Osteochondral Lesions of the Talus: Etiology, Clinical Presentation, Treatment Options, and Outcomes

This article reviews the etiology, clinical presentation, classification schemes, and treatment options for osteochondral lesions of the talus. These lesions typically occur after a traumatic injury and are best diagnosed on MRI. Asymptomatic lesions and incidentally found lesions are best treated conservatively; however, acute displaced osteochondral fragments may require surgical treatment. Lesion characteristics may dictate surgical technique. Outcomes following surgical treatment may be impacted by patient age, BMI, and lesion characteristics.

The Posterior Approach is Associated With Lower Total Encounter and 90-Day Costs When Compared to the Direct Anterior Approach

BACKGROUND

The clinical impact of the surgical approach in total hip arthroplasty (THA) has been widely reviewed. This study evaluated the total encounter and 90-day costs of THA for 2 surgical approaches (posterior [P] and direct anterior [DA]) in 1 tertiary health system.

METHODS

This is a retrospective review of 2,101 THAs (1,092 P and 1,009 DA) by 4 surgeons (2 with the highest volume of DA and P, respectively) from 2017 to 2022 at 1 academic center. Demographics, comorbidities, operative time, length of hospital stay, 90-day hospital returns, and complications were compared. The total encounter cost and 90-day postoperative cost were itemized. Multivariable regression analyses evaluated associations with increased cost at each time point.

RESULTS

The DA cohort had a higher median encounter cost ($8,348.66 versus 7,332.42, P < .01), resulting from higher intraoperative (P < .01) and radiology (P < .01) expenses. Regression analyses demonstrated the DA was independently associated with increased encounter costs (odds ratio 1.1; 95% confidence interval 1.1 to 1.1; P < .01). There was a higher incidence of 90-day emergency department visits in the DA cohort (16 versus 12%, P = .02), with a trend toward increased readmissions. There was no difference in 90-day reoperations. Median 90-day cost was higher in the DA cohort ($126.99 versus 0.00, P < .01), and regression analyses demonstrated the DA had an association with increased 90-day cost (odds ratio 2.2; 95% confidence interval 1.5 to 3.0; P < .01).

CONCLUSIONS

Despite a younger patient population, the DA was independently associated with increased encounter and 90-day costs in a single academic hospital system. This study may underestimate the cost difference, as capital costs such as specialized tables were not analyzed.

Outcomes After Pseudomonas Prosthetic Joint Infections

BACKGROUND

Pseudomonas species are a less common but devastating pathogen family in prosthetic joint infections (PJIs). Despite advancements in management, Pseudomonas PJIs remain particularly difficult to treat because of limited antibiotic options and robust biofilm formation. This study aimed to evaluate Pseudomonas PJI outcomes at a single institution and review outcomes reported in the current literature.

METHODS

All hip or knee PJIs at a single institution with positive Pseudomonas culture were evaluated. Forty-two patients (24 hips, 18 knees) meeting inclusion criteria were identified. The primary outcome of interest was infection clearance at 1 year after surgical treatment, defined as reassuring aspirate without ongoing antibiotic treatment. Monomicrobial and polymicrobial infections were analyzed separately. A focused literature review of infection clearance after Pseudomonas PJIs was performed.

RESULTS

One-year infection clearance was 58% (n = 11/19) for monomicrobial PJIs and 35% (n = 8/23) for polymicrobial PJIs. Among monomicrobial infections, the treatment success was 63% for patients treated with DAIR and 55% for patients treated with two-stage exchange. Monotherapy with an oral or intravenous antipseudomonal agent (minimum 6 weeks) displayed the lowest 1-year clearance of 50% (n = 6/12). Resistance to antipseudomonal agents was present in 16% (n = 3/19), and two of eight patients with monomicrobial and polymicrobial PJIs developed resistance to antipseudomonal therapy in a subsequent Pseudomonas PJI. Polymicrobial infections (55%) were more common with a mortality rate of 44% (n = 10/23) at a median follow-up of 3.6 years.

CONCLUSION

Pseudomonas infections often present as polymicrobial PJIs but are difficult to eradicate in either polymicrobial or monomicrobial setting. A review of the current literature on Pseudomonas PJI reveals favorable infection clearance rates (63 to 80%) after DAIR while infection clearance rates (33 to 83%) vary widely after two-stage revision.

