1. Extracorporeal shockwave therapy is an effective treatment for bone non-unions and delayed unions, achieving healing rates of over 70% according to clinical studies. 2. The mechanism of action involves stimulating osteoblastic activity and new blood vessel formation at the treatment site through a stromal cell response. 3. Proper patient selection and stabilization of the treatment area after shockwave therapy is important for success. Younger, hypertrophic non-unions tend to have better outcomes than older, atrophic cases.

1. Review :
External Shockwaves (ESW) as a new therapeutic tool upon bone pathologies.
Manuel R. Brañes , MD.
Adjunct Professor Faculty of Science , University of Chile.
BioSurgical Unit (ESW) , AraucoSalud Clinic - Santiago.
Email: branesmd.1@vtr.net
Resumen : la terapia de ondas de choque aplicadas en patología ósea están indicadas en
situaciones de retardo de consolidación y no uniones . El análisis histológico del efecto
de las ondas sobre el hueso muestra una reacción estromal con hipercelularidad y aumen
to de nuevos vasos sanguíneos , los que llevan a una intensa producción de osteoide fo-
cal y posterior consolidación;el examen exhaustivo de nuestro material en tendón y hue-
so indican que están aumentados los procesos naturales de cicatrización , muy posible-
mente por desarrollo de células mesenquimales y células endoteliales con capacidad de
diferenciación hacia líneas condroblásticas , tenoblásticas y osteoblásticas.
Los resultados clínicos demuestran , un importante efecto osteogenético que permite ob-
tener curaciones incluso en condiciones de lesiones óseas benignas como rótula bipartita
y fibroma no osificante solitario; las consolidaciones así inducidas muestran en alto por-
centaje la aparición de callo endostal y periostal , junto a remodelación cortical en tiem-
pos algo menores a los habitualmente observados. Nuestra experiencia sobre más de 40
casos nos permite decir que , una adecuada selección de pacientes y patologías otorga
un porcentaje de resoluciones mayor al 70%, logrando evitar cirugías , sus riesgos y
complicaciones.
Palabras claves : ondas de choque , no consolidación , patología ósea benigna .
Key words: extracorporeal shockwaves (SW) , bone non union , bone pathologies.
Initial experience with the use of extracorporeal shockwave on bone non unions came
from the works done by Drs Valchanou and Michailov , and their report was published
in 1991[1] , reporting bony unions in 70 of 82 patients ( various locations ). First’s
studies performed in laboratories showed histological changes in bone architectural
features ( bone fissuring, periostal haematoma, soft tissue haematoma ) , giving the idea
that shockwaves induced a “mechanical re-injury”; later studies indicated that , using
proper energies , is stimulating an “osteoblastic response” based on bone marrow
stromal cells that differentiate towards osteoprogenitors associated with induction of
TGF_1 [2]; also was demonstrated that shockwave induced a neo-vascularization at the
tendon-bone junction [3]. Wang published, 2003, a subsequent article in which he
described the expression of bone morphogenetic proteins during the healing process of
segmental bone defects treated with SW [4].
To date , the most important worldwide experience , performed by a single researcher
correspond to Dr. Wolfgang Schaden from Vienna , defining the most suitable level of
energy and number of pulses for bone pathologies, reaching a success rate of 86% in
204 tibia non unions [5, 6].
Clinical application of shockwaves is considered an “out-patient procedure”, not
requiring anesthesia for highly cooperative patients. Children and non cooperative
patients require mild sedation in operative room; most of the cases require the use of
image intensifier. Delayed bone unions and non unions are diagnosed by x-rays and we
try to obtain 3D-CT-Scans in order to define the precise condition of the gap. After treat
ment stability of the non-union is crucial (casts , external fixation) , as the current treat
ment for any acute fractures.

2. 2
SW can be applied in all cases of delayed or non unions that underwent ORIF or had
prior conservative therapy. If the osteosynthesis implants show signs of loosening, the
non-union is unstable and should be stabilized after shockwave therapy (plaster cast, or-
thesis , external fixator or not weightbearing). This is necessary to protect the capillaries
sprouting over the non-union gap in the initial phase of healing (depending on the
location between three to six weeks). According to Schaden´s experience , chronic
bone infection (osteomyelitis) is not a contraindication for shockwave therapy. He could
show almost the same healing rate as in uninfected cases with an important reduction of
infection activity, reaching bone healing with resolution of infections; in those patients
we should expect the necessity for more than one treatment (two up to three); we
experienced similar results in our patients with chronic infections.
Delayed bone unions show slightly better results than definitive non-unions; this
suggests that patients are loosing biological capability for bone healing according to the
age of the non-union.
Some reports indicate that atrophic non unions are not suitable for this therapy; in our
experience, atrophic and oligotrophic non-unions showed similar results as hypertrophic
ones ( ~75% compared to ~85%) , indicating that , the proper technique and post
treatment care are more important than x-rays images. Dr. Schaden, pointed out, that
the biological response to SW treatment in non unions longer than 3 years, showed less
good results; especially the scaphoid non-union older than one year showed only
healing rates around 40% to 50%.
Our histological findings indicate that short bones (carpal and probably tarsus bone),
reacts with a fibroblastic healing in terms of 3 to 4 weeks after acute fractures without
any treatment. If there is not adequate fracture reduction within days, we would
recommend ORIF.
I would recommend SW for scaphoid delayed unions but not for established non-unions
because of the poor results. I would indicate its use for patients showing poor blood
supply or initial necrosis of the scaphoid bone to improve blood supply in the treated
area also if later on a surgical procedure is necessary.
Fig.1. Female, 59 y.o., right humerus atrophic non union ( nine months waiting for healing using a brace, pain and
disfunction). Single SW treatment , 6000 pulses 0,33mJ/mm2, bone healing in 12 wks, last x-rays at sixth month.
The osteogenetic potential of SW it has been tested in benign bone pathologies, such as
bipartite patella and solitaire non-ossifying fibroma (femur), both conditions correspon-

