed the software application utilized in this study. Interactive steps with video instructions enabled patients to complete dressing and suture removal, capture a wound photo, answer a question about median nerve symptoms and capture a video of finger range of motion. Adult patients undergoing endoscopic or open CTR were enrolled. Prior to their scheduled postoperative visit, patients received and completed the module using their smartphone. Agreement between findings of the virtual visit and the corresponding in-person clinical visit was assessed using kappa values.

RESULTS

Twenty-two patients were contacted regarding study enrolment and 17 patients were enrolled (ages 23-63, mean 48.2, 6M, 11F). Of 16 patients who participated, all completed dressing removal. Ten of 16 patients removed their sutures successfully. Fourteen patients captured a clinically adequate wound photo and 15 patients answered a question about median nerve symptoms. Fourteen patients captured a range of motion video. Software assessments of surgical wounds, nerve symptoms and physical exams agreed strongly with clinical assessments.

DISCUSSION

Most patients were able to respond to a question about their symptoms, provide clinical assessment of their wound via a photo and record a video of their range of motion. Suture removal was the most difficult task. More investigation is needed to determine which patients can reliably remove their sutures.

Postoperative care via smartphone following carpal tunnel release

Introduction

This study explores a novel smartphone application for postoperative care following carpal tunnel release (CTR). We hypothesized that a software-based ‘virtual visit’ for CTR could be safe, effective and convenient for the patient.

Methods

Our group developed the software application utilized in this study. Interactive steps with video instructions enabled patients to complete dressing and suture removal, capture a wound photo, answer a question about median nerve symptoms and capture a video of finger range of motion. Adult patients undergoing endoscopic or open CTR were enrolled. Prior to their scheduled postoperative visit, patients received and completed the module using their smartphone. Agreement between findings of the virtual visit and the corresponding in-person clinical visit was assessed using kappa values.

Results

Twenty-two patients were contacted regarding study enrolment and 17 patients were enrolled (ages 23–63, mean 48.2, 6M, 11F). Of 16 patients who participated, all completed dressing removal. Ten of 16 patients removed their sutures successfully. Fourteen patients captured a clinically adequate wound photo and 15 patients answered a question about median nerve symptoms. Fourteen patients captured a range of motion video. Software assessments of surgical wounds, nerve symptoms and physical exams agreed strongly with clinical assessments.

Discussion

Most patients were able to respond to a question about their symptoms, provide clinical assessment of their wound via a photo and record a video of their range of motion. Suture removal was the most difficult task. More investigation is needed to determine which patients can reliably remove their sutures.

Effects of knockout of the receptor for advanced glycation end-products on bone mineral density and synovitis in mice with intra-articular fractures

Our group employed the mouse closed intra-articular fracture (IAF) model to test the hypothesis that the innate immune system plays a role in initiating synovitis and post-traumatic osteoarthritis (PTOA) in fractured joints. A transgenic strategy featuring knockout of the receptor for advanced glycation end-products (RAGE ^-/- ) was pursued. The 42 and 84 mJ impacts used to create fractures were in the range previously reported to cause PTOA at 60 days post-fracture. MicroCT (μCT) was used to assess fracture patterns and epiphyseal and metaphyseal bone loss at 30 and 60 days post-fracture. Cartilage degeneration, synovitis, and matrix metalloproteinase (MMP-3, -13) expression were evaluated by histologic analyses. In wild-type mice, μCT imaging showed that 84 mJ impacts led to significant bone loss at 30 days (p < 0.05), but recovered to normal at 60 days. Bone losses did not occur in RAGE^-/- mice. Synovitis was significantly elevated in 84 mJ impact wild-type mice at both endpoints (30 day, p = 0.001; 60 day, p = 0.05), whereas in RAGE^-/- mice synovitis was elevated only at 30 days (p = 0.02). Mankin scores were slightly elevated in both mouse strains at 30 days, but not at 60 days. Immunohistochemistry revealed significant fracture-related increases in MMP-3 and -13 expression at 30 days (p < 0.05), with no significant difference between genotypes. These findings indicated that while RAGE ^-/- accelerated recovery from fracture and diminished synovitis, arthritic changes were temporary and too modest to detect an effect on the pathogenesis of PTOA. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2439-2449, 2018.

Leland G. Hawkins, MD-His Life and Orthopaedic Legacy: Talus Fractures and the Hawkins Classification

The long history of excellence and continued success of the University of Iowa Department of Orthopedics and Rehabilitation is due to the dedication and talent of generations of faculty, residents and staff. Many former Iowa Orthopedic residents have made significant contributions and become leaders in Orthopedic surgery. An orthopedic surgeon and scholar with roots at the University of Iowa deserving of tribute is Dr. Leland Greene Hawkins. His seminal investigation and interest in fractures of the talus established the well-known Hawkins Classification for talar neck fractures, which revolutionized treatment and quantified the risk of progression to avascular necrosis, earning him attention and respect worldwide.

The Pursuit of Scholarship: Why We Should Care About Resident Research

Research is a foundational component of an orthopaedic residency. It fosters intellectual curiosity and pursuit of excellence, while teaching discipline and the scientific method. These are the key principles for careers in both community-based practice and academia. Currently, no consensus exists on how to best engage residents and support their research endeavors. In 2014, the American Academy of Orthopaedic Surgeons Board of Specialty Societies Research and Quality Committee convened a Clinician-Scientist Collaboration Workgroup. The workgroup's task was to identify barriers to clinical and basic science research, and to propose feasible recommendations to overcome these barriers. Herein, we have compiled the opinions of various stakeholder constituencies on how to foster scholarly pursuits during an orthopaedic residency. These opinions reflect the workgroup's conclusions that research is directly and indirectly influenced by funding, departmental support, and mentorship, and that early exposure and dedicated time to pursue scholarly activities may have a positive impact on lifelong research interests.

