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

Burden and Treatment of Achondroplasia: A Systematic Literature Review

BACKGROUND

Achondroplasia is the most common form of skeletal dysplasia. Recent advances in therapeutic options have highlighted the need for understanding the burden and treatment landscape of the condition. This systematic literature review (SLR) aimed to identify health-related quality of life (HRQoL)/utilities, healthcare resource use (HCRU), costs, efficacy, safety and economic evaluation data in achondroplasia and to identify gaps in the research.

METHODS

Searches of MEDLINE, Embase, the University of York Centre for Reviews and Dissemination (CRD), the Cochrane Library and grey literature were performed. Articles were screened against pre-specified eligibility criteria by two individuals and study quality was assessed using published checklists. Additional targeted searches were conducted to identify management guidelines.

RESULTS

Fifty-nine unique studies were included. Results demonstrated a substantial HRQoL and HCRU/cost-related burden of achondroplasia on affected individuals and their families throughout their lifetimes, particularly in emotional wellbeing and hospitalisation costs and resource use. Vosoritide, growth hormone (GH) and limb lengthening all conferred benefits for height or growth velocity; however, the long-term effects of GH therapy were unclear, data for vosoritide were from a limited number of studies, and limb lengthening was associated with complications. Included management guidelines varied widely in their scope, with the first global effort to standardise achondroplasia management represented by the International Achondroplasia Consensus Statement published at the end of 2021. Current evidence gaps include a lack of utility and cost-effectiveness data for achondroplasia and its treatments.

CONCLUSIONS

This SLR provides a comprehensive overview of the current burden and treatment landscape for achondroplasia, along with areas where evidence is lacking. This review should be updated as new evidence becomes available on emerging therapies.

Re-use of Motorised Intramedullary Limb Lengthening Nails

Aim

This study reviews the re-use of implanted motorised intramedullary lengthening nails previously used for limb lengthening.

Materials and methods

A retrospective review was performed on the re-use of motorised intramedullary lengthening nails. All patients had a magnetically controlled intramedullary lengthening nail in the femur, tibia, or humerus previously utilised for either lengthening or compression. Patients were included if the magnetically controlled intramedullary lengthening nail underwent attempted re-use either in the same lengthening episode or in a temporally separate lengthening treatment requiring another corticotomy.

Results

Ten patients with 12 lengthening episodes were analysed including five tibial, five femoral and two humeral segments. Overall, seven of 12 nails (58%) were successfully re-deployed without the need for nail exchange. Two of three nails were successfully retracted and re-used for continued distraction in the same lengthening treatment. Five of nine nails (56%) were successfully reactivated in a subsequent, later lengthening episode.

Conclusion

Re-use of a magnetically controlled limb lengthening nail is an off-label technique that may be considered for patients requiring ongoing or later lengthening of the femur, tibia or humerus. Regardless of whether the nail is used in the same lengthening episode or separate lengthening episode, surgeons should be prepared for exchange to a new implant.

Clinical significance

Re-use of a magnetically controlled intramedullary lengthening nail will reduce surgical trauma and save implant cost in limb lengthening treatment but may only be possible in half of attempted cases.

How to cite this article

Georgiadis AG, Nahm NJ, Dahl MT. Re-use of Motorised Intramedullary Limb Lengthening Nails. Strategies Trauma Limb Reconstr 2023;18(2):106-110.

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.

An Update on the Intramedullary Implant in Limb Lengthening: A Quinquennial Review Part 2: Extending Surgical Indications and Further Innovation

The use of the intramedullary lengthening nail has gained in popularity over the last decade. The reduction in complications associated with the use of external fixators and excellent patient outcomes has resulted in the largest change in management of limb length discrepancy since the concept of distraction osteogenesis was accepted by the Western world in the 1980s. Success following "simple" limb lengthening has led to surgeons extending the indications for the lengthening nail, including different bone segments, lengthening associated with potential joint instability and lengthening combined with acute deformity correction. There has been a drive for further implant modification to reduce complications, and enable full weight bearing during the lengthening process. This would offer the opportunity to consider simultaneous limb lengthening. The aim of this review is to evaluate the literature published over the last five years and highlight important learning points and technical tips for these expanding indications.

What Are the Risks and Functional Outcomes Associated With Bilateral Humeral Lengthening Using a Monolateral External Fixator in Patients With Achondroplasia?

