Applications in Musculoskeletal Disorders - part 5 ppt

The current study produced no information on the biomechanical aspect of the healing of bone but addressed the issue of a bony reac-tion to shock waves.. The clinical study described in

Fig 4.8 Semiquantitative radiological grading of

bone growth 5 weeks after SWA 0: Osteolysis; 1:

Unchanged; 2: Positive reaction; 3: Complete bridging;

N.S.: Not significant.

Fig 4.9 Semiautomated image analysis of the

histo-logical sections N.S.: Not significant.

Table 4.1 Radiological evaluation of osseous reaction after creating a defect following ESWT

Mean grade 4

1 3000 impulses of 0.08 mJ/mm 2

2

3000 impulses of 0.28 mJ/mm 2

3 (Control group) received no SWT

4 Comparison of Group I and Group II showed p X 0.05 Comparison of Group I and Group III showed no significant difference Comparison of Group II and Group III showed p X 0.01.

Discussion

At the beginning of the 1990s, first reports on

the use of ESWT were published that went

beyond the already established disintegration

of kidney stones and gallstones Valchanou and

Michailov (1991), and Schleberger and Senge

(1992) introduced shock waves to the

treat-ment of delayed union and nonunion of

frac-tures describing phenomena of local

decortica-tion Noncontrolled, nonrandomized clinical

studies reported success rates between 52 %

and 91 % (Russo et al 1995, Vogel et al 1997)

Unlike in pulsed ultrasound, where excellent prospective clinical studies have demonstrated

an acceleration of bone healing in fresh frac-tures and pseudarthrosis (Frankel et al 1996, Heckman et al 1994, Kristiansen 1990, Xavier and Duarte 1987), the published examinations

on shock wave therapy (SWT) did not meet this quality standard Accordingly, the results of SWT must be viewed with caution

Whereas in pulsed ultrasound the osteoge-netic effect was clearly related to a

piezoelec-Discussion 29

Table 4.2 Experimental data on ESWA on bone

Author Species Effect

Graff Rabbit Damage to osteocytes,

bone marrow necrosis Yeaman Rat Epiphyseal dysplasia

Seemann Rat Delay in bone healing

Augat Sheep Reduction in mechanical

stability Forriol Sheep Delay in fracture healing

tric effect and a low-level mechanical force to

the fracture area, resulting in an increase in

vascularization, in development of soft callus,

and faster enchondral ossification (Pilla et al

1990), the mechanism of shock waves on bone

is not yet understood

Histological studies did produce evidence

for stimulation of osteogenesis, but no

quanti-tative analysis has been presented so far

(Delius et al 1995, Forriol et al 1994, Graff et

al 1988, McCormack et al 1996, Seemann et

al 1992) Most disconcerting were reports on

disturbance of bone healing after SWT of

experimentally produced defects (Augat et al

1995, Ikeda et al 1999, Yeaman et al 1989)

(Table 4.2) Recently, Schmitz (2001) reported

on cellular and molecular investigations after

SWA to the noninjured, intact, distal rabbit

femur 1500 impulses of 0.1, 0.35, 0.5, 0.9, and

1.2 mJ/mm2

were applied After fluochrome labeling, periosteal bone growth was

observed regularly after application of energy

flux densities of 0.5 mJ/mm2

and more, the amount of periosteal reaction increasing with

higher energy flux densities No endosteal

bone growth was observed; no cortical

dam-age was found However, while there were

only minor signs of collateral damage to the

adjacent quadriceps tendon up to 0.5 mJ/mm2,

a significant damage to the tendon was found

after application of 1500 impulses of an

energy flux density of 0.9 or 1.2 mJ/mm2

The inconsistency of results related to

stim-ulation of bone growth may be attributed to

the fact that the lithotripter machines

employed cannot be compared Ideally, shock

wave generators should be classified by

means of acoustic measurements Theoreti-cally they can be defined by the rise time, peak positive and negative pressure, duration

of impulse, spectrum of frequencies, size of focal area, and acoustic energy of every impulse At present there are no standardized hydrophones availabe to produce reliable measurements of these parameters Another reason for the large variation in results is the use of different animal models (dog, sheep, rabbit) with various kinds of osteotomies and subsequent fixation