Inertial Sensor Gait Analysis of Trendelenburg Gait in Patients Who Have Hip Osteoarthritis

BACKGROUND

Gait abnormalities such as Trendelenburg gait (TG) in patients who have hip osteoarthritis (OA) have traditionally been evaluated using clinicians' visual assessment. Recent advances in portable inertial gait sensors offer more sensitive, quantitative methods for gait assessment in clinical settings. This study sought to compare sensor-derived metrics in a cohort of hip OA patients when stratified by clinical TG severity.

METHODS

There were 42 patients who had hip OA and were grouped by TG severity (mild, moderate, and severe) through visual assessment by a single arthroplasty surgeon who had > 30 years of experience. After informed consent, wireless inertial sensors placed at the midpoint of the intercristal line collected gait parameters including pelvic shift, support time, toe-off symmetry, impact, and cadence. Clinical data on hip strength, range of motion, and Kellgren-Lawrence grade were collected.

RESULTS

Worsening TG severity had a higher mean Kellgren-Lawrence grade (2.5 versus 3.2 versus 3.4; P = .014) and reduced passive hip abduction (P = .004). Severe TG group demonstrated predominantly contralateral pelvic shift (n = 9 of 10, 90.0%), while ipsilateral shift was more frequently detected in moderate (n = 10 of 18, 55.6%) and mild groups (n = 9 of 14, 64.3%; P = .021). Contralateral single support time bias was greatest in severe TG (35.7% versus 50.0 versus 90.0%; P = .027). Asymmetric toe-off, impact, and support times were observed in all groups.

CONCLUSIONS

Traditional understanding of TG is that truncal shift occurs to the ipsilateral side. Using sensor-based measurements, the present study demonstrates a shift of the weight-bearing axis toward the contralateral side with increasing TG severity, which has not been previously described. Inertial sensors are feasible, quantitative gait measuring tools, and may reveal subtle patterns not readily discernible by traditional methods.

Younger Patients Undergoing Total Ankle Arthroplasty Experience Higher Complication Rates and Worse Functional Outcomes

BACKGROUND

Although many patients with posttraumatic ankle arthritis are of a younger age, studies evaluating the impact of age on outcomes of primary total ankle arthroplasty (TAA) have revealed heterogenous results. The purpose of the present study was to determine the effect of age on complication rates and patient-reported outcomes after TAA.

METHODS

We retrospectively reviewed the records of 1,115 patients who had undergone primary TAA. The patients were divided into 3 age cohorts: <55 years (n = 196), 55 to 70 years (n = 657), and >70 years (n = 262). Demographic characteristics, intraoperative variables, postoperative complications, and patient-reported outcome measures were compared among groups with use of univariable analyses. Competing-risk regression analysis with adjustment for patient and implant characteristics was performed to assess the risk of implant failure by age group. The mean duration of follow-up was 5.6 years.

RESULTS

Compared with the patients who were 55 to 70 years of age and >70 years of age, those who were <55 years of age had the highest rates of any reoperation (19.9%, 11.7%, and 6.5% for the <55, 55 to 70, and >70-year age groups, respectively; p < 0.001), implant failure (5.6%, 2.9%, and 1.1% for the <55, 55 to 70, and >70-year age groups, respectively; p = 0.019), and polyethylene exchange (7.7%, 4.3%, and 2.3% for the <55, 55 to 70, and >70-year age groups, respectively; p = 0.021). Competing-risk regression revealed a decreased risk of implant failure for patients who were >70 of age compared with those who were <55 years of age (hazard ratio [HR], 0.21 [95% confidence interval (CI), 0.05 to 0.80]; p = 0.023) and for patients who were 55 to 70 years of age compared with those who were <55 years of age (HR, 0.35 [95% CI, 0.16 to 0.77]; p = 0.009). For all subscales of the Foot and Ankle Outcome Score (FAOS) measure except activities of daily living, patients who were <55 years of age reported the lowest (worst) mean preoperative and postoperative scores compared with those who were 55 to 70 years of age and >70 years of age (p ≤ 0.001). Patients who were <55 years of age had the highest mean numerical pain score at the time of the latest follow-up (23.6, 14.4, 12.9 for the <55, 55 to 70, and >70-year age groups, respectively; p < 0.001).

