Bias in Care: Impact of Ethnicity on Time to Emergent Surgery Varies Between Subspecialties.

INTRODUCTION: Disparity in access to emergency care among minority groups continues to exist despite growing awareness of the effect of implicit bias on public health. In this study, we evaluated ethnicity-based differences in time between admission and surgery for patients undergoing emergent procedures at hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program. METHODS: We conducted a retrospective review of 249,296 National Surgical Quality Improvement Program cases from 2006 to 2018 involving general, orthopaedic, and vascular surgeries. Analysis of variance was used to compare "time to operating room" (OR) between ethnic groups. RESULTS: Notable differences in time to OR were noted among general and vascular surgeries but not orthopaedic surgery. Post hoc comparison identified notable variation in general surgery between White and Black/African Americans. In vascular surgery, notable variations were identified between White and Black/African Americans and White and Native Hawaiian/Pacific Islanders. DISCUSSION: These findings suggest that certain surgical subspecialties continue to exhibit disparities in care that may manifest as surgical delay, most notably between White and Black/African Americans. Interestingly, variation in time to OR for patients treated by orthopaedic surgery was not notable. Overall, these results highlight the need for additional research into the role of implicit bias in emergent surgical care in the United States.

Liposomal Bupivacaine Decreases Intravenous Opioid Use in Patients with Hip Fracture: A Modification to a Novel Pain Protocol.

INTRODUCTION: The aim of this study was to determine whether the administration of liposomal bupivacaine decreased opioid use and delirium in patients sustaining a hip fracture. METHODS: A retrospective review of patients with hip fracture from September 2018 to October 2019 was performed through our institution's hip fracture registry. A liposomal bupivacaine cocktail was administered intraoperatively. Opioid requirement was determined for postoperative days 1, 2, and 3. Delirium was identified through chart review. Visual analog scale pain scores were averaged for postoperative days 1, 2, and 3. Four groups were analyzed: patients who received liposomal bupivacaine and IV acetaminophen, patients who only received IV acetaminophen, patients who only received liposomal bupivacaine, and control patients whose data were collected before this intervention. Continuous data were compared using a one-way analysis of variance or Student t-test, as applicable. Categorical data were compared using the Fisher exact test. Significance was set at P < 0.05. RESULTS: One hundred nine patients met the inclusion criteria for the study with a mean age of 81.2 years. Eighty-two patients (75.2%) received intraoperative liposomal bupivacaine during the study year. Intravenous opioid requirement was markedly different among all four groups in all postoperative days. Oral opioid requirement and pain scores were not different between groups on any postoperative day. A notable decrease in IV opioid requirement in all postoperative days was seen in the Intervention groups (day 1 P < 0.001, day 2 P = 0.002, and day 3 P = 0.030). There existed a trend toward decreased delirium rates in the Intervention groups compared with the No Intervention group (23.9% vs. 32.8%, P = 0.272). CONCLUSION: The inclusion of liposomal bupivacaine in our institution's novel pain protocol led to notable decreases in opioid requirement in all postoperative days studied with a trend toward decreased delirium rates as well.

Linguistic Analysis Identifies Emergent Biomaterial Fabrication Trends for Orthopaedic Applications.

The expanse of publications in tissue engineering (TE) and orthopedic TE (OTE) over the past 20 years presents an opportunity to probe emergent trends in the field to better guide future technologies that can make an impact on musculoskeletal therapies. Leveraging this trove of knowledge, a hierarchical systematic search method and trend analysis using connected network mapping of key terms is developed. Within discrete time intervals, an accelerated publication rate for anatomic orthopedic tissue engineering (AOTE) of osteochondral defects, tendons, menisci, and entheses is identified. Within these growing fields, the top-listed key terms are extracted and stratified into evident categories, such as biomaterials, delivery method, or 3D printing and biofabrication. It is then identified which categories decreased, remained constant, increased, or emerged over time, identifying the specific emergent categories currently driving innovation in orthopedic repair technologies. Together, these data demonstrate a significant convergence of material types and descriptors used across tissue types. From this convergence, design criteria to support future research of anatomic constructs that mimic both the form and function of native tissues are formulated. In summary, this review identifies large-scale trends and predicts new directions in orthopedics that will define future materials and technologies.

Case report: vertebral body tethering for idiopathic scoliosis in a patient with bilateral phocomelia.

