Early ACL reconstruction in children leads to less meniscal and articular cartilage damage when compared with conservative or delayed treatment

Unraveling sex-specific risks of knee osteoarthritis before menopause: Do sex differences start early in life?

OBJECTIVE

Sufficient evidence within the past two decades have shown that osteoarthritis (OA) has a sex-specific component. However, efforts to reveal the biological causes of this disparity have emerged more gradually. In this narrative review, we discuss anatomical differences within the knee, incidence of injuries in youth sports, and metabolic factors that present early in life (childhood and early adulthood) that can contribute to a higher risk of OA in females.

DESIGN

We compiled clinical data from multiple tissues within the knee joint-since OA is a whole joint disorder-aiming to reveal relevant factors behind the sex differences from different perspectives.

RESULTS

The data gathered in this review indicate that sex differences in articular cartilage, meniscus, and anterior cruciate ligament are detected as early as childhood and are not only explained by sex hormones. Aiming to unveil the biological causes of the uneven sex-specific risks for knee OA, we review the current knowledge of sex differences mostly in young, but also including old populations, from the perspective of (i) human anatomy in both healthy and pathological conditions, (ii) physical activity and response to injury, and (iii) metabolic signatures.

CONCLUSIONS

We propose that to close the gap in health disparities, and specifically regarding OA, we should address sex-specific anatomic, biologic, and metabolic factors at early stages in life, as a way to prevent the higher severity and incidence of OA in women later in life.

Pediatric ACL Reconstruction in Children-An Evaluation of the Transphyseal Technique's Efficacy and Safety

INTRODUCTION

Injuries of the anterior cruciate ligament (ACL) are commonly found in the general population, both among adult and pediatric patients, and their incidence has been increasing in recent years. Most of the late literature agrees that surgical reconstruction of the ACL is effective in improving long-term outcomes in pediatric patients, while others in the past have pleaded for non-surgical management.

PURPOSE/HYPOTHESIS

Our study aims to verify if ACL reconstruction (ACLR) using transphyseal technique in skeletally immature patients will provide angular deviations or growth restrictions.

STUDY DESIGN

Retrospective cohort study; Level of evidence 4.

METHODS

We perfomed a retrospective study to verify if transphyseal ACLR in children with less than or equal to 2 years of remaining growth leads to either limb length discrepancies or axis deviations.

RESULTS

Most patients who were treated using transphyseal technique showed significant improvements in their functional scores. There were statistically significant differences in lateral distal femoral angles (LDFA) and medial proximal tibial angles (MPTA), with no clinical impact. There was no significant limb length discrepancy (LLD) during the 2-year follow-up.

CONCLUSIONS

Transphyseal ACLR is safe among children who have less than or equal to 2 years of remaining growth and brings no risk of axis deviations or limb length discrepancy.

Revision Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients

Revision anterior cruciate ligament (ACL) reconstruction in the skeletally immature patient is a challenging procedure for pediatric patients with recurrent instability after primary ACL reconstruction. The pediatric population presents unique technical challenges and complications secondary to open physes compared with the adult population. Complications can include growth disturbances, recurrent graft failure, instability, and secondary chondral and/or meniscal injury. Moreover, identifying the etiology of graft failure is critical for a successful revision. Patients should undergo a complete history and physical examination with a focus on patient physiologic age, physeal status, mechanical axis, tibial slope, collagen status, injury mechanism, concomitant injuries, and previous surgical procedures. The surgeon must be adept at reconstruction with various grafts as well as socket or tunnel preparation and fixation, including over-the-top, all-epiphyseal, transphyseal, extra-articular augmentation, and staging approaches. Reported rates of return to sport are lower than those of primary reconstruction, with higher rates of cartilage and meniscal degeneration. Future research should focus on optimizing surgical outcomes and graft survivorship after primary ACL reconstruction with minimized trauma to the physis.

