Faculty Bibliography

PURPOSE/OBJECTIVE:Long-term reports of operative tibial plateau fractures are scarce. This study aimed to define long-term knee survivorship with total knee arthroplasty (TKA) as the primary endpoint, assess radiographic and functional outcomes, and the relationship between reduction and functional outcomes. METHODS:Over 21 years, 170 patients were identified with operatively managed tibial plateau fractures treated by two orthopaedic trauma surgeons (109 unicondylar, 61 bicondylar). Survivorship analysis was performed to identify TKA conversion risk factors. Final follow-up radiographs were assessed for osteoarthritis severity, and clinical and functional outcomes were analyzed (KOS-ADLS, SF-12, and NRS-Pain). RESULTS:In unicondylar fractures, survivorship free of TKA was 93.6% (95% CI 88.7%-98.5%) at 10- and 15-years. Survivorship free of TKA for bicondylar fractures was 88.5% (95% CI 80.5%-96.5%) at 10-years and 84.3% (95% CI 73.1%-95.5%) at 15-years. Bicondylar involvement and non-anatomic reduction were independent risk factors for TKA (HR 2.7, HR 3.7; respectively). Bicondylar fractures demonstrated severe osteoarthritis more frequently than unicondylar (p = 0.043). At average 10-year follow-up (2-24 years), mean KOS-ADLS was 68.7 ± 12.5. Unicondylar patients had increased mean KOS-ADLS compared to bicondylar (71.4, 63.1, respectively; p = 0.005). Mean SF-12 was similar between groups. CONCLUSION/CONCLUSIONS:Approximately 10% of operative tibial plateau fractures underwent TKA at 15-years; this rate approached 15% in bicondylar fractures. Bicondylar fractures had 2.7X higher TKA risk. In unicondylar fractures, non-anatomic reduction was associated with 3.7X higher TKA conversion risk. While both groups had similar SF-12 scores, bicondylar had significantly lower KOS-ADLS scores. Anatomic reduction is critical to prevent TKA conversion in unicondylar fractures.

INTRODUCTION/BACKGROUND:Previous studies have identified perioperative gastric aspiration events as a contributor to varying outcomes following orthopedic trauma patients. However, current literature does not report on the effect an aspiration event has on outcomes for patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA), nor do current studies identify risk factors for perioperative aspiration events. MATERIALS AND METHODS/METHODS:We retrospectively reviewed patients who underwent primary, unilateral total joint arthroplasty (TJA) from May 2011 to December 2021. Patients undergoing primary THA/TKA for fracture and oncological indications were excluded. A total of 35,108 patients were stratified according to no aspiration event (35,077 patients) or perioperative aspiration event (intraoperative, day zero, to day seven, 31 patients). Patient demographics and clinical outcomes data were collected and compared. RESULTS:The perioperative aspiration group had a higher average Charlson Comorbidity Index (CCI) (4.03 vs. 2.96, p = 0.008). The aspiration group was more likely to be placed in a lateral decubitus position (54.8% vs. 30.5%, p = 0.003). Patients experiencing an aspiration event had a longer length of stay (LOS) (5.74 vs. 2.66, p < 0.001) and lower rates of home discharge (58.1% vs. 82.5%; p < 0.001). No difference in adverse outcomes such as rate of readmission, revision, and mortality were observed between groups. Multivariable regressions did not show significantly higher odds of aspiration based on surgery type, positioning, or any other demographic factors. CONCLUSION/CONCLUSIONS:This study demonstrates that patients experiencing a perioperative aspiration event during or immediately following TJA do not incur higher rates of readmission, revision, or mortality if treated in a timely manner. However, they do incur longer LOS and higher non-home discharge rates. Further research can explore non-demographic risk factors for perioperative aspiration.

BACKGROUND:Although hinged prostheses have been used successfully in complex revision total knee arthroplasty (TKA), concerns exist regarding early failure due to aseptic loosening and other mechanical complications. The use of metaphyseal cones and hybrid cement fixation have been studied in unlinked constrained primary or revision TKA, but their impact on the survivorship of hinged prostheses has yet to be investigated. METHODS:We identified a consecutive series of 164 hinged prostheses and collected data on demographics, indications, complications, and re-revisions in patients who had fully cemented versus hybrid stems, with and without metaphyseal cones. A multivariate analysis was performed to identify independent variables associated with re-revision as the primary end point. RESULTS:In total, 84 patients (51.2%) had fully cemented stems, and 80 patients (48.8%) had hybrid stems. Cones were used in 73 patients (44.5%). At a mean follow-up of 3.4 ± 2.2 years, 42 patients underwent re-revision (25.8%), most commonly for infection (12.2%), followed by loosening (6.7%) and periprosthetic fracture (3.7%). Patients who had fully cemented stems had lower re-revision rates than hybrid fixation constructs (19 versus 26%, P = .043). Using multivariable regression, a construct with hybrid fixation with cones (odds ratio = 2.39; P = .037) was an independent risk factor for failure. Utilization of cones alone did not have an effect on re-revision rates at 3.4-year follow-up. CONCLUSIONS:While we found no difference with the use of cones, patients undergoing revision TKA with a hinge prosthesis and fully cemented stems had better overall survivorship than hybrid stems.

