Citations

Background: The limb symmetry index (LSI) is a measure comparing strength and functional movement between the surgical and nonsurgical limbs, used after anterior cruciate ligament reconstruction (ACLR) to guide rehabilitation and assess return-to-sport readiness. With increasing use of the quadriceps tendon autograft (QT-ACLR), limited data exist on whether the LSI score correlates with patient-reported outcome measures (PROMs). Hypothesis/Purpose: To evaluate the predictive value of postoperative strength and functional LSI tests at 3, 6, and 9 months for short-term PROMs, determine Patient Acceptable Symptom State (PASS) thresholds, and assess differences based on PASS achievement. It was hypothesized that quadriceps strength LSI score would more strongly predict 2-year PROMs than hamstring strength LSI score, and that higher 9-month isokinetic quadriceps LSI scores would be associated with higher International Knee Documentation Committee (IKDC) and Lysholm scores. Study Design: Case series; Level of evidence, 4. Methods: Patients undergoing primary QT-ACLR from 2021 to 2024 with LSI testing during rehabilitation (isometric and isokinetic lower extremity strength, Y-Balance, hop testing) and no revision or additional knee surgery were included. The LSI score was assessed at 3, 6, and 9 months, and PROMs, including Lysholm and IKDC scores, were collected at a mean follow-up of 2.0 ± 0.7 years. Multivariable linear regression was used to evaluate associations between LSI measures and PROMs after adjusting for age, sex, and body mass index (BMI). Receiver operating characteristic analysis was used to determine PASS thresholds. Results: A total of 100 knees in 100 patients (mean age, 25.3 ± 11.2 years; BMI, 25.9 ± 6.5 kg/m 2 ; 52% male) were included. Quadriceps and hamstring strength and functional performance progressively improved from 3 to 9 months, with the LSI score reaching 77% to 81% for quadriceps strength and 98% to 100% for hamstring strength by 9 months postoperatively. At a mean follow-up of 2.0 ± 0.7 years, the mean satisfaction score was 8.4 of 10, the Lysholm score was 90.7, and the IKDC score was 77.8. Linear regression, adjusted for age, sex, and BMI, demonstrated that 3-month isometric quadriceps LSI score had a strong effect on IKDC score, explaining substantial variance (β = 3.9; adjusted R 2 [Adj R 2 ] = 0.36; P < .03); 6-month isokinetic quadriceps and hamstrings showed moderate but significant effects (β = 2.9-3.7; Adj R 2 = 0.13-0.17; P < .05) on IKDC score; and 9-month fast quadriceps had a strong effect explaining substantial variance in Lysholm and IKDC scores (β = 3.9-4.7; Adj R 2 = 0.34-0.35; P ≤ .003). Lysholm and IKDC scores correlated with satisfaction and accurately discriminated PASS thresholds (area under the curve, 0.927-0.937; P < .001). Patients achieving the IKDC PASS demonstrated higher LSI scores across time points and all PROMs. Conclusion: After QT-ACLR, strength-associated LSIs were independently associated with PROMs at a mean 2-year follow-up, after adjusting for age, sex, and BMI. Early isometric quadriceps strength at 3 months predicted higher 2-year IKDC scores, with PASS achievers generally attaining a 60% to 70% LSI score by 3 months. Isokinetic quadriceps strength at 9 months predicted both IKDC and Lysholm scores. These findings highlight the importance of early quadriceps strength recovery and the value of LSI measures in predicting PROMs and informing early rehabilitation.

Background African American adults experience a disproportionate burden of dementia, shaped by structural and clinical factors that remain unclear. Objective To quantify associations between multimorbidity, polypharmacy, and cognition in the context of neighborhood disadvantage. Methods This study is a cross-sectional analysis of 348 African American adults aged 45–92 years (mean 64.3 years; 73.6% female) from the Aging Research Characterizing Health Exposome via Social drivers (ARCHES) cohort. Comorbidity burden was assessed using a modified Charlson Comorbidity Index (CCI), polypharmacy as ≥5 medications, and neighborhood disadvantage using the Area Deprivation Index (ADI). Linear regression estimated associations with a Preclinical Alzheimer’s Cognitive Composite (PACC). The polypharmacy model included modified CCI as a covariate, and effect modification by ADI was assessed using an interaction term between polypharmacy and ADI. Results Higher modified CCI was associated with lower cognitive performance (B = −0.071; 95% CI: −0.130, −0.012). Polypharmacy was not independently associated with cognition after modified CCI adjustment (B = −0.081; β = −0.057; p = 0.257). No significant ADI interaction was found (p = 0.064).

