Bone Lengthening in the Pediatric Upper Extremity

Achondroplasia current concept of orthopaedic management

Achondroplasia, the most common form of inherited disproportionate short stature, is caused by mutations in the fibroblast growth factor receptor 3 gene. The typical clinical features of achondroplasia include short stature, rhizomelic disproportion, joint hyperlaxity, spinal deformity and deformity of the upper and lower limbs. The latter are among the challenges of state-of-the-art orthopaedic treatment plans and significantly contribute to the burden of the disease in individuals with achondroplasia. Multidisciplinary preoperative individual decision-making concerning surgical interventions should be considered. New medical treatments for achondroplasia have been developed and (some) have been approved for clinical use in several countries. While the number of research articles on achondroplasia is increasing rapidly, many unknown or controversial orthopaedic topics remain. Furthermore, in view of new medical developments with improvements in growth and potentially other effects, the timing and algorithms of orthopaedic treatments (e.g. guided growth, limb lengthening and deformity correction) need to be re-evaluated. While standing height is the primary research focus in medical therapy, it is crucial to comprehensively assess orthopaedic parameters in this multifactorial disease. The current treatment of patients with achondroplasia requires specialised multidisciplinary centres with transitional care and individual orthopaedic counselling.

Bilateral humeral lengthening and deformity correction with hexapod external fixator in an achondroplastic patient: A case report

INTRODUCTION AND IMPORTANCE

Achondroplasia, a prevalent skeletal dysplasia, often results in limb asymmetry and functional limitations, typically managed surgically with bone lengthening techniques.

CASE PRESENTATION

We present the case of a 10-year-old girl with achondroplasia who underwent bilateral humeral lengthening using hexapod external fixators. The patient, previously treated for lower limb lengthening, exhibited significant upper limb shortening affecting daily activities. Surgical intervention involved two stages, employing two hexapod external fixators for precise correction and lengthening. Symmetrical lengthening of 6 cm in both humeri was achieved without major complications. Follow-up assessments revealed improved functionality and satisfactory outcomes, emphasizing the importance of addressing upper limb deformities in achondroplasia patients.

CLINICAL DISCUSSION

While humeral lengthening is less common than lower extremity lengthening due to historical concerns about neurovascular complications and functional implications, recent advancements highlight its potential benefits, particularly in achieving functional and aesthetic balance.

CONCLUSION

This case highlights the efficacy and safety of hexapod fixators in achieving multiplanar correction and functional improvement in upper limb lengthening. Further investigation should be carried out to study broader application in similar cases.

Clinical evaluation of new bone formation during limb lengthening in children using ultrasound combined with superb microvascular imaging

Aims

Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new bone formation when limb lengthening is undertaken in paediatric patients. The aim of this study was to assess the use of ultrasound combined with SMI in monitoring new bone formation during limb lengthening in children.

Methods

In this retrospective cohort study, ultrasound and radiograph examinations were performed every two weeks in 30 paediatric patients undergoing limb lengthening. Ultrasound was used to monitor new bone formation. The number of vertical vessels and the blood flow resistance index were compared with those from plain radiographs.

Results

We categorized the new bone formation into three stages: stage I (early lengthening), in which there was no obvious callus formation on radiographs and ultrasound; stage II (lengthening), in which radiographs showed low-density callus formation with uneven distribution and three sub-stages could be identified on ultrasound: in Ia punctate callus was visible; in IIb there was linear callus formation which was not yet connected and in IIc there was continuous linear callus. In stage III (healing), the bone ends had united, the periosteum was intact, and the callus had disappeared, as confirmed on radiographs, indicating healed bone. A progressive increase in the number of vertical vessels was noted in the early stages, peaking during stages IIb and IIc, followed by a gradual decline (p < 0.001). Delayed healing involved patients with a prolonged stage IIa or those who regressed to stage IIa from stages IIb or IIc during lengthening.

Conclusion

We found that the formation of new bone in paediatric patients undergoing limb lengthening could be reliably evaluated using ultrasound when combined with the radiological findings. This combination enabled an improved assessment of the prognosis, and adjustments to the lengthening protocol. While SMI offered additional insights into angiogenesis within the new bone, its role primarily contributed to the understanding of the microvascular environment rather than directly informing adjustments of treatment.

