Faculty Bibliography

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.

OBJECTIVE:To evaluate the outcomes of a single-stage surgical protocol to treat a presumed aseptic long-bone nonunion with positive intraoperative cultures obtained at the time of surgery. DESIGN/METHODS:Retrospective comparative series. SETTING/METHODS:Orthopaedic specialty hospital. PATIENTS AND METHODS/METHODS:We retrospectively identified 77 patients with long-bone nonunions thought to be aseptic preoperatively, which grew bacteria from cultures obtained at the time of index nonunion surgery. INTERVENTION/METHODS:Fifty (65%) patients underwent open debridement of the nonunion site followed by surgical stabilization through plates and screws. Twenty-seven (35%) patients underwent exchange nailing with canal reamings used for cultures. MAIN OUTCOME MEASUREMENT/METHODS:Rate of radiographic union, time to clinical and radiographic union, nonunion rate after index nonunion surgery, and final union rate after revision procedures. RESULTS:Osseous union after the index nonunion surgery was achieved in 84% of the patients (65 of 77). Time to clinical union was 6.3 months (range, 1-24 months), and time to radiographic union was 7.4 months (range, 2-24 months). Eighteen percent (14 of 77 patients) did not heal after the index nonunion surgery and required additional surgeries. The final union rate after revision surgery was 99% (76 of 77 patients). CONCLUSIONS:Eighty-four percent of presumed aseptic nonunions of long-bone fractures with positive intraoperative cultures fully healed after a single-stage surgical protocol and long-term antibiotic when appropriate. When patients are diagnosed with a subclinical infected nonunion, they should be counseled about the higher likelihood of reoperation, but in most cases can expect excellent union rates after 1 additional surgery. LEVEL OF EVIDENCE/METHODS:Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:The use of chemoprophylaxis to prevent thromboembolic disease after primary THA and TKA can be associated with postoperative bleeding complications. Mechanical prophylaxis has been studied as an alternative to chemoprophylaxis with greater safety in patients undergoing THA, but no data have been published comparing the safety of chemoprophylaxis versus mechanical methods for patients undergoing TKA. The risk of readmission resulting from bleeding and venous thromboembolism (VTE) has also not been determined for patients undergoing THA or TKA when treated with low-molecular-weight heparin (LMWH) alone compared with mechanical prophylaxis plus aspirin (ASA). QUESTION/PURPOSES:We sought to answer four questions: For the THA and TKA cohorts, respectively, (1) was the incidence of readmission resulting from VTE and bleeding complications higher with LMWH than mobile compression plus ASA; and (2) was the incidence of wound bleeding complications higher with LMWH than mechanical compression plus ASA? For the TKA cohort specifically, (3) was the frequency of systemic bleeding events and complications related to chemical prophylaxis higher with LMWH compared with mechanical compression plus ASA? (4) Was there a difference in symptomatic VTEs between LMWH and mechanical compression plus ASA? METHODS:Between November 2008 and April 2011, 632 patients underwent primary THA and TKA. Seventy-two patients (11%) were identified before surgery as being at high risk for VTE (31 patients) or bleeding (41 patients) and were excluded from the study. Five hundred sixty patients (89%) were considered to be at standard risk for VTE and bleeding and comprise the study cohort. Between November 2008 and November 2009, 252 patients (76 THAs, 176 TKAs) underwent THA and TKA and were treated with LMWH (5 mg dalteparin given subcutaneously daily for 14 days) and in-hospital nonmobile mechanical compression. Between November 2009 and April 2011, a total of 308 patients undergoing THA and TKA (108 THAs, 200 TKAs) were treated using a mobile compression device plus oral aspirin once daily for 2 weeks after surgery. All complications and readmissions that occurred within 6 weeks of surgery were noted. There were no differences between the VTE treatment groups with regard to age, sex, or body mass index. RESULTS:For the THA cohort, there was no difference in the frequency of readmission for a bleeding complication (wound or systemic) between the two groups (2.6% for LMWH versus 0.9% for mobile compression; p = 0.57; odds ratio [OR], 2.9). Patients undergoing TKA treated with LMWH had higher readmission rates within 6 weeks of surgery because of a bleeding complication, a wound infection, or the development of a VTE (6.8% for LMWH versus 1.5% for mobile compression; p = 0.015; OR, 4.8). For the THA cohort, there was higher wound bleeding complication frequency with LMWH (9.2% for LMWH versus 0.9% for mechanical compression; p = 0.009; OR, 10.9). Patients undergoing TKA treated with LMWH had a higher frequency of wound bleeding complications or infection (3.9% for LMWH versus 0.5% for mobile compression; p = 0.028; OR, 8.2). Patients undergoing TKA treated with LMWH had higher rates of systemic bleeding or a complication secondary to LMWH administration (2.8% for LMWH versus 0% for mobile compression; p = 0.022; OR, 12.8). No difference was noted in the rate of symptomatic VTEs between either group (for THA: 2.6% for the LMWH group versus 1.9% for the mechanical compression group; p = 1; for TKA: 1.1% versus 0%, respectively; p = 0.22). CONCLUSIONS:Based on these results, we advocate for routine use of mobile mechanical compression devices in the prevention of VTEs and complications associated with more potent chemical anticoagulants. However, more focused randomized clinical trials are needed to validate these findings. LEVEL OF EVIDENCE:Level III, therapeutic study.