Abstract Orthopaedic literature often establishes cutoffs when evaluating risk factors for an outcome of interest, whether patellar instability or most any other pathology. Although such cutoffs are intuitively easy to apply to clinical practice and testing situations, they leave much to be desired when it comes to nuanced patient care. As we increasingly recognize patient‐to‐patient differences, our approach to historic cutoffs such as tibial tubercle‐trochlear groove distance merits a revisit. A reasonable first step is to adjust for patient‐specific factors such as height and sex. However, as larger datasets and deeper mechanistic insights become available, we may ultimately move beyond simplistic thresholds altogether, advancing instead toward truly individualized precision medicine.

Purpose To compare short‐term outcomes of intratunnel anchor fixation versus transtibial pull‐through repair for meniscus root tears with a minimum of 12‐month follow‐up. Methods Patients who underwent primary meniscus root repair between 2011 and 2024 at a single institution were retrospectively reviewed. Inclusion criteria consisted of primary medial or lateral meniscus root repair using either intratunnel anchor fixation or transtibial pull‐through repair, availability of preoperative radiographs, and completion of postoperative patient‐reported outcome measures with a minimum of 12‐month follow‐up. The groups were propensity‐matched by age, sex, body mass index, operative side, root laterality, and concomitant procedures. Baseline radiographic characteristics (hip‐knee‐ankle angle and posterior tibial slope) were measured. Outcomes included Lysholm score, International Knee Documentation Committee score, Tegner activity score (preoperative and postoperative), Visual Analog Scale for pain at rest and with activity, satisfaction, subjective surgical outcome, and reoperations. Results Fifty patients who underwent intratunnel anchor fixation (mean age, 44 years) were propensity‐matched to 100 patients who underwent transtibial pull‐through repair (mean age, 41 years). Mean follow‐up was 1.5 years (range, 1.0‐2.3) in the intratunnel anchor group and 6.1 years (range, 2.7‐13.7) in the transtibial pull‐through group. Reoperation rates were 8% and 14%, respectively ( P = .43), with repair failure occurring in 4% and 6% ( P > .99). Preoperative and postoperative Tegner scores were similar between groups. Tegner minimal clinical important difference was 0.8, and 26.5% of intratunnel anchor patients achieved this compared with 0% of transtibial pull‐through patients. Patients in the intratunnel anchor cohort reported slightly lower Visual Analog Scale pain with activity (1.8 vs 2.5, P = .02). Postoperative Lysholm (87 vs 83, P = .05) and International Knee Documentation Committee scores (79 vs 76, P = .09) were comparable between groups. A greater proportion of intratunnel anchor patients achieved Patient Acceptable Symptomatic State compared with transtibial pull‐through patients for Visual Analog Scale with activity (74% vs 56%, P = .03) and Lysholm (66% vs 47%, P = .01). Most patients in both cohorts rated their outcome as “much better” or “slightly better” ( P = .49), and satisfaction scores were high. Conclusions At short‐term follow‐up, both the intratunnel anchor and transtibial pull‐through techniques showed high patient satisfaction and comparable overall clinical outcomes. There were no differences in reoperation rates between techniques. Level of Evidence Level III, retrospective comparative case series.