Correction of symbrachydactyly: a systematic review of surgical options

Symbrachydactyly is a rare congenital malformation of the hand characterized by short or even absent fingers with or without syndactyly, mostly unilaterally present. The hand condition can vary from a small hand to only nubbins on the distal forearm. This study aims to systematically review the surgical management options for symbrachydactyly and compare functional and aesthetic outcomes.The review was performed according to the PRISMA guidelines. Literature was systematically assessed searching the Cochrane Library, PubMed, Embase, and PROSPERO databases up to January 1, 2023. Studies were identified using synonyms for 'symbrachydactyly' and 'treatment'. Inclusion criteria were the report of outcomes after surgical treatment of symbrachydactyly in humans. Studies were excluded if they were written in another language than English, German, or French. Case reports, letters to the editor, studies on animals, cadaveric, in vitro studies, biomechanical reports, surgical technique description, and papers discussing traumatic or oncologic cases were excluded.Twenty-four studies published were included with 539 patients (1037 digit corrections). Only one study included and compared two surgical techniques. The quality of the included studies was assessed using the Modified Coleman Methodology Score and ranged from 25 to 47. The range of motion was the main reported outcome and demonstrated modest results in all surgical techniques. The report on aesthetics of the hand was limited in non-vascularized transfers to 2/8 studies and in vascularized transfers to 5/8 studies, both reporting satisfactory results. On average, there was a foot donor site complication rate of 22% in non-vascularized transfers, compared to 2% in vascularized transfers. The hand-related complication rate of 54% was much higher in the vascularized group than in the non-vascularized transfer with 16%.No uniform strategy to surgically improve symbrachydactyly exists. All discussed techniques show limited functional improvement with considerable complication rates, with the vascularized transfer showing relative high hand-related complications and the non-vascularized transfer showing relative high foot-related complications.There were no high-quality studies, and due to a lack of comparing studies, the data could only be analysed qualitatively. Systematic assessment of studies showed insufficient evidence to determine superiority of any procedure to treat symbrachydactyly due to inadequate study designs and comparative studies. This systematic review was registered at the National Institute for Health Research PROSPERO International Prospective Register of Systematic Reviews number: CRD42020153590 and received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.Level of evidenceI.Systematic review registrationPROSPERO CRD42020153590.

Anatomic consideration of the radial nerve in relation to humeral length for unilateral external fixation: a retrospective study using magnetic resonance imaging findings in korean

BACKGROUND

This study aimed to present a safe zone for distal pin insertion for external fixation using magnetic resonance imaging (MRI) images.

METHODS

All patients who took at least one upper arm MRI from June 2003 to July 2021 were searched via a clinical data warehouse. For measuring the humerus length, proximal and distal landmarks were set as the highest protruding point of the humeral head and lowermost margin of ossified bone of the lateral condyle, respectively. For children or adolescents with incomplete ossification, the uppermost and lowermost ossified margin of the ossification centers were set as proximal and distal landmarks respectively. The anterior exit point (AEP) was defined as the location of the radial nerve exiting the lateral intermuscular septum to the anterior humerus and distance between the distal margin of the humerus and AEP was measured. The proportions between the AEP and full humeral length were calculated.

RESULTS

A total of 132 patients were enrolled for final analysis. The mean humerus length was 29.4 cm (range 12.9-34.6 cm). The mean distance between the ossified lateral condyle and AEP was 6.6 cm (range 3.0-10.6 cm). The mean ratio of the anterior exit point and humeral length was 22.5% (range 15.1-30.8%). The minimum ratio was 15.1%.

CONCLUSION

A percutaneous distal pin insertion for humeral lengthening with an external fixator may be safely done within 15% length of the distal humerus. If pin insertion is required more proximal than distal 15% of the humeral shaft, an open procedure or preoperative radiographic assessment is advised to prevent iatrogenic radial nerve injury.