Complementary models reveal cellular responses to contact stresses that contribute to post-traumatic osteoarthritis

Two categories of joint overloading cause post-traumatic osteoarthritis (PTOA): single acute traumatic loads/impactions and repetitive overloading due to incongruity/instability. We developed and refined three classes of complementary models to define relationships between joint overloading and progressive cartilage loss across the spectrum of acute injuries and chronic joint abnormalities: explant and whole joint models that allow probing of cellular responses to mechanical injury and contact stresses, animal models that enable study of PTOA pathways in living joints and pre-clinical testing of treatments, and patient-specific computational models that define the overloading that causes OA in humans. We coordinated methodologies across models so that results from each informed the others, maximizing the benefit of this complementary approach. We are incorporating results from these investigations into biomathematical models to provide predictions of PTOA risk and guide treatment. Each approach has limitations, but each provides opportunities to elucidate PTOA pathogenesis. Taken together, they help define levels of joint overloading that cause cartilage destruction, show that both forms of overloading can act through the same biologic pathways, and create a framework for initiating clinical interventions that decrease PTOA risk. Considered collectively, studies extending from explants to humans show that thresholds of joint overloading that cause cartilage loss can be defined, that to at least some extent both forms of joint overloading act through the same biologic pathways, and interventions that interrupt these pathways prevent cartilage damage. These observations suggest that treatments that decrease the risk of all forms of OA progression can be discovered. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:515-523, 2017.

Total knee arthroplasty for posttraumatic osteoarthritis in military personnel under age 50

United States military personnel frequently suffer knee injuries. The resulting progressive posttraumatic osteoarthritis (PTOA) causes significant disability in these young high-demand patients for which total knee arthroplasty (TKA) is the only effective treatment of their pain and impairment. Yet the use of this option for treatment of PTOA has not been studied. This retrospective review identified 74 knees in 64 U.S. military personnel who underwent TKA at ≤50 years of age during an 8-year period at a tertiary-care, academic, military medical center. Fifty-five knees (74.3%) experienced one or more prior ligamentous, meniscal, or chondral injuries prior to arthroplasty. Only one subject had a history of osteochondral intra-articular fracture. The average at injury was 29.2 years (95%CI of ±2.50) with an average age at arthroplasty of 44.3 years (±1.11). The most common injury was anterior cruciate ligament rupture (n = 19) with a mean time to TKA of 23.1 (±10.54) and 18.8 years (±7.01) when concomitant meniscal pathology was noted. Nineteen patients were noted to have radiographic and symptomatic end-stage osteoarthritis without a specified etiology at 41.4 years (±1.47) and underwent subsequent TKA. This is the first study to evaluate treatment of end-stage PT OA in young people treated with TKA, finding that the incidence of PTOA as an indication for arthroplasty is significantly higher than among civilians. In this otherwise healthy, high-demand patient population, the rate of OA progression following knee injury is accelerated and the long term implications can be career and life altering. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:677-681, 2017.

The Scarcity of Orthopaedic Physician Scientists

Breakthrough advances in medicine almost uniformly result from the translation of new basic scientific knowledge into clinical practice, rather than from assessment, modification or refinement of current methods of diagnosis and treatment. However, as is intuitively understood, those most responsible for scientific conception and creation-scientists - are generally not the ones applying these advances at the patient's bedside or the operating room, and vice versa. Recognition of the scarcity of clinicians with a background that prepares them to develop new basic knowledge, and to critically evaluate the underlying scientific basis of methods of diagnosis and treatment, has led to initiatives including federally funded Physician-Scientist programs, whereby young, motivated scholars begin a rigorous training, which encompasses education and mentorship within both medical and scientific fields, culminating in the conferment of both MD and PhD degrees. Graduates have demonstrated success in integrating science into their academic medical careers. However, for unknown reasons, orthopaedic surgery, more than other specialties, has struggled to recruit and retain physician-scientists, who possess a skill set evermore rare in today's increasingly complicated medical and scientific landscape. While the reasons for this shortfall have yet to be completely elucidated, one thing is clear: If orthopaedics is to make significant advances in the diagnosis and treatment of musculoskeletal diseases and injuries, recruitment of the very best and brightest physician-scientists to orthopaedics must become a priority. This commentary explores potential explanations for current low-recruitment success regarding future orthopaedic surgeon-scientists, and discusses avenues for resolution.

Enhanced phagocytic capacity endows chondrogenic progenitor cells with a novel scavenger function within injured cartilage

OBJECTIVE

Articular cartilage harbors chondrogenic progenitor cells (CPCs), a population that responds chemotactically to cell death. Because this behavior is reminiscent of macrophages, we hypothesized that CPCs have macrophage-like capabilities for scavenging cell and tissue debris through phagocytosis.

DESIGN

CPCs, chondrocytes, synoviocytes, and macrophages were cultured with fluorophore-labeled chondrocyte debris for 3, 6, 12, or 24 h. Debris internalization was quantified by confocal microscopy and flow cytometry. Confocal microscopy was also used to test CPCs and chondrocytes for uptake of fluorophore-labeled fibronectin fragments (Fn-fs), a form of extracellular matrix debris. Lysosome activity and mass in CPCs and chondrocytes were measured using fluorescent probes. The relative expression of phagocytosis-related genes and proteins was evaluated by polymerase chain reaction (PCR) and immunoblotting, respectively. Pulse-chase experiments were performed to determine if the debris internalized by CPCs and chondrocytes was cleared, and if clearance was affected by a cathepsin B inhibitor.

RESULTS

More macrophages, synoviocytes, and CPCs internalized cell debris than chondrocytes at all time points. While uptake remained flat in chondrocytes at ∼10%, in the other cell types it peaked at more than 60% after 12-24 h. Relative to chondrocytes, CPCs showed significantly higher rates of Fn-fs engulfment, greater lysosome activity and mass, and over-expressed phagocytosis-related genes and proteins. Pulse-chase experiments revealed time- and cathepsin B-dependent clearance of cell debris in CPCs, but not in chondrocytes.

