Patient interest & the evolving role of adjunctive support in fracture healing
Current research indicates growing interest in functional and integrative orthopedic approaches. Many patients with delayed fracture healing explore supportive strategies alongside standard care, including optimized nutrition, physical therapy, and rehabilitation (Einhorn & Gerstenfeld, 2015). Within this adjunctive framework, growth factor preparations — such as bone morphogenetic proteins (BMPs), platelet-derived growth factor (PDGF), and platelet-rich plasma (PRP) — have been investigated to enhance the biological environment. This educational review summarizes preclinical and early clinical evidence while reflecting current guideline recommendations from orthopedic societies.
Umbilical cord mesenchymal stem cells within an integral medicine framework for bone healing
Umbilical cord-derived MSCs (UC-MSCs) secrete paracrine factors including osteogenic cytokines (BMP-2, VEGF, IGF-1) that may support bone regeneration. Preclinical models of critical-size bone defects suggest that UC-MSC conditioned medium promotes osteoblast differentiation and angiogenesis (Wang et al., 2021). Within an integral functional medicine framework, UC-MSCs are an area of active research that could complement conventional fracture care, nutritional support, and physical therapy. However, clinical translation remains in early stages, and all MSC-based strategies are categorized as adjunctive, not yet approved for routine delayed fracture healing.
Growth factor preparations: mechanisms and preclinical evidence
Delayed fracture healing is associated with insufficient signaling of endogenous growth factors. Recombinant human BMP-2 and BMP-7 have been studied for their osteoinductive properties. In animal models of delayed union, localized administration of BMP-2 is associated with increased callus formation and biomechanical strength (Carreira et al., 2015). PDGF-BB, delivered via collagen scaffolds, has been observed to enhance mesenchymal cell recruitment and proliferation. Preclinical research indicates that combination strategies (BMP + PDGF) may produce additive effects, although optimal dosing remains under investigation.
| Preclinical study / Year | Growth factor / Model | Observed outcomes (adjunctive context) |
|---|---|---|
| Einhorn et al., 2015 (review) | BMP-2, rodent femoral defect | ↑ bone volume, ↑ mechanical stiffness |
| Carreira et al., 2015 | PDGF-BB in rabbit ulna | Enhanced mesenchymal recruitment, ↑ callus density |
| Gomes et al., 2018 | PRP in rat tibial delayed union | Modest improvement in radiographic healing scores |
Early clinical evidence and current guidelines overview
Early clinical studies have explored growth factor injections using minimally invasive techniques for long bone nonunions. A systematic review reported that BMP-2 (INFUSE) and BMP-7 (OP-1) have been used off-label in tibial nonunions, with healing rates ranging from 70–85% in case series (Bishop et al., 2020). However, randomized controlled trials are scarce and show inconsistent efficacy compared to autograft. The American Academy of Orthopaedic Surgeons (AAOS) guideline on the treatment of tibial fractures states that the use of BMPs may be considered as an adjunct in revision surgery, but evidence is limited and does not support routine application (AAOS, 2020). PRP preparations have not demonstrated clear superiority over placebo in most controlled trials. All described growth factor strategies remain categorized as adjunctive; none are universally approved for first-line delayed fracture healing.
Adjunctive integral approach: combining rehabilitation, nutrition, and growth factors
Current research indicates that an integral functional medicine approach — including protein/calcium/vitamin D optimization, supervised physical therapy, and smoking cessation — may improve fracture healing outcomes. Within this framework, growth factor preparations could play a supportive role when conventional healing is compromised. However, individual responses vary depending on age, comorbidity, fracture stability, and biological environment. Large-scale prospective studies are needed to define patient subsets that may benefit from adjunctive growth factor therapy.
1. Einhorn TA, Gerstenfeld LC. Fracture healing: mechanisms and interventions. Nat Rev Rheumatol. 2015;11(1):45-54.
2. Carreira AC, Lojudice FH, Halcsik E, et al. Bone morphogenetic proteins: structure, biological function and therapeutic applications. Arch Biochem Biophys. 2015;561:64-73.
3. Bishop JA, Palanca AA, Bellino MJ, Lowenberg DW. Assessment of competing risks of nonunion in fractures. J Orthop Trauma. 2020;34(6):e206-e211.
4. American Academy of Orthopaedic Surgeons. Management of Tibial Fractures Evidence-Based Clinical Practice Guideline. AAOS; 2020.