Advanced Graft Development Approaches for ACL Reconstruction or Regeneration

The Anterior Cruciate Ligament (ACL) is one of the major knee ligaments, one which is greatly exposed to injuries. According to the British National Health Society, ACL tears represent around 40% of all knee injuries. The number of ACL injuries has increased rapidly over the past ten years, especially in people from 26-30 years of age. We present a brief background in currently used ACL treatment strategies with a description of surgical reconstruction techniques. According to the well-established method, the PubMed database was then analyzed to scaffold preparation methods and materials. The number of publications and clinical trials over the last almost 30 years were analyzed to determine trends in ACL graft development. Finally, we described selected ACL scaffold development publications of engineering, medical, and business interest. The systematic PubMed database analysis indicated a high interest in collagen for the purpose of ACL graft development, an increased interest in hybrid grafts, a numerical balance in the development of biodegradable and nonbiodegradable grafts, and a low number of clinical trials. The investigation of selected publications indicated that only a few suggest a real possibility of creating healthy tissue. At the same time, many of them focus on specific details and fundamental science. Grafts exhibit a wide range of mechanical properties, mostly because of polymer types and graft morphology. Moreover, most of the research ends at the in vitro stage, using non-certificated polymers, thus requiring a long time before the medical device can be placed on the market. In addition to scientific concerns, official regulations limit the immediate introduction of artificial grafts onto the market.

Epidemiology and Revision Rates of Pediatric ACL Reconstruction in New York State

BACKGROUND

There are limited epidemiologic data examining the incidence of pediatric anterior cruciate ligament reconstruction (ACLR) over the past decade.

PURPOSE

To examine statewide population trends in the incidence of ACLR in a pediatric population.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Inpatient and outpatient claims for pediatric patients who underwent ACLR between 2009 and 2017 were identified in the New York Statewide Planning and Research Cooperative System database via International Classification of Diseases (ICD), Revision 9, Clinical Modification; ICD, Revision 10, Clinical Modification and Procedural Classification System; or Current Procedural Terminology codes. New York population data for each year between 2009 and 2017 were used from the New York State Department of Health to calculate the rates of ACLR per 100,000 people aged 3 to 19 years and determine the 95% confidence limits. The rates were then stratified by age, sex, and insurance. Two-year rates of revision and contralateral ACLR were also analyzed by sex.

RESULTS

Between 2009 and 2017, 20,170 pediatric ACLRs were identified. The rates of pediatric ACLR increased steadily from 49.3 per 100,000 in 2009 (95% CI, 47.2-51.4) to a peak of 61.0 (95% CI, 58.6-63.4) in 2014 and decreased to 51.8 (95% CI, 49.6-54.1) by 2017. The age group 15 to 17 years had the highest rates of ACLR of all age groups, peaking at 198.5 (95% CI, 188.3-208.7) per 100,000. Analysis by sex showed that ACLR rates between males and females were not different. Males had a 2-year ipsilateral revision rate of 4.3%, while females had a rate of 3.3% (P = .0001). Females had a contralateral ACLR rate of 4.0%, while males had a rate of 2.6% (P = .0002).

CONCLUSION

Pediatric ACLR rates continued to rise until 2014, but there was a demonstrable decrease in rates after 2014. This decline in pediatric ACLR may point to the efficacy of injury prevention programs or changes in practice management. The high revision rate in males and high contralateral surgery rate in females can help guide patient counseling for return to play and complication risk.

CLINICAL RELEVANCE

This study showed that ACLR in pediatric patients may be decreasing in recent years. There were differences in revision and contralateral ACLR by sex.

Early Operative Versus Delayed Operative Versus Nonoperative Treatment of Pediatric and Adolescent Anterior Cruciate Ligament Injuries: A Systematic Review and Meta-analysis

BACKGROUND

Treatment options for pediatric and adolescent anterior cruciate ligament (ACL) injuries include early operative, delayed operative, and nonoperative management. Currently, there is a lack of consensus regarding the optimal treatment for these injuries.

