Abstract: The physeal-sparing iliotibial band (ITB) anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-established technique for treating skeletally immature patients with ACL rupture. However, the long-term implications of the procedure on the intricacies of kinetic and kinematic function of the knee have not been comprehensively investigated. Purpose: To assess the short-, mid-, and long-term effects of ITB ACLR on kinetic and kinematic parameters of knee functions. Study Design: Case series; Level of evidence, 4. Methods: A total of 38 patients who had undergone an ITB ACLR as a skeletally immature child were recruited to participate in a 3-dimensional (3D) motion analysis testing protocol at an institutional injury prevention center between 1 and 20 years after reconstruction. Exclusion criteria were congenital ACL deficiency and any other major knee injury (defined as an injury requiring surgery or rehabilitation 〉 3 months) on either knee. 3D and force plate parameters included in the analysis were knee moment, ground-reaction force, and vertical jump height measured during drop vertical jump and vertical single-limb hop. Paired t tests and equivalency analyses were used to compare the parameters between cases (ITB ACLR limb) and controls (contralateral/nonsurgical limbs). Results: Paired t tests showed no statistically significant differences between limbs, and equivalency analyses confirmed equivalency between limbs for all tested outcome variables. Conclusion: The ITB ACLR appears to restore normal, symmetric, physiologic kinetic and kinematic function in the growing knee by 1 year after reconstruction, with maintenance of normal parameters for up to 20 years.

Abstract: Anterior cruciate ligament (ACL) tears are among the most devastating orthopaedic injuries affecting young athletes, especially when they occur in children and adolescents. Growing interest in physeal-sparing techniques has prompted various investigations into the combined extra-articular/intra-articular modified-Macintosh ACL reconstruction with Iliotibial band autograph (ACLR-ITB), which is often used for younger skeletally immature patients with complete ACL ruptures. However, several aspects of the long-term function of knees undergoing this technique remain under-investigated. Therefore, the purpose of the current study was to determine two critical parameters of knee function—the vertical ground reaction force (VGRF) and vertical jump height - at various time intervals following the ACLR-ITB: 1-2 years, 2-5 years, 5-10 years, and 〉 10 years post-surgically. Methods: The current investigation was conducted at a single pediatric tertiary care center using a cross-sectional, laboratory-controlled study design. Inclusion criteria were skeletally immature patients with ACL tears who underwent an ACLR-ITB procedure. Exclusion criteria were major knee injuries (requiring rehabilitation 〉 3 months) or subsequent surgery on the ipsilateral knee and/or any surgery on the contralateral knee. During data collection, 29 reflective markers were applied to participants who performed drop vertical jumps (DVJ) three consecutive times and vertical single-limb hops (one time, each limb). A three dimensional (3D) motion analysis system with force plates was used. Kinematic and kinetic data were collected at 240 Hz and 1080 Hz respectively, and synchronized in time. The sequence of which limb was tested first in the vertical single-limb hop test was randomized. The instance of initial contact was identified and the landing phase was defined as the first 500 ms after initial contact. Major outcome variables included VGRF and vertical jump height. The VGRF were normalized by mass (kg), and mean peak values of the landing phase were used for analysis. Vertical jump height was calculated through following equation: ½ g(t/2)2, where g=9.81 m/s2 and t=time in seconds in the air. Descriptive statistics were used to analyze basic demographic characteristics. Paired t-tests were employed to compare VGRF and vertical jump height between the two limbs by four groups (1-2 years, 2-5 years, 5-10 years, and 〉 10 years) separately. Additionally, equivalence analysis using two one-sided paired t-tests was applied to further support comparison of the two limbs. Any difference in the outcome measures (VGRF and vertical jump height) at the 26 patient-level was further tested to examine equivalency between the two limbs using a margin of equivalence of 4 (a difference less than 4 was not considered clinically important). The a priori