CONCLUSIONS

Studies involving large sample sizes with intermediate to long-term follow-up are critical to reveal age-related impacts on outcomes after TAA. In the present study, which we believe to be the largest single-institution series to date evaluating the effect of age on outcomes after TAA, younger patients had higher rates of complications and implant failure and fared worse on patient-reported outcome measures.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Risk factors for failure after rotational muscle flap coverage for prosthetic knee infections

INTRODUCTION

Soft tissue defects are a devastating complication of prosthetic joint infections (PJI) after total knee arthroplasty (TKA). Rotational flaps are commonly utilized to address these defects with variable reports of success. This study aimed to identify predictors of poor outcomes in rotational muscle flap placement after prosthetic knee infections. The authors hypothesized that outcomes may vary based on infecting pathogen and treatment characteristics.

METHODS

44 cases of rotational muscle flaps for prosthetic knee infection were retrospectively evaluated at a tertiary referral hospital from 2007 to 2020. Muscle flap types included 39 medial and four lateral gastrocnemius, and one anterior tibialis. Minimum follow-up was 1 year (median: 3.4 years). Primary outcome was flap-related complications. Secondary outcomes included recurrent infection requiring additional surgery, final joint outcomes, and mortality.

RESULTS

One-year complication-free flap survivorship was 83.9%, recurrent infection-free survivorship was 65.7%, and amputation-free survivorship was 79%. Multivariable cox regression revealed that rheumatoid arthritis diagnosis (HR: 3.4; p = .028) and methicillin-resistant Staphylococcus aureus-positive culture (HR: 4.0; p = .040) had increased risk, while Coagulase-negative Staphylococcus infections had reduced risk for recurrent or persistent infection (HR: 0.2; p = .023). Final joint outcome was retained TKA implant in 18 (40.9%), amputation in 15 (34.1%) patients, and definitive treatment with articulating spacer in 10 (22.7%). 5-years survivorship from death was 71.4%.

CONCLUSION

Rotational muscle flaps for soft tissue coverage of the knee are often performed in limb salvage situations with poor survivorship from flap complications, reinfections, and amputation. When considering surgical options for limb salvage, patients should be counseled on these risks.

Biomechanical profile of varying suture button constructs in cadaveric specimens: a systematic review and meta-analysis

Background

Suture button fixation of syndesmotic injuries allows for more physiologic motion of the ankle joint while maintaining adequate reduction and may avoid the need for additional surgeries, given the lower risk of syndesmotic diastasis and implant failure. Few studies have examined the optimal number and configuration of suture buttons for syndesmotic disruption. The purpose of this systematic review and meta-analysis is to compare different suture button configurations from the cadaveric literature and to assess their relative effect on the stability of the syndesmotic reduction and functional movement of the ankle.

Methods

A literature search in the databases MEDLINE via PubMed, Embase via Elsevier, Scopus via Elsevier, and SPORTDiscus via EBSCO were searched through December 2022 to identify studies related to cadaveric modeling of the syndesmosis. Only cadaveric studies with suture button fixation and studies in English were included. The quality of cadaveric studies was assessed using the Quality Assessment for Cadaveric Studies (QUACS) tool. Revman 5.3 software was used to perform the meta-analysis.

Results

The meta-analysis included 5 studies and 86 limbs. The systematic review included 15 studies. When comparing single and double suture button configurations, no difference was found between groups with regard to fibular rotation (MD =-0.9; 95% CI: -2.09 to 0.27; I2=79%; P=0.13) and both groups had similar rotational stability. The double suture button technique did demonstrate less sagittal fibular translation compared to the single suture button (MD =0.48; 95% CI: 0.02-0.94; I2=66%; P=0.04). When comparing two suture buttons in parallel and divergent configurations, studies did not find any differences with regard to strength or stability.

Conclusions

There were no significant differences in biomechanical parameters when comparing single and double suture button constructs. While single button suture constructs result in minimal fibular rotation, double suture button constructs minimize fibular translation. This review may serve as a guide for clinicians when approaching these injuries.

Total Ankle Arthroplasty: Does Obesity Matter?

BACKGROUND

There is limited data evaluating the effect of obesity on outcomes following total ankle arthroplasty (TAA), especially in adequate sample sizes to detect impacts on patient-reported outcomes (PROs). The purpose of this study was to assess the effect of obesity on complication rates and PROs.