Monorail External Fixation in Humeral Lengthening and Deformity Correction with Glenohumeral Reduction: A Case Report

CASE

External fixation has an established use in humeral lengthening and deformity correction. An 11-year-old boy presented with left-sided humeral shortening, proximal varus deformity, and glenohumeral dislocation. Anatomical and functional corrections were achieved through innovative monorail external fixation, including bifocal osteotomies of the surgical neck and diaphysis proximal to the deltoid insertion.

CONCLUSION

Monorail external fixation with bifocal osteotomies of the surgical neck and diaphysis proximal to the deltoid insertion may improve the anatomical and functional outcomes in humeral shortening and proximal varus deformity with glenohumeral dislocation.

Derotational osteotomy and internal fixation of a 180° malrotated humerus: A case report

BACKGROUND

Humeral shaft fractures are relatively common in adults. Rotational malalignment is reported as one complication but severe rotational deformity of the humerus is extremely rare. To our knowledge, only three cases of symptomatic humeral malrotation have been reported. There are sparse literature reports of humeral reconstruction correction.

CASE SUMMARY

We present a case of extreme rotational deformity of the humerus (180°) after humeral shaft fracture. The patient complained of pain and difficulties with activities of daily living. In addition, she found the deformity cosmetically unacceptable. Therefore, she was searching for surgical correction. Neurolysis of the radial nerve followed by derotational osteotomy of the humerus and internal fixation were performed. Postoperatively, the patient demonstrated transient iatrogenic radial nerve palsy which recovered completely during postoperative follow-up. The Disabilities of the Arm, Shoulder, and Hand score improved from 55 preoperatively to 16 at the final 2-year follow-up.

CONCLUSION

Single-stage radial neurolysis, derotational osteotomy and stable fixation is a feasible option to improve anatomic and functional problems of severely malrotated humeral shaft fractures.

Current trends on limb length discrepancy treatment: results of a survey among 11 dedicated Italian centres

Limb length discrepancies (LLD) are quite frequent, especially in lower limbs. The evolution of the available devices and the refinement of the techniques for correcting the differences in limb length have progressively improved the approach to these deformities. Nevertheless, several points still remain debated. The aim of the study was to investigate the Italian pediatric orthopedic surgeons' choices in approaching and treating LLD in both lower and upper limbs. A survey on the treatment of limb length discrepancy was sent to a group of 11 Italian orthopedic centers, specialising in limb lengthening and belonging to the Italian Society of Pediatric Orthopedics and Trauma and the Italian Society of External Fixation. Despite improvements in knowledge of bone biology and distractional osteogenesis as well as the increase in available hardware for lengthening, many aspects of LLD correction still remain debated. Both the relative rarity of the conditions which lead to significant shortening and the lack of wide groups of patients analysed at adult age, continue to be the main limitations for every surgeon who deals with LLD. Only by overcoming our own convictions and sharing our experiences in multicentric studies, may we reach our goal of developing a shared treatment protocol.

Diagnosis, treatment and complications of radial head and neck fractures in the pediatric patient

Radial head and neck fractures represent up to 14% of all pediatric elbow fractures and can be a difficult challenge in the pediatric patient. In up to 39% of proximal radius fractures, there is a concomitant fracture, which can easily be overlooked on the initial standard radiographs. The treatment options for proximal radius fractures in children range from non-surgical treatment, such as immobilization alone and closed reduction followed by immobilization, to more invasive options, including closed reduction with percutaneous pinning and open reduction with internal fixation. The choice of treatment depends on the degree of angulation and displacement of the fracture and the age of the patient; an angulation of less than 30 degrees and translation of less than 50% is generally accepted, whereas a higher degree of displacement is considered an indication for surgical intervention. Fractures with limited displacement and non-surgical treatment generally result in superior outcomes in terms of patient-reported outcome measures, range of motion and complications compared to severely displaced fractures requiring surgical intervention. With proper management, good to excellent results are achieved in most cases, and long-term sequelae are rare. However, severe complications do occur, including radio-ulnar synostosis, osteonecrosis, rotational impairment, and premature physeal closure with a malformation of the radial head as a result, especially after more invasive procedures. Adequate follow-up is therefore warranted.

