Development of a novel murine femur fracture and fixation model

BACKGROUND

Animal models have been used for decades to simulate human fractures in the laboratory setting. Fracture models in mice are attractive because they offer a high volume, relatively low-cost method of investigating fracture healing characteristics. We report on the development of a novel murine femur fracture model that is rapid, reproducible and inexpensive.

METHODS

As part of a pilot study to investigate the effects of smoking on fracture healing, fifteen 35-43 g twelve-week old female CD-1 mice underwent a novel surgical protocol using direct visualization of femur fracture creation and fixation. Following surgery, mice were sacrificed at 14 days, 28 days and 42 days. After sacrifice, the femora were analyzed using MicroCT and histology to evaluate progression of healing.

RESULTS

Of the 14 mice that survived the surgical procedure (one succumbed to a complication of anesthesia), two lost reduction and did not heal. Histology demonstrated at 14 days 44.1% (SD±2.9%) of callus composed of cartilage. At 28 days there was 19.0% (SD±3.4%) of callus composed of cartilage. At 42 days there was 8.4% (SD±2.6%) callus composed of cartilage (p < 0.005). MicroCT demonstrated that from 14 to 42 days the average callus volume decreased from 101.6 mm3 to 68.2 mm3 while the relative bone volume of callus increased from 14 to 42 days (15%-31%) (p = 0.068).

CONCLUSIONS

Our novel fracture and fixation model is an effective, rapid, reproducible and inexpensive method to simulate a fracture in a laboratory setting. Additionally, our model reliably creates a reproducible progression of radiographic and histological bone healing.

Arthroscopic Technique for Treating Patella and Femoral Condyle Lesions With DeNovo Natural Tissue Allograft

Use of juvenile particulate cartilage allograft has been previously described for the treatment of full-thickness chondral lesions of the knee. Although this procedure has traditionally been performed with an open approach, it can be performed using arthroscopic techniques with the potential for less morbidity and accelerated rehabilitation. This article describes an all-arthroscopic technique for treating patella and femoral condyle lesions with DeNovo Natural Tissue allograft, including clinical indications and a rehabilitation protocol.

Cost minimization analysis of the treatment of distal radial fractures in the elderly

AIMS

The aim of this study was to test the null hypothesis that there is no difference, from the payer perspective, in the cost of treatment of a distal radial fracture in an elderly patient, aged > 65 years, between open reduction and internal fixation (ORIF) and closed reduction (CR).

MATERIALS AND METHODS

Data relating to the treatment of these injuries in the elderly between January 2007 and December 2015 were extracted using the Humana and Medicare Advantage Databases. The primary outcome of interest was the cost associated with treatment. Secondary analysis included the cost of common complications. Statistical analysis was performed using a non-parametric t-test and chi-squared test.

RESULTS

Our search yielded 8924 patients treated with ORIF and 5629 patients treated with CR. The mean cost of an uncomplicated ORIF was more than a CR ($7749 versus $2161). The mean additional cost of a complication in the ORIF group was greater than in the CR group ($1853 versus $1362).

CONCLUSION

These findings show that there are greater payer fees associated with ORIF than CR in patients aged > 65 years with a distal radial fracture. CR may be a higher-value intervention in these patients. Cite this article: Bone Joint J 2018;100-B:205-11.

Anatomic humeral head replacement with a press-fit prosthesis: An in vivo radiographic study

Successful total shoulder arthroplasty is, in part, dependent on anatomic reconstruction of the glenohumeral joint. The purpose of this study was to evaluate the post-operative anatomy of total shoulder arthroplasty with an anatomic implant design in patients with primary glenohumeral osteoarthritis and compare it to published normative anatomic measurements. Fifty-one patients (56 shoulders) with primary glenohumeral osteoarthritis were treated with a press-fit humeral component as part of a total shoulder arthroplasty (Aequalis, Tornier, Edina, Minnesota). Analysis of postoperative true anterior posterior radiographs was performed with use of a custom software algorithm. The mean humeral inclination (head-shaft angle), mean humeral implant anatomical humeral axis, mean greater tuberosity height, and mean humeral head center offset (medial offset) were 135.4±5.1°, 1.73±1.7°, 6.9±2.4 mm, and 3.8±1.8 mm, respectively. All parameters were within the ranges reported in the literature for normal shoulders except the mean humeral head center offset, which was less than reported in the literature. Anatomic parameters of a total shoulder arthroplasty can be achieved with an anatomically designed, modular adaptable press-fit design. Reduced medial humeral head center offset was likely dependent upon implant specific design parameters.

