Pediatric Orthopedic Emergencies

Intra-articular migration of tibial suture button in pediatric full epiphyseal anterior cruciate ligament reconstruction. A case report

We report a case of a 12-years-old boy that underwent anterior cruciate ligament (ACL) reconstruction and lateral meniscus repair. The all-epiphyseal, all-inside technique, with quadriceps tendon autograft and adjustable suspensory button fixation was utilized due to the open physes. Intraoperative fluoroscopy confirmed optimal position of the buttons, while arthroscopic evaluation of the graft showed proper tension, with full range of motion and knee stability. Nevertheless, routine radiographic evaluation of the knee, 6 ​h postoperatively, revealed tibial button migration through the tunnel into the knee joint, while the knee was unstable in clinical examination. The graft was removed and reloaded with extended buttons. The femoral socket was retained in the revision surgery while a new tibial socket was drilled with the transphyseal technique (all-inside technique). The postoperative course was uneventful. The patient returned to unrestricted activities at twelve months after revision surgery and remains fully active two years postoperatively. This is the first case of tibial button migration reported in the literature, with immediate migration after surgery, intra-articular position of the button and negative impact on graft tension. Failure to recognize and treat this detrimental complication could be catastrophic for the knee. The technique of the surgical treatment is also described. Surgeons should be aware of this rare complication, that could adversely affect the clinical outcome.

Does Shorter Time to Treatment of Pediatric Supracondylar Humerus Fractures Impact Clinical Outcomes?

BACKGROUND

Treatment of supracondylar humerus (SCH) fractures within 18 hours of presentation is a tracked quality metric for ranking of pediatric hospitals. This is in contrast with literature that shows time to treatment does not impact outcomes in SCH fractures. We aim to determine whether an 18-hour cutoff for pediatric supracondylar humerus fracture treatment is clinically significant by comparing the complication risks ofpatients on either side of this timepoint. Our hypothesis is that there will be no statistically significant differences based on time to treatment.

METHODS

A retrospective review of clinical outcomes was performed for 472 pediatric patients who underwent surgical management of isolated supracondylar humerus fractures between 1997 and 2022 at a single level I pediatric trauma hospital. The cohort was split based on time to surgery (within or ≥18 h from Emergency Department admission).

RESULTS

Surgical treatment occurred within 18 hours of arrival in 435 (92.2%) patients and after 18 hours in 37 (7.8%) patients. Mean age was 5.6±2.2 years and 51.5% of patients were female. Gartland fracture classification was type II [n=152 (32.3%)], type III [n=284 (60.3%)], type IV [n=13 (2.8%)], or flexion-type [n=18 (3.8%)]. There were no differences in demographic characteristics or fracture classification between cohorts. Fractures in the ≥18-hour cohort were treated more commonly with 2 pins (62.2% vs. 38.5%, P =0.04). There were no statistically significant differences in open versus closed reduction, utilization of medial pins, or postoperative immobilization between cohorts. We were unable to detect any differences in postoperative complications, including non-union, delayed union, stiffness, malunion, loss of reduction, iatrogenic nerve injury, or infection. This remained true when type II fractures were excluded.

CONCLUSIONS

Using an arbitrary time cutoff of <18 hours does not influence clinical outcomes in the surgical treatment of SCH fractures. This held true when type II fractures were excluded. For this reason, we recommend modification to the USNWR guidelines to decrease emphasis on time-to-treatment of SCH fractures.

LEVEL OF EVIDENCE

Level III.

Greenstick fractures of the proximal metaphyseal tibia: a retrospective multicenter study on the outcome after non-surgical or surgical treatment and the occurrence of posttraumatic tibia valga

Purpose

This study investigates the occurrence of (progressive) posttraumatic valgus deformity after proximal metaphyseal greenstick fractures of the tibia in young children, and whether non-surgical or surgical treatment influences the outcome.

Methods

A retrospective multi-center study was conducted including surveys and X-rays of patients < 12 years of age with a fracture of the proximal tibia. In patients with greenstick fractures, the medial proximal tibia angle (MPTA; defined as the angle of the tibial axis and the joint-line of the knee) was measured at trauma, short-term follow-up (st-FU), and long-term FU (lt-FU) as defined for the 2 groups of non-surgically and surgically treated patients.

Results

Of a total of 322 fractures, 91 were greenstick fractures. Of these, 74 were treated non-surgically and 17 were treated surgically. The mean MPTA at trauma of non-surgically treated patients was 91.14°, and of surgically treated patients was 95.59° (p = 0.020). The MPTA in non-surgically treated patients significantly increased from the timepoint of trauma to st-FU (92,0°; p = 0.030), and lt-FU (92,66°, p = 0.016). In surgically treated patients, the MTPA improved after trauma to st-FU (94.00°; p = 0.290), and increased again to lt-FU (96.41°; p = 0.618).

