Improvise, Adapt & Overcome: Successful Surgery-Sparing Prosthetic Hip Infection Antibiotic Suppression During COVID-19 Crisis.

CASE: A 79-year-old active male presented during the first COVID-19 pandemic surgery moratorium with late Staphylococcus lugdunensis periprosthetic total hip arthroplasty infection. Due to the unprecedented circumstances, novel treatment of IV and oral antibiotic suppression was trialed without preceding surgical intervention. At latest follow-up, the patient has two-year revision-free survival with normalization of inflammatory markers and MRI findings, and resolution of clinical symptoms. CONCLUSION: We report a novel surgery-sparing treatment for periprosthetic hip infection. Judicious caution should be used in the application of similar therapies, as host and organism characteristics likely contributed substantially to the success of this case.

Clinical Outcomes of Nonunions of Hindfoot and Ankle Fusions.

BACKGROUND: While nonunion after foot and ankle fusion surgery has been associated with poor outcomes, we are not aware of any longitudinal study on this subject. Thus, we prospectively evaluated the impact of nonunion on clinical outcomes of foot and ankle fusions and identified potential risk factors for nonunion after these procedures. METHODS: Using data from a randomized clinical trial on recombinant human platelet-derived growth factor-BB (rhPDGF-BB; Augment Bone Graft, BioMimetic Therapeutics), union was defined either by assessment of computed tomography (CT) scans at 24 weeks by a reviewer blinded to the type of treatment or by the surgeon's composite assessment of clinical and radiographic findings at 52 weeks and CT findings at 24 or 36 weeks. The nonunion and union groups (defined with each assessment) were then compared in terms of clinical outcome scores on the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale (AOFAS-AHS), Foot Function Index (FFI), and Short Form-12 (SF-12) as well as age, sex, body mass index (BMI), smoking status, diabetes status, work status, and arthrodesis site. RESULTS: Blinded CT assessment identified nonunion in 67 (18%) of 370 patients, and surgeon assessment found nonunion in 21 (5%) of 389 patients. Postoperatively, the nonunion group scored worse than the union group, regardless of the method used to define the nonunion, on the AOFAS-AHS and FFI, with mean differences of 10 and 12 points, respectively, when nonunion was determined by blinded CT assessment and 19 and 20 points when it was assessed by the surgeon. The nonunion group also had worse SF-12 Physical Component Summary scores. Differences between the union and nonunion groups were clinically meaningful for all outcome measures, regardless of the nonunion assessment method. The concept of an asymptomatic nonunion (i.e., imaging indicating nonunion but the patient doing well) was not supported. Patients with nonunion were more likely to be overweight, smokers, and not working. CONCLUSIONS: This prospective longitudinal study demonstrated poorer functional outcomes in patients with a nonunion after foot and ankle fusion, regardless of whether the diagnosis of nonunion was based on CT only or on combined clinical, radiographic, and CT assessment. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Prospective Randomized Controlled Trial of Hindfoot and Ankle Fusions Treated With rhPDGF-BB in Combination With a ß-TCP-Collagen Matrix.