PURPOSE/HYPOTHESIS

The purpose was to determine the optimal treatment strategy for ACL injuries in pediatric and adolescent patients. We hypothesized that (1) early ACL reconstruction results in fewer meniscal tears than delayed reconstruction but yields no difference in knee stability and (2) when compared with nonoperative management, any operative management results in fewer meniscal tears and cartilage injuries, greater knee stability, and higher return-to-sport rates.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic search of databases was performed including PubMed, Embase, and Cochrane Library using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were a pediatric and adolescent patient population (≤19 years old at surgery), the reporting of clinical outcomes after treatment of primary ACL injury, and original scientific research article. Exclusion criteria were revision ACL reconstruction, tibial spine avulsion fracture, case report or small case series (<5 patients), non-English language manuscripts, multiligamentous injuries, and nonclinical studies.

RESULTS

A total of 30 studies containing 50 cohorts and representing 1176 patients met our criteria. With respect to nonoperative treatment, knee instability was observed in 20% to 100%, and return to preinjury level of sports ranged from 6% to 50% at final follow-up. Regarding operative treatment, meta-analysis results favored early ACL reconstruction over delayed reconstruction (>12 weeks) for the presence of any meniscal tear (odds ratio, 0.23; P = .006) and irreparable meniscal tear (odds ratio, 0.31; P = .001). Comparison of any side-to-side differences in KT-1000 arthrometer testing did not favor early or delayed ACL reconstruction in either continuous mean differences (P = .413) or proportion with difference ≥3 mm (P = .181). Return to preinjury level of competition rates for early and delayed ACL reconstruction ranged from 57% to 100%.

CONCLUSION

Delaying ACL reconstruction in pediatric or adolescent patients for >12 weeks significantly increased the risk of meniscal injuries and irreparable meniscal tears; however, early and delayed operative treatment achieved satisfactory knee stability. Nonoperative management resulted in high rates of residual knee instability, increased risk of meniscal tears, and comparatively low rates of return to sports.

Feasibility study of early prediction of postoperative MRI findings for knee stability after anterior cruciate ligament reconstruction

Background

At present, the most effective and mature treatment after ACL injury and tear is ACL reconstruction, but the rehabilitation process after ACL reconstruction that is very long, so it is very important to find early MRI positive findings of knee instability.

Methods

We retrospectively collected the clinical and imaging data of 70 patients who underwent ACL reconstruction from January 2016 to December 2019; Based on clinical criteria, the patients were divided into a stable group (n = 57) and an unstable group (n = 13); We measured the MRI imaging evaluation indexes, including the position of the bone tunnel, graft status, and the anatomical factors; Statistical methods were used to compare the differences of imaging evaluation indexes between the two groups; The prediction equation was constructed and ROC curve was used to compare the prediction efficiency of independent prediction factors and prediction equation.

Results

There were significant differences in the abnormal position of tibial tunnel entrance, percentage of the position of tibial tunnel entrance, position of tibial tunnel exit, lateral tibial posterior slope (LTPS), width of intercondylar notch between stable knee joint group and unstable knee joint group after ACL reconstruction (P < 0.05); The position of tibial tunnel exits and the lateral tibial posterior slope (LTPS) and the sagittal obliquity of the graft were independent predictors among surgical factors and self-anatomical factors (P < 0.05); The prediction equation of postoperative knee stability was established: Logit(P) = -1.067–0.231*position of tibial tunnel exit + 0.509*lateral tibial posterior slope (LTPS)-2.105*sagittal obliquity of the graft; The prediction equation predicted that the AUC of knee instability was 0.915, the sensitivity was 84.6%, and the specificity was 91.2%.

