Paley's multiplier method does not accurately predict adult height in children with bone sarcoma

Management of limb length discrepancy after bone sarcoma resection about the knee in the skeletally immature

Patients with bone sarcomas increasingly choose limb salvage. This can lead to issues with limb length discrepancy (LLD) for the skeletally immature. We synthesize management options into an algorithm and report our results. Patients with bone sarcomas involving any location from the femoral diaphysis to the tibial diaphysis 12 years or younger were reviewed. Our clinical pathway prescribed patients with metadiaphyseal lesions to intercalary allograft reconstruction, epiphyseal lesions and less than 5 cm expected LLD to osteoarticular allograft and patients with more than 5 cm expected LLD to extendable prosthesis. Twenty patients met inclusion criteria: 11 with osteoarticular allografts, 5 with extendable prostheses and 4 with intercalary allografts; median age 11.5 years; median follow-up 8.2 years; and final median LLD 1.6 cm. Five patients had contralateral epiphysiodesis, two patients underwent contralateral femoral shortening and a median of 6 (range 4-8) lengthenings were performed for extendable prostheses. Four patients had residual LLD over 3 cm. There were 13 revisions in 8 patients and 2 amputations. Limb-salvage in paediatric bone sarcoma of the knee can be managed with multiple techniques producing satisfactory results in regards to LLD. Careful pre-operative planning and shared decision making is a requisite given the high rate of secondary procedures for both LLD and reconstructive failures. Level of evidence: Level III Retrospective Comparative Study.

Advancing pediatric bone sarcoma care: navigating complications and innovating solutions in limb salvage and reconstruction-why, when, and how to treat limb length inequalities

Pediatric bone sarcomas, particularly osteosarcomas, present unique challenges in the realm of orthopedic oncology, given their predilection for the metaphyseal regions of long bones and the intricate balance required between achieving oncologic control and preserving limb function. This abstract encapsulates findings from a comprehensive review aimed at advancing pediatric bone sarcoma care, focusing on navigating the complications and innovating solutions for complications of limb salvage and reconstruction focusing on limb length inequalities and accompanying bone defects. Advancements in imaging, surgical techniques, and adjuvant therapies have shifted the paradigm from amputation to limb-sparing surgeries, albeit with significant challenges, especially in young patients where growth potential complicates reconstructive outcomes. The series highlights the complexity of managing limb length discrepancies (LLD), the cornerstone of limb salvage challenges, and the innovative approaches to address them, including modular endoprosthetic reconstruction with expandable prostheses, magnetic lengthening nails and biological reconstruction strategies like vascularized fibula grafts. This review underlines the importance of a multidisciplinary approach in managing pediatric bone sarcomas, where the aim extends beyond mere survival to ensuring quality of life through functional limb preservation. It highlights the need for ongoing innovation in surgical and reconstructive techniques tailored to the pediatric population's unique needs, emphasizing the potential of emerging technologies and methodologies to improve outcomes. Future research should aim to fill the existing knowledge gaps, particularly in comparing pediatric and adult surgical outcomes, to refine treatment protocols and improve patient care in this challenging domain.

[The use of distraction osteogenesis for the reconstruction of bone defects following resection of malignant bone tumours]

The reconstruction of extensive bone defects following resection of malignant bone tumours is a challenge and is mainly influenced by tumour-related factors. In defect reconstructions using distraction osteogenesis isotropic, high-quality (new) bone is formed. For the reconstruction of bone defects and secondary limb length discrepancies following tumour resection, predominately three techniques have been described: bone transport, primary shortening and secondary lengthening, as well as "bio-expandable tumour endoprostheses". The use of distraction osteogenesis represents an excellent method for defect reconstruction and treatment of secondary limb length discrepancies following bone tumour resection. Due to the complex anatomical preconditions in tumour patients, a high degree of expertise in distraction osteogenesis (and tumour endoprostheses) is paramount. Therefore, treatment of these patients at highly specialised centres is recommended.

