Venous thromboembolism prophylaxis in shoulder surgery: a break-even cost-effectiveness study.

BACKGROUND: Venous thromboembolism (VTE) is a serious complication following orthopedic shoulder surgery; however, research is limited involving the break-even cost-effectiveness of VTE prophylaxis. The purpose of this study was to determine whether the cost of aspirin and enoxaparin would break even for VTE prevention in patients following shoulder surgery. METHODS: A drug retail database was used to obtain the lowest price for a course of aspirin (81 mg) and enoxaparin (40 mg) to perform a break-even cost analysis. Our institutional purchasing records were then searched to estimate the cost of treating a symptomatic VTE. The TriNetX national database was queried to establish a rate of VTE after shoulder surgery. A break-even cost analysis was performed by determining the absolute risk reduction (ARR). This value was used to calculate the number of patients who are treated to prevent a single VTE while breaking even on cost. Sensitivity analyses were performed for drugs that did not break even at the database-derived VTE rates. RESULTS: Full medication courses of aspirin and enoxaparin were found to cost $1.18 and $125.37, respectively. The cost of treating a symptomatic VTE was determined to be $9407.00. Data from the TriNetX database showed rates of symptomatic VTE following shoulder arthroplasty, hemiarthroplasty, and arthroscopic rotator cuff repair of 1.60%, 1.50%, and 0.68%, respectively. Aspirin broke even on cost for all procedures if the initial rate decreased by an ARR of 0.01% (number needed to treat, 7972). Similarly, enoxaparin broke even for shoulder arthroplasty and hemiarthroplasty if the initial rate of VTE decreased by an ARR of 1.33% (number needed to treat, 75). Enoxaparin did not break even at the initial VTE rate for arthroscopic rotator cuff repair; however, sensitivity analysis found enoxaparin would break even if the drug could be obtained at a cost of ≤$60.00. Enoxaparin broke even if the cost of treating a symptomatic VTE was ≥$20,000.00. CONCLUSIONS: The cost of a 3-week course of twice-daily aspirin or once-daily enoxaparin breaks even for VTE prophylaxis following shoulder arthroplasty and hemiarthroplasty if these drugs reduce the VTE rate by a calculated ARR. Given the lower rate of VTE observed for patients undergoing arthroscopic rotator cuff repair, only the 3-week course of aspirin broke even under these conditions. Once-daily enoxaparin did not break even at current market rate. Further research is needed to help determine optimal VTE prophylaxis after shoulder surgery.

Establishment of a Neurodegenerative Charcot Mouse Model.

BACKGROUND: This study aimed to mimic the changes from Charcot neuropathic arthropathy in humans by examining the effects of exposing diet-induced obese (DIO) mice to neurotrauma through a regimented running protocol. METHODS: Forty-eight male wild-type C57BL/6J mice were obtained at age 6 weeks and separated into 2 groups for diet assignment. After a 1-week acclimation period, half of the mice consumed a high-fat diet (60% fat by kcal) ad libitum to facilitate neuropathic diet-induced obesity whereas the other half were control mice and consumed an age-matched standard low-fat control diet (10% fat by kcal). At age 12 weeks, half of the animals from each group were subjected to a high-intensity inclined treadmill running protocol, which has been previously demonstrated to induce neurotrauma. Sensory testing and radiographic analyses were periodically performed. Histopathologic analyses were performed post killing. RESULTS: DIO mice had significantly higher bodyweights, higher body fat percentages, and lower bone mineral density than wildtype control mice that were fed a normal diet throughout the experiment (P < .001 for each). DIO mice displayed significantly reduced sensory function in week 1 (P = .005) and this worsened over time, requiring 20.6% more force for paw withdrawal by week 10 (P < .001). DIO mice that ran demonstrated greater midfoot subluxation and tarsal instability over all time points compared with normal-diet mice that ran (P < .001). Histopathologic analyses revealed that DIO mice that ran demonstrated significant changes compared with controls that ran (P < .001 for each parameter). CONCLUSION: Changes akin to the earliest changes observed in or before joint destruction identified in diabetic Charcot neuropathic arthropathy in humans were observed. CLINICAL RELEVANCE: There is currently no standard of treatment for patients with Charcot neuropathic arthropathy. This study establishes a protocol for an animal model that can be used to study and compare interventions to treat this disease.