In the current study, a defect of 5 mm was created in the middle to proximal third of the fibular shaft We did not observe any bridging

of the gap in the control group radiologically

On the contrary, on the radiographs we not only saw no tendency towards bony bridging, but rather further osteolysis in 30 % After the application of 3000 impulses of a low energy density (0.08 mJ/mm2) we saw a positive bony reaction in 20 % This rate quadrupled to 80 % after 3000 high-energy shock waves (0.28 mJ/

mm2) In histopathology, we did not discover any signs for deletary effects of the shock waves, but found significant development of soft callus and enchondral ossification In his-tomorphometry, bone coverage related to the defect area was significantly higher after the application of high-energy shock waves

Of course, the timing of the shock wave application is critical (Forriol et al 1994) We chose the fourteenth postoperative day for the beginning of treatment because we feared that earlier treatment would disrupt hema-toma formation and that later treatment might have no effect on newly formed bone

We cannot rule out that an earlier date for treatment might result in a more propitious effect on bone healing

The same applies to the number of impulses and amount of energy flux density adminis-tered From clinical studies, however, we had strong hints for the effectiveness of the cho-sen parameters Vogel et al (1997) performed only one treatment session because of the anesthesia required Since bone repair occurs

by cellular proliferation and differentiation over a period of several weeks, repeated

4 Dose-Dependent Effects of Extracorporeal Shock Waves in a Fibular-Defect Model in Rabbits

30

applications over the course of a few weeks

might have a beneficial effect that we do not

yet know about

The timing of follow-ups will also influence

the results Bony healing of an osteotomized

rabbit fibula can be expected after 4 weeks

(Pienkowski et al 1994) Of course, this will

not be the case after producing a 5 mm defect

For reasons of sequential labeling and to allow

comparison of the osteotomy and of the

defect group, we chose an identical

posttreat-ment follow-up of 5 weeks, expecting a bony

reaction in the area of the fibular defect

The aim of the current study was not to

evaluate mechanical stability and possible

acceleration of bone healing This would have

required sacrificing the animals at various

periods after the SWT, the latest at the

six-teenth postoperative day when a rabbit

fibu-lar fracture is most responsive to stimulation

and stiffness is greatest (Friedenberg et al

1971) This would, of course, have interfered

with the desired evaluation of sequential

labeling In our study mechanical testing was

useless 7 weeks after the operation as only

three out of 30 fibulae with a defect

osteo-tomy showed consolidation at this point and would have been usable for mechanical exam-ination

The current results cannot be compared with pulsed ultrasound in a comparable ani-mal model (Pienkowski et al 1994, Pilla et al

1990, Wang et al 1994) In these studies non-displaced osteotomies or fractures were treated beginning only a few days after opera-tion In this ideal situation an impressive stimulation of bone growth and fracture heal-ing, as measured with biomechanical testheal-ing, was described

The current study produced no information

on the biomechanical aspect of the healing of bone but addressed the issue of a bony reac-tion to shock waves Although radiographic and histological results correlated well, there was no correlation made with the biomaterial properties of the healing defects Further studies will have to relate the findings observed on radiographs and those occurring

in the tissues to the acquisition of load bear-ing properties, which, of course, is the most important outcome of fracture or bone defect union

Discussion 31

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5 Shock Wave Application for Plantar Fasciitis

Introduction

Plantar fasciitis is one of the most common

painful foot conditions (Atkins et al 1999,

Crawford et al 2000, Leach et al 1983, Young

et al 2001) The specific pathological features

of this clinical entity are not well understood

(Leach et al 1983, Ogden et al 2001) The pain

classically is present when the patient first

stands on his/her feet after awakening; it

per-sists or is worsened by everyday activities

The use of conservative methods will alleviate

the condition in most patients (Pfeffer et al

1999, Probe et al 1999, Schepsis et al 1991,

Sobel et al 1999, Wagner and Sharkey 1991)

Heel elevation to achieve reduction of loading

of the plantar fascia is being controversially

discussed (Kogler et al 2001) Steroid

injec-tions into the painful area also have been used

(Martin et al 1998), but are associated with a

significant risk of subsequent rupture of the

plantar fascia (Leach et al 1983)

