The US healthcare system is currently facing daunting demographic and economic challenges. Because musculoskeletal disorders and disease represent a substantial and growing portion of this healthcare burden, novel approaches will be needed to continue to provide high-quality, affordable, and accessible orthopaedic care to our population. The concept of “disruptive innovations,” which has been studied and popularized by Harvard Business School Professor Clayton Christensen, may offer a potential framework for developing strategies to improve quality and control costs associated with musculoskeletal care. The introduction of mobile fluoroscopic imaging systems, the development of the Surgical Implant Generation Network intramedullary nail for treatment of long bone fractures in the developing world, the expanding role and contributions of physician assistants and nurse practitioners to the orthopaedic team, and the rise of ambulatory surgery centers are all examples of disruptive innovations in the field of orthopaedics. Although numerous cultural and regulatory barriers have limited the widespread adoption of these “disruptive innovations,” we believe they represent an opportunity for clinicians to regain leadership in health care while at the same time improving quality and access to care for patients with musculoskeletal disease.

As the burden of deep hardware infections continues to rise in orthopaedics, there is increasing interest in strategies for more effective debridement of colonized tissues and biofilm. Hydrogen peroxide has been used medically for almost a century, but its applications in orthopaedic surgery have yet to be fully determined. The basic science and clinical research on the antiseptic efficacy of hydrogen peroxide have demonstrated its efficacy against bacteria, and it has demonstrated potential synergy with other irrigation solutions such as chlorhexidine and povidone-iodine. While hydrogen peroxide is effective in infection reduction, there are concerns with wound healing, cytotoxicity, and embolic phenomena, and we recommend against hydrogen peroxide usage in the treatment of partial knee replacements, hemiarthroplasties, or native joints. Additionally, due to the potential for oxygen gas formation, hydrogen peroxide should not be used in cases of dural compromise, when pressurizing medullary canals, or when irrigating smaller closed spaces to avoid the possibility of air embolism. Finally, we present our protocol for irrigation and debridement and exchange of modular components in total joint arthroplasty, incorporating hydrogen peroxide in combination with povidone-iodine and chlorhexidine.

Background

Classical models of the knee assume the joint line is parallel to the floor and the tibial mechanical axis (TMA) is orthogonal to the floor. Our study characterizes the angle subtended by the TMA and floor during bipedal stance, called the tibial axis orientation angle (TAOA), and tests the assumption that the TMA should be orthogonal to the floor.

Methods

We reviewed the nonoperative knee on full-length, standing radiographs in patients undergoing total knee arthroplasty between 2013 and 2017. Radiographic measurements were obtained for hip-knee-ankle axis, medial proximal tibial angle (MPTA), joint line orientation angle, and TAOA and correlated by regression analysis. The cohort was stratified by hip-knee-ankle axis alignment to determine statistical differences in knee angle values. Demographic data were collected to assess associations with knee angles.

Results

Our cohort included 68 patients, with 56% female and average age of 62.3 years. Varus knees comprised 56% of the cohort, with 7% neutral and 37% valgus. The cohort demonstrated an MPTA of 3.06°, TAOA of 2.67°, and joint line orientation angle of 0.36°. Varus knees had a higher MPTA (4.26°) and TAOA (4.74°) than valgus knees (P < .001). MPTA and TAOA were correlated on regression analysis (r² = 0.465), and all angles were statistically different between sexes.

Conclusion

The angle between the TMA and floor, called TAOA, is not orthogonal in normal knees, contrary to assumptions in classical biomechanics. Knee angles vary significantly between varus and valgus cohorts, and the distinction between these cohorts should be noted when evaluating normal joint line angles.