statistical significance was set as p=0.05. Results: The study population consisted of 40 subjects (1-2 years: N=9; 2-5 years: N=13; 5-10 years: N=10; 〉 10 years: N=8), with demographic information presented at Table 1. Based on available data (26 of 40, 19 males and 7 females, 1-2 years: N=6, 2-5 years: N=9, 5-10 years: N=7, 〉 10 years: N=4), paired t-tests showed no statistically significant differences in VGRF and vertical jump height between ACLR-ITB and non-ACLR limbs in DVJ (Table 2) and vertical single-limb hop (Table 3) in any of the follow-up time groups. The equivalence analysis identified that the main outcome measures for the ACLR-ITB limb were equivalent to those of the non-reconstructed limb at the 26 patient-level (DVJ: p=0.016, VSH: p 〈 0.001, JH: p=0.01; Note: p 〈 0.05 confirms equivalency that the measures for the two limbs are close enough so that reconstructed limb cannot be considered superior or inferior to the native limb). Conclusion/Significance: Based on VGRF and vertical jump height in DVJ and vertical single-limb hop maneuvers through kinematic and kinetic analyses, ACLR-ITB knee demonstrated equivalent or superior function to the contralateral uninjured limbs at 1-2 years, 2-5 years, 5-10 years, and 〉 10 years following reconstruction. These data contribute broader scientific support for the ACLR-ITB procedure offering lasting functional benefits for skeletally immature athletes with complete ACL tears. [Table: see text][Table: see text] [Table: see text]

Abstract: Quadriceps tendon autograft represents an increasingly popular graft option for ACL reconstruction (ACLR). However, there is a paucity of literature regarding the early post-operative effects of this graft technique on functional recovery, particularly in adolescents. Purpose/Hypothesis: To quantify post-operative strength, dynamic balance, and functional hop test performance in adolescents 6 months following ACLR with a quadriceps tendon autograft (ACLR-Q) and compare to an adolescent control group who underwent ACLR with hamstring autograft (ACLR-HS). Methods: Patients 12-19 years-old who underwent primary ACLR-Q from 2017-2019 by a single surgeon at a pediatric tertiary care hospital and performed return to sports (RTS) assessments between 5-9 months post-operatively were included. Exclusion criteria were prior ipsilateral or contralateral ACLR and concomitant procedures other than meniscal repair or meniscectomy. RTS tests included manual muscle testing of strength (hamstring, quadriceps, hip abductor), dynamic-Y-balance, and functional hop tests (single-hop, triple-hop, crossover, 6-meter timed hop). Limb Symmetry Index (LSI) was calculated for all measures and each was compared with an ACLR-HS control group using T-tests. One-way between-group multivariate analysis of covariance (MANCOVA) was utilized to control for any baseline differences. Results: There were no significant differences in age, BMI, sex, or rates of meniscal procedures between cohorts (Table 1). The small difference in time of RTS testing was controlled by MANCOVA model. ACLR-Q patients demonstrated a significantly smaller hamstring strength deficit (-3.6%) than the ACLR-HS group (-35.8%, p 〈 0.001, Table 2). The ACLR-Q group showed a significantly greater deficit in quadriceps strength (-11.9% vs. 0.9%, p 〈 0.001). Hamstring-to-quadriceps strength ratios (HS:Q) were lower in the ACLR-HS (operative limb: 0.34 +/- 0.13, non-operative limb: 0.52 +/- 0.01) than the ACLR-Q group (operative limb: 0.61 +/- 0.16, non-operative limb: 0.56 +/- 0.12). Deficits in anterior reach, composite Y-balance score, cross-over hop, timed hop, and single hop were significantly greater in the ACLR-Q group. The deficit in 6-meter timed hop was significantly greater in the ACLR-HS group. Conclusion: Quadriceps strength deficits were greater in adolescents undergoing ACLR-Q (LSI of approximately -12%), while hamstring strength deficits were greater in adolescents undergoing ACLR-HS (LSI of approximately -33%). Hamstring-to-quad ratios were greater in the ACLR-Q patients’ operative knees than their nonoperative knees, while they were significantly lower in the ACLR-HS patients’ operative knee than their nonoperative knees. Hop testing performance was mixed between the 2 graft cohorts. The degree to which these performance metrics influence eventual athletic performance and graft-retear remains a critical area of continued investigation. [Table: see text][Table: see text]