CONCLUSIONS

CPCs phagocytized cell and matrix debris much more efficiently than chondrocytes, supporting the hypothesis that they play a macrophage-like role in injured cartilage.

Return to Sport After Operative Management of Osteochondritis Dissecans of the Capitellum: A Systematic Review and Meta-analysis

BACKGROUND

Capitellar osteochondritis dissecans (OCD) is commonly managed surgically in symptomatic adolesent throwers and gymnasts. Little is known about the impact that surgical technique has on return to sport.

PURPOSE

To evaluate the clinical outcomes and return-to-sport rates after operative management of OCD lesions in adolescent athletes.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The PubMed, CINAHL, EMBASE, SPORTDiscus (EBSCO), and Cochrane Central Register of Controlled Trials databases were queried for studies evaluating outcomes and return to sport after surgical management of OCD of the capitellum. Two independent reviewers conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies reporting patient outcomes with return-to-sport data and minimum 6-month follow-up were included in the review.

RESULTS

After review, 24 studies reporting outcomes in 492 patients (mean age ± SD, 14.3 ± 0.9 years) were analyzed. The overall return-to-sport rate was 86% at a mean 5.6 months. Return to the highest preoperative level of sport was most common after osteochondral autograft procedures (94%) compared with debridement and marrow stimulation procedures (71%) or OCD fixation surgery (64%). Elbow range of motion improved by 15.9° after surgery. The Timmerman-Andrews subjective and objective scores significantly improved after surgery. Complications were low (<5%), with 2 cases of donor site morbidity after osteoarticular autograft transfer (OAT) autograft harvest. The most common indications for reoperation were repeat debridement/loose body removal.

CONCLUSION

A high rate of return to sport was observed after operative management of capitellar OCD. Patients were more likely to return to their highest level of preoperative sport after OAT autograft compared with debridement or fixation. Significant improvements in elbow range of motion and patient outcomes are seen with low complication rates after OCD surgery.

Use of recombinant human stromal cell-derived factor 1α-loaded fibrin/hyaluronic acid hydrogel networks to achieve functional repair of full-thickness bovine articular cartilage via homing of chondrogenic progenitor cells

OBJECTIVE

Articular cartilage damage after joint trauma seldom heals and often leads to osteoarthritis. We previously identified a migratory chondrogenic progenitor cell (CPC) population that responds chemotactically to cell death and rapidly repopulates the injured cartilage matrix, which suggests a potential approach for articular cartilage repair. This study was undertaken to determine whether recombinant human stromal cell-derived factor 1α (rhSDF-1α), a potent CPC chemoattractant, would improve the quality of cartilage regeneration, hypothesizing that increased recruitment of CPCs by rhSDF-1α would promote the formation of cartilage matrix upon chondrogenic induction.

METHODS

Full-thickness bovine chondral defects were filled with hydrogel, composed of fibrin and hyaluronic acid and containing rhSDF-1α. Cell migration was monitored, followed by chondrogenic induction. Regenerated tissue was evaluated by histology, immunohistochemistry, and scanning electron microscopy. Push-out tests and unconfined compression tests were performed to assess the strength of tissue integration and the mechanical properties of the regenerated cartilage.

RESULTS

Use of rhSDF-1α dramatically improved CPC recruitment to the chondral defects at 12 days. After 6 weeks under chondrogenic conditions, cell morphology, proteoglycan density, and the ultrastructure of the repair tissue were all similar to that found in native cartilage. Compared with empty controls, neocartilage generated in rhSDF-1α-containing defects showed significantly greater interfacial strength, and acquired mechanical properties comparable to those of native cartilage.

CONCLUSION

This study showed that stimulating local CPC recruitment prior to treatment with chondrogenic factors significantly improves the biochemical and mechanical properties of the cartilage tissue formed in chondral defects. This simple approach may be implemented in vivo as a one-step procedure by staging the release of chemokine and chondrogenic factors from within the hydrogel, which can be achieved using smart drug-delivery systems.

How do you know it is true? Integrity in research and publications: AOA critical issues

High-quality medical care is the result of clinical decisions based upon scientific principles garnered from basic, translational, and clinical research. Information regarding the natural history of diseases and their responses to various treatments is introduced into the medical literature through the approximately one million PubMed journal articles published each year. Pharmaceutical and device companies, universities, departments, and researchers all stand to gain from research publication. Basic and translational research is highly competitive. Success in obtaining research funding and career advancement requires scientific publication in the medical literature. Clinical research findings can lead to changes in the pattern of orthopaedic practice and have implications for the utilization of pharmaceuticals and orthopaedic devices. Research findings can be biased by ownership of patents and materials, funding sources, and consulting arrangements. The current high-stakes research environment has been characterized by an increase in plagiarism, falsification or manipulation of data, selected presentation of results, research bias, and inappropriate statistical analyses. It is the responsibility of the orthopaedic community to work collaboratively with industry, universities, departments, and medical researchers and educators to ensure the integrity of the content of the orthopaedic literature and to enable the incorporation of best practices in the care of orthopaedic patients.