UNLABELLED: Orthopaedic surgeons are increasingly aware of deleterious effects of the opioid epidemic and the association between overprescription and diversion toward nonmedical opioid use or substance abuse. Opiate prescriptions at the time of hospital discharge have been identified as target for intervention. This study describes the successful outcome of a goal-directed intervention aimed at decreasing opioid overprescription by providing routine feedback to providers regarding their prescribing patterns. METHODS: The amount of opioid medications, quantified as oral morphine equivalents (OMEs), provided to opioid-naive adult patients on discharge after orthopaedic surgery was prospectively collected. As part of an institutional quality improvement initiative, medical providers received reports every 2 months detailing median discharge OMEs prescribed, trended over time. After 6 months, a retrospective comparison was done between preintervention and intervention patient cohorts. RESULTS: There were 401 patients in the preintervention cohort and 429 patients in the intervention cohort. Both groups were similar in regard to age, sex, rates of depression, surgical time, length of stay, orthopaedic subspecialty, and inpatient opioid requirement before discharge. Patients in the intervention cohort were prescribed markedly fewer opioid medications by 25%, equivalent to 20 tablets of 5-mg oxycodone IR (450 versus 600 OMEs, P < 0.001). Despite these opioid medications, opioid refill rates during the first 90 days after discharge did not markedly change between groups. DISCUSSION: It is critical to judiciously treat postoperative pain while avoiding opioid overprescription. This study demonstrated the outcome of a goal-directed initiative to decrease overprescription of opioid medications. The initiative reduced discharge opioid prescriptions yet did not increase the risk of requiring a prescription refill in the postoperative period. This indicates that such an approach can result in opioid reduction, while still providing appropriate care and pain control for patients.

Background

Acute hip fractures carry a high risk of morbidity and are associated with low vitamin D levels. Improvements in screening and treating low vitamin D levels may lead to lower fall rates and a lower likelihood of additional fragility fractures. However, patients with low vitamin D levels often remain unassessed and untreated, even after they experience these fractures.

Questions/purposes

We wished to determine whether a resident-led initiative can improve (1) screening for and (2) treatment of vitamin D deficiency in patients with acute hip fractures.

Methods

Our department initiated a housestaff-led, quality improvement project focused on screening and treating vitamin D deficiency in patients with acute hip fractures. Screening encompassed checking serum 25-hydroxyvitamin D level during the acute hospitalization, and treating was defined as starting supplementation before discharge when the serum 25-hydroxyvitamin D level was less than 30 ng/mL. To evaluate the efficacy of this program, an administrative database identified 283 patients treated surgically for an acute hip fracture between July 2010 and June 2014. This period included 2 years before program initiation (Year 1, n = 65 patients; Year 2, n = 61 patients), the initial program year (Year 3, n = 66 patients), and the subsequent program year (Year 4, n = 91 patients). Followup was extended to 6 weeks after treatment with 9.2% (26/282) of patients lost to followup. Eight patients were excluded owing to documented intolerance of vitamin D supplementation. There were no differences regarding patient demographics, fracture type, or treatment rendered across these 4 years. The primary endpoints were the proportion of patients screened and treated for vitamin D deficiency. The secondary endpoint was the continuation of vitamin D supplementation at the patient's 6 week followup, according to the patient's medication list at that visit. This analysis included all patients, assuming those lost to followup had not continued supplementation. ANOVA and chi-square tests were used to evaluate the differences in demographic data and in screening and treating rates.

Results

Screening for vitamin D deficiency improved after initiation of the resident-led quality improvement program, with screening performed for 31% of patients in Year 1 (20/65; odds ratio [OR], 0.44; 95% CI, 0.26-0.75), 20% of patients in Year 2 (12/61; OR, 0.24; 95% CI, 0.13-0.46), 46% of patients in Year 3 (30/66; OR, 0.83; 95% CI, 0.51-1.35), and 88% of patients in Year 4 (80/91; OR, 7.27; 95% CI, 3.87-13.7) (p < 0.001). Vitamin D supplementation was initiated for 33% of patients in Year 1 (21/63; OR, 0.5; 95% CI, 0.30-0.84), 28% in Year 2 (17/61; OR, 0.39; 95% CI, 0.22-0.68), 50% in Year 3 (32/64; OR,1.00; 95% CI, 0.61-1.63), and 76% in Year 4 (65/86; OR, 3.10; 95% CI, 1.89-5.06) (p < 0.001). At early postoperative followup, we saw substantial improvement in the proportion of patients who continued receiving vitamin D supplementation: Year 1, 12% (8/64; OR, 0.14; 95% CI, 0.07-0.30); Year 2, 15% (9/61; OR, 0.17; 95% CI, 0.09-0.35); Year 3, 26% (16/64; OR, 0.33; 95% CI, 0.19-0.59); and Year 4, 46% (40/86; OR, 0.87; 95% CI, 0.57-1.33) (p < 0.001).

Conclusions

Implementation of a resident-led quality improvement program resulted in higher rates of screening and treating vitamin D deficiency for patients with acute hip fractures. Housestaff-based initiatives may be an effective way to improve care processes that target improvements in bone health.

