Minimizing the Risk of Vascular Injury: Anatomy of the Popliteal Artery in the Pediatric Knee.

BACKGROUND: Displaced pediatric tibial tubercle fractures are commonly stabilized with screws directed posteriorly toward neurovascular structures. Here, we (1) characterize the variation of the popliteal artery among pediatric patients; and (2) recommend a safe screw trajectory for fixation of tibial tubercle fractures. METHODS: We retrospectively identified 42 patients (42 knees; 29 female) aged 12-17 years with lower-extremity magnetic resonance imaging (MRI) at a tertiary academic center. The mean patient age was 14.5 (range: 12-17) years, and the mean body mass index value was 19.1 (range: 14.9-25.1). We included patients with open physes or visible physeal scars and excluded those with prior instrumentation or lower-extremity injury. Using sagittal MRI, we measured the distances from 5 levels each on the anterior and posterior tibial cortex to the popliteal artery (level 1, midpoint of proximal tibial epiphysis; level 2, the proximal extent of the tubercle; level 3, tubercle prominence; level 4, 2 cm distal to the proximal extent of the tubercle; level 5, 4 cm distal to the proximal extent of the tubercle). Using coronal MRI, we measured the width of the tibia at each level and the distance from the lateral-most and medial-most cortex to the artery. RESULTS: The popliteal artery was laterally positioned in all knees. The mean distance between the artery and lateral-most aspect of the tibia at each level ranged from 1.9 to 2.4 cm, and from 2.3 to 3.9 cm from the medial-most aspect of the tibia. The mean distance that a screw can advance before vascular injury was 5.1 cm at level 1. The shortest mean distance to the popliteal artery was 1.7 cm, at level 5. There is minimal distance between the posterior tibial cortex and the artery at all levels. CONCLUSIONS: Understanding the position of the popliteal artery in pediatric patients can help when stabilizing tibial tubercle fractures. Because the artery is close to the posterior cortex, a drill exiting in line with the popliteal artery risks vascular injury. Therefore, we recommend that screws exit within the medial 60% of the tibia. LEVEL OF EVIDENCE: IV.

Body Mass Hides the Curve: Thoracic Scoliometer Readings Vary by Body Mass Index Value.

BACKGROUND: Guidelines suggest referral for scoliosis when rib slope (scoliometer measurement, angle of trunk rotation) is ≥7 degrees. We hypothesized that overweight and obese patients would have lower scoliometer measurements compared with normal-weight and underweight patients for a given spinal curvature, causing overweight and obese patients with adolescent idiopathic scoliosis to present for treatment later and with larger curves. Our goal was to determine the association between scoliometer readings and major curve magnitudes in relation to body mass index (BMI). METHODS: This retrospective cohort study at a tertiary referral center included 483 patients (420 girls) aged 10 to 18 years (mean age, 14±1.6 y) with thoracic adolescent idiopathic scoliosis who presented to 1 orthopaedic surgeon for initial evaluation of spinal deformity from 2010 to 2015. Records were reviewed for BMI percentile for age and sex (underweight, ≤fourth percentile; normal weight, fifth to 84th percentile; overweight, 85th to 94th percentile; obese, ≥95th percentile), patient characteristics, thoracic scoliometer measurements, and thoracic major curves. RESULTS: Of the 483 patients, 23 were underweight, 372 were normal weight, 52 were overweight, and 36 were obese. Obese patients had a larger mean major curve (44 degrees) than normal-weight patients (34 degrees) (P=0.004). The odds of presenting with a major curve ≥20 degrees were 4.9 (95% confidence interval, 1.1-22; P=0.037) times higher for obese versus normal-weight patients. Receiver operating characteristic analysis of major curves (≥20 vs. <20 degrees) estimated the scoliometer values with the greatest sensitivity and specificity to be 8 degrees for underweight patients, 7 degrees for normal-weight patients, 6 degrees for overweight patients, and 5 degrees for obese patients. CONCLUSIONS: Obese patients presented with larger thoracic curves versus normal-weight patients. Differences in chest-wall thickness in patients with different BMI values may alter scoliometer measurements for a given rotational deformity. Our data suggest new referral criteria for the scoliometer test based on BMI values. Specifically, obese patients should be referred at an angle of trunk rotation of 5 degrees. LEVEL OF EVIDENCE: Level II.

Thinner Tibial Spine Fracture Fragments Are Associated With Risk of Fixation Failure.

Purpose: To determine the rate of and risk factors for failure of tibial spine fracture (TSF) repair. Methods: This was a retrospective review of patients aged 18 years or younger with TSF who underwent arthroscopic repair performed by a single orthopaedic surgeon at a large tertiary academic hospital between 2015 and 2022. Demographic, clinical, injury, fracture, and surgical characteristics were collected. Coronal length and sagittal length and height of the fracture fragment were measured on preoperative plain radiographs and magnetic resonance imaging of the knee. Results: Of 25 patients who underwent arthroscopic reduction with internal fixation of TSFs, 2 (8%) experienced fixation failure. In 16 (64%), internal fixation was performed with suture anchors, whereas 8 (32%) underwent internal fixation with screws. There were 19 male patients (76%). There were no differences in demographic factors (age, race, sex, and body mass index), injury characteristics (laterality, mechanism of injury, and activity causing injury), modified Meyers-McKeever fracture classification, or method of internal fixation between the group with fixation failure and the group without failure. Coronal length (14.2 mm vs 18 mm, P = .17) and sagittal length (13.9 mm vs 18.7 mm, P = .17) of the fracture fragment also did not differ significantly between groups. Sagittal height of the fracture fragment was thinner in patients with failure of fixation (4.3 mm) than in those without failure (8 mm) (P = .02). Conclusions: Decreased bone thickness of the displaced fragment was associated with an increased likelihood of fixation failure. Level of Evidence: Level III, retrospective cohort study.