Abstract: Context : To treat anterior cruciate ligament (ACL) injury, ACL reconstruction (ACLR) surgery is currently a standard of the care. However, effect of graft type including bone–patellar tendon–bone (BTB), hamstring tendon, or iliotibial band (ITB) on thigh size, knee range of motion (ROM), and muscle strength are understudied. Objective : To compare postoperative thigh circumference, knee ROM, and hip and thigh muscle strength in adolescent males who underwent ACLR, based on the 3 different autograft types: BTB, hamstring (HS), and ITB. Setting : Biomechanical laboratory. Participants : Male ACLR patients who are younger than 22 years of age (total N = 164). Intervention : At 6- to 9-month postoperative visits, thigh circumference, knee ROM, and hip and thigh muscle strength were measured. Main Outcome Measures : Deficits of each variable between the uninvolved and ACLR limb were compared for pediatric and adolescent ACLR males in the BTB, HS, and ITB cohorts. Baseline characteristics, including physical demographics and meniscus tear status, were compared, and differences identified were treated as covariates and incorporated in analysis of covariance. Results : Data were from 164 adolescent male ACLR patients [mean age 15.7 (1.2) years]. There were no statistical differences in thigh circumference, knee ROM, hip abductor, and hip-extensor strength among the 3 autografts. However, patients with BTB demonstrated 12.2% deficits in quadriceps strength compared with 0.5% surplus in HS patients ( P  = .002) and 1.2% deficits in ITB patients ( P  = .03). Patients with HS showed 31.7% deficits in hamstring strength compared with 5.4% deficits in BTB ( P  = .001) and 7.7% deficits in ITB ( P  = .001) groups at 6- to 9-month postoperative visits. Conclusion : Adolescent male ACLR patients with BTB and HS autografts demonstrated significant deficits in quadriceps and hamstring strength, respectively, at 6 to 9 months postoperatively. Minimal lower-extremity strength deficits were demonstrated in pediatric male ACLR patients undergoing ITB harvest.

Abstract: Successful return to sport after anterior cruciate ligament (ACL) reconstruction (ACLR) can be affected by a patient’s physical and psychological state throughout the rehabilitation process. Purpose: To prospectively compare differences in patients at 6 months after primary ACLR with the ACL–Return to Sport after Injury (ACL-RSI), International Knee Documentation Committee (IKDC) or pediatric (Pedi)-IKDC, Hospital for Special Surgery Pediatric Functional Activity Brief Scale (Pedi-FABS), and Patient-Reported Outcomes Measurement Information System–Psychological Stress Experiences (PROMIS-PSE) scores. Study Design: Prospective cohort study; Level of evidence, 2. Methods: Patients enrolled were 8 to 35 years old who underwent primary ACLR and had their 6-month follow-up appointments between December 2018 and March 2020. Patients were divided into 3 age groups as follows: (1) preadolescents (10-14 years); (2) adolescents (15-18 years); and (3) adults ( 〉 18 years). Outcomes on the ACL-RSI, IKDC/Pedi-IKDC, Pedi-FABS, and PROMIS-PSE were compared according to age group, graft type (hamstring, patellar tendon, quadriceps, or iliotibial band autograft), and sex. Results: A total of 176 patients (69 male, 107 female), with a mean age of 17.1 ± 3.1 years were included in the study. The mean ACL-RSI scores were significantly different among age groups (preadolescents, 75 ± 18.9; adolescents, 61.5 ± 20.4; and adults, 52.5 ± 19.8 [ P 〈 .001]) and graft types ( P = .024). The IKDC and PROMIS-PSE scores were also significantly different among age groups ( P 〈 .001 and P = .044, respectively) and graft types ( P = .034 and P 〈 .001, respectively), with the iliotibial graft and the younger age group performing the best. There was no significant difference in the Pedi-FABS either by age group ( P = .127) or graft type ( P = .198). Female patients had lower ACL-RSI scores and higher (worse) scores on PROMIS-PSE than their male counterparts ( P = .019 and P 〈 .001, respectively), with no sex-based differences on IKDC or Pedi-FABS scores. The ACL-RSI and IKDC were positively correlated (Spearman r = 0.57; P 〈 .001), while the ACL-RSI and PROMIS-PSE were negatively correlated (Pearson r = –0.34; P 〈 .001). Conclusion: This study suggests that psychological profiles and subjective perceptions of knee function 6 months after ACLR may vary in patients of different ages and between the sexes. Preadolescent patients had better scores on a majority of patient-reported outcomes compared with adolescent and adult patients.