Plantar fasciotomy is not without

signifi-cant risk and may be associated with

pro-longed healing and postoperative

rehabilita-tion (Barrett and Day 1991, Benton-Weil et al

1998, Blanco et al 2001, Henricson and West-lin 1984, Tomczak and Haverslock 1995, Ward and Clippinger 1987)

Since 1996 several publications have exhib-ited promising results following extracorpo-real shock wave application (ESWA) (Chen et

al 2001, Krischek et al 1998, Maier et al 2000a, Ogden et al 2001, Perlick et al 1998, Rompe et al 1996b) Randomized, controlled studies and observational trials reported com-parable treatment effects in 50–60 % of patients for various entities (Benson and Hartz 2000, Concato et al 2000) The thera-peutic mechanism involved remains specula-tive (Heller and Niethard 1998, Loew et al 1999) Ogden et al (2001) described shock waves directed at controlled internal fascial tissue microdisruption that initiates a more appropriate healing response within the fas-cia and a better long-term capacity to adapt to biological and biomechanical demands The clinical study described in the following evaluated effects of extracorporeal shock waves on the chronic painful heel in runners

Materials and Methods

The study was planned as a

placebo-controlled trial to determine the effectiveness

of three applications of 2100 impulses of

low-energy shock waves to long-distance runners

with intractable plantar fasciitis

Runners covering distances of more than 30

miles per week and suffering from chronic

plantar fasciitis for more than 12 months were screened and randomized into one of two treatment groups:

> Group I Active treatment: energy flux

den-sity 0.16 mJ/mm2, 2100 impulses, three times at weekly intervals

Fig 5.1 Radiologically proven heel spur.

Fig 5.2 Infection at the insertion of the plantar fascia after repeated corticosteroid injections (a Bone scin-tigraphy; b MRI).

a

b

> Group II Placebo treatment: sham

treat-ment using a sound reflecting pad, energy

flux density 0.16 mJ/mm2

, 2100 impulses, three times at weekly intervals

Inclusion Criteria

For the current study, chronic heel pain was

defined as symptoms of moderate to severe

heel pain in the involved foot at the origin of

the proximal plantar fascia on the medial

cal-caneal tuberosity (Fig 5.1).

The pain had to have persisted for at least

12 months before enrolling in the study, in

patients covering a running distance of at

least 30 miles per week before symptoms

occurred All patients had failed to respond to

at least three attempts at conservative

treat-ment, including at least two prior courses of

intervention with physical therapy, the use of

orthotics, and at least one prior course of

pharmacological treatment, over a period of

more than 6 months

Exclusion Criteria

Exclusion criteria were: dysfunction in the

knee or ankle, local arthritis, generalized

poly-arthritis, rheumatoid poly-arthritis, ankylosing

spondylitis, Reiter syndrome, neurological

abnormalities, nerve entrapment syndrome,

history of previous plantar fascial surgery, age

under 18 years, pregnancy, infections (Fig 5.2)

or tumors, history of spontaneous or

steroid-induced rupture of the plantar fascia, bilateral

heel pain, participation in a workman’s

com-pensation program, receiving systemic

thera-peutic anticoagulants, and receiving nonste-roidal antiinflammatory drugs (NSAIDs) for any chronic conditions

Group I

Group I, receiving a total of 6300 impulses of

an energy flux density of 0.16 mJ/mm2, con-sisted of 10 women and 12 men, with a mean age of 50 years and a mean duration of pain of

20 months

Group II

Group II, receiving sham treatment, consisted

of 13 women, and 10 men, with a mean age of

50 years and a mean duration of pain of 18 months

5 ShockWave Application for Plantar Fasciitis

34

Table 5.1 Laser-hydrophone data on the shockwave device1

(Treatment level)

–6 dB focal extend in x,y,z

direction

f x (−6 dB)

f y (−6 dB)

f z (−6 dB)

mm mm mm

6.0 6.0 58

5.7 5.7 57

5.5 5.5 56

5 MPa focal extent, lateral f x(5 MPa)

f y(5 MPa)

mm mm

2.2 2.2

3 3

5 5

Positive energy of 5 mm focal

area

1 Sonocur Plus provides eight user-selectable energy levels The physical data listed in the table are typical values for the energy levels used in this study All measurements were made using a laser hydrophone.