Osteoclast inhibition impairs chondrosarcoma growth and bone destruction

Because Chondrosarcoma is resistant to available chemotherapy and radiation regimens, wide resection is the mainstay in treatment, which frequently results in high morbidity and which may not prevent local recurrence. There is a clear need for improved adjuvant treatment of this malignancy. We have observed the presence of osteoclasts in the microenvironment of chondrosarcoma in human pathological specimens. We utilized the Swarm rat chondrosarcoma (SRC) model to test the hypothesis that osteoclasts affect chondrosarcoma pathogenesis. We implanted SRC tumors in tibia of Sprague-Dawley rats and analyzed bone histologically and radiographically for bone destruction and tumor growth. At three weeks, tumors invaded local bone causing cortical disruption and trabecular resorption. Bone destruction was accompanied by increased osteoclast number and resorbed bone surface. Treatment of rats with the zoledronic acid prevented cortical destruction, inhibited trabecular resorption, and resulted in decreased tumor volume in bone. To confirm that inhibition of osteoclasts per se, and not off-target effects of drug, was responsible for the prevention of tumor growth and bone destruction, we implanted SRC into osteopetrotic rat tibia. SRC-induced bone destruction and tumor growth were impaired in osteopetrotic bone compared with control bone. The results from our animal model demonstrate that osteoclasts contribute to chondrosarcoma-mediated bone destruction and tumor growth and may represent a therapeutic target in particular chondrosarcoma patients.

Staged Placement of Growing Rods for Metabolic Bone Disease and Insufficient Bone Quality: A Report of Two Cases

CASE

We present two cases of successful staged placement of standard growing-rod instrumentation for early-onset scoliosis in children with metabolic bone disease and poor bone quality.

CONCLUSION

Because use of growing-rod surgery is increasing throughout the world, we propose that a staged approach to placement of growing rods is a practical and safe option for surgeons who encounter patients with early-onset scoliosis and concomitant poor bone quality.

Estimated cause-specific survival continues to improve over time in patients with chondrosarcoma

BACKGROUND

Conditional survival measures change in the risk of mortality given that a patient has survived a defined period of time. This has yet to be reported for chondrosarcoma of bone. This information should be of interest to the clinician and helpful in counseling patients with chondrosarcoma.

QUESTIONS/PURPOSES

Our questions include the following: (1) Does the conditional survival of patients with local/regional chondrosarcoma improve with each additional year of survival? (2) Does the conditional survival of patients with metastatic chondrosarcoma improve with each additional year of survival? (3) Does tumor location, use of radiation, or patient age affect conditional survival? (4) Can chondrosarcoma ever be considered cured?

METHODS

We used the Surveillance, Epidemiology, and End Results Program database maintained by the National Cancer Institute to identify 2138 patients with chondrosarcoma of bone from 1973 to 2009. We used an actuarial life table analysis to explore differences in 5-year cause-specific survival estimates conditional on 1 to 5 years of survival. The cohort was stratified by grade, location (axial versus extremity), use of radiation, and age. Finally, we expanded the analysis to include survival estimates 20 years after diagnosis conditional on survival for 5 and 10 years.

RESULTS

The estimated survival for all grades of local/regional chondrosarcoma improved from baseline with each year of survival after diagnosis. At 5 years after diagnosis, local/regional Grade 1 chondrosarcoma displayed higher conditional survival than Grade 2 and 3 local/regional chondrosarcoma (97.2% [95% confidence interval {CI}, 95.2%-98.4%] versus 92.8% [95% CI, 89.5%-95.0%], p = 0.006 and 83.8% [95% CI, 69.9%-91.7%], p = 0.012). Estimated survival improved from baseline with each year of survival for all grades of metastatic chondrosarcoma. Conditional survival estimates for Grade 3 axial tumors failed to improve from baseline to 5 years after diagnosis (52.9% versus 70.2%, p > 0.05) compared with Grade 3 extremity tumors at baseline and 5 years after diagnosis (58.1% versus 95.8%, p < 0.0001) The 20-year conditional survival estimates reveal that a cancer-specific risk of mortality exists even 10 years after diagnosis, suggesting that although the conditional survival increases considerably over time, it cannot be considered cured.

CONCLUSIONS

The 5-year conditional survival estimate for patients with chondrosarcoma improved with each additional year of survival regardless of grade, site, age, or use of radiation. At 10 years after diagnosis, deaths attributable to cancer were still present, and patients should be aware of this small long-term risk.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

A single blunt impact on cartilage promotes fibronectin fragmentation and upregulates cartilage degrading stromelysin-1/matrix metalloproteinase-3 in a bovine ex vivo model

Post-traumatic osteoarthritis (PTOA) is characterized by progressive cartilage degeneration in injured joints. Since fibronectin-fragments (Fn-fs) degrade cartilage mainly through up-regulating matrix metalloproteinases (MMPs) and pro-inflammatory cytokines, we hypothesized that Fn-fs play a key role in PTOA by promoting chondrolysis in and around injured cartilage. To test this hypothesis, we profiled the catabolic events focusing on fibronectin fragmentation and proteinase expression in bovine osteochondral explants following a single blunt impact on cartilage with a drop tower device which created partial-thickness tissue damage. Injured and control explants were cultured for up to 14 days. The presence of Fn-fs, MMPs (-1, -3, -13), ADAMTS-5 in culture media and in cartilage was determined with immunoblotting. The daily proteoglycan (PG) depletion of cartilage matrix was assessed with DMMB assay. The effect of explant-conditioned media on chondrocytes was also examined with immunoblotting. Impacted cartilage released significantly higher amount of native Fn, three chondrolytic Fn-fs and PG than non-impacted controls did. Those increases coincided with up-regulation of MMP-3 both in culture media and in impacted cartilage. These findings support our hypothesis that PTOA may be propelled by Fn-fs which act as catabolic mediators through up-regulating cartilage-damaging proteinases.