Conclusions

We found that abnormalities of the position of the exit of the bone tunnel, lateral tibial posterior slope (LTPS) and sagittal obliquity of the graft were the early MRI positive findings of knee instability after ACL reconstruction. It is helpful for clinicians to predict the stability of knee joint after ACL reconstruction.

Anatomic Dissection and CT Imaging of the Anterior Cruciate and Medial Collateral Ligament Footprint Anatomy in Skeletally Immature Cadaver Knees

BACKGROUND

Anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries in skeletally immature patients are increasingly recognized and surgically treated. However, the relationship between the footprint anatomy and the physes are not clearly defined. The purpose of this study was to identify the origin and insertion of the ACL and MCL, and define the footprint anatomy in relation to the physes in skeletally immature knees.

METHODS

Twenty-nine skeletally immature knees from 16 human cadaver specimens were dissected and divided into 2 groups: group A (aged 2 to 5 y), and group B (aged 7 to 11 y). Metallic markers were placed to mark the femoral and tibial attachments of the ACL and MCL. Computed tomography scans were obtained for each specimen used to measure the distance from the center of the ligament footprints to the respective distal femoral and proximal tibial physes.

RESULTS

The median distance from the ACL femoral epiphyseal origin to the distal femoral physis was 0.30 cm (interquartile range, 0.20 to 0.50 cm) and 0.70 cm (interquartile range, 0.45 to 0.90 cm) for groups A and B, respectively. The median distance from the ACL epiphyseal tibial insertion to the proximal tibial physis for groups A and B were 1.50 cm (interquartile range, 1.40 to 1.60 cm) and 1.80 cm (interquartile range, 1.60 to 1.85 cm), respectively. The median distance from the MCL femoral origin on the epiphysis to the distal femoral physis was 1.20 cm (interquartile range, 1.00 to 1.20 cm) and 0.85 cm (interquartile range, 0.63 to 1.00 cm) for groups A and B, respectively. The median distance from the MCL insertion on the tibial metaphysis to the tibial physis was 3.05 cm (interquartile range, 2.63 to 3.30 cm) and 4.80 cm (interquartile range, 3.90 to 5.10 cm) for groups A and B, respectively.

CONCLUSION

Surgical reconstruction is a common treatment for ACL injury. Computed tomography scanning of pediatric tissue clearly defines the location of the ACL and MCL with respect to the femoral and tibial physes, and may guide surgeons for physeal respecting procedures.

CLINICAL RELEVANCE

In addition to ACL reconstruction, recent basic science and clinical research suggest that ACL repair may be more commonly performed in the future. MCL repair and reconstruction is also occasionally required in skeletally immature patients. This information may be useful to help surgeons avoid or minimize physeal injury during ACL/MCL reconstructions and/or repair in skeletally immature patients.

Trends in Concomitant Meniscal Surgery Among Pediatric Patients Undergoing ACL Reconstruction: An Analysis of ABOS Part II Candidates From 2000 to 2016

Background

Rates of anterior cruciate ligament (ACL) reconstruction among pediatric and adolescent patients are increasing. Limited knowledge exists about population-level rates of concomitant meniscal surgery in this age group.

Purpose/Hypothesis

This study sought to examine trends in concomitant meniscal procedures and describe short-term complications in pediatric and adolescent patients undergoing ACL reconstruction. We hypothesized that overall meniscal surgery rates are increasing and that the likelihood of performing meniscal repair or meniscectomy is associated with patient- and surgeon-specific factors.

Study Design

Cross-sectional study.

Methods

We queried ACL procedures in patients younger than 19 years reported by American Board of Orthopaedic Surgery (ABOS) part II examination candidates from 2000 to 2016. Regression models examined associations between patient and surgeon characteristics, year of surgery, follow-up time, meniscal procedure type, and number and type of complications.