Cost-Effective Modeling of Thromboembolic Chemoprophylaxis for Total Ankle Arthroplasty.

BACKGROUND: Symptomatic venous thromboembolism (VTE) following total ankle arthroplasty (TAA) can cause substantial morbidity and mortality. To prevent this complication, surgeons often prescribe postoperative chemoprophylaxis. However, much controversy exists regarding the efficacy of chemoprophylaxis because of the limited studies exploring its use. Furthermore, even less is known about its cost-effectiveness. Therefore, this study sought to determine the cost-effectiveness of commonly prescribed chemoprophylactic agents using a break-even analysis economic model. METHODS: The literature was searched, and an online database was used to identify patients who developed a symptomatic VTE after undergoing TAA. Our institutional records were used to estimate the cost of treating a symptomatic VTE, and an online drug database was used to obtain the cost of commonly prescribed chemoprophylactic agents. A break-even analysis was then performed to determine the final break-even rate necessary to make a drug cost-effective. RESULTS: The low and high rates of symptomatic VTE were determined to be 0.46% and 9.8%. From 2011 to 2021, a total of 3455 patients underwent total ankle arthroplasty. Of these patients, 16 developed a postoperative symptomatic VTE (1.01%). Aspirin 81 mg was cost-effective if the initial symptomatic VTE rates decreased by an absolute risk reduction (ARR) of 0.0003% (NNT = 31 357). Aspirin 325 mg was also cost-effective if the initial rates decreased by an ARR 0.02% (NNT = 5807). Likewise, warfarin (5 mg) was cost-effective at all initial rates with an ARR of 0.02% (NNT = 4480). In contrast, enoxaparin (40 mg) and rivaroxaban (20 mg) were only cost-effective at higher initial symptomatic VTE rates with ARRs of 1.48% (NNT = 68) and 5.36% (NNT = 19). Additional analyses demonstrated that enoxaparin (40 mg) and rivaroxaban (20 mg) become cost-effective when costs of treating a symptomatic VTE are higher than our estimates. CONCLUSION: Chemoprophylaxis following TAA can be cost-effective. A tailored approach to VTE prophylaxis with cost-effectiveness in mind may be beneficial to the patient and health system.

Animal model detects early pathologic changes of Charcot neuropathic arthropathy.

Charcot neuropathic arthropathy is a degenerative, debilitating disease that affects the foot and ankle in patients with diabetes and peripheral neuropathy, often resulting in destruction, amputation. Proposed etiologies include neurotraumatic, inflammatory, and neurovascular. There has been no previous animal model for Charcot. This study proposes a novel rodent model of induced neuropathic arthropathy to understand the earliest progressive pathologic changes of human Charcot. High-fat-diet-induced obese (DIO) Wild-type C57BL/6J mice (n = 8, diabetic) and age-matched low-fat-diet controls (n = 6) were run on an inclined high-intensity treadmill protocol four times per week for 7 weeks to induce mechanical neurotrauma to the hind-paw, creating Charcot neuropathic arthropathy. Sensory function and radiologic correlation were assessed; animals were sacrificed to evaluate hindpaw soft tissue and joint pathology. With this model, Charcot-DIO mice reveals early pathologic features of Charcot neuropathic arthropathy, a distinctive subchondral microfracture callus, perichondral/subchondral osseous hypertrophy/osteosclerosis, that precedes fragmentation/destruction observed in human surgical pathology specimens. There is intraneural vacuolar-myxoid change and arteriolosclerosis. The DIO mice demonstrated significant hot plate sensory neuropathy compared (P < 0.01), radiographic collapse of the longitudinal arch in DIO mice (P < 0.001), and diminished bone density in DIO, compared with normal controls. Despite exercise, high-fat-DIO mice increased body weight and percentage of body fat (P < 0.001). This murine model of diet-induced obesity and peripheral neuropathy, combined with repetitive mechanical trauma, simulates the earliest changes observed in human Charcot neuropathic arthropathy, of vasculopathic-neuropathic etiology. An understanding of early pathophysiology may assist early diagnosis and intervention and reduce patient morbidity and mortality in Charcot neuropathic arthropathy.

