Quantification of Malalignment and Corrective Osteotomies in Patients With Malunion After Elastic Stable Intramedullary Nailing of Pediatric Forearm Fractures.

Purpose: This study looked at postoperative malunion with restricted function after elastic stable intramedullary nailing (ESIN) in pediatric patients in their childhood or adolescence. The primary objective was to compare the magnitude of the osseous malposition to the healthy opposite side. Second, these individuals were treated with patient-specific surgical instrumentation, and functional outcomes were documented. Methods: Patients under the age of 18 at the time of a corrective osteotomy due to a forearm malunion after initial ESIN treatment were included in this study. The healthy contralateral side was used as a reference for preoperative analysis and planning of the osteotomy. Osteotomies were performed using patient-specific guides and the direction and extent of the malunion were compared to the change in range of motion (ROM) after the operation. Results: Fifteen patients met the inclusion criteria at three years after initial ESIN placement, with the most pronounced malposition in the rotational axis. The postoperative function significantly improved by 12° (pre-op: 60° ± 17; post-op: 72° ± 10) of pronation and 33° (pre-op: 43° ± 26; post-op: 76° ± 13) of supination. There was no correlation between the amount and direction of malformation and the change in ROM. Conclusions: The most noticeable malunion after forearm fractures treated with the ESIN technique is in the rotational direction. Patient-specific corrective osteotomy of pediatric forearm malunion following forearm fracture fixation with ESIN achieves significant improvement in forearm range of motion. Clinical relevance: The findings are clinically relevant since forearm fractures are the most common pediatric fracture, affecting a large number of patients who can benefit from the findings of this study. It has the potential to raise awareness of the significance of the accurate rotational component of intraoperative bone alignment in the ESIN procedure.

3D planning and patient specific instrumentation for intraarticular corrective osteotomy of trapeziometacarpal-, metacarpal and finger joints.

BACKGROUND: Intra-articular malunions of the finger can lead to deformity and loss of function and can be treated with intra-articular corrective osteotomies. The aim of this study was to evaluate radiographic joint congruency, feasibility and functional outcome of three-dimensional (3D) printed patient-specific instrumentation (PSI) for corrective osteotomies at the trapeziometacarpal and finger joints. METHODS: Computer-tomography (CT) scans were acquired preoperatively for standard 3D planning, which was followed by calculation of cutting planes and the design of individualized bone surface contact drilling, sawing and reposition guides. Follow-up CT scans and clinical examinations (range of motion, grip strength) were performed. Postoperative complications were documented and patient-reported outcome measurements were assessed (Single Assessment Numeric Evaluation (SANE) score, brief Michigan Hand Questionnaire (MHQ)). RESULTS: Ten patients (mean age 28.4 ± 12.8,range 13.8-51.3) years) were included with a mean follow-up of 21 ± 18 (3-59) months including seven osteotomies at the trapeziometacarpal or metacarpophalangeal joints and three at the proximal interphalangeal joint (PIP). All radiographic follow-up examinations showed the planned correction with good joint congruency and regular osseous consolidation. At the latest follow-up, the range of motion (ROM) increased and the average grip strength recovered to the level of the contralateral side. No postoperative complication was detected. The mean SANE score improved from 44 ± 23 (0-70) to 82 ± 12 (60-90) after a mean of 72 ± 20 (44-114) months. The mean postoperative brief MHQ was 92 ± 8 (71-98). CONCLUSION: The use of 3D PSI in treating intra-articular malunions at the trapeziometacarpal and finger joints restored articular congruency accurately. ROM and grip strength improved postoperatively comparable to the healthy contralateral side and patient-reported outcome measures improved after medium-term follow-up.

3D analysis of the distal ulna with regard to the design of a new ulnar head prosthesis.