Age-related Outcomes and Complications of Osteodistraction in the Pediatric Upper Extremity: A Large Retrospective Single-center Study of 61 Cases

BACKGROUND

The study purpose was to assess: (1) the complication rate of osteodistraction in the pediatric upper extremity, its severity and relation to patient-specific and treatment-specific parameters, and (2) dedicated patient-reported outcome scores after these procedures.

METHODS

This retrospective study analyzed a chart of patients undergoing osteodistraction of the upper limb between 2003 and 2020. Demographics, distraction-specific parameters, healing index, and any complications graded according to the Sink grading scale (grades 1 to 5) were extracted. An additional phone interview was performed to assess patient satisfaction and functionality of the elongated limb using the Quick-DASH (Disabilities of Arm, Shoulder, and Hand) score.

RESULTS

This study included 61 cases from 48 individual patients. The mean age at the start of distraction was 11.5±3.6 years. The ulna was the most frequently lengthened bone, with 21 (34.4%) cases. Ninety-four complications were observed, with an average complication rate of 77.0%. Based on the Sink grading scale (1 to 5), grade 3 complications were most common (n=29; 47.5%) followed by grade 1 (n=14; 23.0%), 2 (n=14; 23.0%), and 4 (n=4; 6.6%). A significantly lower and thus better bone healing index was observed for the age category less than 10 years compared with the 14 to 18 years group (P=0.006). The average satisfaction was 4.2±1.0 points of 5. The mean Quick-DASH score was 14.1±12.5, indicating very good clinical outcomes.

CONCLUSIONS

Despite the occurrence of numerous complications, high patient satisfaction and good daily life functionality of the treated limb was observed. An age of more than 14 years at the beginning of therapy had a negative prognostic effect on bone healing during distraction. Thus, osteodistraction in the upper extremity may preferably be performed less than 10 years of age because of enhanced bone regeneration.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Immunomodulatory effects and mechanisms of distraction osteogenesis

Distraction osteogenesis (DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.

Older age and multi-joint external fixator are two risk factors of complications in ulnar lengthening in children with hereditary multiple exostosis

Objectives

Hereditary multiple exostosis (HME) often involves forearm deformities. The aim of this study was to present the clinical results of 37 children who underwent ulnar lengthening with two different types of unilateral external fixators and to investigate the risk factors of complications.

Methods

We evaluated 37 children with forearm deformities caused by HME treated in our hospital from January 2008 to July 2019. The surgical procedures included resection of exostosis, osteotomy of the ulna, and gradual lengthening of the ulna with a unilateral external fixator. According to the type of fixator they received, the children were divided into two groups: group A received monorail fixators and group B received multi-joint fixators. Radiographic and functional parameters were assessed. Complications were recorded.

Results

All patients were followed-up for an average of 4.6 years (3.0 to 6.5). In both group A and group B, the ulna shortening (US), radial articular angle (RAA), carpal slip (CS), elbow flexion, forearm pronation, supination, and Mayo Elbow Performance Score (MEPS) values improved significantly from preoperatively to postoperatively (p < 0.05). However, the ulnar deviation was observed in 4 cases in group B and no cases in group A. According to logistic regression, the difference was only related to age (p < 0.05) and the type of external fixator (p < 0.05).

Conclusions

Ulnar lengthening with unilateral external fixation is a safe and effective procedure for the treatment of HME. Regarding complications, deviation of the ulna axis was more likely to occur in older children with multi-joint external fixators.

Patient-Specific Three-Dimensional-printed Instrumentation for Radius Lengthening Osteotomy by a Volar Approach in Epiphysiodesis Sequelae: A Case Report

Introduction:

Patient-specific guides are used in the correction of malunion sequelae in adult distal radius fractures. They allow a tridimensional correction of radial glenoid orientation. However, lengthening is small in those indications. Distal radius epiphysiodesis correction is much rarer and patient-specific guide after three-dimensional (3D) planning has never been reported for this indication in the literature.