Results

A total of 9766 cases were identified. Females represented 46% (n = 4468) of included cases. Mean patient age was 16.1 years (SD, 1.62 years; range, 0-18 years). The rate of concomitant ACL-meniscal procedures increased from the years 2000 to 2016 (49%-60%; P = .005). Surgeons with sports medicine (+7.0%) or pediatric orthopaedic fellowship (+6.6%) training had a higher likelihood of reporting a concomitant ACL-meniscal procedure (P = .003 and .006, respectively). Sports medicine-trained surgeons were more likely to perform meniscal repair compared with meniscectomy (+3.0%; P = .016). Younger patient age was associated with increased likelihood of undergoing meniscal repair compared with meniscectomy. Overall reported complication rate was 12.8%. Notable reported complications included infection (1.61%), arthrofibrosis (1.14%), and deep venous thrombosis or pulmonary embolism (0.11%). Sports medicine and pediatric orthopaedic fellowship training was associated with higher rates of reporting postoperative stiffness and/or arthrofibrosis.

Conclusion

Among ABOS part II candidates, concomitant ACL-meniscal surgery has become more common than isolated ACL procedures. Procedures involving sports medicine fellowship-trained surgeons and younger patients were associated with increased rates of meniscal repair compared with meniscectomy. Pediatric orthopaedic and sports medicine training was associated with a greater likelihood of being involved in a concomitant ACL-meniscal procedure of any kind, and surgeons with such training also reported a higher incidence of postoperative stiffness and/or arthrofibrosis in patients.

Anterior cruciate ligament reconstruction with an all-epiphyseal "over-the-top" technique is safe and shows low rate of failure in skeletally immature athletes

PURPOSE

The aim of this study was to follow up, clinically and radiographically, skeletally immature patients who underwent ACL reconstruction with an all-epiphyseal "over-the-top" technique.

METHODS

Twenty athletes aged between 8 and 13 years were enrolled and retrospectively evaluated. The subjects underwent surgical ACL reconstruction between 2009 and 2013. The surgical technique consisted of a single-bundle all-epiphyseal ACL reconstruction with an extra-articular lateral tenodesis. The mean follow-up was 54 months [34-123] after surgery. Clinically, the patients were evaluated pre- and post-operatively with Lysholm and KOOS scores; sport activity level was evaluated using the pre-injury, pre-operative and post-operative Tegner scores. Objective IKDC was calculated post-operatively. The joint laxity was evaluated by KT1000 and Rolimeter arthrometers. Panoramic AP standing radiographs of the lower limbs and lateral knee radiographs were also taken at the follow-up to evaluate limb length discrepancies (LLD) and axial malalignment. Normally distributed parameters were presented as mean ± standard deviation, while the non-normally distributed parameters were presented as median [25° percentile, 75° percentile].

RESULTS

Clinical scores showed significant (P < 0.01) improvement: Lysholm and KOOS scores improved from 40 [22; 65] and 59 [42, 73], respectively, to 100 [95; 100] and 99 [97;100] after surgery. Tegner score improved from 2 [2; 2] pre-operatively to 7 [3; 9] at follow-up (P < 0.01). At follow-up, IKDC score was A for 19 patients and one who scored B. All patients returned to sport activity and had good stability at follow-up: the KT1000 showed a median side-to-side difference of 0.0 mm [- 0.4; 1.0] for the standard force evaluation and 0.0 mm [- 1.0; 0.8] for manual-maximum test. The Rolimeter showed median side-to-site difference of 0.0 mm [- 1.0; 0.8]. Three minor leg length discrepancies and axial deviations were observed at the radiograph: one patient had 0.6 cm lengthening and 4° of varus, one had 1 cm lengthening, and one had 3° of varus (in comparison with the non-operated limb). No re-injury was observed.

CONCLUSION

This study demonstrates that the modified all-epiphyseal single-bundle "over-the-top" technique is a viable and safe option for ACL reconstruction in pediatric subjects. These results support once more that not only ACL reconstruction is a safe procedure in skeletally immature patients, but also it is highly recommended for those who want to pursue an active and sportive life.