Purpose To identify risk factors for medial meniscus posterior root tears (MMPRT) and arthroplasty‐free survival in postmenopausal women, while secondary objectives included analyzing menopause‐specific factors associated with MMPRT and defining risk factors for conversion to arthroplasty in patients with a confirmed MMPRT. Methods All patients at our institution with a diagnosed meniscal tear through December 2024 were identified. From this cohort, women with a menopausal diagnosis preceding their meniscal tear were matched one‐to‐one with men by age and body mass index. Imaging studies were reviewed to identify MMPRTs. Subsequent arthroplasty, Charlson Comorbidity Index, menopausal type (surgical or physiologic), hormone replacement therapy, bisphosphonate usage, and bone mineral density were recorded. Logistic and Cox regression were used to define risk factors for MMPRT and arthroplasty; survivorship was determined using Kaplan‐Meier analyses. Results The final cohort consisted of 1564 patients (n = 782 women) with a median age of 63 years, of which 244 patients (15.6%) had MMPRT. Age and female sex were associated with MMPRT. The presence of an MMPRT, female sex, body mass index, and Charlson Comorbidity Index were associated with arthroplasty. Among postmenopausal women, age at menopause, surgical menopause, hormone replacement therapy, and bone mineral density were associated with MMPRT. For patients with MMPRT, female sex was associated with arthroplasty. Ten‐year survivorship‐free from arthroplasty in patients with MMPRT was 53.5% for women and 78.4% for men ( P = .02). Conclusions Postmenopausal status, age, and hormone replacement therapy usage are risk factors for MMPRT. Compared with men, postmenopausal women with MMPRT exhibit reduced arthroplasty‐free survival, underscoring the need for targeted interventions. Level of Evidence Level III, retrospective comparative study.

Purpose To assess the reliability, predictability, and discriminative capacity of 3 anatomic measurements, tibial tubercle‐trochlear groove (TT‐TG), tibial tubercle‐posterior cruciate ligament, and patellar tendon‐lateral trochlear ridge (PT‐LTR), where PT‐LTR may offer a complementary approach to assessing recurrent patellofemoral instability (PFI) risk. Methods Patients diagnosed with PFI before primary patellofemoral stabilization surgery at a single institution between 2022 and 2024 were included. A control group without PFI was propensity matched 1:1 for age, sex, and laterality. Magnetic resonance images were evaluated to measure TT‐TG, tibial tubercle‐posterior cruciate ligament, and PT‐LTR. A priori power analysis determined the cohort size. Statistical analyses compared differences between the PFI and control groups with Student t‐tests, receiver operating characteristic analyses, and area under the curve with resultant sensitivity, specificity, and an optimal cutoff. Results Patients included 50 knees with PFI (28 women, 22 men; mean age 18 ± 5 years). The control group included 50 knees (27 women, 23 men; mean age 18 ± 4 years). Excellent inter‐ and intra‐rater reliability (intraclass correlation coefficient > 0.7) was shown for TT‐TG and PT‐LTR in the PFI and control groups. The distances for TT‐TG, tibial tubercle‐posterior cruciate ligament, and PT‐LTR were significant predictors ( P ≤ .025) of PFI. The average PT‐LTR distance difference for the PFI and control groups was 7.0 mm ( P < .001). PT‐LTR showed an area under the curve of 0.80 and, when ≥4.6 mm, was 66% sensitive and 92% specific for PFI. Conclusions The PT‐LTR distance is a reliable and discriminative metric for identifying PFI in both pediatric and adult populations. A PT‐LTR cutoff value of 4.6 mm showed diagnostic discrimination and substantially high specificity for recurrent PFI, indicating strong ability to identify patients with instability. Level of Evidence Level III, retrospective case control study.

Abstract Meniscus surgery remains one of the most common orthopedic procedures worldwide. Successful meniscus repair requires A natomic reduction, B iologic preparation and augmentation, C ircumferential compression (ABCs), and an optimized rehabilitation protocol. Rehabilitation after surgery is critical for optimizing outcomes, yet the ideal approach remains controversial. A recent international European Union‐United States consensus task force developed recommendations for rehabilitation meniscal surgery. The group concluded that rehabilitation after meniscal repair and reconstruction should progress according to both time‐ and criterion‐based milestones. In practice, 2 rehabilitation pathways are utilized after meniscal repair: a standard protocol for biomechanically stable repairs that tolerate some weight‐bearing in full extension and a complex protocol for repairs requiring greater protection. Standard meniscal repairs (i.e., vertical longitudinal) are biomechanically stable and treated with moderate protection. During the first 4 weeks, patients are restricted to 0° to 90° of knee range of motion, partial weight‐bearing with crutches, and full knee extension during ambulation. Between weeks 4 and 8, patients progress to weight‐bearing as tolerated while avoiding loaded knee flexion beyond 90° until week 16, with emphasis on gait normalization and strengthening. From weeks 8 to 16, aerobic conditioning and strengthening continue. Pending surgeon clearance, return to running begins at week 12, plyometric exercises at week 14, and return to sport at 4 to 8 months. Complex meniscal repairs (e.g., radial or root tears) require a protective rehabilitation approach. During weeks 0 to 6, range of motion is restricted to 0° to 90° with toe‐touch weight‐bearing and full knee extension during ambulation. Range of motion and weight‐bearing progress from weeks 6 to 12, while loaded flexion beyond 90° remains restricted until week 16. Between weeks 12 and 18, aerobic conditioning and strengthening continue. Pending surgeon clearance, running begins at week 14, plyometrics at week 16, and return to sport typically occurs at 6 to 9 months.