METHODS

This was a single-institution, retrospective study of 1093 primary TAA performed between 2001 and 2020. Minimum follow-up was 2 years. Patients were stratified by body mass index (BMI) into control (BMI = 18.5-29.9; n = 615), obesity class I (BMI = 30.0-34.9; n = 285), and obesity class II (BMI > 35.0; n = 193) groups. Patient information, intraoperative variables, postoperative complications, and PRO measures were compared between groups using univariable statistics. Multivariable Cox regression was performed to assess risk for implant failure. Mean follow-up was 5.6 years (SD: 3.1).

RESULTS

Compared to control and class I, class II patients had the lowest mean age (P = .001), highest mean ASA score (P < .001), and greatest proportion of female sex (P < .001) and Black/African American race (P = .005). There were no statistically significant differences in postoperative complications (infection, implant failure, or impingement) across the BMI classes (P > .05).Preoperatively, class II had lower (worse) mean scores for Foot and Ankle Outcome Score pain and ADL subscales than controls (post hoc pairwise P < .001 for both). At final follow-up, both class II and class I had lower (worse) mean Short Musculoskeletal Function Assessment (post hoc pairwise P < .001 and P = .030, respectively) and 36-Item Short Form Health Survey scores (post hoc pairwise P < .001 and P = .005, respectively) than controls.

CONCLUSION

At midterm follow-up, obesity was not associated with increased rates of complications after TAA. Patients with obesity reported worse musculoskeletal function and overall quality of life after TAA but there was no differential improvement in PROs across BMI classes. To our knowledge, this is the largest single-institution study to date examining the effect of obesity on outcomes after primary TAA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Peripheral Nerve Block Delays Mobility and Increases Length of Stay in Patients With Geriatric Hip Fracture

INTRODUCTION

Peripheral nerve blocks (PNB) has been increasingly used in the care of patients with geriatric hip fracture to reduce perioperative opiate use and the need for general anesthesia. However, the associated motor palsy may impair patients' ability to mobilize effectively after surgery and subsequently may increase latency to key mobility milestones postoperatively, as well as increase inpatient length of stay (LOS). The aim of this study was to investigate time-to-mobility milestones and length of hospital stay between peripheral, epidural, and general anesthesia.

METHODS

A retrospective review identified 1,351 patients aged 65 years or older who underwent surgery for hip fracture between 2012 and 2018 at a single academic health system. Patients were excluded if baseline nonambulatory, restricted weight-bearing postoperatively, or sustained concomitant injuries precluding mobilization, with a final cohort of 1,013 patients. Time-to-event analyses for discharge and mobility milestones were assessed using univariate Kaplan-Meier and multivariate Cox proportional hazard regression analyses.

RESULTS

PNB was associated with delayed postoperative time to ambulation (P < 0.001) and time to out-of-bed (P = 0.029), along with increased LOS (P < 0.001). Epidural anesthesia was associated with less delay to first out-of-bed (P = 0.002), less delay to ambulation (P = 0.001), and overall reduced length of stay (P < 0.001).

DISCUSSION

PNB was associated with slower mobilization and longer hospitalization while epidural anesthesia was associated with quicker mobilization and shorter hospital stays. Epidural anesthesia may be a preferable anesthesia choice in patients with geriatric hip fracture when possible.

LEVEL OF EVIDENCE

Level III.

Transitioning to Outpatient Shoulder Arthroplasty: Safety, Efficiency, and Cost in a Diverse Payer Mix

Outpatient shoulder arthroplasty presents potential clinical benefits but also risk without perioperative optimization. Length of stay depends largely on surgeon preferences, and a large single-surgeon cohort may provide insight into optimal strategies and costs for outpatient shoulder arthroplasty. A single-surgeon cohort of 472 anatomic and reverse shoulder arthroplasties performed between 2017 and 2020 was retrospectively reviewed. Cases were stratified by those who did or did not undergo same-day discharge. The 90-day readmission, discharge to post-acute care, cost, and 45 patient/case factors were examined. Two hundred fifty (53%) underwent same-day discharge, with the proportion of outpatient cases increasing over time to nearly 80%, with no significant difference in 90-day readmissions. Revision cases often underwent same-day discharge, whereas fractures were typically admitted. The cost was significantly higher for inpatients, with implants accounting for 52%. Surgeons may safely transition a substantial proportion of shoulder arthroplasties to same-day discharge with some reassurance regarding cost savings and 90-day readmissions. (Journal of Surgical Orthopaedic Advances 32(4):263-269, 2023).