Abstract: The influence of graft type on recovery after anterior cruciate ligament reconstruction (ACLR) has not been adequately studied in pediatric patients. Purpose: To describe lower extremity functional recovery parameters at the 6-month mark after ACLR across 3 distinct groups of skeletally immature patients: pediatric male patients with transphyseal hamstring grafts (PM-HS), pediatric female patients with transphyseal hamstring grafts (PF-HS), and pediatric male patients with extraphyseal iliotibial band grafts (PM-ITB). Study Design: Cohort study; Level of evidence, 3. Methods: Thigh circumference, knee range of motion, lower extremity strength, dynamic balance, and hop test performance were assessed in all patients 6 months postoperatively. All participants were ≤15 years of age with open physes. The limb symmetry index was used to compare deficits between the operated and uninvolved limbs for all 3 groups (PM-HS, PF-HS, and PM-ITB). Analysis of variance with post hoc correction was employed. Results: A total of 93 pediatric patients who underwent ACLR (PM-HS: n = 21 [mean age, 13.6 ± 1.0 years]; PF-HS: n = 33 [mean age, 13.4 ± 0.7 years] ; PM-ITB: n = 39 [mean age, 12.5 ± 1.3 years]) were examined. There was no statistically significant difference in thigh circumference, range of motion, dynamic balance, or hop test performance between the groups. Of the various additional comparisons analyzed, there were statistical differences in hamstring strength deficits among the 3 groups ( P = .004). The PM-HS group showed a greater hamstring strength deficit (–32.2% relative to healthy limb) than the PM-ITB group (–5.4% relative to healthy limb) ( P = .012). The hamstring strength deficit of the PF-HS group (–18.7% relative to healthy limb) was less than that of the PM-HS group and greater than that of the PM-ITB group but not statistically significant in either case. Conclusion: Significant hamstring strength deficits were detected in the PM-HS group compared with the PM-ITB group at 6 months following ACLR. Such findings may influence decisions regarding graft selection, timing of return to sports, and postoperative rehabilitation regimens.