Low-intensity pulsed ultrasound promotes chondrogenic progenitor cell migration via focal adhesion kinase pathway

Low-intensity pulsed ultrasound (LIPUS) has been studied frequently for its beneficial effects on the repair of injured articular cartilage. We hypothesized that these effects are due to stimulation of chondrogenic progenitor cell (CPC) migration toward injured areas of cartilage through focal adhesion kinase (FAK) activation. CPC chemotaxis in bluntly injured osteochondral explants was examined by confocal microscopy, and migratory activity of cultured CPCs was measured in transwell and monolayer scratch assays. FAK activation by LIPUS was analyzed in cultured CPCs by Western blot. LIPUS effects were compared with the effects of two known chemotactic factors: N-formyl-methionyl-leucyl-phenylalanine (fMLF) and high-mobility group box 1 (HMGB1) protein. LIPUS significantly enhanced CPC migration on explants and in cell culture assays. Phosphorylation of FAK at the kinase domain (Tyr 576/577) was maximized by 5 min of exposure to LIPUS at a dose of 27.5 mW/cm(2) and frequency of 3.5 MHz. Treatment with fMLF, but not HMBG1, enhanced FAK activation to a degree similar to that of LIPUS, but neither fMLF nor HMGB1 enhanced the LIPUS effect. LIPUS-induced CPC migration was blocked by suppressing FAK phosphorylation with a Src family kinase inhibitor that blocks FAK phosphorylation. Our results imply that LIPUS might be used to promote cartilage healing by inducing the migration of CPCs to injured sites, which could delay or prevent the onset of post-traumatic osteoarthritis.

Effect of short-term enzymatic treatment on cell migration and cartilage regeneration: in vitro organ culture of bovine articular cartilage

Depending on the damage extent and adjacent tissue condition in traumatic cartilage injury, it is possible to heal the tissue by resident cells. Unlike autologous chondrocyte implantation, short-term enzymatic treatment is an effective single-step procedure without extra cell expansion. Moreover, this method has been shown to significantly increase cellularity in lesion edges, resulting in enhanced integration and interfacial strength. We hypothesize that the locally digested extracellular matrix by treatment allows effortless cell migration from the adjacent tissue. Full-thickness cartilage discs and osteochondral explants were prepared from mature bovine stifle joints. These specimens were treated with collagenase in a culture medium. Two concentrations, 0.25 and 0.5 mg/mL, were used with various treating time of 10, 30, and 180 min. The cartilages were subsequently washed and cultured with fibrin hydrogel. The effect of enzymatic treatment on cell migration was apparent in both experiments of the cartilage disc and full-thickness cartilage defect model. In the disc culture, the treatment resulted in an approximately three to four times higher number of migrated cells than nontreated control. In short-term collagenase-treated groups, the proteoglycan (PG) loss was localized in the edge of tissue with minimal cell death. The treatment also accelerated cell migration in the full-thickness cartilage defects and some cells differentiated into chondrocytes with the deposit of PG. Gene expression results could support the characteristics of migrated cells, which had migratory ability and chondrogenic differentiation potential with overexpression of collagen type I and II, respectively. Based on these results, short-term enzymatic treatment, which can accelerate cell migration into traumatically injured cartilage, has great potential for clinical application.

Inhibition of cell-matrix adhesions prevents cartilage chondrocyte death following impact injury

Focal adhesions are transmembrane protein complexes that attach chondrocytes to the pericellular cartilage matrix and in turn, are linked to intracellular organelles via cytoskeleton. We previously found that excessive compression of articular cartilage leads to cytoskeleton-dependent chondrocyte death. Here we tested the hypothesis that this process also requires integrin activation and signaling via focal adhesion kinase (FAK) and Src family kinase (SFK). Osteochondral explants were treated with FAK and SFK inhibitors (FAKi, SFKi, respectively) for 2 h and then subjected to a death-inducing impact load. Chondrocyte viability was assessed by confocal microscopy immediately and at 24 h post-impact. With no treatment immediate post-impact viability was 59%. Treatment with 10 µM SFKi, 10 μM, or 100 µM FAKi improved viability to 80%, 77%, and 82%, respectively (p < 0.05). After 24 h viability declined to 34% in controls, 48% with 10 µM SFKi, 45% with 10 µM FAKi, and 56% with 100 µM FAKi (p < 0.01) treatment. These results confirmed that most of the acute chondrocyte mortality was FAK- and SFK-dependent, which implicates integrin-cytoskeleton interactions in the death signaling pathway. Together with previous findings, these data support the hypothesis that the excessive tissue strains accompanying impact loading induce death via a pathway initiated by strain on cell adhesion receptors.

Clinical outcomes of patellar chondral lesions treated with juvenile particulated cartilage allografts

BACKGROUND

Juvenile particulated cartilage allograft (DeNovo NT®, Zimmer, Warsaw, IN) transplantation is a relatively new technology for the treatment of high-grade cartilage lesions. To date there is limited literature demonstrating its effectiveness and safety. The present study specifically looks at the short-term efficacy of DeNovo NT® allograft for symptomatic high-grade cartilage lesions of the patella. Clinical outcomes and complications are reported.

METHODS

Seventeen cases of DeNovo NT® allograft transplantation at our institution were retrospectively reviewed from 2010 to 2013. Thirteen patients had the procedure performed for patellar lesions and are included in the present study. A chart review was performed to record demographic data, surgical technique, and complications. In addition, we analyzed preoperative and postoperative KOOS outcome scores.

RESULTS

The mean age was 22.5 years (range, 14-34), with 3 males and 10 females. Mean follow-up was 8.2 months (range, 0.67-32.7). Six of the patients had concomitant anteromedialization of the tibial tubercle. DeNovo NT® allograft transplantation resulted in improvement for each outcome measure used. Overall KOOS score significantly improved from a mean of 58.4±15.7 to 69.2±18.6 (P = 0.04). Improvement in KOOS subscales of pain, ADL, and symptoms all approached but did not reach statistical significance (P values between 0.05 and 0.10). There were no infections or hardware complications.

CONCLUSIONS

This series demonstrates that DeNovo NT® allograft transplantation for symptomatic high-grade cartilage lesions of the patella results in pain relief and improved outcomes in the short term. Further studies are needed to better evaluate this new technology.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Analysis of Intraoperative Neuromonitoring Events During Spinal Corrective Surgery for Idiopathic Scoliosis

STUDY DESIGN

Multicenter review of prospectively collected data.