Cost Drivers in Two-Stage Treatment of Hip Periprosthetic Joint Infection With an Antibiotic Coated Cement Hip Spacer

BACKGROUND

The current gold standard for treating chronic Periprosthetic Joint Infection (PJI) is a 2-stage revision arthroplasty. There has been little investigation into what specific patient and operative factors may be able to predict higher costs of this treatment.

METHODS

An institutional electronic health record database was retrospectively queried for patients who developed a PJI after a total hip arthroplasty, and underwent removal of the prosthesis and implantation of an antibiotic-impregnated articulating hip cement spacer. Patient demographics, surgical variables, hospital readmissions, emergency department visits, and post-operative complications were collected. Total costs were captured through an internal accounting database through 2 years post-operatively. Negative binomial regressions were utilized for multivariable analyses. A total of 55 hips with PJI were available for cost analyses.

RESULTS

A comorbidity index score was associated with a 70% increase (Odds Ratio (OR): 1.7 [1.18-2.5], P = .003) in total costs at 2-years. Illicit drug use was associated with a 70% increase in costs at 1-year post-operatively (OR 1.7 [1.18-2.5], P = .003). Metal-on-poly liners were associated with a 22% decrease in cost at 2-years post-operatively when compared to Cement-on-Bone articulating spacers, and Metal-on-poly -constrained liners accounted for 38% lower costs at 1-year (OR 0.62 [0.44-0.87], P = .004). Use of an intraoperative extended trochanteric osteotomy was associated with a 46 and 61% increase in cost at 1-year (OR 1.46 [1.14-1.89]) and 2-years (OR 1.61 [1.26-2.07], P < .001) post-operatively.

CONCLUSION

Age, comorbidity index score, drug use, and extended trochanteric osteotomy were associated with increased costs of PJI treatment. This may be used to improve reimbursement models and target areas of cost savings.

The Impact of Time and State Opioid Legislation on Opioid Prescription Filling in Total Ankle Arthroplasty

Total ankle arthroplasty (TAA) is an increasingly utilized treatment for ankle arthritis, and opioids are commonly used as part of perioperative pain control. However, many states have enacted opioid-limiting legislation to reduce perioperative opioid prescribing. The aim of this study was to evaluate the impact of time and state legislation on perioperative opioid prescribing in TAA. This study is a retrospective, observational review of 90-day perioperative opioid prescribing in 1,829 patients undergoing TAA throughout the United States using a large insurance database. Initial and cumulative volumes and rates of opioid prescription filling were recorded along with baseline patient and operative characteristics. Dates of state legislation enactment were also recorded. Student t-tests, analysis of variance, and multivariable linear and logistic regression were utilized to analyze the impact of time and state legislation on opioid prescription filling. In the 90-day perioperative time period, initial and cumulative opioid prescription filling in oxycodone 5-mg equivalents has decreased significantly from 2010 (63.8 initial and 163.3 cumulative) to 2019 (41.1 initial and 67.2 cumulative). States with opioid-limiting legislation saw larger and more significant reductions in initial and cumulative opioid prescription filling preact to postact (63.3-50.6 with legislation vs 61.4-51.9 without legislation initial and 146.4-93.3 with legislation vs 125.1-108.6 without legislation cumulative). This study demonstrates that foot and ankle surgeons in states with opioid-limiting legislation have responded by significantly reducing 90-day perioperative opioid prescribing in TAA. These results encourage states without legislation to enact opioid-specific laws to reduce opioid prescribing.

A Multicenter Prospective Investigation on Patient Physical and Mental Health After Girdlestone Resection Arthroplasty

BACKGROUND

Girdlestone resection arthroplasty is a salvage procedure for hip periprosthetic joint infection (PJI) that controls infection and reduces chronic pain, but may result in limited postoperative joint function. The aim of this study was to assess physical function and mental health after Girdlestone.

METHODS

This was a multicenter, prospective study evaluating patients with Girdlestone. The Prosthesis Evaluation Questionnaire (PEQ) and patient-reported outcomes measurement information system (PROMIS) global physical health and mental health surveys were administered postoperatively via telephone. The PEQ consists of four scales (ie, ambulation, frustration, perceived response, and social burden) with scores ranging from 0 to 10. The PROMIS measures generated T-scores (mean: 50, standard deviation: 10) that enable comparison to the general population.