LEVEL OF EVIDENCE

Case series, IV.

Recurrent Instability Episodes and Meniscal or Cartilage Damage After Anterior Cruciate Ligament Injury: A Systematic Review

Background

Delayed anterior cruciate ligament (ACL) reconstruction may be associated with increased risk of subsequent knee joint damage and osteoarthritis (OA). The relationship between recurrent instability episodes and meniscal or cartilage damage after first-time ACL injury is unknown.

Purpose

To assess the association between recurrent knee instability episodes and prevalence of meniscal lesions, cartilage damage, and OA after first-time ACL injury.

Study Design

Systematic review; Level of evidence, 4.

Methods

Six electronic databases were systematically searched using keywords and Medical Subject Heading terms. Studies selected were of English language, included original data, had a prospective design, and provided an outcome of recurrent instability and meniscal lesions, cartilage damage, or OA after first-time ACL injury. Adjusted odds ratios (ORs) were extracted or unadjusted ORs (95% CI) were calculated. PRISMA guidelines were followed, and 2 independent raters assessed study quality using Downs and Black criteria.

Results

Of 905 potentially relevant studies, 7 were included. Sample sizes ranged from 43 to 541, and Downs and Black scores ranged from 2 to 12. Clinical and methodological heterogeneity precluded meta-analysis. Six studies reported a positive association between recurrent instability episodes and medial meniscal damage (OR range, 3.46 [95% CI, 1.24-9.99] to 11.56 [1.37-521.06]). The association between instability episodes and lateral meniscal or cartilage damage was inconsistent. No studies examined the association between instability episodes and OA.

Conclusion

This systematic review provides preliminary evidence that recurrent instability episodes after first-time ACL injury may be associated with increased odds of medial meniscal damage. This highlights the importance of early diagnosis, education, and treatment for individuals with ACL injury, all of which must include a specific focus on the prevention and management of instability episodes. High-quality, prospective cohort studies are needed that assess the effects of diagnostic and treatment delay, recurrent instability episodes on secondary meniscal and cartilage damage, and OA after an initial ACL injury.

Biomechanical Comparison of Epiphyseal Anterior Cruciate Ligament Fixation Using a Cortical Button Construct Versus an Interference Screw and Sheath Construct in Skeletally Immature Cadaveric Specimens

Background:

Anterior cruciate ligament (ACL) ruptures have become increasingly common in pediatric and adolescent athletes. While multiple methods exist, all-epiphyseal ACL reconstruction is a popular technique in the skeletally immature patient. Given the high rate of reruptures in this population and the increasing number of commercially available fixation devices, biomechanical testing is crucial to understand the performance of these devices in pediatric epiphyseal bone. To our knowledge, there has not been a biomechanical analysis of ACL fixation devices in skeletally immature bone.

Purpose:

To compare cortically based button fixation with interference screw and sheath fixation in skeletally immature femoral epiphyseal cadaveric bone. Our hypothesis was that there would be no difference in peak load to failure, stiffness, or cyclic displacement between these 2 fixation constructs.

Study Design:

Controlled laboratory study.

Methods:

Fresh-frozen matched-pair knees from 3 pediatric cadaveric specimens were obtained. A synthetic graft was fixed in an all-epiphyseal femoral tunnel. Both the lateral and medial condyles were utilized to increase the sample size. Specimens were randomized and assigned to receive either an interference screw and sheath construct designed for pediatric patients or an adjustable loop cortical button. Biomechanical testing was performed to obtain ultimate load to failure, stiffness, total displacement after 500 cycles, and the failure mode for each condyle.