Case Report:

We report the case of a 16-year-old teenager with a chronic painful wrist and an ulnar positive variance after a post-traumatic epiphysiodesis sequela of the radius. The radius was 11mm shorter than the ulna. An anatomic reconstruction was decided with a lengthening of the radius. Pre-operative planning and patient-specific guide allowed to control an important radial lengthening, to limit the morbidity of the iliac crest bone graft harvesting, to shape the graft precisely, and to maintain a correct radial glenoid orientation despite the important soft tissue tension. Clinical and radiological results at 6 months showed a complete disappearance of pain, optimal objective and subjective functional scores, and an improvement in the distal ulnar variance (7mm). The teenager went back to sport without limitation or pain.

Conclusion:

3Dplanning and intraoperative patient-specific guides in radial epiphysiodesis sequelae allow achieving 3D accurate measures of the graft and of the deformation, guiding the position and the orientation of the distal metaphysis cut of the radius, and limiting the morbidity of the iliac graft harvesting. In that case, it allowed restoring the full function of the wrist without remaining pain.

Lengthening of the Humerus Using a Motorized Lengthening Nail: A Retrospective Comparative Series

BACKGROUND

Lengthening of the humerus has traditionally been accomplished by the use of external fixation. Intramedullary motorized lengthening nails are now frequently used for lower limb lengthening, and this technology is slowly being adopted for use in the humerus.

METHODS

A retrospective, single-surgeon experience of pediatric humeral lengthenings was performed. The time period surveyed included use of external fixation (EF) for lengthening, and the use of a motorized nail (MN) for lengthening. The primary outcome measures were lengthening magnitude achieved, duration of lengthening, frequency and type of complications encountered, or further procedures required, during each lengthening.

RESULTS

From 1999 to 2018, 13 humeral lengthenings were performed in 9 patients. Six lengthenings were performed using the MN technique and 7 using the EF technique. The average absolute lengthening achieved was 8.5±1.3 cm in the EF group and 6.6±2.3 cm in the MN group. The duration of lengthening averaged 114 days in the MN group and 103 days in the EF group. The average duration of EF time was 215 days. Two patients underwent an initial EF lengthening of a humerus and then underwent a second lengthening using the MN technique. Two of 6 (33%) MN lengthenings and 3 of 7 (43%) EF lengthenings experienced complications during treatment. Two patients in the MN group underwent planned reversal and redeployment of their motorized nails to attain the planned lengthening magnitude.

CONCLUSIONS

Humeral lengthening using motorized intramedullary nails is a safe technique that mitigates some of the complications of EF including pin site infection. It is well tolerated by patients. For lengthenings of a large magnitude, reversal and reuse of MN can be considered.

Limb lengthening history, evolution, complications and current concepts

Limb lengthening continues to be a real challenge to both the patient and the orthopaedic surgeon. Although it is not a difficult operative problem, there is a long and exhausting postoperative commitment which can jeopardize early good results. I aim to review the history, evolution, biology, complications and current concepts of limb lengthening. Ilizarov's innovative procedure using distraction histeogenesis is the mainstay of all newly developing methods of treatment. The method of fixation is evolving rapidly from unilateral external fixator to ring fixator, computer assisted and finally lengthening intramedullary nails. The newly manufactured nails avoid many of the drawbacks of external fixation but they have their own complications. In general, the indications for limb lengthening are controversial. The indications have been extended from lower limb length inequality to upper extremity lengthening, including humeral, forearm and phalangeal lengthening. A wide range in frequency of complications is recorded in the English literature, which may reach up to 100% of cases treated. With developing experience, cosmetic lengthening has become possible using external or internal lengthening devices with an acceptable rate of problems.Level of evidence: V.

Bifocal osteosynthesis to treat radial shortening deformity with dislocation of the inferior radioulnar joint

Background

Several methods have been reported to correct deformity and shortening of the distal radius. However, the results are not entirely satisfactory. The results of bifocal osteosynthesis were retrospectively analyzed in this study.

Methods

Eight patients treated with bifocal osteosynthesis were evaluated retrospectively. Pre-operative and post-operative clinical and radiographic examinations were performed. Subjective symptoms and objective joint function were assessed. Radiographic data of the extent of radial lengthening and distal radial articular angle were collected.