STUDY DESIGN: A retrospective, single center, data analysis. OBJECTIVE: Persistent pain and instability are common complications after distal ulnar head arthroplasty. One main reason may be the insufficient representation of the anatomical structures with the prosthesis. Some anatomical structures are neglected such as the ulnar head offset and the ulnar torsion which consequently influences the wrist biomechanics. METHODS: CT scans of the ulnae of forty healthy and asymptomatic patients were analyzed in a three-dimensional surface calculation program. In the best fit principle, cylinders were fitted into the medullary canal of the distal ulna and the ulnar head to determine their size. The distance between the central axes of the two cylinders was measured, which corresponds to the ulnar offset, and also their rotational orientation was measured, which corresponds to the ulnar torsion. RESULTS: The mean medullary canal diameter was 5.8 mm (±0.8), and the ulnar head diameter was 15.8 mm (±1.5). The distance between the two cylinder axes was 3.89 mm (±0.78). The orientation of this offset was at an average of 8.63° (±15.28) of supination, reaching from 23° pronation to 32° supination. CONCLUSION: With these findings, a novel ulnar head prosthesis should have different available stem and head sizes but also have an existing but variable offset between these two elements. A preoperative three-dimensional analysis is due to the high variation of offset orientation highly recommended. These findings might help to better represent the patients natural wrist anatomy in the case of an ulnar head arthroplasty. LEVEL OF EVIDENCE: III.

Musculoskeletal biomechanics of patients with or without adjacent segment degeneration after spinal fusion.

STUDY DESIGN: A retrospective, single center, case-control study was performed. OBJECTIVE: The present study employed patient-specific biomechanical modeling to find potential biomechanical differences after spinal fusion at L4/5 in patients with and without subsequent development of adjacent segment disease (ASD). METHODS: The study population comprised patients who underwent primary spinal fusion at L4/5 and were either asymptomatic during > 4 years of follow-up (CTRL; n = 18) or underwent revision surgery for ASD at L3/4 (n = 20). Landmarks were annotated on preoperative and follow-up lateral radiographs, and specific musculoskeletal models were created using a custom-built modeling pipeline. Simulated spinal muscle activation and lumbar intervertebral shear loads in unfused segments were analyzed in upright standing and forward flexion. Differences between the pre- and postoperative conditions were computed for each patient. RESULTS: The average postoperative muscle activity in the upright standing posture was 88.4% of the preoperative activity in the CTRL group (p <  0.0001), but did not significantly change from pre- to postoperatively in the ASD group (98.0%). The average shear load magnitude at the epifusional joint L3/4 during upright standing increased from pre- to postoperatively in the ASD group (+ 3.9 N, +/- 17.4 (n = 18)), but decreased in the CTRL group (- 4.6 N, +/- 23.3 (n = 20); p <  0.001). CONCLUSION: Patient-specific biomechanical simulation revealed that spinal fusion surgery resulted in greater shear load magnitude and muscle activation and therefore greater forces at the epifusional segment in those with ASD compared with those without ASD. This is a first report of patient-specific disc load and muscle force calculation with predictive merits for ASD.

Unplanned Return Visits to a Pediatric Emergency Department.

OBJECTIVES: Unplanned return visits (URVs) to emergency departments (EDs) account internationally for 2.5% to 5.2% of all consultations. ED crowding is an increasing challenge, and URVs seem to contribute to this problem. This study aimed to assess factors for URVs at the ED of a tertiary children's hospital to analyze if they are jointly responsible for the steadily rising amount of treated patients. METHODS: All patients with an URV to a pediatric ED in Switzerland between January and December 2013 were included in the study. Data were taken retrospectively from the electronic patient files, and different variables were defined and analyzed. RESULTS: URVs occurred at an incidence of 4.6%, and mostly concerned infants and toddlers (46%). URVs were independent of weekdays and mostly occurred between 10 am and 10 pm. In 84.2% of the cases, the URVs were judged as unnecessary, and in 15.8%, a hospitalization was indicated, mainly for children with a worsening respiratory illness. CONCLUSIONS: The occurrence of URVs in our ED was within the incidence reported in the literature. While URVs lead to hospitalization in some patients, the majority of URVs were unnecessary from a medical point of view. These results indicate that a correct evaluation of the child's health state by parents is often challenging and requires repeated medical attendance following a first ED visit, especially in infants with airway diseases and infections. Intensive counseling and scheduled short-term follow-up consultation at the pediatrician's office could prevent URVs to the ED.