Could Novel Radiographic Findings Help Identify Aseptic Tibial Loosening?

BACKGROUND: Aseptic loosening following total knee arthroplasty remains one of the leading causes of long-term failure. Radiographic identification of loose implants can be challenging with standard views. The purpose of this study was to compare the incidence of novel radiographic findings of anterior heterotopic bone formation and medial or lateral cyst formation in patients who have aseptic loosening to patients who have well-fixed implants. METHODS: A retrospective radiographic review was performed on 48 patients' revised secondary to aseptic tibial loosening. This cohort was compared to two additional cohorts; 48 patients returning for routine postoperative follow-up (control 1), and 48 patients revised secondary to infection or instability who had well-fixed implants (control 2). RESULTS: There were 41 of 48 (85%) patients who had implant loosening and were noted to have anterior heterotopic bone formation compared to 1 of 48 (2%) patients in control 1 and 3 of 48 (6%) patients in control 2 (P ≤ .0001). There were 43 of 48 (90%) patients who had implant loosening and had medial cyst formation compared to 3 of 48 (6%) patients in control 1 and 5 of 48 (10%) in control 2 (P ≤ .0001). There were 42 of 48 (88%) patients who had implant loosening and had lateral cyst formation compared to 2 of 48 (4%) patients in control 1 and 4 of 48 (8%) in control 2 (P ≤ .0001). CONCLUSION: In this study, we describe novel radiographic findings of anterior heterotopic bone formation and cysts that develop in patients who have aseptic loosening following primary total knee arthroplasty. We believe that these radiographic features may lead to easier identification of aseptic loosening.

Efficacy and Safety of the Ultrasonic Bone Scalpel in Lumbar Laminectomies.

Introduction: Despite recent advances in applied instruments and surgical techniques, the incidence of iatrogenic durotomies caused by traditional techniques remains significant. The ultrasonic bone scalpel (UBS) has been shown to improve speed and reduce complications in laminectomies in the cervical and thoracic spine when compared to traditional methods utilizing high-speed burr, punch forceps, or rongeurs. Thus, in this study, we aim to evaluate whether the use of the UBS in the lumbar spine would result in equivalent safety, efficacy, and patient-reported outcomes (PROs) improvement when compared to traditional methods of laminectomy. Methods: Data from a prospectively collected, single-institution registry was queried between January 1, 2019 and September 1, 2021 for patients with a primary diagnosis of lumbar stenosis who received a laminectomy (with or without fusion) using traditional methods or UBS method. Outcomes included 3-month and 12-month values for all PROs Measurement Information System (PROMIS) subdomains, Numerical Rating Scale (NRS) pain score, Oswestry Disability Index (ODI) percentage, Patient Health Questionnaire 9 (PHQ-9) score, operative complications, reoperations, and readmissions. Covariates selected for matching included age, operation type, and number of levels. A variety of statistical tests were utilized. Results: As per our findings, 2:1 propensity matching resulted in 64 "traditional group" patients and 32 "UBS group" patients. Post-match analysis found no differences between the traditional and UBS groups for demographic and baseline measures except for race and ethnicity. For the matched sample, no differences were noted in PROs, reoperations, or readmissions. There was a significant difference in rates of durotomies between the traditional and UBS groups (12.5% vs. 0.0%, p=0.049). Conclusions: Results showed the high-frequency oscillation technology implemented by the UBS helps to decrease the rate of injury to the dura, thus reducing the overall incidence of iatrogenic durotomies. We believe these data provide valuable information to surgeons and patients about the safety and efficacy of the UBS in performing lumbar laminectomies.