Abstract: Young patients are the highest risk demographic for ACL graft failure and revision surgery. Previous studies have shown higher rates of graft failure with the use of allograft tissue for ACL reconstruction (ACLR) in both primary and revision surgeries. However, questions remain regarding the functional consequence of taking a second autograft from the same knee for revision ACLR. Purpose: The purpose of this study was to evaluate 6-month functional testing in patients who underwent revision ACLR with a second autograft from the same knee compared to matched cohorts of primary ACL patients. Methods: We retrospectively reviewed prospectively collected data from patients aged 19 or younger who had revision ACLR with a second autograft at our institution. We excluded patients with iliotibial band autografts, two autografts from a synergistic muscle groups, or grafts from the contralateral knee. Patients with previous significant injury or surgery to the contralateral leg, and those with multiligamentous knee injuries were excluded. Patients underwent functional testing 5-8 months after revision surgery including anthropometric measures, isometric strength, Y-Balance, and hop testing. Side-to-side deficits were then compared to age, sex, and BMI matched cohorts of primary ACLR patients, with hamstring or patellar tendon autografts. Multivariate analysis of variance (MANOVA) was used, and if significance was detected, pairwise comparison was performed by Bonferroni post-hoc correction. Statistical significance of p 〈 0.05 was applied. Results: Thirty-seven adolescents underwent functional testing at 6.25±0.56 months after revision ACLR with a second autograft. These patients were matched to 62 patients who underwent primary ACLR with hamstring autograft, and 47 who underwent ACLR with patellar tendon autograft (Table 1). Revision ACLR patients showed comparable knee extension strength deficits to the patellar tendon group (-9.45±12.09% vs -8.81±13.83%, p=0.999) which were significantly greater than hamstring group (-9.45±12.09% vs -0.99±12.00%, p 〈 0.05). Greater strength deficits were seen in knee flexion strength in the hamstring group than the revision group (-38.90±16.21% vs -28.13±23.22%, p=0.009) which had significantly greater knee flexion strength deficits than the patellar tendon group (-28.13±23.22% vs -1.17±12.41%, p=0.001). The hamstring primary group also showed greater triple hop deficit (-21.08±25.99%) than the other two groups (-21.08±25.99% vs -10.75±12.85 vs -6.84±23.81, p=0.024), which were similar. Conclusions: After revision ACLR with a second autograft from the same knee, adolescents show similar knee extension strength deficits compared to primary ACL patients with patellar tendon grafts, but improved knee flexion strength deficits compared to primary ACL patients with hamstring grafts. Tables/Figures: [Table: see text]

Abstract: The effect of concomitant meniscal tears, and their associated treatment, on strength and functional recovery after anterior cruciate ligament reconstruction (ACLR) has not been adequately investigated in young populations. Hypothesis: Concomitant meniscal tears, treated with or without repair, would not adversely affect strength, balance, or functional hop test performance at 6 months postoperatively. Study Design: Cohort study; Level of evidence, 3. Methods: The authors retrospectively analyzed return-to-sports (RTS) assessments prospectively collected 6 months after ACLR with hamstring autograft in 165 patients ≤25 years of age. Descriptive, surgical, and RTS testing data were analyzed, and subgroups were compared using analysis of covariance models designed to assess the effects of sex, meniscal tear, and meniscal repair on RTS performance. Results: Included were 115 female (70%) and 50 male (30%) patients with a mean age of 16.4 years (range, 12.3-25 years). Of these patients, 58% had concomitant meniscal tears (59% lateral, 27% medial, 14% lateral + medial), comprising 53% of the female and 70% of the male patients. The authors treated 61% of the tears with repair, with range of motion (ROM) and weightbearing limitations imposed within the first 6 weeks postoperatively, whereas 39% were treated with partial meniscectomy, rasping, or trephination (no ROM or weightbearing restrictions). The mean deficit in hamstring strength at 6 months postoperatively was significantly greater in the meniscal tear group than in those without a tear (32.3% vs 24.6%; P = .028). The meniscal repair group had greater hamstring strength deficits than the group with meniscectomy, rasping or trephination (34.3% vs 26.2%; P = .023). Performance on dynamic balance and functional hop tests was similar among all meniscus subgroups. There were no sex-based effects on any subgroup comparisons. Conclusion: At 6 months postoperatively, both young male and young female patients who underwent ACLR with hamstring autograft demonstrated significant hamstring strength deficits compared with their nonoperative leg. The presence of a meniscal tear and subsequent repair, or its related rehabilitation restrictions, appears to have adverse effects on the postoperative recovery of hamstring strength.

