Concomitant anterior medializing osteotomy and MPFL reconstruction improves patellar tilt when compared to MPFL reconstruction alone

PURPOSE

Understanding how surgical procedures influence anatomic factors associated with patellofemoral instability can help guide surgeons when planning treatments for individual patients. This study sought to understand how patellar tilt is affected in adolescent patients with elevated pre-operative tibial tuberosity to trochlear groove (TT-TG) values undergoing medial patellofemoral ligament reconstruction (MPFLR) with or without an anterior medializing osteotomy (AMZ).

METHODS

Utilizing a prospective database of 274 patellofemoral instability patients who underwent MPFLR ± AMZ by one of two orthopedic surgeons at a single institution, those who underwent MPFLR + AMZ were identified. Pre-operative and post-operative magnetic resonance imaging (MRI) were used to measure TT-TG distance, while radiographs were used to measure patellar tilt (tilt). Patients were matched based on age at surgery (within 2 years) and pre-operative TT-TG distance (within 2 mm) to a comparison cohort of patients who underwent isolated MPFLR (iMPFLR) without osseous procedures.

RESULTS

A total of 56 patients were analyzed (28 per group). The mean age of the cohort was 15.5 ± 2.0 years and was similar between both groups (15.9 ± 1.9 versus 15.1 ± 2.0 years [n.s]). When comparing the two cohorts, significant pre- to post-operative decreases in patellar tilt for both MPFLR + AMZ (6.6 degrees, p < 0.001) and iMPFLR (3.9 degrees, p = 0.013) were noted. While there were no differences in pre-operative patellar tilt (21.2 ± 3.5 versus 21.1 ± 3.4 [n.s]), post-operatively, MPFLR + AMZ had significantly less patellar tilt than iMPFLR (13.2 ± 5.5 versus 16.5 ± 4.4, p = 0.017).

CONCLUSIONS

This study found that patellar tilt significantly improved in participants undergoing either MPFLR + AMZ or iMPFLR. In addition, those undergoing MPFLR + AMZ were found to have significantly lower post-operative tilt than those undergoing iMPFLR. If patellar tilt is found pre-operatively to be significantly elevated and a risk for future dislocations, these findings suggest that surgeons might strongly consider MPFLR with AMZ to further address the increased tilt.

LEVEL OF EVIDENCE

III.

Techniques in Pediatric Anterior Cruciate Ligament Reconstruction

In recent years, the frequency of anterior cruciate ligament (ACL) tears and ACL reconstruction (ACLR) in skeletally immature patients has increased. Because distal femoral and proximal tibial physes account for the majority of lower-extremity growth, surgical technique and graft selection are crucial to minimize iatrogenic physeal injury. Combined extra- and intra-articular, all-epiphyseal, and transphyseal with soft-tissue grafts are the most common ACLR techniques used in children. Combined extra- and intra-articular ACLR typically is offered to prepubescent patients with ≥2 years of growth remaining. This technique uses iliotibial band (ITB) autograft passed over the lateral femoral condyle and fixed to the anterior tibial periosteum. All-epiphyseal ACLR is similarly used in patients with ≥2 years of growth remaining, provided sufficient epiphyseal maturity to accommodate an all-epiphyseal socket because both the femoral and tibial tunnels are contained within the epiphyses. In postpubertal patients with <2 years of growth remaining, transphyseal ACLR using a soft-tissue autograft (typically hamstring or quadriceps tendon) and metaphyseal femoral fixation can be performed. This minimizes risk of physeal injury. In borderline patients with approximately 2 years of growth remaining, an additional option includes partial transphyseal ACLR, which uses a soft-tissue graft and a transphyseal tibial tunnel, but an all-epiphyseal or over-the-top femoral graft trajectory. Recently, transphyseal ITB ACLR and hybrid transphyseal hamstring with combined over-the-top ITB ACLR also have been described. Existing clinical studies focused on pediatric and adolescent ACL reconstructions have reported a wide range of graft rupture rates for these techniques (4.3%-25%), with contralateral ACL injury rates of 2.9% to 15.6%. Ongoing multicenter research is underway to directly compare surgical techniques for this demographic and quantify graft rupture rates and other clinical outcomes.

The Role of Vertebral Body Tethering in Treating Skeletally Immature Scoliosis

This is a critical analysis of a study by Hoernschemeyer et al, "Anterior Vertebral Body Tethering for Adolescent Scoliosis with Growth Remaining: A Retrospective Review of 2 to 5-Year Postoperative Results" (J Bone Joint Surg Am, 2020;102[13]:1169-1176), that assessed the clinical and radiographic outcomes of vertebral body tethering (VBT) in the treatment of adolescent scoliosis. The authors demonstrated successful treatment in 74% of patients, based on radiographic outcomes and avoidance of subsequent posterior spinal fusion. Nearly a quarter of patients required revision surgery. Almost half suffered a broken tether, although the effects of such complications are not fully understood. The study provided valuable information for determining which patients are reasonable candidates for VBT and emphasizes several questions surrounding this novel technology that remain unanswered. This analysis discusses the study's strengths and weaknesses, suggests potential directions of future research, and examines the potential indications for VBT.