INTRODUCTION: In two-stage exchange for periprosthetic joint infection (PJI), adding antibiotics to cement spacers is the standard of care; however, little is known about optimal dosage. There is emphasis on using >3.6 g of total antibiotic, including ≥2.0 g of vancomycin, per 40 g of cement, but these recommendations lack clinical evidence. We examined whether recommended antibiotic spacer doses affect treatment success. METHODS: This was a retrospective review of 202 patients who underwent two-stage exchange for PJI from 2004 to 2020 with at least 1-year follow-up. Patients were separated into high (>3.6 g of total antibiotic per 40 g of cement) and low-dose spacer groups. Primary outcomes were overall and infectious failure. RESULTS: High-dose spacers were used in 80% (162/202) of patients. High-dose spacers had a reduced risk of overall (OR, 0.37; P = 0.024) and infectious (OR, 0.35; P = 0.020) failure for infected primary arthroplasties, but not revisions. In multivariate analysis, vancomycin dose ≥2.0 g decreased the risk of infectious failure (OR, 0.31; P = 0.016), although not overall failure (OR, 0.51; P = 0.147). CONCLUSION: During two-stage exchange for PJI, spacers with greater than 3.6 g of total antibiotic may reduce overall and infectious failure for infected primary arthroplasties. Furthermore, using at least 2.0 g of vancomycin could independently decrease the risk of infectious failure.

INTRODUCTION: There is no consensus on whether articulating or static spacers are superior during two-stage exchange arthroplasty for periprosthetic joint infection. We aimed to compare surgical time, need for extensile exposure, surgical costs, and treatment success for articulating and static spacers. METHODS: This was a retrospective review of 229 periprosthetic joint infections treated with two-stage exchange with a minimum of one-year follow-up. For articulating and static spacers, we compared the need for extensile exposure during reimplantation and treatment failure based on an updated definition. Surgical time and costs at both stages were also compared. Subgroup analysis was performed for total knee and hip arthroplasties. RESULTS: There was no difference in the surgical time for spacer insertion; however, articulating spacers demonstrated reduced surgical time during reimplantation (181 vs. 234 minutes, P < 0.001). In multivariate analysis, there was no difference in extensile exposures (odds ratio 2.20, P = 0.081), but treatment failure was more likely for static spacers (odds ratio 2.17, P = 0.009). Overall surgical costs for two-stage exchange were similar between groups (23,782 vs. 23,766, P = 0.495). CONCLUSION: Articulating spacers demonstrated shorter surgical times and a trend toward decreased extensile exposures during reimplantation. They also had higher treatment success rates and similar surgical costs for overall two-stage exchange.

Background

Complex revision total knee arthroplasty (TKA) often calls for endoprosthetic reconstruction to address bone loss, poor bone quality, and soft tissue insufficiency. Larger amounts of segmental bone loss in the setting of joint replacement may be associated with greater areas of devascularized tissue, which could increase the risk of complications and worsen functional results.

Questions/purposes

Are longer endoprosthetic reconstructions associated with (1) higher risk of deep infection; (2) increased risk of reoperation and decreased implant survivorship; or (3) poorer ambulatory status?

Methods

This is a single-institution retrospective case series of nononcologic femoral endoprosthetic reconstructions for revision TKA from 1995 to 2013 (n = 32). Cases were categorized as distal (n = 17) or diaphyseal (n = 15) femoral reconstructions based on extension to or above the supracondylar metaphyseal-diaphyseal junction, respectively. Five patients from each group were lost to followup before 2 years (distal mean 4 years [range, 2-8 years]; diaphyseal mean = 6 years [range, 2-16 years]), and one of the 12 distal reconstructions and two of the 10 diaphyseal reconstructions had not been evaluated within the past 5 years. Clinical outcomes and ambulatory status (able to walk or not) were assessed through chart review by authors not involved in any cases. Prior incidence of periprosthetic joint infection was high in both groups (distal = seven of 12 versus diaphyseal = four of 10; p = 0.670).

