Author:
W. Schaden, A. Fischer, A. Sailler, A. Menschik, N. Haffner
Institution:
Trauma Centre Meidling, Vienna, Austria
The objective of every fracture treatment is to reunite the fracture fragments
in an anatomical position and completely restore the function of the injured
portion of the skeleton as quickly as possible. Despite today’s sophisticated
technologies and good primary treatment, 1-3% of all bone fractures develop
into pseudarthrosis. Surgical treatment with debridement of the pseudoarthrotic
tissue, cleaning of the fragment edges, insertion of autologous spongiosa and
stabilization with osteosynthesis material is considered the “gold standard”
for the treatment of pseudarthrosis. However, these surgical procedures are
extremely traumatic for the patient. They are also costly, time-consuming, and
associated with a high rate of complications. Therefore in December 1998, after
successful pilot studies, the Trauma Centre Meidling commenced a large-scale
prospective study using shockwave therapy to treat non-unions.
To date, more than 1,100 non-unions have been treated with shockwave therapy
in the Trauma Centre Meidling. We have used different electrohydraulic devices
(Orthowave 280, MTS; OssaTron, HMT) and have even compared different technologies
by also using an electromagnetic device (Modulith, Storz Medical) from April
2004 until January 2005.
From the start of the study, more than 50 patient-specific data items were stored
in a database developed especially to permit the combination of a broad range
of parameters. This database structure serves as the basis for quality assurance
measures and enables the researchers to determine the optimal treatment parameters
and other important criteria. This database containing a documentation of the
treatment of pseudarthrosis with ESWT is made available to all interested parties
free of charge; it can be ordered from the authors.
Treatment was basically envisaged as a single treatment. Depending on the region
to be treated, shockwave therapy is administered under general, regional or
local anaesthesia. The patients are positioned such that the pseudarthrosis
gap is clearly visualized in the anterior-posterior projection. The shockwave
focus is positioned on the pseudarthrosis gap and between 2,000 and 4,000 pulses
are applied (1,000 pulses per treatment location). We use an energy flow density
(EFD) of 0.3 to 0.4 ml/mm2 for all bone treatments.
Following shockwave therapy the pseudarthrosis is immobilized like a fresh fracture.
This is usually done with a plaster cast or plastic splint; in 7 patients with
especially mobile tibia non-unions, an external fixator was used. Fixation is
not necessary when the pseudarthrosis has been treated with appropriate osteosynthesis
material and this material exhibits no signs of loosening upon clinical or radiological
examination. It can be assumed that the healing process is initially accompanied
by neovascularization; for this reason, we try to prevent micro-movements of
the non-union during the first 3-4 weeks after treatment to preclude tearing
of the new capillaries. It may be necessary, in some cases, for the patient
to avoid full weight bearing on the affected extremity during this period. The
patient’s cooperation must be elicited by a detailed briefing since most
patients are asymptomatic directly after the treatment, owing to the analgesic
effects of the shockwaves, and want to put their full weight on the affected
extremity again.
If the cardinal symptoms (i.e. pain upon bending or compression, swelling, reddening
and hyperthermia) subside during the early post-treatment phase (i.e. the first
2-3 months after ESWT), the physician can afford to take a “wait and see”
attitude. This applies even if the x-ray findings are ambiguous, since the clinical
findings constitute a more reliable measure of therapeutic success at this stage.
A pseudarthrosis gap with a width greater than 5 mm shows a poor prognosis.
In cases where bony remodelling of the non-union could not be demonstrated after
3 to 6 months, patients were given the option of surgical repair. Numerous patients,
especially those who had undergone multiple operations previously, refused this
option. This led to a relatively high number (18%) of repeat treatments. In
exceptional cases, a third or fourth (and in one instance, even a fifth) treatment
was performed. The group of patients undergoing repeat ESWT included patients
for whom a complicated pseudarthrosis operation was contraindicated for internal
reasons or could have been done only at considerable risk to the patient.
Osseous union was achieved in 67% to 75% (depending on the device) of the pseudarthroses.
As expected, the best therapeutic results were obtained in patients with delayed
osseous union – in this group, ESWT was administered 3-6 months after
the injury or the last operation on bone – and healing was achieved in
75% to 85% of these patients. Of the patients with pseudoarthrosis with an onset
more than six months previous, 60% to 70% experienced osseous union.
Among the more than 1,100 patients treated at the Trauma Center Meidling, no
complications occurred other than the adverse reactions that have already been
observed following shockwave therapy (i.e. local swelling, petecheal bleeding,
haematoma). Even though the mechanism of action of shockwave therapy has not
yet been fully explored, we are convinced that ESWT is an effective, inexpensive
and time-saving therapeutic modality with an almost zero rate of complications.
Therefore we consider ESWT as the first choice thrapy for non-unions and delayed
unions that do not require surgical realignment.