CASE:A 74-year-old man presented with septic shock with infection of his heart transplant and bilateral prosthetic knee joints simultaneously. He underwent bilateral knee resection arthroplasties with placement of articulating spacers. At 3-year follow-up, the patient was alive and ambulating independently. CONCLUSION:This case represents the first report of bilateral hematogenous prosthetic knee infections associated with concomitant enterococcal endocarditis of a heart transplant treated successfully and definitively with radical debridement and placement of articulating spacer with regular implants.

CASE/METHODS:A 43-year-old woman with dermatomyositis presented with Mycobacterium avium complex (MAC) knee septic arthritis with superimposed polymicrobial infection. After poor infection control with antibiotic therapy, she underwent debridement and antibiotic cement spacer placement, followed by knee arthrodesis 6 months later. At 2-year follow-up, she had no pain and was ambulating without assistive devices. CONCLUSION/CONCLUSIONS:As far as we know, this is the first reported case of MAC native-knee septic arthritis successfully treated with antibiotic cement spacer followed by knee arthrodesis. This case sheds insight on treatment strategies for a rare native-knee infection.

BACKGROUND:Owing to COVID-19, arthroplasty fellowship programs will be required to interview virtually for the current application cycle. Unrelated to COVID-19, our arthroplasty fellowship offered the 2019-2020 interviewees the option of an in-person or virtual interview. The purpose of the present study is to compare interviewee perceptions regarding in-person vs virtual interview formats from that application cycle at a single institution. METHODS:A 17-question survey was sent to all 26 interviewees (13 in-person and 13 virtual) shortly after the rank-list submission deadline. Interviewees were asked to what extent they agreed or disagreed with several statements, ranging from whether the interview was enjoyable to whether interviewees felt they were being adequately evaluated. In this Likert scale rating system, "strongly agree" was given 5 points (more positive outlook), and "strongly disagree" was given 1 point (more negative outlook). Chi-square analyses were performed. RESULTS:> .05). On average, interviewees spent $557/in-person interview. Fifteen (88%) said virtual interviews were more convenient, and 14 (94%) said they were more cost-effective. CONCLUSION/CONCLUSIONS:At a single institution, perceptions on interview format, as quantified through Likert scale ratings, were similar between in-person and virtual groups. The vast majority also viewed virtual interviews as more convenient and cost-efficient. These findings have immediate implications for future fellowship application cycles.

Patellar position and alignment may be measured on routine axial radiographs by various techniques; however, the agreement and reliability of such measurements with a resurfaced patella remain unknown. This study evaluated the range and reliability of lateral patellar tilt and lateral patellar displacement following total knee arthroplasty (TKA) with a resurfaced patella among three observers on 45° Merchant view in 139 TKAs. Intraclass correlation coefficient (ICCs) were used to evaluate intraobserver agreement (IOA) and inter-rater reliability (IRR). IRR was high between each of the observers for lateral patellar tilt (ICC = 0.8) and lateral patellar displacement (ICC = 0.87). IOA was also high upon repeat measurement for the same observer for lateral patellar tilt (ICC ≥ 0.90) and lateral patellar displacement (ICC ≥ 0.86). Therefore, lateral patellar tilt and lateral patellar displacement are reproducible measurements of patellar position on a Merchant axial radiograph following a well-functioning TKA with a resurfaced patella.