PURPOSE: The purpose of this study is to present a case report of a patient with bilateral upper extremity phocomelia with progressive scoliosis, who underwent vertebral body tethering (VBT). METHODS: This is a case report on the use of VBT in a patient with scoliosis and bilateral congenital phocomelia, with 5 year follow-up. RESULTS: A male patient with bilateral phocomelia had early onset scoliosis that progressed to 45° at age 10. Surgical options were discussed, including traditional VBT, posterior spinal fusion, growing rods, magnetically controlled growing rods, and vertical expandible prosthetic titanium ribs. These options would limit the flexibility of the spine. Given these pitfalls, VBT was chosen, as it would address the scoliosis while maintaining trunk flexibility. Preoperatively, he had 45° right main thoracic curve, bending to 22°; he was Risser 0 with open triradiate cartilage. He underwent T6-T11 thoracoscopic VBT, with postoperative correction to 37°. Postoperatively, the patient was able to continue to use his lower extremities for writing, feeding, and personal grooming. He had no postoperative complications. At 3 years, his curve was 21°, and at 5 years was 19°. CONCLUSION: This case describes a novel technique for treating scoliosis in patients with bilateral phocomelia. Other forms of scoliosis surgical treatment limit motion of the spine. Due to this, we present VBT as an option for this unique set of patients for correcting scoliosis, while also preserving trunk flexibility for its role in feeding and self-care.

Objects in Mirror Are Closer Than They Appear: Symptoms of Depression and Suicidality in Orthopaedic Surgeons.

BACKGROUND: Suicide and depression among orthopaedic surgeons have recently emerged as rising concerns. Prior research has suggested that orthopaedic surgeons have the highest prevalence of suicide among surgical specialties. We sought to determine the factors associated with depression and suicidal ideation (SI) in orthopaedics, including subspecialty. METHODS: A survey including demographic questions, the Beck Depression Inventory, and the Columbia-Suicide Severity Rating Scale was administered electronically via a listserv to the orthopaedic subspecialties of trauma, adult reconstruction, hand and upper extremity, shoulder and elbow, foot and ankle, spine, pediatrics, sports medicine, and oncology. The responses were quantified according to previously published criteria. The associations of demographic factors, training, and current practice environment with depression and suicidality were assessed using Fisher exact tests. Reverse stepwise multivariable logistic regression models were developed to identify factors associated with depression and SI. RESULTS: The responses were obtained from 661 board-certified, practicing orthopaedic surgeons. In this study, 156 surgeons (23.6%) endorsed some level of active SI in their lifetime, 200 surgeons (30.3%) reported either active or passive SI in their lifetime, and 33 surgeons (5%) reported that, on at least 1 occasion in their lifetime, they had experienced active SI with a specific plan and intention to harm themselves. Gender, relationship status, having children, and residency and/or current practice region were significantly associated with depression and/or SI. Younger age, divorce, adult reconstruction and foot and ankle subspecialties, and attending residency in the Western U.S. were found on multivariable testing to be associated with symptoms of depression and SI (odds ratios, 1.03 [per 1-year decrease in age] to 8.28). CONCLUSIONS: Symptoms of depression and suicidality are not uncommon among orthopaedic surgeons, and variation by gender, relationship status, and geographic location are supported by prior research. Based on our results, depression and/or SI likely affect someone close to you or someone with whom you work. The normalization of discussions surrounding emotional well-being, depression, and SI is imperative.

Nonsurgical treatment reduces tendon inflammation and elevates tendon markers in early healing.

Operative treatment is assumed to provide superior outcomes to nonoperative (conservative) treatment following Achilles tendon rupture, however, this remains controversial. This study explores the effect of surgical repair on Achilles tendon healing. Rat Achilles tendons (n = 101) were bluntly transected and were randomized into groups receiving repair or non-repair treatments. By 1 week after injury, repaired tendons had inferior mechanical properties, which continued to 3- and 6-week post-injury, evidenced by decreased dynamic modulus and failure stress. Transcriptomics analysis revealed >7000 differentially expressed genes between repaired and non-repaired tendons after 1-week post-injury. While repaired tendons showed enriched inflammatory gene signatures, non-repaired tendons showed increased tenogenic, myogenic, and mechanosensitive gene signatures, with >200-fold enrichment in Tnmd expression. Analysis of gastrocnemius muscle revealed elevated MMP activity in tendons receiving repair treatment, despite no differences in muscle fiber morphology. Transcriptional regulation analysis highlighted that the highest expressed transcription factors in repaired tendons were associated with inflammation (Nfκb, SpI1, RelA, and Stat1), whereas non-repaired tendons expressed markers associated with tissue development and mechano-activation (Smarca1, Bnc2, Znf521, Fbn1, and Gli3). Taken together, these data highlight distinct differences in healing mechanism occurring immediately following injury and provide insights for new therapies to further augment tendons receiving repaired and non-repaired treatments.