Abstract: While ACL reconstruction (ACLR) in skeletally immature patients was traditionally delayed until physeal closure, the development of techniques that avoid physeal disturbance have allowed surgical intervention with minimization of growth compromise. Previous reports have shown excellent patient outcomes and functional stability with low re-tear rates at short and mid-term follow-up in one of the most widely used physeal-sparing techniques, the combined extra-articular/intra-articular modified-MacIntosh ACL reconstruction with Iliotibial band autograph (ACLR-ITB). However, there is a lack of evidence regarding the kinematic performance of the reconstruction, which has been referred to as ‘non-anatomic’, as well as the effect of time on function and effectiveness. This component of a single-site, prospective, cross-sectional study of ACLR-ITB patients at different times following their reconstruction, between 1 and 20 years post-operatively, was designed to compare the sports performance-based features of the ACLR-ITB knee to the contralateral, uninjured contralateral knee, including strength, dynamic balance, and functional hop testing, as well as patient-reported functional outcome measures and activity scores. The primary hypothesis is that similar function will be found, between the ACLR-ITB and Non-ACL of individuals, and that the degree of similarity will be maintained with increasing age, growth, and/or time from reconstruction. Methods: Patients who underwent an ACLR-ITB between 1-20 years prior to study initiation were identified from the surgical database of three high-volume surgeons at a tertiary care pediatric hospital. Exclusion criteria were major injury or surgery on the contralateral knee at any time point, or on the ACLR-ITB knee since the time of reconstruction. The resulting study cohort of 40 subjects participated in a single day of testing at a specialized sports injury prevention center. Evaluation consisted of isometric and isokinetic strength (quadriceps, hamstring, hip abductor, hamstring: quadriceps ratio), dynamic Y-balance, and single leg hop testing, with the limb symmetry index (LSI) tabulated to allow for comparisons between knees. Patient-reported functional outcomes and activity level were recorded by Pedi-IKDC and HSS-Pedi FABS questionnaires, respectively. For the comparisons between knees, the LSI values minus 100 were compared to 0 using the Wilcoxon signed rank test. Additionally, equivalence analysis using two one-sided paired t-tests was applied to further support comparison of the two limbs. The LSI-100 measures were tested to examine equivalency between the two limbs using a margin of equivalence of 8 (a difference less than 8 was not considered clinically important). The magnitude of the relationship between test results and time was assessed using Pearson correlation coefficients (r). Results: The 40 study subjects had a mean age of 10.6 years (range 6-14) at time of reconstruction and 18.0 years (range: 9-30) at time of testing. Time between ACLR and time of testing ranged from 1-17 years with 8 patients beyond 10 years (Table 1). Completed Pedi-IKDC and HSS-Pedi FABS resulted in mean scores of 96 (range: 79-100) and 22 (range 0-30), respectively. The outlier subject who reported an athletic activity level of ‘0’ attributed the low score to a busy career in construction. Mean LSI for the single leg hop was 99.2% (p=0.727) and 98.4% (p=0.045) for dynamic Y-balance. Of the isometric and isokinetic strength tests, the three major muscle groups (hip abductors (LSI: 97.9%, p=0.207), quadriceps (LSI: 97.9%, p=0.260) hamstring (LSI: 102.6%, p=0.264)) showed no significant differences. Hamstring to quadriceps ratio for both limbs showed a mean value of 0.5. The equivalence analysis of LSI minus 100 confirmed equivalency, that the measures for the two limbs are close enough so that the reconstructed limb cannot be considered superior or inferior to the native limb (all p 〈 0.05). No correlation between scores and time from reconstruction was observed, other than an expectable decline in HSS-Pedi FABS activity scores (r=-0.37, p=0.018) and improvement in hip abductor LSI (r=0.36, p=0.027) with increasing time from surgery. Conclusion / Significance: Similar to other long-term follow-up studies following ACLR, the current study demonstrated expectably decreasing activity with increasing patient age and time from ACLR-ITB. However, mean activity scores and functional outcome measures in this cohort are superior to age-based normative values, with outcome scores showing no decline in excellent knee function over time, up to 17 years following ACLR-ITB. Moreover, strength and functional hop testing show no clinically significant differences between the uninjured and reconstructed knees after at least 1 year, regardless of time from reconstruction. Equivalence in the measures between the two knees was shown for all LSI measures. The reported ‘non-anatomic’ features of the ACLR-ITB procedure do not appear to translate into clinically meaningful limitations in knee performance and function, which remain absent over time. Tables and figures: [Figure: see text]