Conclusion

Progressive valgus deformity after greenstick fractures of the proximal tibia occurred in both non-surgically and surgically treated patients. In non-surgically treated patients, this was of statistical, but not clinical significance. In surgically treated patients, progressive valgus was observed after metal removal for an unknown reason. Therefore, surgery for proximal greenstick fractures of the tibia in this age group has only limited effect and may be indicated only in selected cases. Further studies are needed to explain the responsible mechanisms.

Level of evidence

III, retrospective analysis.

Automated detection of acute appendicular skeletal fractures in pediatric patients using deep learning

OBJECTIVE

We aimed to perform an external validation of an existing commercial AI software program (BoneView™) for the detection of acute appendicular fractures in pediatric patients.

MATERIALS AND METHODS

In our retrospective study, anonymized radiographic exams of extremities, with or without fractures, from pediatric patients (aged 2-21) were included. Three hundred exams (150 with fractures and 150 without fractures) were included, comprising 60 exams per body part (hand/wrist, elbow/upper arm, shoulder/clavicle, foot/ankle, leg/knee). The Ground Truth was defined by experienced radiologists. A deep learning algorithm interpreted the radiographs for fracture detection, and its diagnostic performance was compared against the Ground Truth, and receiver operating characteristic analysis was done. Statistical analyses included sensitivity per patient (the proportion of patients for whom all fractures were identified) and sensitivity per fracture (the proportion of fractures identified by the AI among all fractures), specificity per patient, and false-positive rate per patient.

RESULTS

There were 167 boys and 133 girls with a mean age of 10.8 years. For all fractures, sensitivity per patient (average [95% confidence interval]) was 91.3% [85.6, 95.3], specificity per patient was 90.0% [84.0,94.3], sensitivity per fracture was 92.5% [87.0, 96.2], and false-positive rate per patient in patients who had no fracture was 0.11. The patient-wise area under the curve was 0.93 for all fractures. AI diagnostic performance was consistently high across all anatomical locations and different types of fractures except for avulsion fractures (sensitivity per fracture 72.7% [39.0, 94.0]).

CONCLUSION

The BoneView™ deep learning algorithm provides high overall diagnostic performance for appendicular fracture detection in pediatric patients.

Custom-made polyurethane-based synthetic bones mimic screw cut-through of intramedullary nails in human long bones

Intramedullary nails are considered the gold standard for the treatment of tibial shaft fractures. Thereby, the screw-bone interface is considered the weakest link. For biomechanical evaluation of osteosyntheses synthetic bones are often used to overcome the disadvantages of human specimens. However, commercially available synthetic bones cannot adequately mimic the local mechanical properties of human bone. Thus, the aim of this study was to develop and evaluate novel cortical bone surrogate materials that mimic human tibial shafts in the screw-loosening mechanisms of intramedullary nails. Bone surrogates, based on two different polyurethanes, were developed and shaped as simple tubes with varying cortical thicknesses to simulate the diaphyseal cortex of human tibiae. Fresh frozen human tibiae and commercially available synthetic bones with similar cortical thickness were used as references. All specimens were treated with a nail dummy and bicortical locking screws to simulate treatment of a distal tibia shaft fracture. The nail-bone construct was loaded in a combined axial-torsional-sinusoidal loading protocol to simulate the physiological load during human gait. The loads to failure as well as the number of load cycles were evaluated. Furthermore, the cut-through length of the screws was analysed by additional micro computed -tomography images of the tested specimens. The failure load of custom made synthetic bone tubes with 6 mm cortical thickness (3242 ± 136 N) was in accordance with the failure load of human samples (3300 ± 307 N, p = 0.418) with a similar cortical thickness of 4.9 ± 1.4 mm. Commercially available synthetic bones with similar cortical thickness of 4.5 ± 0.7 mm were significantly stronger (4575 ± 795 N, p = 0.008). Oval-shaped migration patterns were "cut" into the cortices by the screws due to the cyclical loading. The cut-through length of the self-developed synthetic bones with 6 mm cortices (0.8 ± 0.6 mm, p = 0.516) matched the cut-through of the human tibiae (0.7 ± 0.6 mm). The cut-through of commercially available epoxy-based synthetic bones deviated from the human reference (0.2 ± 0.1 mm, p < 0.001). The results of this study indicate that the novel bone surrogates realistically mimic the failure and screw migration behaviour in human tibiae. Thus, they offer a new possibility to serve as substrate for biomechanical testing. The use of commercially available surrogates is discouraged for biomechanical testing as there is a risk of drawing incorrect conclusions.