Citations

Abstract There are multiple underlying etiologies of patellar instability including both osseous and soft‐tissue factors. Obligate flexion dislocation consists of lateral dislocation of the patella, occurring each time the knee flexes. This generally results from a predominantly lateral contracture of the extensor mechanism and can be technically challenging to manage. Quadricepsplasty can be of particular clinical utility for obligate flexion dislocation and constitutes a realignment of the proximal soft‐tissue attachments of the patella. The described technique features isolation of the 4 muscles of the quadriceps and subsequent stepwise lengthening of the vastus lateralis, advancement of the vastus medialis obliquus, and Z‐lengthening of the rectus femoris and vastus intermedius. This technique can be used in isolation or in combination with other procedures, such as medial patellofemoral ligament reconstruction, to surgically address patellofemoral maltracking. Technique Video video See video under supplementary data.

Background: While patients may report painful or prominent hardware after tibial tubercle osteotomy (TTO), little is known about the frequency, associated factors, and outcomes after removal of symptomatic hardware. Purpose/Hypothesis: The purpose was to investigate the incidence of hardware removal after TTO due to pain or complications, factors associated with hardware removal, and postoperative outcomes after removal. It was hypothesized that clinical outcomes would be similar between patients who underwent TTO without hardware removal and those who underwent TTOs and subsequently hardware removal. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective analysis was performed on patients who underwent TTO at a single institution from 2000 to 2023. Age at the time of the index surgery, sex, race, body mass index, number and size of screws, tibial tubercle–trochlear groove distance, and reason for hardware removal were collected retrospectively. Knee radiographs were reviewed for measurement of soft tissue–hardware distance. Patients were contacted via email to capture final patient-reported outcome measures (PROMs). A univariate logistic regression model was used to determine factors associated with hardware removal. Results: A total of 152 patients representing 171 knees were included. Of the overall cohort, 38 knees (22.2%) in 32 patients underwent TTO with subsequent hardware removal. The most common reason for hardware removal was anterior knee pain (79%). Compared with patients aged 11 to 20 years, patients aged 21 to 30 years demonstrated higher odds of undergoing hardware removal (OR, 3.67; 95% CI, 1.51-9.44; P = .009). Compared with a soft tissue–hardware distance of 0 to 4.9 mm, a distance of 10.0 to 14.9 mm demonstrated lower odds of hardware removal (OR, 0.24; 95% CI, 0.07-0.84; P = .027). Visual analog scale scores (0-10 scale) improved by a mean of 3.6 points after hardware removal ( P = .003). In patients undergoing hardware removal for pain, no difference in final PROMs was found compared with patients who underwent TTO without hardware removal. Conclusion: Hardware removal in patients undergoing TTO was mainly attributed to hardware-related pain/irritation. On average, pain scores improved after hardware removal. There was no difference in final PROMs between patients who had their hardware removed due to pain (eg, without any clinically relevant concomitant pathology) and patients who did not require hardware removal. Size and number of screws were not associated with a subsequent hardware removal procedure. The thickness of the soft tissue envelope overlying implanted hardware was inconsistently associated with lower odds of hardware removal.