Flexible nailing: Pushing the indications for diametaphyseal lower-extremity fractures.

Elastic stable intramedullary nailing (ESIN) has been shown to be an effective form of surgical management for lower-extremity diametaphyseal fractures in pediatric patients, but studies are limited because ESIN treatment for these fractures is relatively uncommon. We sought to determine whether ESIN can be used effectively in the most distal or proximal short-segment forms of these fractures. We queried the electronic medical record system at Johns Hopkins Hospital using Current Procedural Terminology codes for femur and tibia fractures treated with ESIN in patients under 18 years old between January 2015 and October 2022. Preoperative and postoperative radiographs were subsequently reviewed to identify patients with a proximal or distal third femoral or tibial shaft fracture treated with ESIN and to define criteria for short-segment diametaphyseal fractures. We used Beaty radiological criteria to evaluate radiographic outcomes and Flynn titanium elastic nails (TENs) outcome scale to assess clinical recovery after radiographic evidence of union. There were 43 children who met the inclusion criteria. Among them, 10 patients had short-segment diametaphyseal fractures. There were 22 (51.2%) who sustained femur fractures and 21 (48.8%) who sustained tibia fractures. Using Beaty radiologic criteria, ESIN was associated with more satisfactory outcomes in patients with distal or proximal third shaft fractures (32/33) than in patients with short-segment diametaphyseal fractures (7/10) (P = .03). Using the TENs outcome scale, 21 (63.4%) patients with distal or proximal third shaft fractures had excellent results, 11 (33.3%) had satisfactory results, and 1 (3%) had a poor result. Among patients with short-segment diametaphyseal fractures, 4 (40%) had excellent results, 5 (50%) had satisfactory results, and 1 (10%) had a poor result. There were no differences in TENs outcomes between the groups (P = .24). Patients with short-segment lower-extremity diametaphyseal fractures treated with ESIN had worse radiographic outcomes but did no worse clinically than patients with distal or proximal third shaft fractures. Consequently, ESIN should be considered a safe and effective surgical management option for pediatric patients with even the most distal or proximal forms of these fractures.

Discoid Meniscus.

Discoid meniscus is the most common congenital variant of the meniscus. Its variability in pathology leads to a spectrum of clinical presentations in patients. Treatment must be tailored to the specific pathology of the discoid meniscus. Imaging studies such as radiographs and magnetic resonance imaging can be useful in confirming the diagnosis, but may be the most accurate in determining specific pathology. Thorough intraoperative evaluation of the discoid is critical to appropriate surgical management. Rim preservation and repair is preferred to prevent degenerative changes in the knee.

Tibial Spine Fractures in Young Athletes.

Tibial spine fractures are a relatively rare injury in the young athlete. Previously thought to be the equivalent of a "pediatric anterior cruciate ligament (ACL) tear," contemporary understanding of these injuries classifies them as distinct from ACL injuries in this patient population. Successful treatment hinges on accurate diagnosis paying special attention to fracture displacement and the presence of concomitant intraarticular injury. Surgery can be performed using open or arthroscopic techniques and a variety of fixation options. The most common complication after surgical treatment is arthrofibrosis and, therefore, stable fixation is necessary to allow for early, unimpeded knee motion postoperatively.

Combined treatment with vacuum sealing drainage, TopClosure device, and Ilizarov technique for traumatic hemipelvectomy: A rare case report of successful repairing of large-size soft tissue defects.

RATIONALE: Traumatic hemipelvectomy is a rare but lethal catastrophic injury. PATIENT CONCERNS: A case of a very young child with open fracture of left sacroiliac joint dislocation and pubic symphysis diastasis, suffered from a severe large-size soft tissue defects. DIAGNOSIS: Traumatic hemipelvectomy. INTERVENTIONS: Complete amputation was performed and three kinds of surgical techniques including regulated negative pressure-assisted wound therapy (RNPT), TopClosure device, and Ilizarov technique were jointly utilized to secure closure in the further revisions of the soft tissue injury and reconstruct reconstructive surgery. OUTCOMES: Six months after hospital discharge, the patient was able to ambulate with a single limb and a prosthesis and she is independent in many activities of daily living currently. LESSONS: We report this case to share experience with other clinicians in the management of this deadly extensive defects after traumatic hemipelvectomy in patients.

The 5-strand hamstring graft in anterior cruciate ligament reconstruction.

The use of anterior cruciate ligament reconstruction in the pediatric and adolescent population has been increasing in recent years. Autograft hamstring graft is favored in this population, but these patients often have smaller hamstring tendons that yield smaller final graft constructs. These smaller grafts are associated with an increased need for revision surgery. We describe a technique for obtaining a larger-diameter anterior cruciate ligament graft construct from autologous hamstring graft without allograft supplementation.