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.

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.

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.