Lower Complication Rate Following Ankle Fracture Fixation by Orthopaedic Surgeons Versus Podiatrists

Category:

Ankle, Trauma

Introduction/Purpose:

Although the scope of practice for orthopaedic surgeons and podiatrists have considerable overlap in many foot and ankle pathologies, there are significant differences between the training for each surgical specialty that may affect patient outcomes. The purpose of this study was to evaluate complication rates following fixation of ankle fractures based on provider type. Our hypothesis was that patients with ankle fractures treated by orthopaedic surgeons would have lower complication rates compared to patients treated by podiatrists.

Methods:

This was a retrospective cohort study of data extracted from the Humana Claims database for 15,067 patients who underwent ankle fracture fixation between 2007 and 2015. Procedure type was identified by Current Procedural Terminology (CPT) codes. Patient data was subcategorized by surgeon type (orthopaedic surgeon versus podiatrist) and whether the patient underwent operative treatment for a single malleolus fracture (CPT 27766, 27792) versus a bimalleolar or a trimalleolar fracture (CPT 27814, 27822, 27823). The primary outcome was postoperative complications within 3 months including malunion, infection, or deep vein thrombosis (DVT). Secondary outcomes included reoperation rates for implant removal or irrigation and debridement. Complications were identified by International Classification of Disease-9 (ICD-9) codes and reoperations were identified by CPT codes. Chi-squared tests were used to determine differences in complication rates between surgeon types. The Charlson comorbidity index (CCI) was used to compare populations based on medical risk factors for complications.

Results:

14,222 patients with ankle fractures were treated by orthopaedic surgeons and 845 patients were treated by podiatrists. Operative treatment by orthopaedists was associated with lower DVT (p<0.02) and malunion (p<0.02) rates among all types of ankle fractures. There were no differences in complications for patients with single malleolar fractures, although higher rates of implant removal (p<0.01) were noted in patients treated by orthopaedic surgeons. For bimalleolar or trimalleolar fractures, treatment by an orthopaedic surgeon was associated with lower DVT (p<0.03) and malunion (p<0.04) rates. No differences were observed in rates of infection or need for irrigation and debridement based on surgeon type (Table 1). Patients treated by orthopaedic surgeons versus podiatrists were also noted to have a similar median CCI at 2.0 and 2.5, respectively.

Conclusion:

Operative treatment of ankle fractures by orthopaedic surgeons is associated with lower rates of certain postoperative complications compared with podiatrists. Malunion, in particular, is a surgeon related variable that has a significant impact on functional outcome in unstable ankle fracture patients. The specific reasons for the difference in malunion rates is likely multifactorial, and unable to be answered using this dataset, but warrants further investigation. Our findings have important implications for patients who must choose a surgeon to manage their operative ankle fracture, as well as policy makers who determine scope of practice in orthopaedic surgeons and podiatrists alike.

Redefining the Economics of Geriatric Orthopedics

Introduction:

The heath care system in the United States is in the midst of a transition, in large part to help accommodate an older and more medically complex population. Central to the current evolution is the reassessment of value based on the cost utility of a particular procedure compared to alternatives. The existing contribution of geriatric orthopedics to the societal burden of disease is substantial, and literature focusing on the economic value of treating elderly populations with musculoskeletal injuries is growing.

Materials and Methods:

A literature review of peer-reviewed publications and abstracts related to the cost-effectiveness of treating geriatric patients with orthopedic injuries was carried out.

Results:

In our review, we demonstrate that while cost-utility studies generally demonstrate net society savings for most orthopedic procedures, geriatric populations often contribute to negative net society savings due to decreased working years and lower salaries while in the workforce. However, the incremental cost-effective ratio for operative intervention has been shown to be below the financial willingness to treat threshold for common procedures including joint replacement surgery of the knee (ICER US$8551), hip (ICER US$17 115), and shoulder (CE US$957) as well as for spinal procedures and repair of torn rotator cuffs (ICER US$12 024). We also discuss the current trends directed toward improving institutional value and highlight important complementary next steps to help overcome the growing demands of an older, more active society.