OBJECTIVE

To determine the frequency and outcome of intraoperative neuromonitoring (IONM) alerts during surgical correction of idiopathic scoliosis (IS).

SUMMARY OF BACKGROUND DATA

Providing corrective action after identifying IONM events will ideally prevent neurologic complication.

METHODS

Prospectively gathered clinical data and IONM reports recorded during spinal surgery for IS were analyzed. Patients were divided into 2 groups: those with clear IONM changes and those with no IONM events. A neuromonitoring event was defined as a change from baseline transcranial motor evoked potentials or somatosensory evoked potentials in the lower extremities. The risk, rate, cause, and outcome of each neuromonitoring alert were assessed.

RESULTS

A total of 579 IS cases were analyzed. Twenty-one cases (3.6%) had an IONM event. In 18 of the 21 cases (86%), the potentials returned to baseline after corrective action. Of the 3 with remaining abnormalities, 2 (0.3%) awoke with deficits (1 unilateral weakness and 1 unilateral sensory change). In 12 cases, the changes were thought to result from low blood pressure; all responded to elevation of the mean arterial pressure. Five changes were associated with misplaced screws (in 4, the monitoring returned after removal or redirection; all 5 were normal postoperatively). Traction was the cause in 2 cases, both of which responded to reduction in traction. In 4 cases, the cause was unclear. Two remained abnormal and awoke with neurologic deficit. There were no postoperative neurologic deficits in any cases with normal neuromonitoring. Surgical time (416 vs. 291 minutes; p < .001) and percent estimated blood volume lost (64% ± 47% vs. 31% ± 26%; p < .001) were significantly increased in cases in which intraoperative events were observed.

CONCLUSIONS

The rate of neuromonitoring changes was 3.6% when using both transcranial motor evoked potential and somatosensory evoked potential monitoring. When a cause was identified and corrective action was taken, there were no postoperative neurologic deficits.

Conditional survival is greater than overall survival at diagnosis in patients with osteosarcoma and Ewing's sarcoma

BACKGROUND

Conditional survival is a measure of the risk of mortality given that a patient has survived a defined period of time. These estimates are clinically helpful, but have not been reported previously for osteosarcoma or Ewing's sarcoma.

QUESTIONS/PURPOSES

We determined the conditional survival of patients with osteosarcoma and Ewing's sarcoma given survival of 1 or more years.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) Program database to investigate cases of osteosarcoma and Ewing's sarcoma in patients younger than 40 years from 1973 to 2009. The SEER Program is managed by the National Cancer Institute and provides survival data gathered from population-based cancer registries. We used an actuarial life table analysis to determine any cancer cause-specific 5-year survival estimates conditional on 1 to 5 years of survival after diagnosis. We performed a similar analysis to determine 20-year survival from the time of diagnosis.

RESULTS

The estimated 5-year survival improved each year after diagnosis. For local/regional osteosarcoma, the 5-year survival improved from 74.8% at baseline to 91.4% at 5 years-meaning that if a patient with localized osteosarcoma lives for 5 years, the chance of living for another 5 years is 91.4%. Similarly, the 5-year survivals for local/regional Ewing's sarcoma improved from 72.9% at baseline to 92.5% at 5 years, for metastatic osteosarcoma 35.5% at baseline to 85.4% at 5 years, and for metastatic Ewing's sarcoma 31.7% at baseline to 83.6% at 5 years. The likelihood of 20-year cause-specific survival from the time of diagnosis in osteosarcoma and Ewing's sarcoma was almost 90% or greater after 10 years of survival, suggesting that while most patients will remain disease-free indefinitely, some experience cancer-related complications years after presumed eradication.

CONCLUSIONS

The 5-year survival estimates of osteosarcoma and Ewing's sarcoma improve with each additional year of patient survival. Knowledge of a changing risk profile is useful in counseling patients with time. The presence of cause-specific mortality decades after treatment supports lifelong monitoring in this population.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

The Roles of Mechanical Stresses in the Pathogenesis of Osteoarthritis: Implications for Treatment of Joint Injuries

Excessive joint surface loadings, either single (acute impact event) or repetitive (cumulative contact stress), can cause the clinical syndrome of osteoarthritis (OA). Despite advances in treatment of injured joints, the risk of OA following joint injuries has not decreased in the last 50 years. Cumulative excessive articular surface contact stress that leads to OA results from post-traumatic joint incongruity and instability, and joint dysplasia, but also may cause OA in patients without known joint abnormalities. In vitro investigations show that excessive articular cartilage loading triggers release of reactive oxygen species (ROS) from mitochondria, and that these ROS cause chondrocyte death and matrix degradation. Preventing release of ROS or inhibiting their effects preserves chondrocytes and their matrix. Fibronectin fragments released from articular cartilage subjected to excessive loads also stimulate matrix degradation; inhibition of molecular pathways initiated by these fragments prevents this effect. Additionally, injured chondrocytes release alarmins that activate chondroprogentior cells in vitro that propogate and migrate to regions of damaged cartilage. These cells also release chemokines and cytokines that may contribute to inflammation that causes progressive cartilage loss. Distraction and motion of osteoarthritic human ankles can promote joint remodeling, decrease pain and improve joint function in patients with end-stage post-traumatic OA. These advances in understanding of how altering mechanical stresses can lead to remodeling of osteoarthritic joints and how excessive stress causes loss of articular cartilage, including identification of mechanically induced mediators of cartilage loss, provide the basis for new biologic and mechanical approaches to the prevention and treatment of OA.

Risk factors for metastatic disease at presentation with osteosarcoma: an analysis of the SEER database

BACKGROUND

Osteosarcoma is the most common primary bone sarcoma and affects all ages. There are substantial differences in management and outcomes for patients who have localized disease compared with distant spread at the time of diagnosis. Our goal was to examine potential risk factors predictive of metastatic disease at presentation.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) Program database was used to identify all patients diagnosed with osteosarcoma from 2000 to 2008 and to classify each patient as having metastatic or localized disease at the time of diagnosis. Patient-based characteristics, tumor characteristics, and county-level socioeconomic measures were analyzed to determine which factors were predictive of an increased rate of distant metastatic disease at presentation. These factors were analyzed as univariate characteristics as well as in a multivariate logistic regression model.