Does Systemic Chemotherapy Influence Skeletal Growth of Young Osteosarcoma Patients as a Treatment-Related Late Adverse Effect?

The aim of this study was to investigate the influence of systemic chemotherapy on the skeletal growth of young osteosarcoma patients as a treatment-related late adverse effect. We reviewed the height data of 20 osteosarcoma patients (13 males and 7 females) aged ≤18 years. The average (±SD) age at diagnosis was 14.5 (±3.3) years. The average follow-up interval was 89.6 months. After wide resection of the affected bones, reconstruction with tumor prostheses and auto-bone grafting was carried out in 11 and 9 cases, respectively. Pearson’s correlation coefficient was calculated to evaluate the association between actual and predicted (using Paley’s multiplier method) heights. Z-scores were used to compare the initial and final heights with the Japanese national growth curve. Actual and predicted heights were correlated according to Pearson’s correlation coefficient (R = 0.503). Z-analysis showed that statistical significance (p = 0.04) was noted for the height data Z-scores of patients between ≤10 years and >10 years at the final follow-up. Systemic chemotherapy did not reduce skeletal growth in young osteosarcoma patients as a late adverse effect based on two different evaluation methods. However, patients aged ≤10 years at diagnosis may develop a short stature after systemic chemotherapy.

Height and Extremity-Length Prediction for Healthy Children Using Age-Based Versus Peak Height Velocity Timing-Based Multipliers

BACKGROUND

The age-based multiplier method described by Paley et al. markedly simplifies height and limb length predictions but may not adequately accommodate children's maturational differences. Multipliers can be derived relative to any maturity measure. This study compares Paley age-based multipliers with those based on peak height velocity (PHV) timing.

METHODS

In a longitudinal cohort of healthy children (66 male and 70 female), actual adult heights and limb lengths were compared with the measurements predicted using the Paley multipliers and multipliers developed relative to PHV timing. The age-based multipliers (adult divided by current) in our series were compared with those reported by Paley et al. to ensure that there were no systematic differences between the series. Absolute differences between the actual and predicted adult heights and limb lengths and the standard deviations of those differences were compared between the 2 methods.

RESULTS

The average age-based multipliers in our series were nearly identical to those reported by Paley et al. The differences between the predicted and actual adult values showed wide ranges when either the Paley or the PHV multipliers were used during infancy. The Paley method performed better than the PHV method throughout pre-growth-spurt childhood. The PHV-timing-derived multipliers became superior as children entered their growth spurt, whereas the performance of the age-based multipliers worsened. In adolescence, the maximum standard deviation for adult-height-prediction errors with use of the Paley multipliers occurred at the age of 13.5 years for boys and 11.5 years for girls and was 7.0 cm for boys and 5.6 cm for girls. For limb lengths, the maximum standard deviations occurred 6 months earlier and were 3.9 cm for boys and 3.2 cm for girls. The maximum standard deviation for the height prediction error with the age-based method occurred at the average time of PHV for the population. The PHV method became better than the Paley method just before growth-spurt initiation, at age 8 in girls and 11 in boys.

CONCLUSIONS

The age-based multipliers described by Paley et al. are superior to PHV-timing-based multipliers prior to the adolescent growth spurt for predicting height. They become less predictive, with wide standard deviations, as children enter their growth spurts, and PHV-derived multipliers become superior. The Paley height multipliers should be used before the age of 8 years in girls and 11 years in boys. After this, PHV-derived multipliers are superior for height and limb length prediction. In practice, these predictions are currently made using skeletal maturity, which is closely related to PHV during adolescence.

When Do Orthopaedic Oncologists Consider the Implantation of Expandable Prostheses in Bone Sarcoma Patients?

Introduction

Indications discussed for the implantation of expandable prostheses in bone sarcoma patients are unclear. This survey aimed to analyse common practice with this implant type in orthopaedic oncology.

Methods

A web-based survey was sent to 98 orthopaedic oncology surgeons. Factors reported in literature to influence the decision on the implantation of a growing prosthesis were covered in individual questions and three case scenarios.

