U. MEGLI^, O. ZUPANC: SIGNIFICANCE OF THE RADIOGRAPHIC PARAMETERS IN THE DIAGNOSIS ...
747–750
SIGNIFICANCE OF THE RADIOGRAPHIC PARAMETERS IN THE
DIAGNOSIS AND TREATMENT OF A BONY IMPINGEMENT OF
THE ELBOW
POMEN RADIOGRAFSKIH PARAMETROV V DIAGNOZI IN PRI
ZDRAVLJENJU KOSTNE UTESNITVE KOMOLCA
Uro{ Megli~, Oskar Zupanc
Department of Orthopaedic Surgery, University Medical Centre Ljubljana, Zalo{ka cesta 9, 1000 Ljubljana, Slovenia
Prejem rokopisa – received: 2018-10-28; sprejem za objavo – accepted for publication: 2019-05-17
doi:10.17222/mit.2018.232
An elbow’s bony impingement is an early x-ray sign of a degenerative process in the elbow joint. Formatted osteophytes in the
anterior and posterior compartment of the elbow change the elbow geometry and cause an early deficit in the elbow’s range of
motion. Because it has a devastating impact on athletes and manual laborers, it has to be recognized and treated early. To do so,
a reliable diagnostic method is a necessity. In our study we introduced and tested the radiographic parameters that can be used
when diagnosing, pre-operative planning and post-operative evaluating the bony impingement of an elbow.
Keywords: elbow, impingement, osteoarthrosis, radiographic parameters
Kostna utesnitev komolca je znak za~etne degenerativne bolezni komolca. Kostne naplastitve v sprednjem in zadnjem delu
komolca spremenijo geometrijo komolca in povzro~ijo zgodnje zmanj{anje gibljivosti. Zaradi povzro~itve hudih omejitev pri
{portnikih in fizi~nih delavcih, sta diagnostika in zdravljenje nujni v zgodnji fazi bolezni. Za to so potrebni zanesljivi
diagnosti~ni kazalci. V na{i raziskavi smo opredelili in testirali radiolo{ke kazalce, ki jih lahko uporabimo pri diagnostiki,
predoperativnem planiranju in pooperativni oceni kostne utesnitve komolca.
Klju~ne besede: komolec, utesnitev, osteoartroza, radiolo{ki parametri
1 INTRODUCTION
The main functions of the elbow are to position the
hand in space and to act as a stabilizer for actions such as
carrying, throwing, pushing, pulling, and lifting.
1
The
normal arc of motion of the elbow is from 0 degrees of
flexion to 145 degrees of flexion. In order to accomplish
its function, the elbow needs a full or almost full range
of motion (ROM).
2
Recent biomechanical studies con-
cluded that an arc of motion between 30 degrees and 130
degrees is enough to achieve 90 % of the activities of
daily living.
1
However, even a smaller loss of flexion or
extension of the elbow of the dominant hand for an
athlete or physical worker can be devastating and has an
impact on its function.
3
Thus, it has to be recognized in
the early stages of degenerative elbow disease. Early
elbow degenerative changes are caused by several etiolo-
gical factors, mostly due to physical labor or overuse in
sports activities. The bony impingement of the elbow is
one of the earliest x-ray signs of the elbow degenerative
disease that cause symptoms like pain, skipping, pinch-
ing during elbow moving and finally reduced elbow
ROM, especially flexion.
4
It can occur between an
enlarged coronoid process and obliterated coronoid fossa
or enlarged olecranon tip and olecranon fossa due to
osteophyte formation. First, in the elbow’s final flexion
or extension soft tissues (i.e., synovia, joint capsule,
periost, cartilage) are compressed within the joint.
5
If
compressive forces are excessive or too repetitive, dama-
ge and inflammation of these tissues may occur. Inflam-
mation on these sites of the elbow can promote osteo-
blastic activity and the formation of bony osteophytes.
6
In symptomatic patients, first the conservative
treatment and rehabilitation are started, but this can last
for a long period of time, and often with sub-optimal
clinical results.
4
If a conservative treatment is not succes-
sful to maintain and improve the elbow’s function,
arthroscopic debridement and resection of the osteo-
phytes are needed.