Method of Treatment

The extracorporeal shock wave therapy

(ESWT) was applied using a mobile therapy

unit especially designed for orthopedic use

(Sonocur Plus, Siemens AG, Erlangen,

Ger-many), with the shock wave head suspended

by an articulating arm for flexible movement

of the head in three planes The shock wave

head was equipped with an electromagnetic

shock wave emitter Shock wave focus

guid-ance was established by inline integration of

an ultrasound probe—a 7.5 MHz sector

scanner—in the shock head The physical

out-put parameters of the device, measured using

a laser hydrophone, are listed in Table 5.1.

Both groups were treated under the same

conditions and the patients were treated

sin-gly to avoid them influencing one another

Each study subject assigned to active

treat-ment underwent shock wave application (SWA) for a total of 6300 shocks in three treat-ment sessions, with a one-week interval in between, at an energy flux density of 0.16 mJ/

mm2

and at a frequency of 4 Hz, without local anesthesia Ultrasound coupling gel was used between the treatment head and the heel The shock tube head was applied under inline ultrasound control, fine adjustment to the most tender region was performed by palpa-tion and interacpalpa-tion with the patient For those patients assigned to placebo therapy a sound reflecting polyethylene pad was inter-posed between the coupling membrane of the treatment head and the heel to absorb the shock waves by the presence of multiple air cavities

Method of Treatment 35

Method of Evaluation

Follow-ups were done 3 months after the last

application of the ESWT by an independent,

treatment-blinded observer The actual study

procedure was done by a second physician who was aware of the treatment

Results

Follow-up

Twenty-two and 23 patients were

random-ized consecutively to either group

At 3 months, one patient in each of the two

groups denied further cooperation because

shock wave therapy (SWT) had not improved

their condition, leaving 21 patients in Group I

and 22 patients in Group II

Improvement from the baseline at 3 months

posttreatment in the American Orthopaedic

Foot and Ankle Society’s (AOFAS)

Ankle–-Hindfoot Scale was evaluated This strictly

clinical score has a maximum of 100 possible

points (pain: 40 points; function: 50 points;

alignment: 10 points)

Regarding the AOFAS Ankle–Hindfoot Scale,

an increase was observed in both groups

(from 52.7 81.7 points in Group I, and from

49.8 to 62.7 points in Group II) While the

pre-treatment difference was not significant

between Group I and Group II, it was

signifi-cant after 3 months (p = 0.0039)

Before the ESWT started all patients rated their pain condition themselves as “four” in a subjective four-step scale (1 = excellent; 2 = good; 3 = fair; 4 = poor) There was no differ-ence between the groups at this point in time

On the four-step scale an improvement was seen in both groups from 4.0 to 2.3 points in Group I, and from 4.0 to 3.0 points in Group II (p = 0.0179)

Complications

Low-energy ESWT was felt as unpleasant by all patients, though not as unpleasant as the local infiltration all patients had received dur-ing the various and unsuccessful treatment regimes prior to the current study No patient discontinued the shock wave procedure because of severe pain No side effects were seen at any follow-ups There were no hema-tomas, infections or abnormal neurological findings

Discussion

In patients with chronic heel pain, magnetic

resonance imaging (MRI) regularly shows

involvement of the calcaneal insertion of the

plantar aponeurosis (Berkowitz et al 1991,

Grasel et al 1999, Steinborn et al 1999) The

diagnosis of plantar fasciitis is

straightfor-ward, even more so when an inferior

calca-neal spur has been detected However, the

spur may be an incidental finding (Lapidus

and Guidotti 1965) Clinically, the field is wide open for discussion (Pfeffer et al 1999, Probe

et al 1999) Atkins et al (1999) and Crawford

et al (2000) found only 11 randomized con-trolled trials with low methodological assess-ment scores carried out since 1966 There was limited evidence for the effectiveness of topi-cal corticosteroids administered by iontopho-resis; there was limited evidence for the

effec-5 ShockWave Application for Plantar Fasciitis

36

Table 5.2 Overview of prospective studies on use of ESW for the treatment of plantar fasciitis