The porcine accessory carpal bone as a model for biologic joint replacement for trapeziometacarpal osteoarthritis.

Given its complex shape and relatively small size, the trapezium surface at the trapeziometacarpal (TMC) joint is a particularly attractive target for anatomic biologic joint resurfacing, especially given its propensity to develop osteoarthritis, and the limited and sub-optimal treatment options available. For this to advance to clinical translation, however, an appropriate large animal model is required. In this study, we explored the porcine accessory carpal bone (ACB) as a model for the human trapezium. We characterized ACB anatomy, geometry, joint and tissue-scale mechanics, and composition across multiple donors. We showed that the ACB is similar both in size, and in the saddle shape of the main articulating surface to the human trapezium, and that loads experienced across each joint are similar. Using this information, we then devised a fabrication method and workflow to produce patient-specific tissue-engineered replicas based on CT scans, and showed that when such replicas are implanted orthotopically in an ex vivo model, normal loading is restored. Data from this study establish the porcine ACB as a model system in which to evaluate function of engineered living joint resurfacing strategies. STATEMENT OF SIGNIFICANCE: Biologic joint resurfacing, or the replacement of a joint with living tissue as opposed to metal and plastic, is the holy grail of orthopaedic tissue engineering. However, despite marked advances in engineering native-like osteochondral tissues and in matching patient-specific anatomy, these technologies have not yet reached clinical translation. Given its propensity for developing osteoarthritis, as well as its small size and complex shape, the trapezial surface of the trapeziometacarpal joint at the base of the thumb presents a unique opportunity for pursuing a biologic joint resurfacing strategy. This work establishes the porcine accessory carpal bone as an animal model for the human trapezium and presents a viable test-bed for evaluating the function of engineered living joint resurfacing strategies.

Return to Play for Cervical and Lumbar Spine Conditions.

Although the safety of contact sports has improved over the years, participation in any sport always carries a risk of injury. When cervical or lumbar spine injuries do occur, prompt diagnosis is essential, and athletes must be held out of the sport if indicated to prevent further harm and allow for recovery. This article highlights some of the most common cervical spine pathologies (stinger/burners, strain, stenosis/cord neuropraxia, disc herniation, and fracture/instability) and lumbar spine pathologies (strain, disc degeneration, disc herniation, fracture, spondylolysis/spondylolisthesis, and scoliosis) encountered in sports and reviews the associated return to play guidelines and expectations for each condition.

Mechanical properties of the different rotator cuff tendons in the rat are similarly and adversely affected by age.

Rotator cuff tendon tears and tendinopathies are common injuries affecting a large portion of the population and can result in pain and joint dysfunction. Incidence of rotator cuff tears significantly increases with advancing age, and up to 90% of these tears involve the supraspinatus. Previous literature has shown that aging can lead to inferior mechanics, altered composition, and changes in structural properties of the supraspinatus. However, there is little known about changes in supraspinatus mechanical properties in context of other rotator cuff tendons. Alterations in tendon mechanical properties may indicate damage and an increased risk of rupture, and thus, the purpose of this study was to use a rat model to define age-related alterations in rotator cuff tendon mechanics to determine why the supraspinatus is more susceptible to tears due to aging than the infraspinatus, subscapularis, and teres minor. Fatigue, viscoelastic, and quasi-static properties were evaluated in juvenile, adult, aged, and geriatric rats. Aging ubiquitously and adversely affected all rotator cuff tendons tested, particularly leading to increased stiffness, decreased stress relaxation, and decreased fatigue secant and tangent moduli in geriatric animals, suggesting a common intrinsic mechanism due to aging in all rotator cuff tendons. This study demonstrates that aging has a significant effect on rotator cuff tendon mechanical properties, though the supraspinatus was not preferentially affected. Thus, we are unable to attribute the aging-associated increase in supraspinatus tears to its mechanical response alone.