Results:

Each medial and lateral condyle in 3 pairs of skeletally immature cadaveric knees (ages 7, 9, and 11 years) was utilized for testing. One specimen was excluded after it failed by having a transphyseal fracture. The median peak load to failure was 769.80 N (interquartile range [IQR], 628.50-930.41 N) for the screw and sheath group and 862.80 N (IQR, 692.34-872.65 N) for the button group (P = .893). The median displacement after 500 cycles for the screw and sheath group was 0.65 mm (IQR, 0.47-1.03 mm) and 1.13 mm (IQR, 0.96-1.25 mm) for the button group (P = .08). The median stiffness of the screw and sheath group was significantly higher than that of the button group (31.47 N/mm [IQR, 26.40-43.00 N/mm] vs 25.22 N/mm [IQR, 21.18-27.07 N/mm], respectively) (P = .043).

Conclusion:

When comparing femoral fixation with a screw and sheath construct developed for pediatric patients to an adjustable loop cortical button in skeletally immature bone, our results showed that fixation did not significantly differ with respect to cyclic displacement or peak load to failure. While the screw and sheath construct was significantly stiffer, its effect on clinical outcomes is not yet known.

Clinical Relevance:

With regard to femoral fixation, there is no significant biomechanical difference between the use of cortically based button fixation or interference screw and sheath fixation in pediatric epiphyseal cadaveric bone.

Outcomes of Physeal-Sparing ACL Reconstruction with Iliotibial Band Autograft in Skeletally Immature Prepubescent Children

BACKGROUND

Anterior cruciate ligament (ACL) tears are occurring in youth athletes with increasing frequency. Many ACL reconstruction procedures designed to allow for continued growth in patients with open physes have been described, but large series with mid- to long-term outcomes data are lacking. The purpose of the current study was to assess the clinical outcomes of a large cohort of prepubescent children who underwent a physeal-sparing, combined intra- and extra-articular ACL reconstruction with iliotibial (IT) band autograft over a 23-year period.

METHODS

Included in our analysis were 237 patients (240 knees) who underwent ACL reconstruction using IT band autograft at Tanner stage 1 or 2 (mean age of 11.2 ± 1.7 years). Physical examination data were analyzed for 225 of the 240 knees (mean follow-up, 25.8 months), and 137 (57%) of the knees had corresponding patient-reported clinical outcomes (patient-reported graft rupture and Pediatric International Knee Documentation Committee [Pedi-IKDC], Tegner activity scale, and Lysholm scores; mean follow-up, 6.2 years). Rates of growth arrest, IT band graft-harvest morbidity, and return to sports were analyzed.

RESULTS

Physical examination revealed that 96.8% of the knees were grade A on the Lachman test and 98.8% were grade A on the pivot-shift test. Graft rupture occurred in 9 (6.6%) of 137 knees, at an average of 33.5 months (range, 8.2 months to 8.0 years) postoperatively. For patients who did not sustain a graft rupture, the mean Pedi-IKDC score was 93.3 ± 11.0, the mean Lysholm score was 93.4 ± 9.9, and the mean score on the Tegner activity scale was 7.8 (mode, 7). While lateral thigh asymmetry at the IT band harvest site was noted by 48% of the subjects, only 1.6% reported associated pain. No cases of limb-length discrepancy or angular deformity were observed.

CONCLUSIONS

This procedure was associated with excellent functional outcomes, minimal risk of growth disturbance, and a low graft-rupture rate in skeletally immature prepubescent children. These results appear durable at mid- to long-term follow-up, at an average of >6 years postoperatively.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Incidence of Meniscal Entrapment and Associated Knee Injuries in Tibial Spine Avulsions

BACKGROUND

Tibial spine avulsions (TSA) have historically been treated as isolated injuries. Data on associated injuries are limited with existing literature reporting wide ranging incidences. The purpose of this multicenter study was to (1) describe the incidence of meniscal entrapment and associated knee injuries in TSA and to (2) compare surgical and magnetic resonance image (MRI) findings for these injuries. Our hypothesis is that tibial spine injuries are not usually isolated injuries, and other meniscal, ligament, and cartilage injuries may be present.