Results

The mean follow-up period was 46 months (37–68 months). Satisfactory wrist appearance and radial lengthening was achieved in all patients. All patients were satisfied with the wrist appearance and willing to undergo the same treatment again. The range of motion (ROM) of the forearm and wrist was significantly improved. Pin-track infections occurred in two patients, for which they received wound care and oral antibiotics. Complications such as fixation device failure, tendon rupture, fracture of regenerated bone or nerve impairment did not occur. The duration of lengthening depended on the shortening of the radius. Delayed union in the docking site was observed in two patients and union was achieved after bone grafting.

Conclusions

Bifocal osteosynthesis using the Ilizarov method provides a useful method for correction of radial shortening deformity with dislocation of the inferior radioulnar joint. Despite the fact that we did not validate pre-and post-operation functional outcome scores, all patients were satisfied with the wrist appearance and function.

Complications and Outcomes Following Humerus Lengthening - An Illustrative: Case Report

Introduction

Upper limb physeal injuries are dealt with differently simply because they do not hinder with the functional abilities of an individual. Humerus lengthening was first attempted in 1978 after which it encouraged many surgeons to safely perform the procedure. Radial nerve palsy occurring as a complication of humeral lengthening was a major concern.

Case Report

We report a case of a 17-year-old girl with physeal arrest at the proximal physis of the humerus with etiology of post-trauma/post-infection. She presented with a shortening of 8 cm and restricted shoulder movements. We performed a lengthening of the humerus based on the principle of distraction osteogenesis. We used the paediatric limb reconstruction system to distract the corticotomy. However, postoperatively, she developed radial nerve palsy, despite our intraoperative precautionary measures. Distraction was started at 1mm/day. She then showed the progress of radial nerve recovery and full recovery was noted by 5 months post-operatively. The length of the distraction compression assembly had to be changed twice to longer sizes to accommodate the required amount of lengthening. After consolidation of regenerate was confirmed with serial radiographs, external fixator was removed. She was then maintained on a functional brace. We were able to achieve 8cm of lengthening following distraction, and the cosmetic appearance of the patient improved to the patient's and attenders' satisfaction.

Conclusion

Humeral lengthening can safely be performed. Careful insertion of the distal pins and performance of the corticotomy will ensure the safety of the radial nerve. Even if radial nerve palsy occurs after all precautions are taken, recovery can be expected.

Mechanical solutions to salvage failed distraction osteogenesis in large bone defect management

INTRODUCTION

Ilizarov bone transport for large bone defect is challenging and may end in distraction osteogenesis failure.

MATERIAL AND METHODS

Ten forearm and seven tibial defect cases with failed regeneration due to ischaemia during bone transport were studied retrospectively. Mean forearm and tibial defects were 5.5 ± 0.8 and 7.6 ± 1 cm respectively, or 22.3 ± 3.6 and 20 ± 2.3% as compared with healthy segments. Most patients had numerous previous operations (2.6 ± 0.5 and 3.4 ± 0.8 per patient, respectively), extensive scars locally and post-traumatic neuropathy. There were seven infected defects. Mechanical solutions used were (1) additional osteotomy and transport of the fragment to compact the ischaemic regenerate (10 forearms, 4 tibias) and (2) compaction of the connective tissue layer in the tibial regenerate with either two 5-mm steps (two cases) or gradually (one case).

RESULTS

Bone integrity was restored in all the cases. Complete compensation of the defects was achieved in 12 patients with the first technique. Two patients with 8-cm ulna defects remained with residual discrepancy. In the forearm, mean compaction was 1.7 ± 0.4 cm. It took 25.7 ± 5.4 days followed by an average fixation period of 107.1 ± 11.8 days. In the tibia, mean longitudinal compaction by distraction measured 1.7 ± 0.8 cm. The second technique ended up with an acceptable shortening of 1 cm in two cases. Four centimeters were compressed in the third case gradually.

CONCLUSION

The technical solutions used for mechanical effects on the ischaemic distraction regenerate resulted in its rescue and bone union in all the cases.