Results

The completion rate of the survey was 45% (n = 44). Twenty-seven of 44 surgeons (61%) had implanted between 1 and 15 expandable prostheses within three years. The minimum median patient age was 6.5 years, and 3–5 cm of predicted growth deficit was the minimum before implanting a growing prosthesis. One-third of surgeons do not use growth calculation methods. Two out of three surgeons would rather not implant a growing prosthesis in children with metastatic disease.

Conclusions

Our survey confirmed the literature with 3-4 cm as the minimum estimated growth deficit. The minimum age for the implantation of a growing prosthesis is approx. 6.6 years, and therefore the patients are younger than those reported in previous publications. One-quarter of orthopaedic surgeons do not use growing prostheses at all. It remains unclear whether growing prostheses are indicated in patients with metastatic disease.

Multiplier method may be unreliable to predict the timing of temporary hemiepiphysiodesis for coronal angular deformity

Background and purposes

The multiplier method was introduced by Paley to calculate the timing for temporary hemiepiphysiodesis. However, this method has not been verified in terms of clinical outcome measure. We aimed to (1) predict the rate of angular correction per year (ACPY) at the various corresponding ages by means of multiplier method and verify the reliability based on the data from the published studies and (2) screen out risk factors for deviation of prediction.

Methods

A comprehensive search was performed in the following electronic databases: Cochrane, PubMed, and EMBASE™. A total of 22 studies met the inclusion criteria. If the actual value of ACPY from the collected date was located out of the range of the predicted value based on the multiplier method, it was considered as the deviation of prediction (DOP). The associations of patient characteristics with DOP were assessed with the use of univariate logistic regression.

Results

Only one article was evaluated as moderate evidence; the remaining articles were evaluated as poor quality. The rate of DOP was 31.82%. In the detailed individual data of included studies, the rate of DOP was 55.44%.

Conclusion

The multiplier method is not reliable in predicting the timing for temporary hemiepiphysiodesis, even though it is prone to be more reliable for the younger patients with idiopathic genu coronal deformity.

Is There a Reliable Method to Predict the Limb Length Discrepancy after Chemotherapy and Limb Salvage Surgery in Children with Osteosarcoma?

Background:

For a child with osteosarcoma, prediction of the limb length discrepancy at maturity is important when planning for limb salvage surgery. The purpose of this study was to provide a reliable prediction method.

Methods:

A retrospective review of Chinese children receiving chemotherapy for osteosarcoma before skeletal maturity was conducted. Standing full-length radiographs of the lower extremity were used for length measurements. Length-for-age curves were constructed using the LMS method. The lower limb multiplier for a specific age and gender was calculated using the formula M = L_m/L, where M was the gender- and age-specific multiplier, L_m was the bone length at maturity, and L was the age-specific bone length. Prematurity and postmaturity radiographs were used to assess the accuracy of the prediction methods.

Results:

A total of 513 radiographs of 131 boys and 314 radiographs of 86 girls were used to calculate the coefficients of the multiplier. The multipliers of 8-, 9-, 10-, 11-, 12-, 13-, 14-, 15-, 16-, 17-, and 18-year-old boys after chemotherapy for osteosarcoma were 1.394, 1.306, 1.231, 1.170, 1.119, 1.071, 1.032, 1.010, 1.004, 1.001, and 1.000, respectively; while for girls at the same ages, the multipliers were 1.311, 1.221, 1.146, 1.092, 1.049, 1.021, 1.006, 1.001, 1.000, 1.000, and 1.000, respectively. Prematurity and postmaturity femoral and tibial lengths of 21 patients were used to assess the prediction accuracy. The mean prediction error was 0 cm, 0.8 cm, and 1.6 cm for the multiplier method using our coefficients, Paley's coefficients, and Anderson's method, respectively.

Conclusions:

Our coefficients for the multiplier method are reliable in predicting lower limb length growth of Chinese children with osteosarcoma.