7
For doing so, a reliable diagnostic
method is a necessity. In the literature there is no des-
cription of the standardized radiographic parameters for
diagnosing bony elbow impingement. In our study we
introduced and tested radiographic parameters that can
be used in diagnosing, pre-operative planning and
post-operative evaluating of a bony impingement of the
elbow.
2 MATERIALS AND METHODS
In our study group we included 31 patients with clini-
cally significant bony elbow impingement recruited for
operative treatment to the Department of Orthopaedic
Materiali in tehnologije / Materials and technology 53 (2019) 5, 747–750 747
UDK 543.442:616.71:617.573 ISSN 1580-2949
Original scientific article/Izvirni znanstveni ~lanek MTAEC9, 53(5)747(2019)
*Corresponding author's e-mail:
uros.meglic@kclj.si

Surgery, University Medical Centre Ljubljana. As a con-
trol group we included 31 patients, treated at the same
department because of other elbow pathologies (epi-
condylitis, ulnar neuritis etc.), but with a normal range of
motion and no signs of clinical elbow impingement.
Patients with a clinical history of previous injury, upper
extremity abnormality and severe arthrosis were ex-
cluded from the study. A standard clinical examination
was performed. Standard antero-posterior and lateral
x-ray views were obtained. Unsatisfactory films were
repeated in order to maintain consistency. Radiographic
measurements were made prior to any further treatment.
The Mayo elbow score was used to evaluate the clinical
significance of the elbow disease in both groups.
8
Besides the x-ray signs of bony impingement, bone
osteophytes were confirmed with arthroscopy during the
arthroscopic debridement.
Radiographic measurements of the two impingement
arcs were obtained prior to the operative treatment. The
impingement arcs were measured on standard lateral
X-ray images by first drawing the largest standard circle
that would best fill the greater sigmoid notch. The center
of the circle represented the center of rotation. Then the
ulnar bone direction line and its parallel through the cen-
ter of rotation were drawn. The angle between the cen-
tralized ulnar direction line and the line between the
center of rotation and the tip of the coronoid process is
named the Anterior Impingement (AI) arc. The angle
between the centralized ulnar direction line and the line
between the center of rotation and the tip of the
olecranon process is named the Posterior Impingement
(PI) arc. An example of AI and PI arc measurements on
a lateral elbow X-ray is demonstrated in Figure 1. These
parameters were then used for diagnosing the elbow’s
bony impingement and in the study group for preopera-
tive planning and post-operative evaluation.
Microsoft Excel 2016 and SPSS version 20 were
used for the analyses. The Student t test was used for
group comparisons when normality was accepted and the
Mann-Whitney U test was used when normality was
rejected. The Chi-square test was used for group com-
parisons of two categorical variables.APv alue of <0.05
was considered statistically significant.
The National Medical Ethics Committee’s approval
was obtained for this study.
3 RESULTS
All the patients included in the study and the control
group were analyzed (100 %). Table 1 summarizes the
patients’ characteristics. During a pre-operative evalu-
ation the clinical examination showed a statistically
significant difference in the ROM between the groups.
The study group presents with a mean 115° of flexion
and 19° of extension deficit, which is considered patho-
logic according to the literature. In the control group the
ROM was normal, with full flexion and extension. In the
study group the impingement arcs on lateral radiographs
were statistically significantly higher compared to the
control group. In the study group the AI arc is 44±7°, the
PI arc is 172±10°. In the control group the AI arc is
20±4°, the PI arc °. Table 3 summarizes the measure-
ments in the study group comparing the measurements
before and after the operation. During the post-operative
evaluation there was no statistically significant diffe-
rence in the ROM and impingement arcs on the post-
operative radiographs between the groups.
4 DISCUSSION
Elbow bony impingement is an early x-ray sign of a
degenerative process in the elbow joint.
9
Formatted
osteophytes in the anterior and posterior compartments
of the elbow change the elbow’s geometry and cause
early flexion or extension deficit of the elbow movement.
It is an important disability factor in patients who over-
use their elbow, such as in professional overhead athletes
and manual laborers
3
and must be recognized and treated
early.