BACKGROUND:Opioids have been the mainstay of treatment in the physiologically young geriatric hip fracture patient undergoing total hip arthroplasty (THA). However opioid-related side effects increase morbidity. Regional anesthesia may provide better analgesia, while decreasing opioid-related side effects. The goal of this study was to examine the effect of perioperative continuous femoral nerve blockade with regards to pain scores, opioid-related side effects and posthospital disposition in hip fracture patients undergoing THA. METHODS:Twenty-nine consecutive geriatric hip fracture patients (22 women/7 men) underwent THA. Average follow-up was 8.3 months (6 weeks-39 months). Fifteen patients were treated with standard analgesia (SA). Fourteen patients received an ultrasound-guided insertion of a femoral nerve catheter after radiographic confirmation of a hip fracture. All complications and readmissions that occurred within 6 weeks of surgery were noted. RESULTS:Continuous femoral nerve catheter (CFNC) patients were discharged home more frequently than SA patients (43% for CFNC vs 7% for SA; P = .023). CFNC patients reported lower average pain scores preoperatively (P < .0001), on postoperative day 1 (P = .005) and postoperative day 2 (P = .037). Preoperatively, CFNC patients required 61% less morphine equivalent (P = .007). CFNC patients had a lower rate of opioid-related side effects compared with SA patients (7% vs 47%; P = .035). CONCLUSION:CFNC patients were discharged to home more frequently. Use of a CFNC decreased daily average patient-reported pain scores, preoperative opioid usage, and opioid-related side effects after THA for hip fracture. Based on these data, we recommend routine use of perioperative CFNC in hip fracture patients undergoing THA.

OBJECTIVE:To evaluate the effect of continuous femoral nerve catheter (CFNC) for postoperative pain control in geriatric proximal femur fractures compared with standard analgesia (SA) treatment. DESIGN/METHODS:Retrospective comparative study. SETTING/METHODS:Academic Level 1 trauma center. PATIENTS/PARTICIPANTS/METHODS:We retrospectively identified 265 consecutive geriatric hip fracture patients who underwent surgical treatment. INTERVENTION/METHODS:One hundred forty-nine patients were treated with standard analgesia without nerve catheter whereas 116 patients received an indwelling CFNC. MAIN OUTCOME MEASUREMENT/METHODS:Daily average preoperative and postoperative pain scores, daily morphine equivalent consumption, opioid-related side effects and discharge disposition. RESULTS:Patients with CFNC patients reported lower average pain scores preoperatively (1.9 ± 1.7 for CFNC vs. 4.7 ± 2 for SA; P < 0.0001), on postoperative day 1 (1.5 ± 1.6 for CFNC vs. 3 ± 1.7 for SA; P < 0.0001) and postoperative day 2 (1.2 ± 1.5 for CFNC vs. 2.6 ± 2.1 for SA; P < 0.0001). CFNC group consumed 39% less morphine equivalents on postoperative day 1 (4.4 ± 5.8 mg for CFNC vs. 7.2 ± 10.8 mg for SA; P = 0.005) and 50% less morphine equivalent on postoperative day 2 (3.4 ± 4.4 mg for CFNC vs. 6.8 ± 13 mg for SA; P = 0.105). Patients with CFNC had a lower rate of opioid-related side effects compared with patients with SA (27.5% for CFNC vs. 47% for SA; P = 0.001). More patients with CFNC were discharged to home with or without health services than patients with SA (15% for CFNC vs. 6% for SA; P = 0.023). CONCLUSION/CONCLUSIONS:Continuous femoral nerve catheter decreased daily average patient-reported pain scores, narcotic consumption while decreasing the rate of opioid-related side effects. Patients with CFNC were discharged to home more frequently. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.