RESULTS

Thirty-five patients completed all surveys. The average time from procedure to survey completion was 6 years (range, 1 to 20). The median scores for the ambulation, frustration, perceived response, and social burden scales of the PEQ were 0.0 [interquartile range: 0-4.1], 6.0 [3.0-9.3], 9.0 [7.2-10.0], and 7.5 [4.3-9.5]. The median raw scores of the PROMIS global physical health and mental health were 11.91 [interquartile range: 9-14] and 14.0 [10.0-16.0]. These corresponded to average T scores of 39.7 (standard error : 4.3) for physical health and 46.1 (standard error: 3.8) for mental health, which were 10.3 points and 3.9 points below the average score in the United States general population, respectively.

CONCLUSION

Girdlestone can have a substantial negative impact on physical functions; however, mental health and social interaction may be only moderately affected. These outcomes can be used to guide patient expectations, as this procedure may be necessary in certain salvage scenarios.

976. E coli Periprosthetic Joint Infections: Poor Infection Clearance at One Year

Background

Escherichia Coli (E coli) is a gram-negative rod that can cause devastating periprosthetic joint infections (PJIs) in patients with total hip and knee replacements (THA/TKA). Minimal literature exists on outcomes of E coli PJIs.

Methods

Retrospective review of our institution’s electronic medical record from 2009-2020 identified 21 patients that met MusculoSkeletal Infection Society criteria for E coli hip or knee PJI. Primary outcome was 1-year infection clearance - eradication of infection off antibiotics with no further surgeries for 1 year after completion of standard postoperative antibiotics. Minimum followup was 1 year.

Results

We analyzed 21 patients (mean age 66.6 yrs, 47.6% male, 23.8% nonWhite, 38.1% knee PJIs). There were 11 acute, 8 acute hematogenous (AH), and 2 chronic PJIs. Several patients had recent gastrointestinal/urinary tract surgery (14.3%), recurrent urinary tract infections (9.5%), or >1 E coli urine culture <1 mo pre-PJI (14.3%). Surgical treatments included DAIR (66.7%), 2-stage revision (14.3%), Girdlestone/Resection Arthroplasty (G/RA; 14.3%), and fusion (4.8%), with 7.1%, 100%, 66.7%, and 100% 1-year infection clearance, respectively, and 33.3% 1-year infection clearance overall (p=.001). Common reasons for treatment failure were reinfection requiring surgery (57.1%) and chronic antibiotics (38.1%). Patients clear at 1 year had a longer mean time from most recent surgery to index PJI surgery (48.7 vs 7mo;p=.043) and more AH than acute or chronic infections (54.6% vs 27.3% vs 18.2%;p=.0412). Patients who were not clear at 1 year had more acute infections (80% vs 20% AH;p=.0412). The E coli PJI persisted in 23.8% of patients. Outcomes at final followup included G/RA (28.6%), original prosthetic (28.6%), new prosthetic (19%), above knee amputation (9.5%), destination spacer (9.5%), and arthrodesis (4.8%).

Conclusion

E coli PJI 1-year infection clearance is poor, with DAIR being the most common yet least effective surgical treatment. Most E coli PJIs occurred postoperatively as opposed to hematogenously, as is sometimes assumed. This serves as a foundation for future studies evaluating E coli treatment outcomes.

Disclosures

William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson & Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith & Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

986. Pseudomonas Prosthetic Joint Infections: Is there a role for monotherapy?

Background

Pseudomonas species are a less common but devastating pathogen family in prosthetic joint infections (PJI). Despite advancements in management, Pseudomonas PJI remains particularly difficult to treat due to fewer antibiotic options and robust biofilm formation. The purpose of this study was to better evaluate outcomes after Pseudomonas PJI treatment.

Methods

All hip or knee PJIs, at a single institution, with positive Pseudomonas culture were analyzed. 51 patients (29 hips and 22 knees) meeting inclusion criteria were identified. The primary outcome of interest was infection clearance at 1-year after surgical treatment, defined as reassuring aspirate without ongoing antibiotic treatment or death within one year post-operatively. Monomicrobial and polymicrobial infections were evaluated separately.