BACKGROUND

Many patients with achondroplasia experience functional impairments because of rhizomelic upper extremities (proximal limb shortening). Bilateral humeral lengthening may overcome these functional limitations, but it is associated with several risks, such as radial nerve palsy and insufficient bone regeneration. Only a few studies have reported on patient satisfaction and functional outcome after humeral lengthening in patients with achondroplasia. Furthermore, the reported numbers of adverse events associated with lengthening procedures using external fixators vary widely.

QUESTIONS/PURPOSES

(1) Does bilateral humeral lengthening with a monolateral external fixator in patients with achondroplasia reliably improve patient function and autonomy, and what proportion of patients achieved at least 8 cm of humeral lengthening? (2) What adverse events occur after bilateral humeral lengthening with monolateral external fixators?

METHODS

Between 2011 and 2019, 44 patients underwent humeral lengthening at our institution. Humeral lengthening was performed in patients with severe shortening of the upper extremities and functional impairments. In humeri in which intramedullary devices were not applicable, lengthening was performed with monolateral external fixators in 40 patients. Eight patients were excluded because they underwent unilateral lengthening for etiologies other than achondroplasia, and another four patients did not fulfill the minimum study follow-up period of 2 years, leaving 28 patients with bilateral humeral lengthening to treat achondroplasia available for analysis in this retrospective study. The patients had a median (interquartile range) age of 8 years (8 to 10), and 50% (14 of 28) were girls. The median follow-up time was 6 years (4 to 8). The median humeral lengthening was 9 cm (9 to 10) with a median elongation of 73% (67% to 78%) from an initial median length of 12 cm (11 to 13). To determine whether this treatment reliably improved patient function and autonomy, surgeons retrospectively evaluated patient charts. An unvalidated retrospective patient-reported outcome measure questionnaire consisting of nine items (with answers of "yes" or "no" or a 5-point Likert scale) was administered to assess the patient's functional improvement in activities of daily living, physical appearance, and overall satisfaction, such that 45 points was the highest possible score. The radiographic outcome was assessed on calibrated radiographs of the humerus. To ascertain the proportion of adverse events, study surgeons performed a chart review and telephone interviews. Major complications were defined as events that resulted in unplanned revision surgery, nerve injury (either temporary or permanent), refracture of the bone regenerate, or permanent functional sequelae. Minor complications were characterized as events that resolved without further surgical interventions.

RESULTS

On our unvalidated assessment of patient function and independence, all patients reported improvement at their most recent follow-up compared with scores obtained before treatment (median [IQR] 24 [16 to 28] before surgery versus 44 [42 to 45] at latest follow-up, difference of medians 20 points, p < 0.001). A total of 89% (25 of 28) of patients achieved the desired 8 cm of lengthening in both arms. A total of 50% (14 of 28) of our patients experienced a major complication. Specifically, 39% (11 of 28) had an unplanned reoperation, 39% (11 of 28) had a radial nerve palsy, 18% (5 of 28) had a refracture of the regenerate, and 4% (1 of 28) concluded treatment with a severe limb length discrepancy. In addition, 82% (23 of 28) of our patients experienced minor complications that resolved without further surgery and did not involve radial nerve symptoms. Radial nerve palsy was observed immediately postoperatively in eight of 13 segments, and 1 to 7 days postoperatively in five of 13 segments. The treatment goal was not achieved because of radial nerve palsy in 5% (3 of 56) of lengthened segments, which occurred in 7% (2 of 28) of patients. Full functional recovery of the radial nerve was observed in all patients after a median (IQR) of 3 months (2 to 5). Refractures of bone regenerates were observed in 11% (6 of 56) of humeri in 18% (5 of 28) of patients. Of those refractures, 1 of 6 patients was treated nonsurgically with a hanging cast, while 5 of 6 patients underwent revision surgery with intramedullary rodding.

CONCLUSION

Most patients with achondroplasia who underwent humeral lengthening achieved the treatment goal without permanent sequelae; nonetheless, complications of treatment were common, and the road to recovery was long and often complicated, with many patients experiencing problems that were either painful (such as refracture) or bothersome (such as temporary radial nerve palsy). However, using a subjective scale, patients seemed improved after treatment; nevertheless, robust outcomes tools are not available for this condition, and so we must interpret that finding with caution. Considering our discoveries, bilateral humeral lengthening with a monolateral external fixator should only be considered in patients with severe functional impairments because of rhizomelic shortening of the upper extremities. If feasible, internal lengthening devices might be preferable, as these are generally associated with higher patient comfort and decreased complication rates compared with external fixators.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Humerus Lengthening with a Motorized Intramedullary Nail: A Systematic Review of Outcomes and Complications

Aim

In the past decade, internal limb lengthening nails have gained popularity. In this study, we aim to systematically review the literature on humerus limb lengthening with a motorized intramedullary nail (MIN). We intend to assess the outcome and complications of this technique.