Results

Patients with diaphyseal femoral replacements were more likely to develop postoperative deep infections than patients with distal femoral replacements (distal = three of 12 versus diaphyseal = nine of 10; p = 0.004). Implant survivorship (revision-free) for diaphyseal reconstructions was worse at 2 years (distal = 100%, 95% confidence interval [CI], 100%-100% versus diaphyseal = 40%, 95% CI, 19%-86%; p = 0.001) and 5 years (distal = 90%, 95% CI, 75%-100% versus diaphyseal = 30%, 95% CI, 12%-73%; p = 0.001). Infection-free, revision-free survival (retention AND no infection) was worse for diaphyseal femoral replacing reconstructions than for distal femoral replacements at 2 years (distal = 70%, 95% CI, 48%-100% versus diaphyseal = 20%, 95% CI, 6%-69%; p = 0.037) and 5 years (distal = 70%, 95% CI, 48%-100% versus diaphyseal = 10%, 95% CI, 2%-64%; p = 0.012). There was no difference with the small numbers available in proportion of patients able to walk (distal reconstruction = eight of 11 versus diaphyseal = seven of 10; p = 1.000), although all but one patient in each group required walking aids.

Conclusions

Endoprosthetic femoral reconstruction is a viable salvage alternative to amputation for treatment of failed TKA with segmental distal femoral bone loss. In our small series even with substantial loss to followup and likely best-case estimates of success, extension proximal to the supracondylar metaphyseal-diaphyseal junction results in higher infection and revision risk. In infection, limb salvage remains possible with chronic antibiotic suppression, which we now use routinely for all femoral replacement extending into the diaphysis.

Level of evidence

Level III, therapeutic study.

Background

Prior studies have demonstrated that depression is an independent risk factor for developing a prosthetic joint infection (PJI) after total joint arthroplasty (TJA). To our knowledge, there is no literature examining whether PJI or aseptic failure increases the risk of developing a new mental health diagnosis.

Methods

PearlDiver Patient Database (Colorado Springs, CO) was used to identify 80,826 patients who underwent TJA without a pre-existing diagnosis of depression, anxiety, a stress and/or adjustment disorder, and/or current use of a selective serotonin reuptake inhibitor within the year prior to surgery. The odds of developing a new mental health issue or being prescribed a selective serotonin reuptake inhibitor within 1 year of an uncomplicated TJA was compared to those who developed PJI or mechanical failure within 90 days after TJA as well as to those who subsequently underwent revision surgery within 30 days of either complication using Fisher's exact test and Baptista-Pike.

Results

A total of 6474 (8%) patients were diagnosed with a new mental health issue after TJA. PJI or mechanical failure led to significantly higher odds of new diagnoses with an odds ratio of 1.67 (95% confidence interval = 1.26, 2.22) and 1.57 (1.24, 2.00), respectively. Undergoing revision surgery for PJI or mechanical failure increased the odds of developing a new mental health diagnosis to 2.10 (1.29, 3.42) and 2.24 (1.36, 3.72), respectively. There was no significant difference comparing those who developed PJI vs those who sustained mechanical complications.

Conclusion

Patients who sustain complications after TJA are at increased odds of receiving a new mental health diagnosis, an effect further amplified if revision surgery is required.

How pathogenic cluster of differentiation 4 (CD4) T cells in rheumatoid arthritis (RA) develop remains poorly understood. We used Nur77-a marker of T cell antigen receptor (TCR) signaling-to identify antigen-activated CD4 T cells in the SKG mouse model of autoimmune arthritis and in patients with RA. Using a fluorescent reporter of Nur77 expression in SKG mice, we found that higher levels of Nur77-eGFP in SKG CD4 T cells marked their autoreactivity, arthritogenic potential, and ability to more readily differentiate into interleukin-17 (IL-17)-producing cells. The T cells with increased autoreactivity, nonetheless had diminished ex vivo inducible TCR signaling, perhaps reflective of adaptive inhibitory mechanisms induced by chronic autoantigen exposure in vivo. The enhanced autoreactivity was associated with up-regulation of IL-6 cytokine signaling machinery, which might be attributable, in part, to a reduced amount of expression of suppressor of cytokine signaling 3 (SOCS3)-a key negative regulator of IL-6 signaling. As a result, the more autoreactive GFP^hi CD4 T cells from SKGNur mice were hyperresponsive to IL-6 receptor signaling. Consistent with findings from SKGNur mice, SOCS3 expression was similarly down-regulated in RA synovium. This suggests that despite impaired TCR signaling, autoreactive T cells exposed to chronic antigen stimulation exhibit heightened sensitivity to IL-6, which contributes to the arthritogenicity in SKG mice, and perhaps in patients with RA.