Congenital pseudarthrosis of the tibia (CPT) is a diagnosis that allows for no shortcuts: it requires integrating biology and mechanics, and thinking in "stages," not single interventions. Even when initial union is achieved, the real risk is that the bone will not hold up over time: refracture and its sequelae (deformity, ankle instability, limb length discrepancy) are often what determine long-term quality of life.
A comprehensive and very up-to-date review published in 2025 in JBJS Reviews summarizes the modern conceptual framework well: CPT is strongly associated with neurofibromatosis type 1 (NF1) and an unfavorable biological environment, where periostosis/fibrous hamartoma and cellular alterations promote a cycle of non-union and refractures [1]. Radiographic classifications (Andersen, Boyd, Crawford, Paley, etc.) remain useful primarily as a common language and for framing prognosis and timing, but the actual therapeutic choice hinges on several recurring issues: segment stability, quality of the bone ends, fibula involvement, and axis control [1].
The problem is not "just" union: it is union
** without refracture**
Historically, many techniques have reported decent union rates but with a constant weakness: refracture during follow-up. This theme is also central to Paley's 2019 article, which explicitly discusses how to increase the mechanical "robustness" of the reconstructed limb: it is not enough to fuse two thin bone ends; it is necessary to increase the resistant cross-section and protect the segment over time [2].
It is precisely on this rationale that the concept of tibia-fibula cross-union is based: deliberately creating a bony "bar" between the tibia and fibula to increase the overall cross-section and reduce the probability that, under load, the reconstructed segment will fail again [2][3]. The technique is complex and does not lend itself to simplification, but the available literature (though not randomized) has reported very strong results on the point that interests us most: refracture.
A retrospective study published on PMC (39 pseudarthroses in 36 patients) describes the cross-union protocol with hamartoma resection, bone grafting, intramedullary support (including telescopic nails), and adjuvants (the protocol includes zoledronate and BMP-2). In that series, tibial union and tibia-fibula cross-union were reported in all cases, and most importantly, absence of refractures in the reported follow-up (up to approximately 7 years) [3]. In the same cohort, non-trivial "course" problems are described—for example, migration/"pull-through" of the Fassier-Duval through the physis, requiring management during planned revision—which do not necessarily compromise the final outcome but remind us how much this is a long-term treatment, not a single surgical act [3].
The 2025 JBJS review places cross-union among the options that have changed the prognosis of CPT in recent years, while emphasizing that the literature is still heterogeneous and based on centers with very high expertise [1]. This is a key point: excellent results in expert hands do not automatically translate into a "universal standard" without a learning curve, careful selection, and a solid follow-up network.
TEN/ESIN, Ilizarov, telescopic nails, vascularized graft: where do they stand today?
Contemporary literature tends to think in terms of combinations rather than "pure" techniques. Historically, circular fixators like Ilizarov and vascularized fibular grafts have been important strategies; in many modern pathways, they remain useful tools, especially when deformities need to be corrected, shortening managed, the axis controlled, or when the bone ends are particularly atrophic [1].
On the intramedullary support front, the use of telescopic systems (such as the Fassier-Duval) is often integrated into reconstructive protocols to maintain support during growth and reduce vulnerability to refracture. There are also practical works discussing technical criticalities of revisions and removal, precisely because CPT often requires planned re-interventions throughout growth [4]. In other words: even when the strategy is "correct," follow-up is as much a part of the cure as the surgery itself.
Medications: useful, but not "the solution"
BMP and bisphosphonates frequently appear in the literature, but the 2025 JBJS review is cautious: the results are non-uniform, and pharmacological therapy alone does not seem to reverse the unfavorable biological environment of CPT, especially in CPT associated with NF1 [1]. Rather than "miracle drugs," they are described as possible adjuvants in complex protocols where mechanical stability and the radicality of hamartoma resection remain decisive [1][2].
A practical message that the literature converges to support
Looking at the totality of recent sources, the recurring message is consistent:
- Long-term mechanical stability is the true driver against refracture, not just initial union [1–3].
- Fibula management is not a detail: it influences the axis, stability, and overall mechanical behavior of the segment [1–3].
- The most "robust" protocols are often those that increase the resistant cross-section (cross-union) and maintain protective intramedullary support during growth [1–3].
- Complications and secondary interventions (revision, axial corrections, limb length discrepancy management) are frequent and should be anticipated from the outset as part of the journey [1][3][4].
Limitations of evidence and what remains open
Despite progress, it must be acknowledged that the highest level of evidence is difficult to obtain in a rare disease like CPT. Much of the most "incisive" literature comes from retrospective series from specialized centers, with very structured protocols and often excellent but not always reproducible results everywhere [1][3]. Furthermore, even when union is stable, sequelae (limb length discrepancy, deformity, ankle/foot problems) remain a source of medium-to-long-term morbidity and an area where the literature is more fragmented [1][3].
In summary: today, CPT is no longer a "sentence" as it was described in the past, but it remains a pathology that requires strategy, experience, and follow-up throughout growth. The direction of recent literature is clear: union yes, but above all, union that holds—that is, a reconstruction capable of resisting the risk of refracture.
Disclaimer
This content is for informational purposes only and does not replace an individual clinical evaluation.
References
[1] Al Ramlawi A, Chenard SW, Sidani M, Herzenberg JE, Schoenecker JG, McClure PK. Congenital Pseudarthrosis of the Tibia: A Comprehensive Literature Review. JBJS Rev. 2025;13(6). doi:10.2106/JBJS.RVW.25.00035. PMID: 40472164.
PubMed: https://pubmed.ncbi.nlm.nih.gov/40472164/
[2] Paley D. Congenital pseudarthrosis of the tibia: biological and biomechanical considerations to achieve union and prevent refracture. J Child Orthop. 2019;13(2):120-133. doi:10.1302/1863-2548.13.180147. PMID: 30996736. PMCID: PMC6442511.
PubMed: https://pubmed.ncbi.nlm.nih.gov/30996736/
PMC full text: https://pmc.ncbi.nlm.nih.gov/articles/PMC6442511/
[3] Paley D, et al. Cross-Union Surgery for Congenital Pseudarthrosis of the Tibia. (Retrospective study; full text on PMC). PMID: 34202921. PMCID: PMC8303361.
PubMed: https://pubmed.ncbi.nlm.nih.gov/34202921/
PMC full text: https://pmc.ncbi.nlm.nih.gov/articles/PMC8303361/
[4] McClure PK, Franzone JM, Herzenberg JE. Challenges with Fassier-Duval rod exchanges in congenital pseudarthrosis of the tibia: explant roadblock and solution. J Pediatr Orthop B. 2022;31(1):e95-e100. doi:10.1097/BPB.0000000000000907. PMID: 34380988.