BACKGROUND:The changing demographics of our society will lead to an increasing number of patients presenting for orthopedic surgery with increasing comorbidity. We investigated the association between comorbidity and both the risks (complications) and benefits (improved function) of total hip arthroplasty (THA) for primary hip osteoarthritis, whilst controlling for potential confounders including age. METHODS:One thousand five hundred and eighty-four patients (67.1 ± 10.6 years; 54% men) in our tertiary care orthopedic hospital completed the Oxford Hip Score before and 12 months after THA. Comorbidity was assessed using the American Society of Anesthesiologists (ASA) grade and Charlson Comorbidity Index (CCI). Details regarding perioperative complications (hospital stay plus 18 days after discharge; mean 27 ± 3 days) were extracted from the clinic information system and graded for severity. RESULTS:For ASA1, 2, and ≥3, respectively, there were 3.1%, 3.0%, and 6.6% surgical/orthopedic complications; 3.7%, 12.5%, and 27.4% general medical complications; and 6.7%, 14.5%, and 29.8% complications of either type. ASA was associated with complication severity (P < .001). In multiple regression, increasing ASA grade (OR 1.74; 95% CI, 1.33-2.29) and age (OR 1.06; 95% CI, 1.05-1.08), both showed an independent association with increased risk of a complication; CCI explained no further significant variance. CCI, but not age, was associated with the 12-month Oxford Hip Score (beta coefficient, -0.742; 95% CI, -1.130 to -0.355; P = .002) while ASA grade explained no further variance. CONCLUSION:Greater comorbidity was associated with increased odds of a complication and (independently) slightly worse patient-rated outcome 12 months after THA. Comorbidity indices can be easily obtained for all surgical patients and may assist with preoperative counseling regarding individual risks and benefits of THA.

BACKGROUND:Cementation of a constrained liner is a viable option for treating instability after total hip arthroplasty (THA) when the acetabular component is well fixed and well aligned. However, concerns regarding long-term mechanical failure and recurrent instability remain. The aim of this study was to evaluate the long-term survivorship, complications, and clinical and radiographic outcomes of constrained polyethylene liners cemented into well-fixed acetabular components at the time of revision THA. METHODS:We identified 125 cases in which a constrained liner of 1 design was cemented into a retained, osseointegrated acetabular component during revision THA between 1998 and 2006. The mean patient age at revision was 70 years. Mean follow-up was 7 years. Survivorship data, risk of instability, and clinical and radiographic outcomes were analyzed. RESULTS:Survivorship free from revision for instability was 86% at 5 years and 81% at 10 years. Survivorship free from aseptic acetabular component revision was 78% at 5 years and 65% at 10 years, with the most common failure mechanism being dissociation of the constrained liner from the acetabular component. Survivorship free from revision for any reason was 76% at 5 years and 60% at 10 years. The most common complications were instability and periprosthetic joint infection, with cumulative incidences at 7 years of 18% and 11%, respectively. Harris hip scores did not significantly improve. Cup position did not affect implant survivorship or risk of dislocation. CONCLUSIONS:Cementing a constrained liner into a retained acetabular shell at the time of revision THA has durable long-term results, with 8 in 10 patients free from instability at 10 years. Aseptic acetabular survivorship was worse (65%) at 10 years, primarily due to dissociation of the constrained liner from the acetabular component. LEVEL OF EVIDENCE/METHODS:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Trauma, surgery, and other inflammatory conditions can lead to debilitating joint contractures. Adjunct pharmacologic modalities may permit clinical prevention and treatment of recalcitrant joint contractures. We investigated the therapeutic potential of rosiglitazone by intra-articular delivery via oligo[poly(ethylene glycol)fumarate] (OPF) hydrogels in an established rabbit model of arthrofibrosis. OPF hydrogels loaded with rosiglitazone were characterized for drug elution properties upon soaking in minimum essential media (MEM) with 10% fetal bovine serum and measurements of drug concentrations via High Performance Liquid Chromatography (HPLC). Drug-loaded scaffolds were surgically implanted into 24 skeletally mature female New Zealand White rabbits that were divided into equal groups receiving OPF hydrogels loaded with rosiglitazone (1.67 mg), or vehicle control (10 µl DMSO). After 8 weeks of joint immobilization, rabbits were allowed unrestricted cage activity for 16 weeks. Contracture angles of rabbit limbs treated with rosiglitazone showed statistically significant improvements in flexion compared to control animals (mean angles, respectively, 64.4° vs. 53.3°, p < 0.03). At time of sacrifice (week 24), animals in the rosiglitazone group continued to exhibit less joint contracture than controls (119.0° vs. 99.5°, p = 0.014). The intra-articular delivery of rosiglitazone using implanted OPF hydrogels decreases flexion contractures in a rabbit model of arthrofibrosis without causing adverse effects (e.g., gross inflammation or arthritis). Statement of Clinical Significance: Post-traumatic joint contractures are common and debilitating, with limited available treatment options. Pharmacologic interventions can potentially prevent and treat such contractures. This study is translational in that a commercially approved medication has been repurposed through a novel delivery device. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2949-2955, 2018.