This week I was visited by my good friend and two time NBA champion Pau Gasol. We discussed the arduous road to recovering from a tarsal navicular fracture. Pau underwent surgical repair of his navicular with two screws and a bone graft in May of 2019 and has yet to return to play. This is not uncommon for this injury.
The navicular takes its’ name from a strong concave surface that resembles a boat. It is a tarsal bone located on the inside of the mid-foot and is an integral structural link between the hind-foot and mid-foot and the mid-foot and the fore-foot. It provides stability for the foots three arches and is the keystone to force transmission.
Navicular fractures are sustained from either trauma or chronic overload. They are complicated because of poor blood supply in the middle one-third of the bone and the complexity of the joints it creates. They account for about 25% of all stress fractures. A study of 200 navicular stress fractures showed they were more common in males in their mid-twenties of which 98.5% were athletes. They are difficult to diagnose without proper imaging. Traditional x-ray has a very low sensitivity for navicular stress fracture. MRI is about 71% accurate while some believe CT scan is the gold standard for diagnosis at 91.9% accuracy. Foot and sports medicine specialist, Dr. Ken Jung uses MRI initially if he suspects a fracture. If the MRI shows bone edema or a fracture he follows up with a CT scan to delineate the fracture line.
To help focus on how to approach navicular fractures Saxena et al created a tarsal navicular classification system diagnosed on CT scan. Fractures were classified as Type I, II or III based on the plane of the fracture and the degree on comminution. The same group conducted a longitudinal study from 2005 to 2016 published in the Journal of Foot and Ankle Surgery. Their finding was most Type III fractures underwent surgery with an average time of return to play at 8.8 months.
Torg et al did a comparative treatment study of 251 fractures. They reported in the American Journal of Sports Medicine that early diagnosis and complete non-weight bearing was the most successful plan for return to play at 96% vs 82% from surgery. Partial weight-bearing was the least successful and should not be considered. My experience with elite athletes is that they require surgery for the best result due to the high physical demands required from sports.
But statistically non-displaced navicular fractures do well with immobilization for 6 – 8 weeks followed up with a graduated weight-bearing program. Coming back too soon will delay healing and may result in a non-union or fibrous union of the fracture.
There has been more recent research into other areas of interest to augment the treatment of navicular fracture. There is great interest in the role of Vitamin D deficiency due to its effect on calcium absorption. Teriparatide injection is a form of parathyroid hormone that has been used successfully to treat osteoporosis by stimulating osteoblasts to generate new bone. Traditionally we used bone stimulators to speed up healing but there is little research to back up it’s efficacy. There is also little downside as far as I can see.
Regenerative medicine is becoming quite popular with biologics playing an increasing role in orthopedic medicine. Stem cells can be harvested from many sources such as bone marrow, adipose tissue, synovial tissue, embryonic, amniotic and others. Although there is good rationale in using biologics to induce tissue healing the jury is still out. There are many celebrities and athletes endorsing the use of biologics which translates into widespread misuse and abuse. There are over 400 complete or ongoing clinical trials of PRP and 800 on stem cells and we still have not acquired enough solid evidence to warrant widespread use. My experience and conversations with many doctors is that although the concept is good, we’re just not there yet. Insurance is not covering many of these procedures which leads to “pirate clinics” who offer biologics for cash.
My friend Pau is a case of surgical intervention for a navicular fracture resulting in a non-union.
Pau went to his native country of Spain for biologic therapy (bone marrow aspirate). He is still on crutches but is showing healing from the biologics. In Pau’s case, doctors in Spain have greater freedom with regenerative medicine. Incubation periods are longer to develop cultures that would not be approved by the FDA in the United States.
Recently the European Union launched the Starstem Project to study and understand the dynamics and distribution of stem cells. Many believe regenerative medicine is the future to the quality of life.
Time will tell.