Results

Among monomicrobial PJIs, ten (50.0%) patients were clear of infection at one year post-operatively. Patients treated with 2-stage exchange (n=11) had a 1-year clearance rate of 54.5% compared to 60.0% with DAIR (n=5) and 25.0% with resection or amputation (n=4). Two of six patients treated with fluoroquinolone monotherapy met 1-year infection clearance, despite fluoroquinolone sensitivity, compared to four of five patients meeting 1-year clearance when treated with combined intravenous and oral therapy for at least 6 weeks. Resistance to anti-pseudomonal agents was infrequent (20%, n=4/20), and three of ten mono- and polymicrobial PJI patients with recurrent Pseudomonas PJI developed resistance to anti-pseudomonal therapy. Polymicrobial infections were the most common presentation (54.9%) of Pseudomonas positive PJI with a mortality rate of 46.4% (n=13/28) at a median follow-up of 4.2 years [IQR: 3.4-5.7].

Conclusion

Despite surgical and antibiotic treatment regimens consistent with traditional treatment algorithms, our data portrays poor clearance rate of Pseudomonas PJI with relatively poor outcomes in patients treated with oral or intravenous monotherapy. Pseudomonas infections are difficult to eradicate and likely require deviations from classical therapeutic protocols to improve treatment success.

Disclosures

William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson & Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith & Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

980. Enterobacter: An Early-Onset Pathogen of Prosthetic Hip and Knee Infections with Poor Prognoses

Background

Enterobacter sp. is a gram-negative, often drug-resistant bacillus that is classically identified from mucosal surfaces, such as pulmonary or urinary tracts. Despite its virulence, Enterobacter represents a less common pathogen in prosthetic joint infections (PJI). This study aims to resolve the current paucity of described clinical characteristics and treatment success of Enterobacter PJI.

Methods

Thirty-three patients with Enterobacter aerogenes-, cloaecae/asburiae-, or hormachei-positive PJIs were identified at a single institution. Infection clearance was defined as absence of infection or repeat surgery at one year and off all adjunct antibiotic therapy. Patient demographics, PJI characteristics, treatments, and clinical outcomes were compared between patients with and without clearance.

Results

In this cohort, mean age was 66.8 years (SD: 11.6), mean BMI was 31.0 (SD: 7.1), and mean Elixhauser Comorbidity Score was 9.1 (SD: 4.5). 54.5% had a prior PJI in the same joint, and 87.9% had more than one prior surgery in that joint. Median time of PJI diagnosis after surgery was 22 days [IQR: 18-60]. Patients initially treated with debridement antibiotics and implant retention (n=11) had a 45.5% clearance rate, compared to 23.1% for 2-stage exchange (n=13) and 44.4% for those requiring resection arthroplasty or amputation (n=9). With a median follow-up of 2.9 years, final joint outcomes included resection arthroplasty in 9 (27.3%), above-knee amputation in 7 (21.2%), definitive treatment with an articulating spacer in 6 (18.2%), and arthrodesis in 2 (6.1%) patients.

Conclusion

Enterobacter PJI often presents acutely and is a difficult pathogen to treat. The outcomes of our cohort reflect the virulence of Enterobacter, with high rates of failure and ultimate joint- or limb-sacrificing procedure. Despite being a less common cause of PJI, prognosis is exceptionally poor with traditional treatment algorithms when compared to historical cohorts of more common pathogens.

Disclosures

William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson & Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith & Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

Intraoperative fractures in shoulder arthroplasty: risk factors and outcomes

Background

The incidence of shoulder arthroplasty in the United States continues to increase, and while the risk of intraoperative complications such as fracture remains relatively low, there has been little investigation into whether certain patient-specific risk factors predispose to this complication. This study characterizes the incidence of intraoperative fracture during shoulder arthroplasty and additionally hypothesizes that certain risk factors may exist in addition to potentially leading to worsened near-term outcomes.

Methods

An institutional database of shoulder arthroplasties (N = 1773; 994 anatomic, 779 reverse) was retrospectively reviewed, and the operative reports for each case were examined for documentation of an intraoperative fracture, including during which surgical step the fracture took place. Various preoperative and intraoperative factors were tested for comparative significance (P < .05) using chi-square and Kruskal-Wallis tests as appropriate. Length of stay, 90-day readmission, and discharge to rehabilitation or skilled nursing facility (SNF) were further examined as secondary outcomes.