METHODS

MRI and surgical reports for patients with a diagnosis of a tibial spine fracture were retrospectively reviewed. Type of fracture was recorded as noted in the reports along with concomitant meniscal entrapment and osteochondral, ligamentous, and meniscal injury. Images and reports were reviewed by an orthopaedic surgeon at each respective institution.

RESULTS

A total of 163 patients were included in this study. MRI was done for 77 patients and surgery was performed in 144 cases. Meniscal entrapment was found in 39.9% of all patients. MRI diagnosed meniscus, osteochondral, and non-anterior cruciate ligament ligamentous injury was found in 31.2%, 68.8%, and 32.4% of cases, respectively. Surgically diagnosed meniscus, chondral, and non-anterior cruciate ligament ligamentous injury was found in 34.7%, 33.3%, and 5.6% of patients, respectively.

CONCLUSIONS

TSA fractures are associated with significant risk for concomitant knee injuries including meniscal tear, bone contusion, and chondral injury. Incidence of meniscal entrapment found during surgery was high, in spite of low incidence of positive findings by MRI.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Lateral Radiographic Landmarks for ACL and LCL Footprint Origins During All-Epiphyseal Femoral Drilling in Skeletally Immature Knees

BACKGROUND

This study was conducted to evaluate the spatial relationship of the anterior cruciate ligament (ACL) and lateral collateral ligament (LCL) femoral footprint origins in knee specimens from skeletally immature donors as viewed on lateral radiographs.

METHODS

Fourteen cadaver specimens of skeletally immature knees from children between 7 and 11 years old at the time of death were examined through gross dissection. Metallic pins were placed at the center of the ACL and LCL femoral footprints, and computed tomography (CT) scans were performed. Sagittal plane CT images were merged to create a view analogous to an intraoperative C-arm image with overlaid ACL and LCL ligament footprints. Ligament origins were then measured as a percent of the epiphyseal depth (% P-A [posterior-anterior]) and height (% P-D [proximal-distal]).

RESULTS

The ACL origin was centered at a point located 14% (14% P-A) of the total lateral femoral condyle (LFC) depth from the most posterior aspect of the LFC and 38% (38% P-D) of the LFC height from the most proximal aspect of the posterior physis. The LCL origin was centered at a point 27% P-A and 37% P-D. When viewed on a sagittal CT reconstruction analogous to a perfect lateral intraoperative fluoroscopic view, the ACL footprint origin is posterior and slightly inferior to the LCL origin. Both origins are distal to the distal femoral physis and are posterior to the origin of the popliteus.

CONCLUSIONS

This study demonstrates a consistent relationship between the origin of the ACL and LCL, which may be useful in guiding safe tunnel placement during all-epiphyseal ACL reconstruction in skeletally immature knees.

CLINICAL RELEVANCE

This anatomic reference can be used intraoperatively to guide and radiographically evaluate ACL tunnel placement while avoiding the LCL origin in skeletally immature patients.

Magnetic resonance imaging after anterior cruciate ligament reconstruction: A practical guide

Anterior cruciate ligament (ACL) reconstruction is one of the most common orthopedic procedures performed worldwide. In this regard, magnetic resonance imaging (MRI) represents a useful pre-operative tool to confirm a disruption of the ACL and to assess for potential associated injuries. However, MRI is also valuable post-operatively, as it is able to identify, in a non-invasive way, a number of aspects and situations that could suggest potential problems to clinicians. Graft signal and integrity, correct tunnel placement, tunnel widening, and problems with fixation devices or the donor site could all compromise the surgical outcomes and potentially predict the failure of the ACL reconstruction. Furthermore, several anatomical features of the knee could be associated to worst outcomes or higher risk of failure. This review provides a practical guide for the clinician to evaluate the post-surgical ACL through MRI, and to analyze all the parameters and features directly or indirectly related to ACL reconstruction, in order to assess for normal or pathologic conditions.