RESULTS

We identified 2017 cases of high-grade osteosarcoma, and 464 (23.0%) of the patients presented with metastatic disease. In the unadjusted logistic regression analysis, patients had increased odds of metastatic disease at presentation if they had an age of sixty years or more (odds ratio [OR] = 2.22; 95% confidence interval [CI], 1.71 to 2.89), had a tumor located in the axial skeleton (OR = 2.47; 95% CI, 1.88 to 3.26), and lived in a county with low socioeconomic status (OR = 1.59; 95% CI, 1.08 to 2.35). These factors remained significant when combined in multivariate models controlling for age, location, and socioeconomic status. For patients with recorded tumor size information (n = 1398), the odds of metastasis at presentation increased by 10% with each additional centimeter of tumor size (OR = 1.10; 95% CI, 1.08 to 1.13). When the patients with missing tumor size information were excluded, socioeconomic status was no longer a significant risk factor for metastasis at presentation in the multivariate model.

CONCLUSIONS

Osteosarcoma patients with advanced age, a tumor in the axial skeleton, a larger tumor size, and a residence in a less affluent county were more likely to have metastatic disease at presentation.

Mechanical stress and ATP synthesis are coupled by mitochondrial oxidants in articular cartilage

Metabolic adaptation of articular cartilage under joint loading is evident and matrix synthesis seems to be critically tied to ATP. Chondrocytes utilize the glycolytic pathway for energy requirements but seem to require mitochondrial reactive oxygen species (ROS) to sustain ATP synthesis. The role of ROS in regulating ATP reserves under a mechanically active environment is not clear. It is believed that physiological strains cause deformation of the mitochondria, potentially releasing ROS for energy production. We hypothesized that mechanical loading stimulates ATP synthesis via mitochondrial release of ROS. Bovine osteochondral explants were dynamically loaded at 0.5 Hz with amplitude of 0.25 MPa for 1 h. Cartilage response to mechanical loading was assessed by imaging with dihydroethidium (ROS indicator) and a Luciferase-based ATP assay. Electron transport inhibitor rotenone and mitochondrial ROS scavenger MitoQ significantly suppressed mechanically induced ROS production and ATP synthesis. Our findings indicate that mitochondrial ROS are produced as a result of physiological mechanical strains. Taken together with our previous findings of ROS involvement in blunt impact injuries, mitochondrial ROS are important contributors to cartilage metabolic adaptation and their precise role in the pathogenesis of osteoarthritis warrants further investigation.

Chondrogenic progenitor cells respond to cartilage injury

OBJECTIVE

Hypocellularity resulting from chondrocyte death in the aftermath of mechanical injury is thought to contribute to posttraumatic osteoarthritis. However, we observed that nonviable areas in cartilage injured by blunt impact were repopulated within 7-14 days by cells that appeared to migrate from the surrounding matrix. The aim of this study was to assess our hypothesis that the migrating cell population included chondrogenic progenitor cells that were drawn to injured cartilage by alarmins.

METHODS

Osteochondral explants obtained from mature cattle were injured by blunt impact or scratching, resulting in localized chondrocyte death. Injured sites were serially imaged by confocal microscopy, and migrating cells were evaluated for chondrogenic progenitor characteristics. Chemotaxis assays were used to measure the responses to chemokines, injury-conditioned medium, dead cell debris, and high mobility group box chromosomal protein 1 (HMGB-1).

RESULTS

Migrating cells were highly clonogenic and multipotent and expressed markers associated with chondrogenic progenitor cells. Compared with chondrocytes, these cells overexpressed genes involved in proliferation and migration and underexpressed cartilage matrix genes. They were more active than chondrocytes in chemotaxis assays and responded to cell lysates, conditioned medium, and HMGB-1. Glycyrrhizin, a chelator of HMGB-1 and a blocking antibody to receptor for advanced glycation end products (RAGE), inhibited responses to cell debris and conditioned medium and reduced the numbers of migrating cells on injured explants.

CONCLUSION

Injuries that caused chondrocyte death stimulated the emergence and homing of chondrogenic progenitor cells, in part via HMGB-1 release and RAGE-mediated chemotaxis. Their repopulation of the matrix could promote the repair of chondral damage that might otherwise contribute to progressive cartilage loss.

Factors affecting outcomes in patients treated surgically for upper extremity tumors and tumor-like lesions

There is little data available regarding outcomes of patients who have undergone surgery for tumors of the upper extremity. Functional data after surgery for upper extremity tumors would aid in guiding patient expectations in the peri-operative period. The purpose of this study was to identify patient, tumor, and surgery-related characteristics associated with patient-reported physical and emotional function before and after surgery for tumors of the upper extremity. Pre- and post-operative mental and physical Medical Outcomes Study Short Form 36 (SF-36) scores were collected from 79 patients with benign and malignant neoplasms of the upper extremity. A retrospective chart review was performed to ascertain whether tumor behavior, type, location, patient sex, age, surgical specimen size, or type of surgery were correlated with differing outcomes. Our outcome measure was patient-reported physical and mental score (SF-36) at less than one year, one to two years, and greater than two years post-operatively. We found that patients with tumors proximal to the elbow and patients with right-sided tumors had statistically significantly lower post-operative physical scores at minimum two-year follow-up (p=0.02). Additionally, lower physical scores were associated with age greater than 50 (p=0.03) and tumor resection rather than curettage (p=0.01). The subset of patients with hereditary multiple exostoses had significantly lower post-operative physical scores than other patient sub-populations. There was no difference in physical function after surgery between patients with benign and malignant tumors, patients with tumors larger than 5 cm and less than 5 cm in greatest dimension, and patients with bone versus soft tissue tumors. Interestingly, we found that there was no difference in mental function scores between any comparisons. Our results suggest that patient age, tumor location, and type of surgery are correlated with patient-reported physical function following surgery. These findings could be helpful in counseling patients undergoing surgery for tumors of the upper extremity.