Results

Twenty-one (1.2%) intraoperative fractures were documented, a majority of which occurred in reverse shoulder arthroplasties compared to anatomic procedures (overall incidence: 2.5% vs. 0.2%, P < .001). These most commonly occurred during either stem broaching (33%) or seating (33%) and were most likely to involve the metaphysis (53%) or greater tuberosity (33%). Five fractures occurred during revision arthroplasty, while 16 fractures occurred during primary procedures (overall incidence: 3.0 vs. 1.0%, P = .03). Patient factors reaching statistical significance included female gender and liver disease, while age and smoking history were notably not associated with intraoperative fracture. The fracture cohort had a significantly longer mean length of stay (2.42 vs. 2.17 days, P < .001). While the rates of 90-day readmission and discharge to SNF/rehab were higher in the fracture cohort, these values did not reach statistical significance.

Conclusion

Intraoperative fractures are a rare complication (1.2%) in shoulder arthroplasty, with reverse shoulder arthroplasty, revision cases, and female gender associated with an elevated overall risk. While these patients had a longer inpatient hospitalization, the substantially higher rates of 90-day readmission and discharge to SNF/rehab did not reach significance in our limited institutional cohort. The aforementioned incidence and risk factors serve as crucial evidence for use during the preoperative counseling process with patients as part of a shared decision-making model.

From Patient to Procedure: The Process of Creating a Custom 3D-Printed Medical Device for Foot and Ankle Pathology

Three-dimensional (3D) printing technology has advanced greatly over the past decade and is being used extensively throughout the field of medicine. Several orthopaedic surgery specialties have demonstrated that 3D printing technology can improve patient care and physician education. Foot and ankle pathology can be complex as the 3D anatomy can be challenging to appreciate. Deformity can occur in several planes simultaneously and bone defects either from previous surgery or trauma can further complicate surgical correction. Three-dimensional printing technology provides an avenue to tackle the challenges associated with complex foot and ankle pathology. A basic understanding of how these implants are designed and made is important for surgeons as this technology is becoming more widespread and the clinical applications continue to grow within foot and ankle surgery.Levels of Evidence: Level V.

Clinical applications of custom 3D printed implants in complex lower extremity reconstruction

Background

Three dimensional printing has greatly advanced over the past decade and has made an impact in several industries. Within the field of orthopaedic surgery, this technology has vastly improved education and advanced patient care by providing innovating tools to complex clinical problems. Anatomic models are frequently used for physician education and preoperative planning, and custom instrumentation can assist in complex surgical cases. Foot and ankle reconstruction is often complicated by multiplanar deformity and bone loss. 3D printing technology offers solutions to these complex cases with customized implants that conform to anatomy and patient specific instrumentation that enables precise deformity correction.

Case presentation

The authors present four cases of complex lower extremity reconstruction involving segmental bone loss and deformity – failed total ankle arthroplasty, talus avascular necrosis, ballistic trauma, and nonunion of a tibial osteotomy. Traditional operative management is challenging in these cases and there are high complication rates. Each case presents a unique clinical scenario for which 3D printing technology allows for innovative solutions.

Conclusions

3D printing is becoming more widespread within orthopaedic surgery. This technology provides surgeons with tools to better tackle some of the more challenging clinical cases especially within the field of foot and ankle surgery.

Particulated juvenile articular cartilage allograft transplantation for osteochondral lesions of the knee and ankle

Introduction: Osteochondral lesions have been challenging to treat due to the limited regenerative capacity of native hyaline cartilage. Although surgical options are available, a newer technique, Particulated Juvenile Cartilage Allograft Transplantation (PJCAT) has shown promise for lesions of the knee and ankle. Short-term studies have been encouraging of its use, but there is still limited evidence of its long-term durability.Areas covered: This review will summarize the surgical options currently available for osteochondral lesions, outline the indications and contraindications of PJCAT, present the basic science and clinical evidence of the procedure, and describe the surgical approaches of this technique.Expert opinion: PJCAT is a promising method to treat osteochondral lesions. However, continued research is needed to document the efficacy of this technique and potential superiority over other techniques. Benefits include ease of application, potential for arthroscopic or minimally invasive delivery, no need for perpendicular access, no donor site morbidity, and delivery of viable chondrocytes in hyaline cartilage.