Humeral lengthening in patients with achondroplasia and in patients with post-septic shortening: comparison of procedure efficiency and safety

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.

Achondroplasia in Latin America: practical recommendations for the multidisciplinary care of pediatric patients

Background

Achondroplasia is the most common bone dysplasia associated with disproportionate short stature, and other comorbidities, such as foramen magnum stenosis, thoracolumbar kyphosis, lumbar hyperlordosis, genu varum and spinal compression. Additionally, patients affected with this condition have higher frequency of sleep disorders, ear infections, hearing loss and slowed development milestones. Considering these clinical features, we aimed to summarize the regional experts’ recommendations for the multidisciplinary management of patients with achondroplasia in Latin America, a vast geographic territory with multicultural characteristics and with socio-economical differences of developing countries.

Methods

Latin American experts (from Argentina, Brazil, Chile and Colombia) particiáted of an Advisory Board meeting (October 2019), and had a structured discussion how patients with achondroplasia are followed in their healthcare centers and punctuated gaps and opportunities for regional improvement in the management of achondroplasia.

Results

Practical recommendations have been established for genetic counselling, prenatal diagnosis and planning of delivery in patients with achondroplasia. An outline of strategies was added as follow-up guidelines to specialists according to patient developmental phases, amongst them neurologic, orthopedic, otorhinolaryngologic, nutritional and anthropometric aspects, and related to development milestones. Additionally, the role of physical therapy, physical activity, phonoaudiology and other care related to the quality of life of patients and their families were discussed. Preoperative recommendations to patients with achondroplasia were also included.

Conclusions

This study summarized the main expert recommendations for the health care professionals management of achondroplasia in Latin America, reinforcing that achondroplasia-associated comorbidities are not limited to orthopedic concerns.

International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia

Achondroplasia, the most common skeletal dysplasia, is characterized by a variety of medical, functional and psychosocial challenges across the lifespan. The condition is caused by a common, recurring, gain-of-function mutation in FGFR3, the gene that encodes fibroblast growth factor receptor 3. This mutation leads to impaired endochondral ossification of the human skeleton. The clinical and radiographic hallmarks of achondroplasia make accurate diagnosis possible in most patients. However, marked variability exists in the clinical care pathways and protocols practised by clinicians who manage children and adults with this condition. A group of 55 international experts from 16 countries and 5 continents have developed consensus statements and recommendations that aim to capture the key challenges and optimal management of achondroplasia across each major life stage and sub-specialty area, using a modified Delphi process. The primary purpose of this first International Consensus Statement is to facilitate the improvement and standardization of care for children and adults with achondroplasia worldwide in order to optimize their clinical outcomes and quality of life.

Staged upper and lower limb lengthening performing bilateral simultaneous surgery of the femur and tibia in achondroplastic patients

INTRODUCTION

Surgical lengthening and angular correction of the limbs are an option for treating the orthopedic clinical manifestations in patients with achondroplasia. This study assesses a staged limb lengthening protocol, performing simultaneous bilateral lengthening of the femur and tibia (stage I [S1]), and humeral lengthening (stage II [S2]).

MATERIALS AND METHODS

Twenty-one achondroplastic patients were included in this study, and 106 segments (34 femurs, 34 tibias and 38 humeri) were lengthened. Achondroplasia patients with a growth curve below the mean of the standard growth curves for achondroplasia were included in S1. The remaining patients were included directly in S2. Variables analyzed included anthropometric measurements, lengthening outcomes, difficulties, and functionality.

RESULTS

Of the all patients included in the protocol, 15 patients completed S1 and S2, 4 only completed S2, and 2 only completed S1. Height and limb-trunk ratio before S1 were 107.65 ± 7.14 cm and 1.89 ± 0.10 and after S1 were 126.50 ± 9.19 cm and 1.64 ± 0.09, respectively. Limbs were lengthened 14.43 ± 1.41 cm (femurs and tibias) for S1 and 9.95 ± 0.60 cm for S2 (humeri), with a stage healing index of 18.23 ± 3.54 in S1 and 28.92 ± 4.42 in S2. Correction of lower angular deviations, functional improvement, and a controlled complications rate were achieved in all patients.

CONCLUSIONS

The limb lengthening protocol proposed in this study is a suitable treatment for achondroplasia patients to achieve the agreed-upon objectives (limb-trunk ratio, improved functionality, and lower limb alignment). The reproducibility of the procedure and patient safety were upheld.

Ten-year retrospective review of paediatric septic arthritis in a New Zealand centre

BACKGROUND

Paediatric septic arthritis, although a rare diagnosis in the developed world, remains a significant challenge in the New Zealand population. In recent years, there has been effort to characterize the nature of paediatric bone and joint infection for New Zealand due to rising incidence of osteomyelitis and staphylococcal sepsis [1, 2]. We have sought to identify trends in presentation, diagnosis and management of paediatric septic arthritis, with added focus on ethnicity and access to healthcare.

METHODS

A ten year retrospective review of all cases < 16 years with presumed septic arthritis presenting to a tertiary referral centre between 2008 and 2018 was performed.