Biomechanical Effects of Δ9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD), the Major Constituents of Cannabis, in a Sprague Dawley Rat Achilles Tendon Surgical Repair Model: A Pilot Study.

BACKGROUND: The use of cannabis is common among athletes and the US population at large. Cannabinoids are currently being evaluated as alternatives to opioid medications for chronic pain management. However, the effects of recreational and/or medical use of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on musculoskeletal injury and healing remain largely unknown. HYPOTHESIS/PURPOSE: The purpose of this study was to evaluate the biomechanical effects of CBD and THC on tendon-to-tendon healing in a rat Achilles tendon repair model. The hypothesis was that rats administered CBD would demonstrate decreased tensile load to failure of surgically repaired Achilles tendons compared with the THC and control groups. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 33 Sprague Dawley rats underwent Achilles tendon surgical transection and repair and were randomized to receive subcutaneous injection of THC, CBD, or vehicle once daily starting on the day of surgery and for 5 total days. After sacrifice, biomechanical tensile load-displacement testing was performed to determine Achilles tendon load to failure and stiffness. Data were analyzed by 1-way analysis of variance. RESULTS: The THC group demonstrated the highest median load to failure, 18.7 N (95% CI, 15.3-19.2 N); the CBD group had the second highest at 16.9 N (95% CI, 15.1-19.8 N), and the control group had the lowest at 14.4 N (95% CI, 12.1-18.3 N). Stiffness was highest in the THC group at 4.1 N/mm (95% CI, 2.7-5.1 N/mm) compared with 3.6 N/mm (95% CI, 2.9-4.1 N/mm) for the CBD group and 3.6 N/mm (95% CI, 2.8-4.3 N/mm) for the control group. No statistically significant differences for strength and stiffness were observed between the groups. CONCLUSION: In this pilot study using an animal tendon-to-tendon repair model, neither THC nor CBD resulted in altered biomechanical characteristics compared to control. CLINICAL RELEVANCE: Cannabinoids do not appear to adversely affect Achilles tendon healing.

Increased Load to Failure in Biceps Tenodesis With All-Suture Suture Anchor Compared With Interference Screw: A Cadaveric Biomechanical Study.

PURPOSE: To compare the biomechanical characteristics of a single radially expanding all-suture anchor with an interference screw for open subpectoral long head of biceps tendon (LHBT) tenodesis. METHODS: Eighteen fresh-frozen matched-pair human cadaveric humeri were used for this biomechanical study. The matched pair humeri were randomly assigned into 2 experimental biceps tenodesis groups: conventional interference screw (CIS) or all-suture suture anchor (ASSA). Open subpectoral LHBT tenodesis was then performed and biomechanical testing was performed using a servohydraulic test frame. A preload of 5 N was applied for 2 minutes before cyclic loading. Displacement was recorded at cycle 300 (D300) and cycle 500 (D500) and at ultimate failure. Data recorded included displacement, load to failure, displacement at failure. Paired t test was used for analysis. RESULTS: Decreased displacement was observed for the CIS group at D300 (1.67 ± 0.57 mm vs 3.35 ± 2.24 mm; P = .04), D500 (2.00 ± 0.76 mm vs 3.87 ± 2.20 mm; P = .04), and at failure (5.17 ± 3.05 mm vs 10.76 ± 2.66 mm; P < .001). Load to failure was lower in CIS specimens (170 ± 24.5 N vs 217.8 ± 51.54 N; P = .02). Failure in each case was tendon pullout for all CIS specimens; in ASSA 6 specimens failed as the suture pulled through the tendon, 2 specimens failed by suture breakage. No difference in stiffness was observed between the 2 groups (CIS = 98.33 ± 22.98 N/m vs ASSA = 75.94 ± 44.83 N/m; P = .20). CONCLUSIONS: Our study found that open subpectoral biceps tenodesis performed with an ASSA construct results in increased load to failure as compared with CIS. However, the CIS did demonstrate decreased displacement as compared to ASSA in this cadaveric biomechanical study. CLINICAL RELEVANCE: ASSA and CIS at time zero provide fixation as indicated by the provider intraoperatively for LHBT tenodesis. ASSA, however, does remove less cortical bone than does CIS and therefore produces a smaller stress riser in the proximal humerus. Further testing as to the integrity of ASSA is warranted to determine the integrity of the tenodesis with cyclical loading.