Conclusion:

The geriatric population places a significant burden on the health care system. However, studies have shown that treating this demographic for orthopedic-related injuries is cost effective and profitable for providers under certain scenarios.

Biochemical and Cellular Assessment of Acetabular Chondral Flaps Identified During Hip Arthroscopy

PURPOSE

To analyze chondral flaps debrided during hip arthroscopy to determine their biochemical and cellular composition.

METHODS

Thirty-one full-thickness acetabular chondral flaps were collected during hip arthroscopy. Biochemical analysis was undertaken in 21 flaps from 20 patients, and cellular viability was determined in 10 flaps from 10 patients. Biochemical analysis included concentrations of (1) DNA (an indicator of chondrocyte content), (2) hydroxyproline (an indicator of collagen content), and (3) glycosaminoglycan (an indicator of chondrocyte biosynthesis). Higher values for these parameters indicated more healthy tissue. The flaps were examined to determine the percentage of viable chondrocytes.

RESULTS

The percentage of acetabular chondral flap specimens that had concentrations within 1 SD of the mean values reported in previous normal cartilage studies was 38% for DNA, 0% for glycosaminoglycan, and 43% for hydroxyproline. The average cellular viability of our acetabular chondral flap specimens was 39% (SD, 14%). Only 2 of the 10 specimens had more than half the cells still viable. There was no correlation between (1) the gross examination of the joint or knowledge of the patient's demographic characteristics and symptoms and (2) biochemical properties and cell viability of the flap, with one exception: a degenerative appearance of the surrounding cartilage correlated with a higher hydroxyproline concentration.

CONCLUSIONS

Although full-thickness acetabular chondral flaps can appear normal grossly, the biochemical properties and percentage of live chondrocytes in full-thickness chondral flaps encountered in hip arthroscopy show that this tissue is not normal.

CLINICAL RELEVANCE

There has been recent interest in repairing chondral flaps encountered during hip arthroscopy. These data suggest that acetabular chondral flaps are not biochemically and cellularly normal. Although these flaps may still be valuable mechanically and/or as a scaffold in some conductive or inductive capacity, further study is required to assess the clinical benefit of repair.

Acute pediatric leg compartment syndrome in chronic myeloid leukemia

Acute compartment syndrome is an orthopedic surgical emergency and may result in devastating complications in the setting of delayed or missed diagnosis. Compartment syndrome has a variety of causes, including posttraumatic or postoperative swelling, external compression, burns, bleeding disorders, and ischemia-reperfusion injury. Rare cases of pediatric acute compartment syndrome in the setting of acute myeloid leukemia and, even less commonly, chronic myeloid leukemia have been reported. The authors report the first known case of pediatric acute compartment syndrome in a patient without a previously known diagnosis of chronic myeloid leukemia. On initial examination, an 11-year-old boy presented with a 2-week history of progressive left calf pain and swelling after playing soccer. Magnetic resonance imaging scan showed a hematoma in the left superficial posterior compartment. The patient had unrelenting pain, intermittent lateral foot parethesias, and inability to bear weight. Subsequently, he was diagnosed with acute compartment syndrome and underwent fasciotomy and evacuation of a hematoma. Laboratory results showed an abnormal white blood cell count of 440×10(9)/L (normal, 4.4-11×10(9)) and international normalized ratio of 1.3 (normal, 0.8-1.2). Further testing included the BCR-ABL1 fusion gene located on the Philadelphia chromosome, leading to a diagnosis of chronic myeloid leukemia. Monotherapy with imatinib mesylate (Gleevec) was initiated. This report adds another unique case to the growing literature on compartment syndrome in the pediatric population and reinforces the need to consider compartment syndrome, even in unlikely clinical scenarios.

Readability of patient education materials on the American Orthopaedic Society for Sports Medicine website

BACKGROUND

The recommended readability of patient education materials by the American Medical Association (AMA) and National Institutes of Health (NIH) should be no greater than a sixth-grade reading level. However, online resources may be too complex for some patients to understand, and poor health literacy predicts inferior health-related quality of life outcomes.