The Role of Weightbearing Computed Tomography Scan in Hallux Valgus.

BACKGROUND: Hyperpronation of the first metatarsal in hallux valgus (HV) is poorly understood by conventional weightbearing radiography. We aimed to evaluate this parameter using weightbearing computed tomography (WBCT) and to understand its association with other standard measurements. METHODS: Retrospective evaluation of WBCT and weightbearing radiographs (WBXRs) was performed for 20 patients with HV feet and 20 controls with no such deformity. Axial computed tomography images of both groups were compared for the first metatarsal pronation angle (alpha angle) and tibial sesamoid subluxation (TSS) grades. The HV angle (HVA), first-second intermetatarsal angle (IMA), first metatarsal-medial cuneiform angle (MMCA), Meary's angle, and calcaneal pitch (CP) angle of the study and control groups were compared on both WBXR and the corresponding 2-dimensional images of WBCT. All measurements were independently performed by 1 musculoskeletal radiology fellow and 1 foot and ankle surgical fellow. Measurements were averaged and interobserver reliability was calculated. RESULTS: The HV group demonstrated significantly higher values for TSS grade (P < .001) but not for alpha angle (P = .121) compared with controls. Likewise, significantly elevated HVA and IMA were noted in the HV group on both imaging modalities, while no such differences were observed for the CP angle. Higher MMCA and Meary's angle in the HV group were evident only on WBXR (MMCA, P = .039; Meary's, P = .009) but not on WBCT (MMCA, P = .183; Meary's, P = .171).Among all, the receiver operating characteristic (ROC) curves demonstrated the greatest area under the curve (AUC) for HVA, followed by IMA. The alpha angle performed only just outside the range of chance (AUC, 0.65; 95% CI, 0.52-0.69). The Pearson's correlations of the alpha angle, in the HV group, revealed a significant linear relationship with TSS grade and with HVA on WBXR, and only trended toward a weak linear relationship with IMA and with HVA on WBCT. CONCLUSION: The alpha angle, a measure of abnormal hyperpronation of the first metatarsal, was an independent factor that may coexist with other parameters in HV, but in isolation had limited diagnostic utility. "Abnormal" alpha angles were even observed in individuals without HV. Increases in IMA and MMCA were not necessarily associated with similar increases in alpha angle, despite moderate correlations with TSS grade and HVA on WBXR. Nevertheless, the WBCT was a useful method for assessing hyperpronation and guiding surgical management in individual cases. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Fabrication and maturation of integrated biphasic anatomic mesenchymal stromal cell-laden composite scaffolds for osteochondral repair and joint resurfacing.

Articular cartilage injury can lead to joint-wide erosion and the early onset of osteoarthritis. To address this, we recently developed a rapid fabrication method to produce patient-specific engineered cartilage tissues to replace an entire articular surface. Here, we extended that work by coupling a mesenchymal stromal cell-laden hydrogel (methacrylated hyaluronic acid) with the porous polycaprolactone (PCL) bone integrating phase and assessed the composition and mechanical performance of these constructs over time. To improve initial construct stability, PCL/hydrogel interface parameters were first optimized by varying PCL pretreatment (with sodium hydroxide before ethanol) before hydrogel infusion. Next, cylindrical osteochondral constructs were formed and cultured in media containing transforming growth factor ß3 for up to 8 weeks, with constructs evaluated for viability, histological features, and biochemical content. Mechanical properties were also assessed in axial compression and via an interface shear strength assay. Results showed that the fabrication process was compatible with cell viability, and that construct biochemical content and mechanical properties increased with time. Interestingly, compressive properties peaked at 5 weeks, while interfacial shear properties continued to improve beyond this time point. Finally, these fabrication methods were combined with a custom mold developed from limb-specific computed tomography imaging data to create an anatomic implantable cell-seeded biologic joint surface, which showedmaturation similar to the osteochondral cylinders. Future work will apply these advances in large animal models of critically sized osteochondral defects to study repair and whole joint resurfacing.

Acetabular reconstruction in revision total hip arthroplasty.