Natural History of 321 Flatfoot Reconstructions in Adult Acquired Flatfoot Deformity Over a 14-Year Period.

The purpose of this study was to report the natural history, demographics, and mechanisms of requirement for additional surgery in patients undergoing flatfoot reconstruction for adult acquired flatfoot. A total of 321 consecutive patients undergoing flatfoot reconstruction over a 14-year period were included (2002-2016). All procedures were performed by a senior orthopaedic foot and ankle surgeon at our institution. Demographic data, operative reports, clinic notes, and radiographs were available for review. Statistical analysis included calculation of relative risk (RR) ratios. The majority of patients were female (83.2%,) and most patients were overweight with a body mass index greater than 25 kg/m2 (56.4%). Patient comorbidities included diabetes (13.7%) and rheumatoid arthritis (3.7%). Additional surgery was required for 54 patients (16.8%). The most common reasons for additional surgery were the following: painful calcaneal hardware (57.4%), conversion to triple arthrodesis (16.7%), and wound healing complications (9.1%). An increased risk of need for additional surgery was associated with female gender (RR = 3.4; P = .0005), smoking status (RR = 1.9; P = .0081), and age (<60 years of age; RR = 1.8; P = .042). Although retrospective, the results provide insight into the natural history of this procedure. Clinicians may use these data to appropriately counsel patients who are at increased risk of requirement for additional surgery, such as smokers, women, and patients <60 years old, regarding treatment options.Levels of Evidence: Level IV.

Efficacy of local infiltration anesthesia versus interscalene nerve blockade for total shoulder arthroplasty.

BACKGROUND: Optimal modalities for pain control in shoulder arthroplasty are not yet established. Although regional nerve blockade has been a well-accepted modality, complications and rebound pain have led some surgeons to seek other pain control modalities. Local injection of anesthetics has recently gained popularity in joint arthroplasty. The purpose of this study was to evaluate the effectiveness and complication rate of a low-cost local anesthetic injection mixture for use in total shoulder arthroplasty (TSA) compared with interscalene brachial plexus blockade. METHODS: A total of 314 patients underwent TSA and were administered general anesthesia with either a local injection mixture (local infiltration anesthesia [LIA], n = 161) or peripheral nerve block (PNB, n = 144). Patient charts were retrospectively reviewed for postoperative pain scores, 24-hour opioid consumption, and 90-day postoperative complications. RESULTS: Immediate postoperative pain scores were not significantly different between groups (P = .94). The LIA group demonstrated a trend toward lower pain scores at 24 hours postoperatively (P = .10). Opioid consumption during the first 24 hours following surgery was significantly reduced in the LIA group compared with the PNB group (P < .0001). There was a trend toward fewer postoperative nerve and cardiopulmonary complications in the LIA group than the PNB group (P = .22 and P = .40, respectively). CONCLUSION: Periarticular local injection mixtures provide comparable pain control to regional nerve blocks while reducing opioid use and postoperative complications following TSA. Local injection of a multimodal anesthetic solution is a viable option for pain management in TSA.

Outcomes of NCAA Defensive Football Players Following Achilles Tendon Repair.