3. 3
ding to an abnormal focal non-forming bone lesion , existing a “fibroid stroma” , filling
the gap observed on images ( figs. 2 , figs.3 ). Cystic lesions in bones are unsuitable for
SW indication, because there is no “ stroma ” to be induced towards ossification and
there is no pathological study ruling out others conditions.
Fig.2. Male, 13 y.o.,bipartite patella, symptomatic. Single SW treatment 5000p- 0,33mJ/mm2 . Pain disappear shortly
after procedure , knee brace for 20 wks, showing significant bone fusion at that time. Last x-rays at 2 and a half year.
Fig.3.Male,14 y.o., solitaire non-ossifying fibroma , symptomatic. Single SW treatment 6000p 0,33mJ/mm2. Progre-
ssive disappearance of pain ; complete bone repair in 26 weeks with cortical remodelling.
Clinical experience on paediatric patients include cases of delayed bone healing in Proxi
mal Femoral Focal Deficiency ( fig.4), or Congenital Tibial Pseudoarthrosis in NeuroFi-
bromatosis (NF1) (fig.5), [9].
a b c d e f
Fig.4. a- 5yo., b- 6yo., c- 7yo., d- 8yo and SW treatment. e- 10 wks after SW and f- 3D-CT-Scan.
SW 5000 p 0,33mJ/mm2 , single session without anesthesia ; at 12 wks., patient with active hip motion and starting
walk with canes and heel supply.
Fig.5. Congenital tibial pseudoarthrosis in NF1. Single SW treatment 5000p 0,33mJ/mm2 under sedation and image
intensifier. Tibial consolidation in 55 days after treatment , 3DCT-Scan at sixth months .

4. 4
Dr. Schatz K.D. from Vienna presented his experience using SW in 4 cases of
congenital tibial pseudoarthrosis with good results in 2002 [7].
Our histological observation about bone responses to SW indicate a “stromal reaction”
with active hypercellularity that provokes new osteoid deposition and neo-vasculariza-
tion that supports a high blood supply to the area , corresponding to Wang´s report.
a b c
Fig.6. a-, normal bone remodelling area ; b-, after SW , we appreciate more blood vessels with a greater number of li-
nning osteoblast forming osteoid ; c-, stromal reaction of bone marrow filling all spaces, normal osteoclast on the left.
a b
Fig.7. a-, very illustrative section of bone after SW, showing an intense stromal reaction , high number of neo-blood
vessels ; b-, active stromal reaction on the right that its forming new bone ( light pink area , top center).
We have never seen in these histological sections for bone (and rotator cuff tendon also)
that have received SW, images that depicts signs of displasia or anaplasia or focal necro
sis. Biopsies of tendon and bone have been obtained from patients with rotator cuff rup-
tures and significant tendinosis , that received SW in an attempt to improve the vascular
response and quality of the tendon before surgery for better bone-tendon healing [8].
Other material came from failures of intended SW treatment upon non unions ( fig.8).
Fig.8. Male , 51 yo., long-standing carpal scaphoid non union ( 3 years ). It was intended a SW treatment and subse-
quent cast immobilization for 10 weeks. Patient decided surgical option , during which both scaphoid fragments were
covered by firm fibro-chondroid tissue (left section) ; it was removed and a segmental bone graft was obtained from
the distal radius including a biopsy (right section) : stromal reaction in spongiosa bone , active , because its forming
new bone (pink areas along old trabecular bone).