A Novel Shorthand Approach to Knee Bone Age Using MRI: A Validation and Reliability Study

Background:

Bone-age determination remains a difficult process. An atlas for bone age has been created from knee-ossification patterns on magnetic resonance imaging (MRI), thereby avoiding the need for radiographs and associated costs, radiation exposure, and clinical inefficiency. Shorthand methods for bone age can be less time-consuming and require less extensive training as compared with conventional methods.

Purpose:

To create and validate a novel shorthand algorithm for bone age based on knee MRIs that could correlate with conventional hand bone age and demonstrate reliability across medical trainees.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

Included in this study were adolescent patients who underwent both knee MRI and hand bone age radiographs within 90 days between 2009 and 2018. A stepwise algorithm for predicting bone age using knee MRI was developed separately for male and female patients, and 7 raters at varying levels of training used the algorithm to determine the bone age for each MRI. The shorthand algorithm was validated using Spearman rho (r_S) to correlate each rater’s predicted MRI bone age with the recorded Greulich and Pyle (G&P) hand bone age. Interrater and intrarater reliability were also calculated using intraclass correlation coefficients (ICCs).

Results:

A total of 38 patients (44.7% female) underwent imaging at a mean age of 12.8 years (range, 9.3-15.7 years). Shorthand knee MRI bone age scores were strongly correlated with G&P hand bone age (r_S = 0.83; P < .001). The shorthand algorithm was a valid predictor of G&P hand bone age regardless of level of training, as medical students (r_S = 0.75), residents (r_S = 0.81), and attending physicians (r_S = 0.84) performed similarly. The interrater reliability of our shorthand algorithm was 0.81 (95% CI, 0.73-0.88), indicating good to excellent interobserver agreement. Respondents also demonstrated consistency, with 6 of 7 raters demonstrating excellent intrarater reliability (median ICC, 0.86 [range, 0.68-0.96]).

Conclusion:

This shorthand algorithm is a consistent, reliable, and valid way to determine skeletal maturity using knee MRI in patients aged 9 to 16 years and can be utilized across different levels of orthopaedic and radiographic expertise. This method is readily applicable in a clinical setting and may reduce the need for routine hand bone age radiographs.

Septic Arthritis of the Knee in Children: A Critical Analysis Review

» Septic arthritis of the knee is the most common type of septic arthritis in children, and it may result in irreversible joint damage. » Staphylococcus aureus is the most common pathogen associated with septic arthritis, but other causative pathogens are possible in children with certain risk factors. » The diagnosis of septic arthritis of the knee is based on history and physical examination, blood tests, and arthrocentesis. » Empiric treatment with anti-staphylococcal penicillin or a first-generation cephalosporin is usually recommended but may be tailored according to local resistance patterns and clinical culture data. » Open or arthroscopic surgical debridement including extensive lavage is effective in eradicating infection, and most patients do not require additional surgical intervention.

Socioeconomic Deprivation and Its Adverse Association with Adolescent Fracture Care Compliance

Background:

Socioeconomic deprivation increases fracture incidence in adolescents, but its impact on fracture care is unknown. The area deprivation index (ADI), which incorporates 17 factors from the U.S. Census, measures socioeconomic deprivation in neighborhoods. This investigation aimed to determine the impact of socioeconomic deprivation and other socioeconomic factors on fracture care compliance in adolescents.

Methods:

This study included patients who were 11 to 18 years of age and received fracture care at a single urban children’s hospital system between 2015 and 2017. Demographic information (sex, race, caregiver status, insurance type) and clinical information (mechanism of injury, type of treatment) were obtained. The ADI, which has a mean score of 100 points and a standard deviation of 20 points, was used to quantify socioeconomic deprivation for each patient’s neighborhood. The outcome variables related to compliance included the quantity of no-show visits at the orthopaedic clinic and delays in follow-up care of >1 week. Risk factors for suboptimal compliance were evaluated by bivariate analysis and multivariate logistic regression.

Results:

The cohort included 457 adolescents; 75.9% of the patients were male, and the median age was 16.1 years. The median ADI was 101.5 points (interquartile range, 86.3 to 114.9 points). Bivariate analyses demonstrated that higher ADI, black race, single-parent caregiver status, Medicaid insurance, non-sports mechanisms of injury, and surgical management are associated with suboptimal fracture care compliance. Adolescents from the most socially deprived regions were significantly more likely to have delays in care (33.8% compared with 20.1%; p = 0.037) and miss scheduled orthopaedic visits (29.9% compared with 7.1%; p < 0.001) compared with adolescents from the least deprived regions. ADI, Medicaid insurance, and initial presentation to the emergency department were independent predictors of suboptimal care compliance, when controlling for other variables.

Conclusions:

Socioeconomic deprivation is associated with an increased risk of suboptimal fracture care compliance in adolescents. Clinicians can utilize caregiver and insurance status to better understand the likelihood of fracture care compliance. These findings highlight the importance of understanding differences in each family’s ability to adhere to the recommended follow-up and of implementing measures to enhance compliance.