AIM

This study evaluated whether the American Orthopaedic Society for Sports Medicine (AOSSM) website's patient education materials meet recommended readability guidelines for medical information. We hypothesized that the readability of these online materials would have a Flesch-Kincaid formula grade above the sixth grade.

METHODS

All 65 patient education entries of the AOSSM website were analyzed for grade level readability using the Flesch-Kincaid formula, a widely used and validated tool to evaluate the text reading level.

RESULTS

The average (standard deviation) readability of all 65 articles was grade level 10.03 (1.44); 64 articles had a readability score above the sixth-grade level, which is the maximum level recommended by the AMA and NIH. Mean readability of the articles exceeded this level by 4.03 grade levels (95% CI, 3.7-4.4; P < 0.0001). We found post-hoc that only 7 articles had a readability score ≤ an eighth-grade level, the average reading level of US adults. Mean readability of the articles exceeded this level by 2.03 grade levels (95% CI, 1.7-2.4; P < 0.0001).

CONCLUSION

The readability of online AOSSM patient education materials exceeds the readability level recommended by the AMA and NIH, and is above the average reading level of the majority of US adults. This online information may be of limited utility to most patients due to a lack of comprehension. Our study provides a clear example of the need to improve the readability of specific education material in order to maximize the efficacy of multimedia sources.

Treatment of diaphyseal forearm fractures in children

Both bone forearm fractures are common orthopedic injuries. Optimal treatment is dictated not only by fracture characteristics but also patient age. In the pediatric population, acceptable alignment can tolerate greater fracture displacement due to the bone’s ability to remodel with remaining growth. Generally, these fractures can be successfully managed with closed reduction and casting, however operative fixation may also be required. The optimal method of fixation has not been clearly established. Currently, the most common operative interventions are open reduction with plate fixation versus closed or open reduction with intramedullary fixation. Plating has advantages of being more familiar to many surgeons, being theoretically superior in the ability to restore radial bow, and providing the possibility of hardware retention. Recently, intramedullary nailing has been gaining popularity due to decreased soft tissue dissection; however, a second operation is needed for hardware removal generally 6 months after the index procedure. Current literature has not established the superiority of one surgical method over the other. The goal of this manuscript is to review the current literature on the treatment of pediatric forearm fractures and provide clinical recommendations for optimal treatment, focusing specifically on children ages 3-10 years old.

Forearm diaphyseal fractures in the adolescent population: treatment and management

BACKGROUND

Pediatric both-bone diaphyseal forearm fractures are commonly treated in a variety of clinical settings. Most often, closed reduction followed by immobilization leads to satisfactory results. However, in the adolescent population (10-16 years of age), forearm fractures are more challenging due to less remodeling potential. The purpose of this review was to provide an overview of the anatomy, biomechanics, and treatment options relevant to adolescent patients.

METHODS

A systematic review of peer-reviewed publications and abstracts related to the treatment for pediatric both-bone diaphyseal forearm fractures in adolescents was carried out.

RESULTS

Forearm fractures in the pediatric population are most common following indirect blows to the forearm. When treating these fractures using closed reduction, it is important to recognize the muscular attachments of the forearm. In roughly 70-90% of cases, closed reduction leads to adequate alignment. In all cases, return to function is the primary goal; however, exact alignment parameters remain controversial. In the adolescent population, surgical treatment has risen substantially in the last few decades. Intramedullary nailing and open reduction using plate fixation are the two most common operative techniques. Unfortunately, recent results have shown that nonunion, malunion, and overall complication rates are higher in older pediatric patients. Moreover, no consensus exists regarding one technique over another.

CONCLUSIONS

Both-bone diaphyseal fractures in the adolescent population present unique challenges regarding optimal treatment, especially when considering surgical intervention. Further research is necessary to better understand indications for specific surgical treatment.