RESULTS

A total of 103 cases met inclusion criteria. Mean age was 5.9 years (SD +/- 4.17) with a male predominance (64%). Traditional laboratory culture method isolated an organism in 66% of cases: Staphylococcus aureus was the most common pathogen identified (61%). Incidence varied greatly by ethnicity 1:16,000 for NZ European children; 1:8760 for Pacifica and 1:4300 for Māori. Mean distance travelled by patients to reach the nearest emergency department was 38.3 km, ranging from 2 to 188 km. Assessment using NZ deprivation scores showed the Māori paediatric population were likely to reside in areas of worse socioeconomic deprivation (p = 0.0005). The majority (66%) of cases were treated surgically with a low recurrence rate (2.9%). Delayed presentation was associated with worse outcomes and more likely in patients residing > 20 km away from the nearest emergency department.

CONCLUSION

The incidence of paediatric septic arthritis in New Zealand is concerningly high within Māori and Pacific populations. Future health interventions should consider environmental, socioeconomic, and microbiological trends in the burden of disease.

Anatomical Considerations of Intramedullary Humeral Nailing and Lengthening

Intramedullary lengthening, in cases of extensive humeral shortening, offers the advantages of preventing external-fixator-associated problems. The humeral cavity, as the main parameter in nailing, however, has been neglected in recent literature. It was hypothesized that available implants might be too large and therefore increase the risk of intraoperative fractures. The aim of this cross-sectional study was to describe the humeral canal and how it might affect the choice of implant and the surgical approach. Thirty humeri (15 female, 15 male) from clinical patients and anatomical specimens were studied. Specifically, the medullary cavity width (MCW), cortical thickness (CoT), and the course of the medullary canal were examined. The smallest MCW diameters were found at the distal third of the humeral shaft with mean diameters of 10.15 ± 1.96 mm. CoTs of female humeri were significantly smaller than those of male humeri (p < 0.001). The mean angles of the pro- and recurvatum were 4.01 ± 1.68° and 10.03 ± 2.25°, and the mean valgus bending was 3.37 ± 1.58°. Before implanting a straight lengthening nail into a doubly curved humerus, X-rays and, in selected cases, CT-scans should be performed. The unique size and course of the humeral canal favors an antegrade approach in cases of intramedullary lengthening.

[Intramedullary upper arm lengthening]

The new technology of motorized intramedullary telescopic nails has simplified the treatment for upper limb lengthening surgery. Improved patient comfort, low infection rates and absence of fractures in the regenerated bone are contrasted by the limitations of the methods, such as a current maximum distraction of 5cm and the fact that they cannot be used when the growth plates are still open.

Innovative Technique in Extended Intramedullary Humeral Lengthening: A Case Report

CASE

Intramedullary humeral lengthening is still a very uncommon procedure to treat humeral limb length discrepancy (LLD). This approach has various advantages compared with external devices but is limited in its ability to lengthen bones because of the length of the telescopic nail. This case report describes a middle-aged patient with a short right humerus secondary to a childhood growth plate injury that was successfully lengthened with an off-label application of a tibial distracting device. Hereby, a novel treatment technique with unlocking, backwinding, and reinterlocking of the telescopic nail for extended humeral distraction was performed.

CONCLUSIONS

Extended intramedullary humeral lengthening with unlocking, backwinding, and reinterlocking of the nail is a cost-effective, minimally invasive procedure in cases of massive humeral LLD with limitations in the distraction capacity of the telescopic nail.

Achondroplasia: a comprehensive clinical review

Achondroplasia is the most common of the skeletal dysplasias that result in marked short stature (dwarfism). Although its clinical and radiologic phenotype has been described for more than 50 years, there is still a great deal to be learned about the medical issues that arise secondary to this diagnosis, the manner in which these are best diagnosed and addressed, and whether preventive strategies can ameliorate the problems that can compromise the health and well being of affected individuals. This review provides both an updated discussion of the care needs of those with achondroplasia and an exploration of the limits of evidence that is available regarding care recommendations, controversies that are currently present, and the many areas of ignorance that remain.

Surgical technique and outcomes for bilateral humeral lengthening for achondroplasia: 26-year experience

BACKGROUND

Elongation in patients with achondroplasia provides better overall skeletal proportionality and significantly improves such individuals' access to their perineal region to self-manage personal hygiene. This paper describes our surgical technique and outcomes for bilateral humeral lengthening in achondroplasia patients over 26 years.

METHODS

Ours was a retrospective study of 55 patients with achondroplasia-related short stature, in whom bilateral humeral lengthening was performed from 1990 to 2016. We describe the surgical technique and analyze mean gain in humeral length, days using an external fixator, mean percentage of lengthening, external fixation index, type of callus, and complications. Pre- and postoperative radiographic measurements were obtained. Patients also were contacted by telephone and asked about their ability to perform peri-anal self-hygiene and about their overall satisfaction.

RESULTS

In total, 110 humeri were lengthened (28 males and 27 females) with medium elongation of 9.5 cm on the right and 9.6 cm on the left, while averaging 220 days in an external fixator. We observed 14 minor complications. There was no significant association between pin position and type of callus, and elongation most often external and in the presence of a straight callus. Before elongation, 77.1% of patients reported difficulties with perineal hygiene and 85.4% could not put their hands in their pockets. Upon completion of lengthening, 100% could perform both tasks and 94.5% were very satisfied.

CONCLUSIONS

Bilateral humeral elongation yields significant improvements in patient autonomy, with a relatively low complication rate and very high patient satisfaction.