The number of total hip arthroplasty (THA) procedures performed annually continues to rise. Specific challenges, including acetabular bone loss, are commonly encountered at the time of revision surgery, and orthopaedic surgeons must be prepared to address them. This review focuses on topics related to acetabular reconstruction, including pre-operative patient evaluation (clinical and radiographic), pre-operative planning, common causes of acetabular failure, classification of acetabular bone loss, methods of acetabular reconstruction, and clinical results based on reconstruction method. Pre-operative patient evaluation for revision THA begins with a thorough history and physical examination as well as laboratory workup to rule out infection. Detailed radiographic evaluation and pre-operative planning are also essential and will facilitate communication amongst all members of the operative team. Although there are several ways to describe acetabular bone loss, the Paprosky classification system - defined by anterosuperior and posteroinferior acetabular column integrity - is the system most commonly used today and will guide treatment strategy. Several treatment strategies have been developed and may be termed either "cemented" (e.g. impaction grafting, ring and cage construction, structural allograft) or "uncemented" (e.g. hemispheric shell ± porous metal augment, cup-cage, custom triflange acetabular component). Although each strategy has its advantages and disadvantages, the general principles remain the same. Successful treatment depends upon detailed pre-operative assessment, planning, and team-based plan execution. Uncemented techniques that allow for biologic fixation are preferred. In the special case of pelvic discontinuity, acetabular distraction is the authors' preferred technique. Longer term studies are still needed to evaluate the longevity of each of the various reconstruction methods presented.

The application of the Nice knots as an auxiliary reduction technique in displaced comminuted patellar fractures.

PURPOSE: To evaluate intraoperative and early postoperative clinical outcomes using the Nice knot as an auxiliary reduction technique in displaced comminuted patellar fractures. METHODS: Thirty-nine patients with unilateral closed displaced comminuted patellar fractures received open reduction and internal fixation (ORIF), utilizing either Nice knot (the NK group, 24 patients) or traditional reduction (the TR group, 23 patients) techniques, were retrospectively reviewed in this study. Intra-operative surgical time and peri-operative hemoglobin were recorded. Post-operative clinical outcomes were measured using visual analgesic score, range of motion of the knee joint and the Böstman scales, and radiographic outcomes were used to evaluate fracture healing. Complications including infection, bone non-union, implant loosening, fragment displacement and painful hardware were also assessed. RESULTS: In-hospital records indicated significantly shorter surgical duration (32.6 min) in the NK group than in the TR group (63.9 min). Intraoperative blood loss was also significantly decreased in the NK group (64.7 ml) compared to the TR group (189.1 ml). Patients in the NK and TR groups were followed for mean of 12.9 months and 12.5 months respectively. The union rate was 100% (24/24) in the NK group and 91.3% (21/23) in the TR group. In the TR group, there were two non-unions, including one infected non-union. There was no difference in the visual analgesic score, the range of motion of the knee joint or the Böstman scale at last follow-up between the two groups. CONCLUSION: The sliding, self-stabilizing Nice knot was associated with reduced surgical time, decreased intraoperative blood loss, and satisfactory postoperative outcomes in the treatment of displaced patellar fractures. Future studies are needed to ensure the generalizability of these findings to additional patient populations at other institutions.

Hypoalbuminemia remains an independent predictor of complications following total joint arthroplasty.

INTRODUCTION: Hypoalbuminemia (<3.5 mg/dL) is an accepted marker of malnutrition, but it was unknown if low albumin remained an independent predictor of post-operative complications following primary total hip (THA) and knee (TKA) arthroplasty. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for patients undergoing primary THA and TKA. Propensity score-matched analysis was used to control for co-morbid conditions. RESULTS: Patients with low albumin demonstrated greater odds of death (by 2-21x), morbidity (by 25-51%), re-admission (by 45-54%), and increased length of stay. CONCLUSION: Low albumin remains an independent predictor of adverse outcomes following primary total joint arthroplasty.

Effects of immobilization angle on tendon healing after achilles rupture in a rat model.

Conservative (non-operative) treatment of Achilles tendon ruptures is a common alternative to operative treatment. Following rupture, ankle immobilization in plantarflexion is thought to aid healing by restoring tendon end-to-end apposition. However, early activity may improve limb function, challenging the role of immobilization position on tendon healing, as it may affect loading across the injury site. This study investigated the effects of ankle immobilization angle in a rat model of Achilles tendon rupture. We hypothesized that manipulating the ankle from full plantarflexion into a more dorsiflexed position during the immobilization period would result in superior hindlimb function and tendon properties, but that prolonged casting in dorsiflexion would result in inferior outcomes. After Achilles tendon transection, animals were randomized into eight immobilization groups ranging from full plantarflexion (160°) to mid-point (90°) to full dorsiflexion (20°), with or without angle manipulation. Tendon properties and ankle function were influenced by ankle immobilization position and time. Tendon lengthening occurred after 1 week at 20° compared to more plantarflexed angles, and was associated with loss of propulsion force. Dorsiflexing the ankle during immobilization from 160° to 90° produced a stiffer, more aligned tendon, but did not lead to functional changes compared to immobilization at 160°. Although more dorsiflexed immobilization can enhance tissue properties and function of healing Achilles tendon following rupture, full dorsiflexion creates significant tendon elongation regardless of application time. This study suggests that the use of moderate plantarflexion and earlier return to activity can provide improved clinical outcomes. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

