Nguyen, Joseph

Objectives: Current standard of care after a First-Time patellar instability event is non-operative management, with exceptions for patients with osteochondral fracture or loose body requiring immediate surgical intervention, patients with significant pathoanatomy, or contralateral patellar instability. For recurrent patellar instability, there is controversy as to when isolated medial patellofemoral ligament reconstruction (MPFL-R) is enough. The purpose of this study is to determine (1) the comparative outcomes of isolated MPFL-R after first-time patellar instability (FTPI) and recurrent patellar instability (RPI) and (2) the impact of osteochondral injury on outcomes after surgical treatment of FTPI. Methods: A prospective, multicenter cohort study (JUPITER: Justifying Patellar Instability Treatment by Results) database was queried for patients who underwent patellar stabilization surgery (PSS) between December 2016 and September 2022. Patients were included if they underwent a medial patellofemoral ligament reconstruction (MPFL-R) for FTPI or RPI. Those with less than 2 years of clinical follow-up, revision PSS, or concomitant bony procedures at the time of MPFL-R were excluded. Independent t-tests were performed to compare means for continuous variables, and chi-squared tests were performed to compare frequency for categorical variables, between groups. Results: A total of 739 patients met inclusion criteria with a mean age of 15.6 ± 3.3 years, and 59.9% female sex. FTPI occurred in 216 (27.2%) patients, and of these 104 (48.1%) sustained an operative chondral or osteochondral lesion. Those with FTPI had a significantly greater trochlear depth (2.9 mm vs. 2.6 mm; P = .048), but a significantly lower rate of pathological trochlear bump > 5 mm (52.3% vs. 67.8%; P = .008) than those with RPI (Table 1). Among the FTPI cohort, those with treatment of a chondral lesion were less likely to have patella alta (Caton-Deschamps Index > 1.3) (14.9% vs. 41.3%, P = .006), and less frequently had a mild or severe J-sign (25.0% vs. 42.7%, p = .016) than those without a chondral intervention (Table 2). Postoperatively, there were no differences with rates of recurrent instability (8.3% vs. 12.3%; P = .130) or return to sport (90.4% vs. 94.5%; P = .182) between FTPI and RPI, respectively (Table 3). There were no differences with rates of recurrent instability (7.6% vs. 9.1%; P = .807) or return to sport (89.1% vs. 91.7%; P = .755) between those with or without a chondral intervention, respectively (Table 4). Conclusions: This study demonstrates no difference in rates of recurrent post-operative instability between FTPI and RPI with rates consistent with the current literature. MPFL reconstruction remains as a durable surgical treatment option for patients presenting with either FTPI or RPI with relatively low rates of recurrent instability. In this patient population, patella alta was found to be protective of osteochondral injury which is also consistent with existing literature. Continued, long-term investigation is needed to understand outcomes for First-Time patellar instability and to better define the indications for surgical interventions in this population.

Background: Particulated juvenile articular cartilage (PJAC) implantation has demonstrated promising early results in the treatment of symptomatic articular cartilage defects of the patella. However, some uncertainty exists regarding the stability of this cell-based technique in lesions that are not well contained or shouldered. Purpose: To compare clinical and magnetic resonance imaging (MRI) outcomes of PJAC treatment in shouldered versus unshouldered full-thickness cartilage defects of the patella. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review of prospectively collected data from an institutional knee registry was conducted to identify patients treated with PJAC for full-thickness symptomatic patellar cartilage lesion between January 2009 and August 2017. Cartilage defects were graded arthroscopically according to the Outerbridge classification and characterized as shouldered or unshouldered. For the primary outcome, postoperative MRI studies were read by a musculoskeletal fellowship-trained radiologist who characterized the percentage of fill based on both coronal and sagittal images. Patient-reported outcome measures (PROMs) were obtained at baseline and 2-year follow-up. MRI and PROM results were compared between the shouldered and unshouldered cohorts. Results: A total of 64 knees in 60 patients (mean age, 26.3 ± 7.6 years) were identified, of which 62 (97%) knees underwent a concomitant patellar stabilization or offloading procedure. There were 32 (50%) shouldered and 32 (50%) unshouldered defects. On postoperative MRI, 68.8% of shouldered lesions demonstrated 67% to 100% fill, compared with 59.4% of unshouldered lesions; 12.5% of shouldered lesions and 15.6% of unshouldered lesions demonstrated 34% to 66% fill; and 18.8% of shouldered lesions and 25.0% of unshouldered lesions demonstrated 0% to 33% fill ( P = .604). At 2 years, significant improvements were observed in Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QOL) (23.1 to 65.3; P < .001), International Knee Documentation Committee (IKDC) (41.2 to 76.0; P < .001), KOOS Physical Function Shortform (PS) (34.8 to 13.9; P < .001), Kujala (52.0 to 87.5; P < .001), 12-Item Short Form Survey (SF-12) Physical Health (39.5 to 51.5; P < .001), Veterans Rand 12 Item Health Survey (VR-12) Physical Health (40.7 to 52.8; P < .001), Veterans Rand 6D (0.66 to 0.79; P < .001), SF-12 Mental Health (48.9 to 53.4; P = .015), and VR-12 Mental Health (49.4 to 54.0; P = .019) values. No significant change was observed in Pediatric Functional Activity Brief Scale score (9.1 to 10.3; P = .384). All PROMs were equivalent between shouldered and unshouldered defects at the 2-year follow-up ( P = .318-.980). There was a greater improvement in both KOOS PS (27.2 vs 10.7; P = .015) and Kujala (44.3 vs 26.9; P = .039) values from baseline to the 2-year follow-up in the shouldered group. Conclusion: PJAC implantation with concomitant patellar stabilization led to significantly improved PROMs for both shouldered and unshouldered patellar cartilage lesions over time. Additionally, minimal differences were observed between shouldered and unshouldered defects treated with PJAC at the 2-year follow-up.