Musculoskeletal education: an assessment of the clinical confidence of medical students

Musculoskeletal (MSK) conditions account for nearly 15-30 % of encounters in a primary care practice. Yet, studies demonstrate that medical students and residents lack the knowledge and confidence to care for many MSK conditions. This study addresses the design of focused MSK educational practices towards improving students' knowledge, interest, and confidence for conducting MSK examinations. Students attending a voluntary educational symposium on sports medicine were recruited to participate. The symposium was directed toward teaching elements of the MSK exam. Participants completed validated pre- and post-workshop surveys that assessed confidence in performing MSK examinations as well as satisfaction and perceived importance of MSK education. Additionally, mean survey responses from a convenience group of students who did not participate in the symposium were compared against the intervention group. Thirteen students participated in the educational symposium. Hundred and nine students completed the general survey. In the non-intervention group, students demonstrated knowledge and confidence improvements through the second year of medical school but did not show similar improvement in subsequent years. No difference in MSK confidence scores between fourth-year students going into high versus low MSK focused specialities was observed. In the intervention group students demonstrated improvements in confidence with respect to the knee, shoulder and ankle exams (p < 0.01). Areas not covered such as concussions and neuromuscular impairments failed to show significant change. Current core clinical training, at least at our school, does not achieve satisfactory levels of knowledge and confidence with respect to caring for MSK conditions. However, a focused didactic and skill development intervention does produce significant improvements. Follow-up is needed to determine whether these improvements are sustained.

Thermal stability of high concentration lysozyme across varying pH: A Fourier Transform Infrared study

AIM:

The current work is aimed at understanding the effect of pH on the thermal stability of hen egg white lysozyme (HEWL) at high concentration (200 mg/mL).

MATERIALS AND METHODS:

Fourier Transform Infrared (FTIR) Spectroscopy with modified hardware and software to overcome some of the traditional challenges like water subtraction, sample evaporation, proper purging etc., are used in this study.

RESULTS:

HEWL was subjected to thermal stress at pH 3.0-7.0 between 25°C and 95°C and monitored by FTIR spectroscopy. Calculated T_m values showed that the enzyme exhibited maximum thermal stability at pH 5.0. Second derivative plots constructed in the amide I region suggested that at pH 5.0 the enzyme possessed higher amount of α-helix and lower amount of aggregates, when compared to other pHs.

CONCLUSIONS:

Considering the fact that HEWL has attractive applications in various industries and being processed under different experimental conditions including high temperatures, our work is able to reveal the reason behind the pH dependent thermal stability of HEWL at high concentration, when subjected to heat denaturation. In future, studies should aim at using various excipients that may help to increase the stability and activity of the enzyme at this high concentration.

Panurethral stricture after photovaporization of the prostate for benign prostatic hyperplasia

PURPOSE

To report the development of panurethral stricture disease and other lower urinary tract abnormalities as a complication of photovaporization of the prostate (PVP).

PATIENTS AND METHODS

We evaluated three patients who were referred for the treatment of urethral stricture disease after PVP. Evaluation included antegrade cystoscopy, urethroscopy, retrograde urethrography, and cystourethrography.

RESULTS

All three patients had panurethral stricture disease, and a low capacity bladder with bilateral vesicoureteral reflux had developed in one patient as a complication of PVP.

CONCLUSIONS

Although not previously reported, a potential complication of PVP is devastating panurethral stricture disease.

Thermal unfolding curves of high concentration bovine IgG measured by FTIR spectroscopy

The purpose of this research is to study the thermal unfolding of high concentration bovine Immunoglobulin G (IgG) under 26 different experimental conditions by Fourier Transform Infrared spectroscopy with improved purge conditions and software calculations. When bovine IgG (25-200 mg/mL) was thermally denatured between pH 4.0 and 8.0, it was observed that at 25 mg/mL concentration, the protein exhibited maximum thermal stability at pH 6.0 and 7.0 as evident from the apparent T(m) values. Increasing the concentration from 25 to 100 mg/mL at those pH values increased the thermal resistance of the protein by 2-3 °C. But, at 200 mg/mL, IgG showed a small decrease in its transition temperature. Presence of 100 mM Trehalose enhanced the T(m) values at all conditions and possibly prevented the complete loss of IgG as insoluble aggregates at higher temperatures. Second derivative plots were constructed to explain the conformational changes of IgG during thermal unfolding.