The Saline Load Test is Effective at Diagnosing Traumatic Arthrotomies of the Wrist.

BACKGROUND: The saline load test has previously been shown to be an effective tool to diagnose traumatic arthrotomies, but no studies have assessed the test's efficacy in the wrist. The purpose of this study was to investigate the amount of fluid required during a saline load test to detect intra-articular wrist involvement of traumatic wounds with high sensitivity. METHODS: A cadaveric study was conducted using 7 thawed, fresh-frozen forequarter amputations from 7 different donors (3 male, 4 female). Specimen age (mean: 67.7 y, range: 52 to 80 y), laterality (1 right, 6 left), body weight (mean: 164.3 lbs, range: 100 to 223 lbs), and wrist range of motion (ROM) was assessed before testing. The wrist capsule was punctured with an 11-blade scalpel through the 6R radiocarpal portal site under fluoroscopic guidance to ensure the injury was intra-articular. A 19-G needle was then placed through the 3,4 radiocarpal portal site and confirmed with fluoroscopy to ensure intra-articular placement. Normal saline was then injected at a steady rate into the 3,4 radiocarpal portal site until extravasation of the saline was observed from the 6R radiocarpal arthrotomy site. The volume of saline required for extravasation from the 6R radiocarpal arthrotomy was recorded as the volume required to detect the arthrotomy. A plot of saline volumes (by percentile) was created, and a logarithmic distribution was calculated. A Wilcoxon rank-sum test was used to compare injection volumes between male and female specimens, and Pearson Coefficients were used to determine any correlations between injection volume and ROM. RESULTS: The average amount of saline that resulted in extravasation was 4 mL (range: 2 to 7 mL). In order to identify 75%, 90%, 95%, and 99% of the simulated wrist arthrotomies, 5 (95% confidence interval: 3-7), 6 (4-9), 7 (4-10), and 9 (5-14) mL were required, respectively. Pretest ROM did not correlate with saline volume. CONCLUSIONS: This study demonstrates the efficacy of the saline load test in detecting traumatic arthrotomies of the wrist joint with 95% sensitivity after loading 7 mL of saline. Prompt and accurate diagnosis of traumatic arthrotomies is paramount to guide management and optimize postinjury outcomes.

Temporal Healing of Achilles Tendons After Injury in Rodents Depends on Surgical Treatment and Activity.

INTRODUCTION: Achilles tendon ruptures affect 15 of 100,000 women and 55 of 100,000 men each year. Controversy continues to exist regarding optimal treatment and rehabilitation protocols. The objective of this study was to investigate the temporal effects of surgical repair and immobilization or activity on Achilles tendon healing and limb function after complete transection in rodents. METHODS: Injured tendons were repaired (n = 64) or left nonrepaired (n = 64). The animals in both cohorts were further randomized into groups immobilized in plantar flexion for 1, 3, or 6 weeks that later resumed cage and treadmill activity for 5, 3, or 0 weeks, respectively (n = 36 for each regimen), which were euthanized at 6 weeks after injury, or into groups immobilized for 1 week and then euthanized (n = 20). RESULTS: At 6 weeks after injury, the groups that had 1 week of immobilization and 5 weeks of activity had increased range of motion and decreased ankle joint toe stiffness compared with the groups that had 3 weeks of immobilization and 3 weeks of activity. The groups with 6 weeks of immobilization and no activity period had decreased tendon cross-sectional area but increased tendon echogenicity and collagen alignment. Surgical treatment dramatically decreased fatigue cycles to failure in repaired tendons from groups with 1 week of immobilization and 5 weeks of activity. Normalized comparisons between 1-week and 6-week postinjury data demonstrated that changes in tendon healing properties (area, alignment, and echogenicity) were maximized by 1 week of immobilization and 5 weeks of activity, compared with 6 weeks of immobilization and no activity period. DISCUSSION: This study builds on an earlier study of Achilles tendon fatigue mechanics and functional outcomes during early healing by examining the temporal effects of different immobilization and/or activity regimens after initial postinjury immobilization. CONCLUSION: This study demonstrates how the temporal postinjury healing response of rodent Achilles tendons depends on both surgical treatment and the timing of immobilization/activity timing. The different pattern of healing and qualities of repaired and nonrepaired tendons suggest that two very different healing processes may occur, depending on the chosen immobilization/activity regimen.