4
In order to establish the treatment algorithms and
evaluate the outcomes, common and reliable methods of
measurement and assessment are necessary. In our
research we established radiographic criteria that can be
used for diagnosing and evaluating the bony impinge-
ment of the elbow. All of the elbows in our study group
demonstrated a significantly higher value of the AI and
PI arcs compared to the control group. There is no
overlapping of the AI arc and the PI arc values between
the groups. In our opinion this gives us valuable criteria
for diagnosing anterior and posterior elbow impinge-
ments. In all cases the bony impingement was confirmed
during arthroscopic debridement and other possible
causes were clinically excluded. Thus, the AI arc is
utilized to assess the bony spurs formatted on the tip of
the coronoid process, and the PI arc can be used to assess
the bony osteophytes formatted on the olecranon
process. Also, a significant decrease of the AI and PI arc
values in the control group after surgery was observed
and supported by a clinical improvement of the patients.
The decreased values of the AI and PI arcs are in the
range of those measured in the control group, thus
further increasing the value of both criteria. With these
results we can confirm the establishment of a set of
radiographic parameters that can be used for the
investigation of a bony impingement of the elbow.
In the literature several conditions have been des-
cribed regarding elbow overuse in professional athletes.
K. P.Valkering et al. referred to posterolateral elbow
impingement in boxers as boxers elbow;
10
S. Tyrdal and
R. Bahr described repeated hyperextension trauma,
called as handball goalies elbow
11
; valgus extension
overload syndrome in overhead-throwing athletes was
described by F.S. Chen et al.,
12
but none of those
researches gives us any common and reliable methods of
measurement. Some information exists describing the
U. MEGLI^, O. ZUPANC: SIGNIFICANCE OF THE RADIOGRAPHIC PARAMETERS IN THE DIAGNOSIS ...
748 Materiali in tehnologije / Materials and technology 53 (2019) 5, 747–750

normal radiographic anatomy of the elbow.
13
Previous
literature focuses primarily on fracture outcomes,
14
ossification patterns
15
and gender differences.
16
A recent
investigation in adults presented several new measure-
ment techniques in an effort to identify the predisposing
factors for elbow arthrosis.
17
However, there is no infor-
mation describing radiographic techniques in diagnosing
and evaluating early degenerative changes such as bony
impingement.
The weakness of our research is the small group
study with only one orthopedic surgeon evaluating the
radiographs. Thus, further research, with a larger subject
group and more radiograph evaluators is needed to assess
the reliability of these techniques.
5 CONCLUSIONS
Our study proved that measuring anterior and pos-
terior impingement arcs on standard lateral elbow
radiographs is a useful method for the easy and early
diagnosis of early elbow degenerative disease. It is also
useful for pre-operative planning and post-operative
evaluating in symptomatic patients. With these radio-
graphic parameters we established a firm basis for fur-
ther research and for the development of a biomechanical
model that can be used for computer-assisted elbow
arthroscopy and even robotic operative techniques.
Table 1: Patients’ characteristics
Study group
(n = 31)
Control group
(n = 31)
Sex 24 male, 7 female 14 male, 17 female
Age 45±11 37±12
Dominant hand 74 % right 71 % right
Pathology on
dominant hand
74.20 % 87.10 %
Table 2: Elbow measurements during first evaluation (Mean ± stand-
ard deviation (SD))
Study group
(n = 31)
Control group
(n = 31)
p
Flexion 115±8° 139±5° < 0.05
Extension –19±12° 0±0° < 0.05
ROM 96±4° 139±5° < 0.05
AI arc 44±7° 20±4° < 0.05
PI arc 172±10° 150±5° < 0.05
Mayo elbow
score
5±13 81±9 < 0.05
Table 3: Elbow measurements in study group before and after oper-
ation (Mean ± SD)
STUDY GROUP
Before operation
(n = 31)
After operation
(n = 31)
P
Flexion 11±8° 131±9° < 0.05
Extension –19±12° –5±5° < 0.05
ROM 96 4° 127±9° < 0.05
AI arc 44±7° 23±5° < 0.05
PI arc 172±0° 153±7° < 0.05
Mayo elbow
score
59±13 78±11 < 0.05
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