Materials and methods

A systematic review was performed in the following databases: PubMed, Embase, Web of Science, and the Journal of Limb Lengthening and Reconstruction. The inclusion criteria included limb lengthening of the humerus using an intramedullary nail, clinical studies, all levels of evidence, and no restriction to the date of publication.

Results

Our search yielded 239 journal articles. A total of nine articles remained relevant based on the inclusion and exclusion criteria. The total number of patients was 20, with 22 segments lengthened. The mean age of the patients was 20.8-year-old [standard deviation (SD), 12.0; range, 13-51]. The mean gained length was 5.7 cm (SD, 0.9; range, 5-7.5) with a mean distraction protocol of 0.82 mm/day (SD, 0.2; range, 0.6-1). The average duration of lengthening was 71.6 days (SD, 12.8; range, 50-93), and the mean duration of consolidation was 192.3 days (SD, 40.5; range, 120-228). Reported complications included a range of motion (ROM) limitation, hardware failure, and hypertrophic bone regeneration.

Conclusion

Humeral lengthening with an MIN provides favourable outcomes with low complication rates. Future high-level studies should focus on comparing long-term outcomes of humeral lengthening utilising internal and external fixation techniques.

Clinical significance

Humeral lengthening using MIN can be used safely. Each surgical approach and type of nail have different risks and benefits. These should be carefully discussed when planning the surgery.

How to cite this article

Lorange JP, Alamiri N, Marwan Y, et al. Humerus Lengthening with a Motorized Intramedullary Nail: A Systematic Review of Outcomes and Complications. Strategies Trauma Limb Reconstr 2022;17(3):165-171.

Femoral lengthening in young patients: An evidence-based comparison between motorized lengthening nails and external fixation

BACKGROUND

Femoral lengthening is a procedure of great importance in the treatment of congenital and acquired limb deficiencies. Technological advances have led to the latest designs of fully implantable motorized intramedullary lengthening nails. The use of these nails has increased over the last few years.

AIM

To review and critically appraise the literature comparing the outcome of femoral lengthening in children using intramedullary motorized lengthening nails to external fixation.

METHODS

Electronic databases (MEDLINE, CINAHL, EMBASE, Cochrane) were systematically searched in November 2019 for studies comparing the outcome of femoral lengthening in children using magnetic lengthening nails and external fixation. The outcomes included amount of gained length, healing index, complications and patient reported outcomes.

RESULTS

Of the 452 identified studies, only two (retrospective and non-randomized) met the inclusion criteria. A total of 91 femora were included. In both studies, the age of patients treated with nails ranged from 15 to 21 years compared to 9 to 15 years for patients in the external fixation group. Both devices achieved the target length. Prevalence of adverse events was less in the nail (60%-73%) than in the external fixation (81%-100%) group. None of the studies presented patient reported outcomes.

CONCLUSION

The clinical effectiveness of motorized nails is equivalent or superior to external fixation for femoral lengthening in young patients. The available literature is limited and does not provide evidence on patient quality of life or cost effectiveness of the interventions.

International recognition of the Ilizarov bone reconstruction techniques: Current practice and research (dedicated to 100th birthday of G. A. Ilizarov)

The Ilizarov method is one of the current methods used in bone reconstruction. It originated in the middle of the past century and comprises a number of bone reconstruction techniques executed with a ring external fixator developed by Ilizarov GA. Its main merits are viable new bone formation through distraction osteogenesis, high union rates and functional use of the limb throughout the course of treatment. The study of the phenomenon of distraction osteogenesis induced by tension stress with the Ilizarov apparatus was the impetus for advancement in bone reconstruction surgery. Since then, the original method has been used along with a number of its modifications developed due to emergence of new fixation devices and techniques of their application such as hexapod external fixators and motorized intramedullary lengthening nails. They gave rise to a relatively new orthopedic subspecialty termed “limb lengthening and reconstruction surgery”. Based on a comprehensive literature search, we summarized the recent clinical practice and research in bone reconstruction by the Ilizarov method with a special focus on its modification and recognition by the world orthopedic community. The international influence of the Ilizarov method was reviewed in regard to the origin country of the authors and journal’s rating. The Ilizarov method and other techniques based on distraction osteogenesis have been used in many countries and on all populated continents. It proves its international significance and confirms the greatest contribution of Ilizarov GA to bone reconstruction surgery.