Toward improved clinical relevance of cartilage insult models in the rabbit knee: surgical access to the habitual weight-bearing region

OBJECTIVE

This article addresses considerations for using a posterior (popliteal) instead of anterior (para-patellar) approach for experimental insult to the rabbit knee medial femoral condyle (MFC) surface in vivo. The posterior approach is particularly advantageous when intending to address the pathomechanisms of OA associated with habitual cartilage loading, or the efficacy of a cartilage repair method, in a clinically relevant experimental setting.

DESIGN

Studies using anterior versus posterior approaches for such purposes in survival rabbit models of the MFC articular surface insults were systematically surveyed. The anterior-posterior span of the primary weight-bearing region of that surface was demonstrated cadaverically.

RESULTS

Of a total of 31 papers identified in 2007-2012, an anterior approach was utilized in 28 studies (> 90%). More than half (17/28) explicitly regarded the cranial half (inferior aspect) of the MFC surface as being a "weight-bearing" region. The insult site through anterior approach (identified in figures) was located in the cranial half region in all cases. Cadaverically, however, the center of habitual tibio-femoral contact locations on the MFC surface was located in the caudal half region (posterior aspect) of the MFC surface. The majority of the habitual contact region was accessible only by a posterior surgical approach.

CONCLUSION

For the above-noted purposes, use of a posterior (popliteal) approach, rather than an anterior approach, is highly recommended.

Serum protein electrophoresis in the evaluation of lytic bone lesions

Serum protein electrophoresis (SPEP) is often obtained at the initial evaluation of a radiolucent bone lesion of unknown etiology. The results are considered convincing evidence of the presence or absence of a plasma cell neoplasm. The sensitivity and specificity of the SPEP have not been reported in this clinical scenario. Our purpose is to assess the diagnostic value of the SPEP in the initial work-up of the radiolucent bone lesion. We identified 182 patients undergoing evaluation of a radiolucent bone lesion that included tissue biopsy and an SPEP value. We then calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SPEP as a diagnostic test for a plasma cell neoplasm in this clinical scenario. Forty-six of 182 (25.3%) patients in our series were diagnosed with a plasma cell neoplasm by histopathologic analysis. The sensitivity of SPEP was 71% and the specificity was 83%. PPV was 47% and NPV was 94%. When analyzing only those presenting with multiple lesions, the percentage of patients diagnosed with multiple myeloma increased to 44.7% (34 of 76 patients). The SPEP, however, did not have a substantially increased diagnostic accuracy with sensitivity of 71%, specificity 79%, PPV 40% and NPV 93%. SPEP lacks sensitivity and positive predictive value to provide a definitive diagnosis of myeloma in radiolucent bone lesions, but has a high negative predictive value which may make it useful in ruling out the disease. We recommend that this test either be performed in conjunction with urine electrophoresis, immunofixation electro-phoresis and free light chain assay, or after biopsy confirming the diagnosis of myeloma.

Neuronal populations in the basolateral nuclei of the amygdala are differentially increased in humans compared with apes: a stereological study

In human and nonhuman primates, the amygdala is known to play critical roles in emotional and social behavior. Anatomically, individual amygdaloid nuclei are connected with many neural systems that are either differentially expanded or conserved over the course of primate evolution. To address amygdala evolution in humans and our closest living relatives, the apes, we used design-based stereological methods to obtain neuron counts for the amygdala and each of four major amygdaloid nuclei (the lateral, basal, accessory basal, and central nuclei) in humans, all great ape species, lesser apes, and one monkey species. Our goal was to determine whether there were significant differences in the number or percent of neurons distributed to individual nuclei among species. Additionally, regression analyses were performed on independent contrast data to determine whether any individual species deviated from allometric trends. There were two major findings. In humans, the lateral nucleus contained the highest number of neurons in the amygdala, whereas in apes the basal nucleus contained the highest number of neurons. Additionally, the human lateral nucleus contained 59% more neurons than predicted by allometric regressions on nonhuman primate data. Based on the largest sample ever analyzed in a comparative study of the hominoid amygdala, our findings suggest that an emphasis on the lateral nucleus is the main characteristic of amygdala specialization over the course of human evolution.

Cytoskeletal dissolution blocks oxidant release and cell death in injured cartilage

The mechanisms by which articular surface impact causes post-traumatic osteoarthritis are not well understood, but studies of cartilage explants implicate the mitochondrial electron transport chain as a source of oxidants that cause chondrocyte death from mechanical injury. The linkage of mitochondria to the cytoskeleton suggests that they might release oxidants in response to mechanical strain, an effect that disrupting the cytoskeleton would prevent. To test this we investigated the effects of agents that promote the dissolution of microfilaments (cytochalasin B) or microtubules (nocodazole) on oxidant production and chondrocyte death following impact injury. Osteochondral explants treated with cytochalasin B or nocodazole for 4 h were impacted (7 J/cm(2)) and stained for oxidant production directly after impact and for cell viability 24 h after impact. Surfaces within and outside impact sites were then imaged by confocal microscopy. Both agents significantly reduced impact-induced oxidant release (p < 0.05); however, cytochalasin B was more effective than nocodazole (>60% reduction vs. 40% reduction, respectively). Both agents also prevented impact induced cell death. Dissolution of the cytoskeleton by both drugs was confirmed by phalloidin staining and confocal microscopy. These findings show that chondrocyte mortality from impact injury depends substantially on mitochondrial-cytoskeletal linkage, suggesting new approaches to stem mechanically induced cartilage degeneration.