BACKGROUND: Ankle and hindfoot arthrodesis is often supplemented with autograft to promote bony union. Autograft harvest can lead to increased perioperative morbidity. Purified recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB) has stimulated bone formation in mandibular defects and hindfoot fusion. This randomized controlled trial evaluated the efficacy and safety of rhPDGF-BB combined with an injectable, osteoconductive beta-tricalcium phosphate (ß-TCP)-collagen matrix versus autograft in ankle and hindfoot fusions. METHODS: Seventy-five patients requiring ankle or hindfoot fusion were randomized 5:1 for rhPDGF-BB/ß-TCP-collagen (treatment, n = 63) or autograft (control, n = 12). Prospective analysis included 142 autograft control subjects from another clinical trial with identical study protocols. Standardized operative and postoperative protocols were used. Patients underwent standard internal fixation augmented with autograft or 0.3 mg/mL rhPDGF-BB/ß-TCP-collagen. Radiologic, clinical, and quality-of-life outcomes were assessed over 52 weeks. Primary outcome was joint fusion (50% or more osseous bridging on computed tomography) at 24 weeks. Secondary outcomes included radiographs, clinical healing status, visual analog scale pain score, American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale score, Foot Function Index score, and Short Form-12 score. Noninferiority P values were calculated. RESULTS: Complete fusion of all involved joints at 24 weeks as indicated by computed tomography was achieved in 53 of 63 (84%) rhPDGF-BB/ß-TCP-collagen-treated patients and 100 of 154 (65%) autograft-treated patients (P < .001). Mean time to fusion was 14.3 ± 8.9 weeks for rhPDGF-BB/ß-TCP-collagen patients versus 19.7 ± 11.5 weeks for autograft patients (P < .01). Clinical success at 52 weeks was achieved in 57 of 63 (91%) rhPDGF-BB/ß-TCP-collagen patients and 120 of 154 (78%) autograft patients (P < .001). Safety-related outcomes were equivalent. Autograft controls had 2 bone graft harvest infections. CONCLUSIONS: Application of rhPDGF-BB/ß-TCP-collagen was a safe, effective alternative to autograft for ankle and hindfoot fusions, eliminating the pain and morbidity associated with autograft harvesting. LEVEL OF EVIDENCE: Level I, prospective randomized study.

Establishing the relationship between clinical outcome and extent of osseous bridging between computed tomography assessment in isolated hindfoot and ankle fusions.

BACKGROUND: Determining the success of joint fusion operations is often a diagnostic dilemma, and many factors may be considered. Most would agree that the broad categories of clinical success and radiographic success are likely most useful to determine the overall success of a joint fusion operation. Very little evidence exists to assist the surgeon in determining what constitutes a successful radiographic fusion. The aim of this study was to determine the extent of osseous bridging as measured by computed tomography (CT) that was associated with a good clinical outcome as measured by the 12-Item Short Form (SF-12), Foot Function Index (FFI), and American Orthopaedic Foot & Ankle Society (AOFAS) clinical outcomes questionnaires at 24 weeks. METHODS: Patients who had isolated joint fusions were evaluated (n = 275) to determine the correlation of extent of osseous bridging with clinical outcome. The extent of osseous bridging across the joint in question was categorized as absent (0%-24%), minimal (25%-49%) moderate (50%-74%), or complete (75%-100%). Clinical outcome scores included the SF-12, FFI, and AOFAS outcomes score. RESULTS: Patients evaluated to have at least minimal osseous bridging at fusion sites (25%-49%) on CT reported a clinically important improvement in SF-12, FFI, and AOFAS, whereas those with "absent" osseous bridging (0%-24%) did not report a clinically important improvement in outcome scores. CONCLUSION: This study suggests that osseous bridging of greater than 25% to 49% at the fusion site measured by CT may be necessary to consider a hindfoot or ankle fusion clinically successful. LEVEL OF EVIDENCE: Level IV, case series.

Predicting pulmonary embolus in orthopedic trauma patients using the Wells score.

The decision to perform computed tomography pulmonary angiography (CTPA) to rule out pulmonary embolism (PE) in orthopedic trauma patients is challenging. The Wells score is a commonly used clinical probability tool developed to determine the likelihood of PE and assist in determining the need for CTPA examination. This study evaluated the usefulness of the Wells score for predicting PE in patients admitted to the orthopedic trauma service. All patients who were admitted to the orthopedic trauma service at the authors' institution between 2001 and 2011 who underwent CTPA were identified. The Wells score was calculated retrospectively for each patient, and risk categories using the traditional and alternative interpretations of the Wells score were assigned. Pulmonary embolism was diagnosed in 27 (16%) of 169 patients who underwent CTPA. In total, 27 (0.39%) of 6854 patients admitted to the orthopedic trauma service were diagnosed with PE during initial hospitalization. Mean Wells score was 3.31 (95% confidence interval, ±.28) for the entire population, 3.32 for those without PE (95% confidence interval, ±.31), and 3.28 for those with PE (95% confidence interval, ±.72) (P=.91). Average times from admission to CTPA examination for those with and without PE were 6.18 and 5.7 days, respectively (P=.94). No significant correlation existed between the Wells score and CTPA results, indicating that the Wells score is limited in predicting PE risk in orthopedic trauma patients.