Humerus Lengthening: A Comparison of the Internal Lengthening Nail to External Fixation

Introduction: Magnetic internal lengthening nails (MILNs) have been used for humeral lengthening to avoid complications associated with external fixation. Purpose/Questions: We compared the 1-year Disabilities of the Arm, Shoulder and Hand (DASH) score, adjacent joint range of motion (ROM), bone healing index (BHI), length achieved, distraction rate, and complications when lengthening the humerus using MILN vs using external fixation. Methods: We conducted a retrospective cohort study of 18 patients (22 humeri) from January 2001 to March 2020 divided into 2 groups, the MILN group (7 patients, 7 humeri) and the mono-lateral fixator group (11 patients, 15 humeri). Results: The MILN group showed larger improvement of DASH scores (average 26.8 and 8 for MILN and fixator groups, respectively), less loss of elbow ROM (average 5° and 7° for MILN and fixator groups, respectively), and shorter time to full recovery of elbow ROM (average 39 days and 122 days for MILN and fixator groups, respectively). In the MILN group, there was slower distraction rate (average 0.66 mm/day and 0.86 mm/day for MILN and fixator groups, respectively), less lengthening achieved (average 5.2 cm and 7 cm for MILN and fixator group, respectively), and a lower lengthening percentage (average 19% and 41% for MILN and fixator group, respectively). Bone healing index (BHI) of 0.94 and 0.99 months/cm for the MILN and the fixator groups were similar. Conclusion: Humeral lengthening using the MILN allowed for early full recovery of joint ROM with comparable functional and radiographic outcomes compared with using external fixators.

Upper Limb Lengthening in Achondroplasia Using Unilateral External Fixation

PURPOSE

The purpose of this study was to analyze the long-term results of humeral lengthening in achondroplastic patients and make suggestions on the most appropriate surgical technique to improve patient outcomes.

METHODS

Fifty-four humeral lengthening procedures performed in 27 achondroplastic patients were reviewed. Elongations were performed by means of callotasis with unilateral external fixation. Inclusion criteria were: achondroplastic patients under 17 years without prior arm operations and minimum follow-up of 36 months.

RESULTS

Fifty humeri in 25 patients (13 men and 12 women), aged between 9 and 17 years, met the inclusion criteria. Mean humeral lengthening was 8.82 cm (range: 5 to 10.5 cm), which represented an elongation of 54.80% (range: 46% to 63%) of the original length. The healing index was 0.91 months (range: 0.72 to 1.4 mo) per centimeter gained. Shoulder and elbow range of motion and stability were preserved in 47 limbs. Noncomplicated cases consistently experienced a significant functional improvement in the performance of activities of daily living such as putting on footwear and personal hygiene. Short-term complications included 11 pin-tract infections, 1 radial nerve neuropraxia, and 1 failure of the regenerated bone formation. None of these complications prevented from completion of treatment. Long-term complications included 2 cases of nonunion, 3 elbow flexion contractures, and 2 cases of psychological dissatisfaction, all of them in 4 patients. Factors associated with long-term complications were intraoperative fragment displacement and distal humeral osteotomy. No fractures of the regenerated bone were identified in the long term.

CONCLUSIONS

Callotasis with unilateral external fixation is a reliable and well-tolerated procedure for humeral lengthening in achondroplastic patients, with an acceptable complication rate. Guided fixator placement and a proximal humeral osteotomy are strongly recommended technical tips as they may help prevent complications and improve outcomes.

LEVEL OF EVIDENCE

Level IV-case series.

Complications of Limb Lengthening With Motorized Intramedullary Nails

Intramedullary limb lengthening (LL) is now achievable through motorized intramedullary devices. While this technology mitigates some complications of external-fixation-based lengthening, many complications common to all lengthening procedures persist. New challenges and complications exclusive to this newer technology are also presented. The LL surgeon should be aware of and ready to respond to complications involving device malfunctions, poor local bony and soft-tissue biology, patient compliance, neurovascular compromise, joint instability, regenerate problems, and others. While technology will continue to evolve, study of and adherence to foundational principles of LL will minimize risks and optimize patient outcomes.