Anesthesia RCT2

FU3

(Mo) Success (%)

Rompe JD Arch Orthop Trauma Surg 1996 36 L 4

1 Energy flux density

2

Randomized controlled trial

3 Follow up

4

Low

5 High

6 Improvement compared with control group No specific percentage mentioned in publication

tiveness of dorsiflexion night splints; and

there was limited evidence for the

effective-ness of low-energy ESWT

A previous study from the presenting author

had shown comparable short-term results for

patients with plantar fasciitis and heel spur

(Rompe et al 1996b) In the meantime, this

positive outcome has been confirmed in

vari-ous clinical studies (Krischek et al 1998,

Per-lick et al 1998, Sistermann and Katthagen

1998) Maier et al (2000) obtained good or

excellent results according to the Roles and

Maudsley score in 75 % of 48 heels 29 months

after applying low-energy shock waves

with-out local anesthesia three times at weekly

intervals The clinical outcome was not

influ-enced by the length of follow-up periods No

negative side effects were reported Wang et

al (2000) reported 33 patients out of 41

patients to be either free of complaint or

sig-nificantly better at 12 weeks after SWT Ogden

et al (2001) published a randomized

placebo-controlled study with 119 patients in the

treat-ment group and 116 patients in the placebo

group Twelve weeks after a single application

of 1500 high-energy shock waves under local

anesthesia success was observed in 47 % of the

patients After sham treatment the success

rate was only 30 % Buch et al (2001) reports

early results of a randomized

placebo-controlled study involving 150 patients

Ther-apy was applied once, with 3800 high-energy impulses under local anesthesia After 3 months 70 % of the patients in the treatment group fulfilled the success criteria, as did 40 %

of the placebo group

Most recently, Rompe et al (in press) reported a randomized controlled trial on 112 patients Group I received 1000 impulses of a low energy flux density three times; Group II received 10 impulses on three occasions over

a period of 2 weeks Comparing the rates of good and excellent outcome in a four-step score in the two groups, there was a signifi-cant difference of 47 % in favor of Group I treatment at 6 months At 6 months pressure pain had dropped for patients in Group I from

77 points to 19 points on a Visual Analogue Scale (VAS) In Group II the ratings were sig-nificantly worse: from 79 points to 77 points

In Group I walking became completely free from pain in 25 out of 50 patients, compared with 0 out of 48 patients of Group II By 5 years, comparing the rates of good or excel-lent outcomes in the four-step score, the dif-ference of only 11 % in favor of Group I was no longer significant; pressure pain was down to

9 points in Group I, and to 29 points in Group

II Meanwhile, 5 out of 38 patients (13 %) had undergone an operation of the heel in Group I, compared with 23 of 40 patients (58 %) in

Group II (Table 5.2).

Discussion 37

In the current study better results were

observed 3 months after low-energy SWA of

2100 impulses compared with placebo

treat-ment Cointerventions remained on a

compa-rable, low level in both groups No side effects

have so far been noticed with low-energy

ESWA compared with calcification after

ste-roid injections or postsurgical development of

wound infections, hypertrophic sensitive

scars or calcaneal fractures (Conti and Shinder

1991, Schepsis et al 1991) Our clinical

experi-ence is in accordance with histological and

MRI-based studies (Maier et al 2000, Rompe

et al 1998a) High-energy shock waves, also in

use for the treatment of heel pain (Perlick et

al 1998, Sistermann and Katthagen 1998), on the other hand may produce side effects such

as periosteal detachments and small fractures

of the inner surface of the cortex (Ikeda et al 1990)

Although the Food and Drug Administration

of the United States Department of Health and Human Services (FDA) recently approved a shock wave device for therapy of heel pain (Henney 2000), as long as the therapeutic mechanism involved remains speculative (Heller and Niethard 1998, Loew et al 1999) further studies should verify the results of the studies available

5 ShockWave Application for Plantar Fasciitis

38