Objective The purpose of this study was to compare the results of a biphasic synthetic scaffold (TruFit, Smith & Nephew) to microfracture for the treatment of knee cartilage defects and identify patient- and lesion-specific factors that influence outcomes. Design Prospectively collected data from 132 patients (mean age, 41.8 years; 69% male) with isolated chondral or osteochondral femoral defects treated with biphasic synthetic scaffolds ( n = 66) or microfracture ( n = 66) were reviewed. Clinical outcomes were evaluated longitudinally over 5 years with the Short Form–36 (SF-36), Activities of Daily Living of the Knee Outcome Survey (KOS-ADL), International Knee Documentation Committee (IKDC), and Marx Activity Scale. Cartilage-sensitive magnetic resonance imaging (MRI) was performed to evaluate osseous integration and cartilage fill in a subgroup of patients. Multivariate regression analysis was used to identify predictors of clinical outcomes within the scaffold group. Results Both groups demonstrated clinically significant improvements in knee clinical scores over 5 years ( P < 0.01). There were no significant differences in KOS-ADL and IKDC scores between groups up to 5 years postoperatively. Marx activity level scores in the microfracture group declined over time, while significant improvements in activity level scores were observed in the scaffold group over 5 years ( P < 0.01). Good-quality tissue fill and cartilage isointensity were more often observed in the scaffold group compared with the microfracture group, particularly with longer time intervals. Increasing age, high body mass index, prior microfracture, and traumatic etiology were predictors for inferior outcomes in the scaffold group. Conclusions Activity level and MRI appearance following treatment of cartilage lesions with the biphasic synthetic scaffold were superior to microfracture over time in this nonrandomized, retrospective comparison.

Background: Oblique injuries are known to be a common cause of time out of play for professional baseball players, and prior work has suggested that injury rates may be on the rise in Major League Baseball (MLB). Purpose: To better understand the current incidence of oblique injuries, determine their impact based on time out of play, and to identify common injury patterns that may guide future injury prevention programs. Study Design: Descriptive epidemiological study. Methods: Using the MLB Health and Injury Tracking System, all oblique injuries that resulted in time out of play in MLB and Minor League Baseball (MiLB) during the 2011 to 2015 seasons were identified. Player demographics such as age, position/role, and handedness were included. Injury-specific factors analyzed included the following: date of injury, timing during season, days missed, mechanism, side, treatment, and reinjury status. Results: A total of 996 oblique injuries occurred in 259 (26%) MLB and 737 (74%) MiLB players. Although the injury rate was steady in MiLB, the MLB injury rate declined ( P = .037). A total of 22,064 days were missed at a mean rate of 4413 days per season and 22.2 days per injury. The majority of these occurred during batting (n = 455, 46%) or pitching (n = 348, 35%), with pitchers losing 5 days more per injury than batters ( P < .001). The leading side was injured in 77% of cases and took 5 days longer to recover from than trailing side injuries ( P = .009). Seventy-nine (7.9%) players received either a corticosteroid or platelet-rich plasma injection, and the mean recovery time was 11 days longer compared with those who did not receive an injection ( P < .001). Conclusion: Although the rate of abdominal oblique injuries is on the decline in MLB, this is not the case for MiLB, and these injuries continue to represent a significant source of time out of play in professional baseball. The vast majority of injuries occur on the lead side, and these injuries result in the greatest amount time out of play. The benefit of injections for the treatment of oblique injuries remains unknown.

Introduction Acetabular component position can be an important determinant of joint stability and bearing surface wear after THA. Nonetheless, the incidence of malpositioning is high. Patient obesity, low surgeon volume, and minimally invasive approaches are known risk factors for malposition. As the incidence of obesity continues to increase, it is important to recognise its effect on intraoperative component positioning in THA. Objectives Our goal was to assess the impact of obesity on component position for a high-volume surgeon using a standard postero-lateral approach. Methods A consecutive series of 120 obese (BMI >30, mean BMI 34.4) and 120 non-obese patients (mean BMI 25.4), who had undergone primary THA by a single surgeon, were included in our retrospective study. AP pelvis and cross-table radiographs obtained at the first postoperative visit were analysed using EBRA software to determine inclination and anteversion angles. Optimal position was defined as 30-45° of inclination and 5-25° of anteversion. Results Mean inclination and anteversion were 40.6 (+/-5.4°) and 16.6 (+/-5.5°) respectively, in the obese group and 39° (+/-5.0°) and 16.2° (+/-7.5°) in the non-obese group. In the obese group 89 (74%) patients were within the desired range for both measurements, 31 (26%) were out of range in at least one, compared to 91 (76%) and 29 (24%) in the non-obese group, respectively. The overall incidence of malpositioning was 25% for both groups. Among outliers, mean deviation from the optimal range was ≤3.8° in both groups. Conclusions The risk of component malpositioning in THA may be reduced when surgery is performed by an experienced, high volume surgeon utilising a standard posterolateral approach. In this setting the deleterious effect of obesity may be overcome.