Complex rigid foot deformity correction with hexapod external fixator system

PURPOSE

Complex rigid foot deformities include three-plane deformities and usually presents with poor soft tissue coverage. In the last decades, gradual correction with computer-assisted fixator became an appropriate option for the treatment rigid foot deformities. This study aims to report our experience about treatment of complex foot deformities using Smart Correction fixator system®.

METHODS

We retrospectively analyzed 13 complex rigid foot deformities of ten consecutive patients treated with Smart Correction fixator system® from 2016 to 2020. Primary outcomes were classified as good, fair, and poor according to previously determined criteria. The outcomes were also assessed with The Manchester-Oxford Foot Questionnaire (MOXFQ). Non-parametric analysis (Wilcoxon test) for continuous variables and the Fisher's exact test for categorical variables were used.

RESULTS

Plantigrade foot was achieved in all patients after correction program. Supramalleolar osteotomy was applied in nine feet, midfoot osteotomy was applied in two feet, hindfoot osteotomy was required in one foot, and only soft tissue distraction performed in two feet. Two patients had recurrent deformity managed by further acute corrections. The mean MOXFQ scores improved from 72.7 preoperatively to 24.8 at last follow-up.

CONCLUSIONS

Present study shows that SCF the reliable option for the treatment of complex foot deformities, which also facilitates three-plane correction and concomitant lengthening with gradual soft tissue balance.

Experimental assessment of changes in bone fragment position using infraread diodes on saw bone models with a hexapod fixator

BACKGROUND

The purpose of this study was an experimental assessment of changes in bone fragment position in patients with non-union of the tibia treated with a hexapod fixator.

HYPOTHESIS

We hypothesized that the use of hexapod fixators leads to differences between the planned and actual position of bone fragments.

METHODS

The study was conducted in physical models of the hexapod fixator-bone fragment system. Bone fragment displacement was measured using the Optotrak Certus Motion Capture System. We assessed differences between the planned and actual position of bone fragments.

RESULTS

Assessment of bone fragment compression demonstrated a difference between the target and actual correction ranging from 1.5% to 13.2% (depending on the force applied to bone fragments) for configuration 1, from17% to 21.3% for configuration 2, and from 13.2% to 17.9% for configuration 3. The achieved varus deformity correction constituted 93.7-98.4% of the target correction for configuration 2 and 98.3-98.9% of the target correction for configuration 3. Torsional deformity correction showed considerable discrepancies between the target and achieved correction, ranging from 65.6% to 83%.

DISCUSSION

The value of the applied compression force had no marked effect on the differences between the target and achieved correction or on the magnitude of unintended rotational and transverse displacement of bone fragments. The use of hexapod fixators helped achieve complete correction of the simulated varus deformity; however, complete correction of torsional deformities was not achieved. Deformity correction in physical models with the use of a hexapod fixator yielded instances of unintended rotational and transverse bone-fragment displacement. The use of hexapod fixators in physical models leads to differences between the planned and actual position of bone fragments.

LEVEL OF EVIDENCE

IV, case series.

Orthoplastic management of open tibial fractures in children : a consecutive five-year series from a paediatric major trauma centre

AIMS

Open tibial fractures are limb-threatening injuries. While limb loss is rare in children, deep infection and nonunion rates of up to 15% and 8% are reported, respectively. We manage these injuries in a similar manner to those in adults, with a combined orthoplastic approach, often involving the use of vascularised free flaps. We report the orthopaedic and plastic surgical outcomes of a consecutive series of patients over a five-year period, which includes the largest cohort of free flaps for trauma in children to date.

METHODS

Data were extracted from medical records and databases for patients with an open tibial fracture aged < 16 years who presented between 1 May 2014 and 30 April 2019. Patients who were transferred from elsewhere were excluded, yielding 44 open fractures in 43 patients, with a minimum follow-up of one year. Management was reviewed from the time of injury to discharge. Primary outcome measures were the rate of deep infection, time to union, and the Modified Enneking score.

RESULTS

The mean age of the patients was 9.9 years (2.8 to 15.8), and 28 were male (64%). A total of 30 fractures (68%) involved a motor vehicle collision, and 34 (77%) were classified as Gustilo Anderson (GA) grade 3B. There were 17 (50%) GA grade 3B fractures, which were treated with a definitive hexapod fixator, and 33 fractures (75%) were treated with a free flap, of which 30 (91%) were scapular/parascapular or anterolateral thigh (ALT) flaps. All fractures united at a median of 12.3 weeks (interquartile range (IQR) 9.6 to 18.1), with increasing age being significantly associated with a longer time to union (p = 0.005). There were no deep infections, one superficial wound infection, and the use of 20 fixators (20%) was associated with a pin site infection. The median Enneking score was 90% (IQR 87.5% to 95%). Three patients had a bony complication requiring further surgery. There were no flap failures, and eight patients underwent further plastic surgery.

CONCLUSION

The timely and comprehensive orthoplastic care of open tibial fractures in this series of patiemts aged < 16 years resulted in 100% union and 0% deep infection, with excellent patient-reported functional outcomes. Cite this article: Bone Joint J 2021;103-B(6):1160-1167.

The role of external fixation in paediatric limb lengthening and deformity correction

Limb deformity and shortening remains a common presenting complaint in paediatric orthopaedics. The ability to restore length, alignment with consistent bone formation allows standardised treatment in these difficult conditions. The use of an external fixator produces a stable construct which allows manipulation of the bone segments, with a controlled rate and rhythm. Deformity analysis permits the surgeon to plan osteotomy levels and frame application to produce accurate correction. Complications, especially in congenital conditions remain an issue and modification of the treatment is required to try and reduce their incidence. New types of fixators, the latest being hexapod frames, have increased the versatility in deformity correction. The aim of this paper is to review the use of external fixators in elective paediatric orthopaedics and highlight the latest changes in technique and application for the limb reconstruction surgeon.

Unstable Cervical Spinal Injury in Children - Case Report and Review of the Literature

Large studies about the management of pediatric patients with unstable flexion-distraction injuries of the midcervical spine are rare. We present the case of a 12-year-old girl who sustained a cervical spinal injury with unilateral facet dislocation and discuss details and problems of diagnostic procedures and treatment in the light of the recent literature. The management and pitfalls of a unilateral facet dislocation in a child are summarized. After initial reposition, a multisegmental instability with neurology developed. Although distraction-flexion cervical spine injuries are common in adults and often occur with concomitant neurological sequelae, they also can occur in the pediatric population. In conclusion, an MRI seems advisable. A treatment of postoperative malalignment with reposition via a halo-fixator cannot be recommended. Repositioning is possible but was lost when the fixator was removed. Comparing the historic and recent literature there is only weak evidence overall, nevertheless a ventral fusion seems to be the treatment option of choice.