5. 5
The lessons we learned from our failures, showed to us, that we have to be more
diligent to the patient´s clinical development after SW, supposing that we have done a
critical patient selection , before to induce a reactivation of bone metabolism and it´s
repair capabilities; next clinical example shading more light about this statement:
a b c d
Fig.9. Female, 26 yo., left humeral closed fracture (July 2005), uneventfully ORIF same day. A-, x-rays (July 06)
showing non union and loosening plate/broken screw. We attempted a SW treatment (5000i 033mJ/mm2) and hu-
meral perfect-fit brace. We did not see any reaction at the end of eight weeks (September 06) , repeating the sche-
dule (2º treatment). B-, x-rays November 06 , reveals cortical bone fade-out under plate and lessening of sclerotic
bone areas with wider gap, patient´s complaints include dull pain/dysfunction. C-, Alloy Metallosis. D-, biopsy sec-
tion featuring deep foreign bodies staining.
We should see a definite sign of bone response in x-rays latest 8 weeks after SW treat-
ment; if this does not occur, we need to re-check everything looking for clues.
a b c d e
Fig.10. Female , 20 yo., A-, right femur fracture (car accident), ORIF (not stable), same day. B-C, Delayed bone
union x-rays at 4 months. D-, CT-Scan showing gap condition; SW therapy 6000 pulses 0,33mJ/mm2 , thigh brace .
E-, patient showed consolidation bone signs at 12-14 wks; perfect bone remodelling was obtained, 12 months x-rays.
a b c d e
Fig.11. Male, 30 y.o. A-, right femur comminute open fracture, immediate ORIF (2006). During 2007 patient
underwent 2 surgical procedures to control bone infection and bone grafting. B-, bone scintigraphy (June 07). C-, SW
therapy, 7000 pulses 0,33mJ/mm2 over entire area , under fluoroscopic guidance (July 07). Patient was referred from
other hospital and surgeon in charge decided a new surgical procedure adding a vascularised fibula bone graft at 12
wks after SW (considering a SW-failure, Nov 07). D-, H-E section from fibrous tissue found in focus, showing new
vessels (H-E x20). E-, Trichrome Masson staining ( x100), important induced neo-vascularization in the area. When
infection complicate the normal bone repair process , we should expect a longer time to obtain signs of bone
consolidation and probably for this case, we would wait 6 months before to declare a SW procedure failed.

6. 6
When to decide a failed SW procedure ?
Our statement is that extracorporeal shockwaves therapy acts as a “biological inducer”
of normal ontological healing mechanism, so when we apply this therapy upon bone
healing disturbance, we should consider normal times described for bone healing. In the
case of bone infection we have to consider that the healing time could be up to 3 times
the normal span. We have to look very carefully for “subtlest instabilities” in the focus
after SW treatments because this fact could be a main reason for failures. Another cause
for failures is the wrong indication, because SW should be applied upon bone gap up to
5 millimetres and not over a “segmental cortical bone defect” (fig.12).
a b c
Fig.12. Female , 10 y.o., Achondroplasia . A , B -, this patient during her surgical schedule for limb lengthening
showed a medial cortical femoral no growth. SW therapy was applied twice to solve the condition, waiting for 6
months the expected bone reaction. She was operated later, adding segmental bone to fill the defect and resolution
was uneventfully.
According to the experience obtained with this new tool, in cases of non response
attributed to biological origin, we explain to patient what is occurring and in consensus
with him we choose the next option : many times , these exhausted patients that under-
went 2 or 3 failed surgical procedures decide to repeat the SW treatment , improving ra-
tes of healing after re-treatments. The clinical condition describes as “recalcitrant bone
non-union” , fortunately has not been seen by the author during last 31 years.
Bibliography.
1. Valchanou V.D., Michailov P.: High energy shock waves in the treatment of delayed and non-
union of fractures. Int Orthop 15:181-184,1991.
2. Wang F.S., Yang K.D.,Chen R.F.,Wang C-J., Sheen-Chen S.H.: Extracorporeal shock wave
promotes growth and differentiation of bone-marrow stromal cells towards osteoprogenitors asso
ciated with induction of TGF-b1. J Bone Joint Surg [Br] 2002;84-B:457-61.
3. Wang C-J et al. Shock wave therapy induces neovascularization at the tendon-bone junction. A
study in rabbits. J Orthop Res 21 (2003):984-989.
4. Wang F.S et al. Temporal and spatial expression of bone morphogenetic proteins in extracorpo-
real shock wave-promoted healing of segmental defect. Bone 32 (2003): 387-396.
5. Schaden W., Fischer A., Sailler A. Extracorporeal shock wave therapy of nonunion or delayed
osseous union. Clin Orthop 387 :90-94, 2001.
6. Schaden W. Personal communication.
7. Schatz K.D., Nehrer S., Dorotka R., Kotz R. 3D-navigated high energy shockwave therapy and
axis correction after failed distraction treatment of congenital tibial pseudoarthrosis. Orthopade
2002 Jul ;31 (7):663-666.
8. Brañes M., Guiloff L., Brañes J.A., Contreras L. Tendinosis of the shoulder and related entities
treated with SW.Histopathological and Clinical Correlation. ISMST News Letter Nº 3, 2007:5-6.
9. Brañes J.A., Sepúlveda D., Brañes M., Guiloff L. Delayed Union and Non Nnion in paediatric pa
tients treated with ESWT. 11th International Congress of ISMST, June 5th – 7th 2008 , Jan des
Pins, France.