Age-related gastrointestinal dysfunction is common, but the mechanisms of aging-associated smooth muscle failure remain unclear. We show that aging in mice slows whole gut and colonic transit, increases regional stiffness, and reduces smooth muscle contractility. Inducible smooth muscle cell (SMC)– specific deletion of Piezo1 preserved youthful transit and force generation, whereas Piezo1 activation in young mice phenocopied aging-associated transit delay. Single-cell transcriptomics, RNA velocity, stiffness-controlled cell and tissue cultures, and pharmacologic studies revealed that Piezo1 couples increased stiffness to Ca 2+ –calcineurin–NFAT signaling, loss of contractile gene programs, leading to age- related contractile loss and contractile-to-synthetic SMC remodeling and gut wall stiffening. Human intestinal SMCs supported conservation of this pathway, and PIEZO1 gain-of-function carriers showed a trend toward delayed colonic transit. Thus, maladaptive SMC Piezo1 mechanotransduction is a targetable mechanism of aging-associated gut dysmotility. Aging alters organ structure, yet how these changes drive functional decline remains poorly defined. We show that progressive stiffening of the gut with age activates the mechanosensitive ion channel Piezo1 in smooth muscle cells, initiating a maladaptive response that impairs contractility and slows intestinal transit. On the other hand, deletion of smooth muscle Piezo1 prevents age-related gut dysmotility. These findings reveal that age-related physical shifts actively drive functional decline through mechanotransduction pathways. By identifying Piezo1 as a critical link between tissue mechanics and organ aging, this work provides a framework for understanding how mechanical cues contribute to age-related dysfunction in the gut and possibly other smooth muscle organs.

Purpose To evaluate implantation rates, time to implantation, and predictors of implantation following matrix‐induced autologous chondrocyte implantation (MACI) biopsy for knee chondral defects. Methods Patients undergoing MACI biopsy or implantation for symptomatic knee chondral defects from 2017 to 2024 at a single institution were reviewed. At a minimum 1‐year follow‐up, the decision to proceed with implantation, recurrent symptoms, complications, and reoperations were assessed. Kaplan‐Meier analysis estimated time to implantation, and multivariable logistic regression identified predictors of MACI implantation. Results A total of 208 knees in 202 patients (mean age 28.0 ± 10.9 years, range 11‐59) underwent MACI biopsy for 243 chondral defects (patella [38%], femoral condyle [34%], and trochlea [26%]). At a mean follow‐up of 4.3 years (range 1.0‐8.3), 64 knees (31%) proceeded to second‐stage MACI implantation. Among 144 knees not implanted, 87 (60%) reported symptom improvement, and 26 (18%) had persistent symptoms. The remaining 22% did not undergo implantation due to another cartilage procedure, insurance denial, or pending scheduling. Patients who underwent biopsy at the home institution had a shorter time from biopsy to implantation compared with those biopsied at outside institutions (6.1 vs 13.1 months, P = .001). Median time to implantation was 9.4 months (95% confidence level: 7.2‐12.2) for home biopsies. Lower body mass index was associated with progression to implantation after adjusting for covariates (odds ratios 0.92, P = .019). Patients implanted within 4 months had larger chondral defects (4.0 vs 3.0 cm 2 , P = .045). At a mean 4.1‐year follow‐up, 6 patients (8%) experienced postoperative complications, including 3 (4%) who required revision chondroplasty. Conclusions MACI biopsy for knee chondral defects resulted in approximately one‐third of patients proceeding to MACI implantation, at a median of 9.4 months after biopsy. Lower body mass index was associated with higher likelihood of progression to implantation, larger chondral defects with earlier implantation, and among patients who did not proceed to implantation, approximately 60% reported symptom improvement following concomitant chondroplasty at the time of biopsy. Level of Evidence Level IV, retrospective case series.