Objective Early‐onset Alzheimer's disease (EOAD) and late‐onset Alzheimer's disease (LOAD) differ in many respects. Here, we address the issue of possible differences in fibrillar amyloid pathology as measured by positron emission tomography (PET), which remains unresolved due to the lack of large‐scale comparative studies. Methods Three hundred ninety‐nine cognitively impaired participants younger than 65 years of age from the multicenter Longitudinal Early‐onset Alzheimer's Disease Study (LEADS) and 450 cognitively impaired participants older than 65 years from the Alzheimer's Disease Neuroimaging Initiative (ADNI) underwent clinical assessment, brain magnetic resonance imaging (MRI), and amyloid PET and were included in this study. We compared amyloid PET outcomes (positivity rate based on visual read and quantified tracer uptake expressed as Centiloids [CLs]) between the 2 cohorts and studied their association with age, sex, APOE genotype, and cognition. Results The amyloid positivity rate was higher in LEADS (78%, 95% confidence interval [CI] = 74–82) than in ADNI (71%, 95% CI = 67–75, p = 0.02). Lower Mini‐Mental State Examination (MMSE) and APOE4 genotype increased the odds of amyloid positivity in both cohorts. Visually positive scans had higher CLs in LEADS (EOAD, mean = 95.3 ± 26.1) than in ADNI (LOAD, mean = 80.9 ± 36.8, p < 0.0001), predominantly in parietal cortex/precuneus, superior temporal, and frontal cortices. In amyloid‐positive patients, (1) CLs were higher in female patients in both cohorts; (2) APOE4 carriership was associated with lower CLs in EOAD, which was not observed in LOAD; and (3) correlations between CLs and MMSE scores were significantly stronger in EOAD than in LOAD. Interpretation Differences in the burden of amyloid pathology may contribute to differences in clinical and anatomic patterns in sporadic EOAD and LOAD, and have implications for optimizing therapeutic strategies in each group. ANN NEUROL 2025;98:236–248

Abstract Hip arthroscopy is a technically demanding procedure that can require a substantial volume of irrigation fluid. Techniques should be explored to optimize fluid use while ensuring satisfactory surgical instrumentation and labral repair. In this technical note, we present a method for performing a dry arthroscopic labral repair. This technique can be used in the treatment of a variety of labral pathologies, including primary labral repair with knotless or hand‐tied anchors, revision labral repair, and labral reconstruction, without the need for irrigation fluid. Additionally, we discuss supplemental techniques that can be used during other portions of the arthroscopic hip procedure to limit irrigation fluid use. Technique Video video See video under supplementary data.

Abstract The standard of care for hip labral tears is arthroscopic repair, with labral reconstruction performed more commonly for irreparable tears in order to avoid isolated labral debridement. However, labral reconstruction can be technically demanding. We provide a concise step‐by‐step guide for performing labral reconstruction or augmentation using a modified retrograde pull‐through technique, including tips, tricks, and surgeon pearls, and pitfalls. Despite the procedure's technically challenging nature, we believe our technique highlights several important steps to improve the practicality and efficiency of the case and produce satisfactory patient outcomes. Technique Video video See video under supplementary data.

Background: Nonoperative and operative management techniques after anterior cruciate ligament (ACL) injury are both appropriate treatment options for selected patients. However, the subsequent development of posttraumatic knee osteoarthritis (PTOA) remains an area of active study. Purpose: To compare the risk of PTOA between patients treated without surgery and with ACL reconstruction (ACLR) after primary ACL disruption using a machine learning causal inference model. Study Design: Cohort study; Level of evidence, 3. Methods: A geographic database identified patients undergoing ACLR between 1990 and 2016 with minimum 7.5-year follow-up. Variables collected include age, sex, body mass index, activity level, occupation, relevant comorbid diagnoses, radiographic findings, injury characteristics, and clinical course. Treatment effects of ACLR on the development of PTOA and progression to total knee arthroplasty (TKA) were analyzed with machine learning models (MLMs) in a causal inference estimator (targeted maximum likelihood estimation, TMLE), while controlling for confounders. Results: The study included 1194 patients with a minimum follow-up of 7.5 years, among whom 974 underwent primary reconstruction and 220 underwent nonoperative treatment. A total of 215 (22%) patients developed symptomatic PTOA in the ACLR group compared with 140 (64%) in the nonoperative treatment group ( P < .001), whereas 25 (3%) patients underwent TKA in the ACLR group compared with 50 (23%) in the nonoperative treatment group ( P < .001). Patients in the ACLR group had delayed TKA compared with patients in the nonoperative treatment group (193.4 vs 166.0 months, respectively; P = .02). TMLE evaluation revealed that reconstruction decreased the risk of PTOA by 11% (95% CI, 8%-13%; P < .001) compared with nonoperative treatment but did not demonstrate a significant effect on the rate of progression to TKA. Survival analysis with random forest algorithm demonstrated significant delay to the onset of PTOA as well as time to progression of TKA in patients undergoing ACLR. Additional risk factors for the development of PTOA, irrespective of treatment, included older age at injury, greater body mass index, total number of arthroscopic knee surgeries, and residual laxity at follow-up. Conclusion: MLMs in a causal inference estimator found ACLR to exert a significant treatment effect in reducing the rate of development of PTOA by 11% compared with nonoperative treatment. ACLR also delayed the onset of PTOA and progression to TKA.