Acute Deep Infections of the Upper Extremity: The Utility of Obtaining Atypical Cultures in the Presence of Purulence.

PURPOSE: In the setting of acute deep upper extremity infections, evidence is lacking to guide the decision whether to send atypical cultures (fungal and acid-fast-bacillus [AFB]) during surgical debridement, especially in the presence of purulent fluid that is commonly observed with typical bacterial infections. Our purpose was to determine the frequency of positive atypical cultures and the frequency with which they alter treatment, and identify factors associated with positive atypical cultures. METHODS: We retrospectively identified 100 adult patients undergoing surgical debridement of acute deep infections of the upper extremity in which fungal and/or AFB cultures were sent. Necrotizing and superficial infections were excluded. Descriptive statistics were used to describe patient characteristics, infection diagnoses, number of cultures sent with corresponding rates of positivity, and treatments. Cohorts with positive and negative atypical cultures were compared with bivariate analysis for all collected variables. RESULTS: One or more immunocompromising comorbidities were present in 46% of patients. Diagnoses included soft tissue abscess (46%), suppurative flexor tenosynovitis (22%), septic arthritis (21%), osteomyelitis (9%), and septic bursitis (2%). Aerobic bacterial, anaerobic bacterial, fungal, and AFB cultures were sent in 100%, 99%, 94%, and 82% of patients, respectively. Corresponding rates of positivity were 74%, 34.3%, 5.3%, and 2.4%, respectively. Atypical cultures were positive for 7% of patients and 2.9% of all atypical tests sent. Antibiotic treatment was influenced by atypical culture data for 4% of patients. For patients with positive atypical cultures, purulence was observed during surgery in 86% of cases. Bivariate analysis demonstrated symptom duration greater than 7 days as potentially associated with atypical culture positivity. CONCLUSIONS: Intraoperative purulence at the time of surgical intervention should not deter the surgeon from obtaining atypical cultures. As expected, atypical cultures are infrequently positive given the rarity of associated diseases. Symptoms greater than 7 days may predict a higher incidence of atypical culture positivity for patients being treated surgically within 30 days of initial symptom onset. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Mechanical, histological, and functional properties remain inferior in conservatively treated Achilles tendons in rodents: Long term evaluation.

Conservative treatment (non-operative) of Achilles tendon ruptures is suggested to produce equivalent capacity for return to function; however, long term results and the role of return to activity (RTA) for this treatment paradigm remain unclear. Therefore, the objective of this study was to evaluate the long term response of conservatively treated Achilles tendons in rodents with varied RTA. Sprague Dawley rats (n=32) received unilateral blunt transection of the Achilles tendon followed by randomization into groups that returned to activity after 1-week (RTA1) or 3-weeks (RTA3) of limb casting in plantarflexion, before being euthanized at 16-weeks post-injury. Uninjured age-matched control animals were used as a control group (n=10). Limb function, passive joint mechanics, tendon properties (mechanical, histological), and muscle properties (histological, immunohistochemical) were evaluated. Results showed that although hindlimb ground reaction forces and range of motion returned to baseline levels by 16-weeks post-injury regardless of RTA, ankle joint stiffness remained altered. RTA1 and RTA3 groups both exhibited no differences in fatigue properties; however, the secant modulus, hysteresis, and laxity were inferior compared to uninjured age-matched control tendons. Despite these changes, tendons 16-weeks post-injury achieved secant stiffness levels of uninjured tendons. RTA1 and RTA3 groups had no differences in histological properties, but had higher cell numbers compared to control tendons. No changes in gastrocnemius fiber size or type in the superficial or deep regions were detected, except for type 2x fiber fraction. Together, this work highlights RTA-dependent deficits in limb function and tissue-level properties in long-term Achilles tendon and muscle healing.