BACKGROUND: The incidence of Achilles ruptures has been on the rise in National Collegiate Athletic Association (NCAA) football players, but the career impact of this injury is not fully understood. In this study, we analyzed a large series of Achilles tendon injuries in NCAA Football Bowl Subdivision (FBS) defensive football players who required repair in order to determine their return to play, performance, and career outcomes afterward. METHODS: FBS defensive football players who required Achilles repair from 2010 to 2016 were identified. The return to play of the eligible underclassmen athletes was then determined and the preinjury and postoperative performances of players who met criteria were compared with matched controls. The number of underclassmen who went on to participate in the National Football League (NFL) Combine or play in at least 1 NFL game was also determined and compared with controls. RESULTS: Fifty-seven total Achilles ruptures were identified, 40 of which occurred in underclassmen, who returned at a rate of 92.5%. Of the players who met performance criteria, only defensive backs differed from matched controls in terms of solo tackling (P = .025) and total tackling (P = .038), while still increasing compared with preoperative performance. Only 5.0% of underclassmen performed at NFL Combine and only 7.5% competed in at least 1 NFL game (20.0% and 21.3%, respectively, for matched controls). CONCLUSION: Defensive FBS players returned at a high rate following Achilles rupture and did not seem to experience a significant drop-off in performance upon return. An Achilles rupture did appear to impact their chances of playing professionally in the future, however. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Three-Dimensional Morphometric Modeling Measurements of the Calcaneus in Adults with Stage IIB Posterior Tibial Tendon Dysfunction: A Pilot Study.

Background: The pathophysiology of adult-acquired flatfoot deformity (AAFD) is not fully explained by degeneration of the posterior tibial tendon alone. While a shortened or dysplastic lateral column has been implicated in flatfoot deformity in pediatrics, there is no study that has quantified the degree of dysplasia in adults with a stage IIb flatfoot deformity, or if any exists at all. Methods: An institutional radiology database was queried for patients with posterior tibial tendon dysfunction (PTTD) who had computed tomography (CT) performed. Controls were patients receiving CT scan for an intra-articular distal tibia fracture without preexisting foot or calcaneal pathology. Clinical notes, physical examination, and weightbearing radiographs were used to find patients that met clinical criteria for stage IIb PTTD. Morphometric measurements of the calcanei were performed involving the length of the calcaneal axis (LCA), height of the anterior process (HAP), and length of the anterior process (LAP). All measurements were performed independently by separate observers, with observers blinded to group assignment. We considered a difference of ±4 mm as our threshold. Results: 7 patients and 7 controls were available for reconstruction and analysis. On average, the LCA was 3.1 mm shorter in patients with stage IIb PTTD compared with controls (P < .05). The LAP was shorter in PTTD patients compared with controls 3.4 mm (P < .001). Conclusions: Our results support the hypothesis that the calcaneus of adult patients with stage IIb AAFD is dysplastic when compared with healthy controls, which further supports the utility of lateral column lengthening. Levels of Evidence: Level III: Case-control study.

Ascites Module for Third-Year Medical Students: Group-Based Learning Workshop on the Diagnosis, Workup, and Management of Ascites.

INTRODUCTION: As medical students transition from didactic courses to clinical rotations, they will frequently encounter patients with cirrhosis and ascites. It is paramount that they have a firm foundation of how to diagnose ascites and perform a proper diagnostic workup in order to understand the etiology and therefore the proper management. This module is designed as a group-based, interactive learning workshop for those transitioning students. METHODS: The session begins with the students obtaining a pertinent history of a standardized patient case. The students are then divided into four groups and rotate through four stations: physical examination, diagnostic studies, paracentesis, and ascitic fluid analysis. Each station is designed for up to 10-12 students and typically lasts 20 minutes. After all of the students have rotated through each station, they reconvene to review ascites management, case conclusions, and summary. The total time allocated for this module is 125 minutes for 40-48 students. RESULTS: Postmodule evaluations by the students showed a high level of satisfaction and improvement in the students' fund of knowledge and clinical skills. Evaluations completed by the students after each workshop revealed more than 95% either agreeing or strongly agreeing with the learning objectives being clear, the learning materials being effective, overall satisfaction with the learning material and teaching, and having a better understanding of the evaluation, diagnosis, and management of ascites. DISCUSSION: Through this team-based interactive module, students obtain clinical and hands-on experience that better prepares them for their clinical rotations.