Betzbone

Betzbone is a telescopic nail that lengthens by ratchet, not by motor. The Becker Betz Institute, which developed it and is the only place that implants it, describes it as 'a further development, modification and improvement of the Albizzia', the French ratchet nail of the 1990s. The lengthening principle is inherited from that design: rotate the leg back and forth by about 20 degrees until you hear a click. There are 'no electronic control systems' and no external remote. It is a different family from the Fitbone, the electric nail Prof Betz co-developed, which the same page says is driven by an internal motor fed through a skin transmitter.

Your day during distraction is clicks plus stretching. The institute ties speed to stretching time: two to three hours a day supports 0.5 mm; five to six hours allows up to 0.8 mm. Its patient videos cover muscle-relaxant medication given to make clicking easier, and what to do about 'accidental' clicks, a candid admission that a twist of the leg in bed can advance the ratchet when you did not intend it.

One clinic, one surgeon. Betzbone is implanted at the Becker Betz Institute in Freiburg, a private clinic whose site states that every lengthening operation is performed by Dr Axel Becker. The inventor, Prof Augustin Betz, co-authored the 1990 paper that introduced the first fully implantable lengthening nail with a programmable drive, the Fitbone. We found no second clinic anywhere that implants Betzbone. The institute says its patients come from the USA, Saudi Arabia, Japan, China, Russia, Brazil and across Europe, and that it performs roughly 200 lengthenings a year, a figure it reports about itself.

It suits a patient who wants to walk with full load from day one, who is choosing the femur or the tibia rather than both (the institute does not lengthen both at once, calling that too risky), and who accepts that follow-up, removal and any revision run through a single German clinic. The stated capacity, 12.3 cm on the femur and 10 cm on the tibia, will attract patients wanting more than the 6 to 8 cm typical of other nails. Read the risk section before that number decides anything.

The institute's published timeline: arrive 48 hours before surgery; two and a half to three hours in theatre for both femurs, four and a half to five for both tibias, under general anaesthetic; three to four days as an inpatient; rehabilitation and training organised by the clinic from day 4 to day 14. Clicking begins five to seven days after femoral surgery and nine to ten days after tibial surgery.

The daily rate is where the institute's own pages disagree with each other. The FAQ says 'approximately 1.0 mm every day' and gives 9 cm in three to four months as an example; the same FAQ, two answers earlier, says 0.5 mm a day with two to three hours of stretching and 0.8 mm with five to six hours. Ask which applies to you, because at 0.5 mm a day a 9 cm gain takes six months, not three.

Removal is 'an outpatient procedure' at the institute, after 'one to two years' in one FAQ answer and 'two to three years' in another. Cost is not published; the site asks patients to call for 'an approximate framework of costs'.

No published complication rate exists for Betzbone, so what follows is qualitative, drawn from the mechanism and from the institute's own material.

Pain when clicking. The institute's FAQ says pain has two peaks: right after surgery, and again 'as soon as the lengthening process starts'. Calder's 2017 historical review in Injury records that the Fitbone was built to remove the pain 'resulting from the manual rotation of the leg required to achieve the ratchet progression'. Betzbone's inventor co-developed that Fitbone, then returned to the ratchet for stability and length; the pain trade-off comes back with it.

Unintended clicks. Any twist can advance the ratchet; the institute's videos address 'accidental' clicks directly.

Length ambition. A 12 cm capacity is what the implant can extend, not what your muscles and nerves tolerate. The Marwan 2020 systematic review found a mean gain of 6.7 cm across 795 cosmetic patients. Nothing published tells you how Betzbone patients fare at 10 cm and beyond.

Corrosion. The institute stresses anti-corrosion material, a fair point after the FDA's 2021 Class II recall of the PRECICE Stryde for junction corrosion. But the claim is the maker's; no retrieval studies of Betzbone implants have been published.

None in the peer-reviewed literature. A PubMed search for 'Betzbone' returns zero results (September 2026). The device is absent from the 2020 Bone & Joint Research systematic review of cosmetic stature lengthening (795 patients, 11 studies), from Frost's 2023 multicentre cohort of 314 Fitbone and PRECICE nails, and from every other nail series we checked. The institute's website is currently the entire public record.

That is not the same as saying it does not work. The Albizzia it descends from has small published series from the 1990s and 2000s, and the inventor's engineering record is real. But a patient cannot check the clinic's statements about 1,500 operations, full load-bearing or 12 cm gains against anyone else's numbers, and the clinic reports its outcomes only in its own patient videos.

Practically, this puts Betzbone in a different evidence class from PRECICE 2, where complication rates are published by centres that do not sell the implant. If independent data matters to you, that difference is the decision.

The Becker Betz Institute's pages are unusually specific, which makes them easy to test. Use that.

'Highest stability and lengthening capacity of all intramedullary distraction nails.' A comparison table on the Betzbone page lists PRECICE at 'part load, 8 cm' and Fitbone at 'part load, 6 cm'. Those are the maker's characterisations of its competitors; ask for the bench-test data behind 'full load'.

'Over 1,500 minimally invasive limb lengthening operations' and 'approximately 200 extensions per year.' Ask how many were Betzbone femurs, how many tibias, the mean gain, and how many needed a return to theatre. A clinic with 1,500 cases has that spreadsheet.

Removal timing and daily rate. Two answers each on the site. Get the one that applies to you in writing.

Cost. Not published. Get the quote itemised: surgery, implant, the 14-day rehabilitation, follow-up X-rays, and the removal operation one to three years later, plus what a second trip to Freiburg costs if lengthening stalls. A single-clinic device means a single place to fix it.