Background: Medial patellofemoral ligament reconstruction is frequently indicated for recurrent lateral patellar instability. The preoperative presence and severity of a J-sign have been associated with poorer postoperative outcomes. Purpose: To determine the underlying anatomic factors that contribute to the presence, severity, and jumping quality of the J-sign. Study Design: Cross-sectional study; Level of evidence, 3. Methods: All patients undergoing evaluation for patellar instability at a single institution between 2013 and 2023 and healthy controls without patellar instability were included. Patients with a history of knee osteotomies were excluded. The presence of a jumping J-sign and its relationship to patellofemoral measures including the Caton-Deschamps Index (CDI), trochlear dysplasia (Dejour grade), tibial tubercle–trochlear groove (TT-TG) distance, tibial tubercle lateralization, trochlear bump height, mechanical alignment, femoral anteversion, tibial torsion, trochlear medialization, patellar width, axial patellar/trochlear overlap, patellar height, trochlear height, and knee rotation angle (KRA) were measured using standardized 1.5-T magnetic resonance imaging (MRI). Univariate pairwise and multivariable analyses were performed to determine the factors associated with J-sign presence, severity, and quality. Results: Of the 130 knees with patellar instability, 89 (68.5%) demonstrated a J-sign on physical examination. In total, 44 (33.8%) patients demonstrated a 1-quadrant J-sign, 32 (24.6%) demonstrated a 2-quadrant smooth J-sign, and 13 (10.0%) demonstrated a jumping J-sign. A total of 22 control, noninstability cases were included. On multivariable analysis, increasing TT-TG distance (OR, 1.1 increase per millimeter; P = .04), external KRA (OR, 1.1 increase per degree; P = .02), and increasing CDI (OR, 1.3 increase per 0.1 increase in CDI; P = .02) were associated with J-sign presence. Increasing bump height (OR, 1.72 increase per millimeter; P = .007) and decreasing patellar width (OR, 0.89 decrease per millimeter; P = .076) were associated with a larger J-sign, when present. Increasing bump height (OR, 1.80 increase per millimeter; P = .018), increasing patellar width (OR, 1.33 increase per millimeter; P = .047), and decreasing CDI (OR, 0.009 decrease per 0.01 increase in ratio; P = .008) were associated with a jumping J-sign in comparison with a smooth 2-quadrant J-sign. A KRA of 10° (AUC, 0.70) and a cartilaginous bump height of 6.6 mm (AUC, 0.73) were thresholds associated with jumping J-sign presence. Conclusion: The presence of a J-sign is associated with MRI findings of relatively greater external tibiofemoral rotation, increased TT-TG distance, and increased patellar height, while J-sign severity and jumping quality are associated with the presence of additional underlying trochlear factors such as increased bump height. The anatomic drivers identified in this study should be further evaluated as possible factors associated with suboptimal outcomes after surgical management.

Abstract Among 64 patients with Erdheim-Chester disease treated with a BRAF inhibitor (median follow-up 4 years), we found high response rates (85%) but frequent discontinuations (61%), primarily because of adverse events. Additionally, patients experienced poor health-related quality of life and high symptom burden.