The value of elbow arthroscopy in diagnosing and treatment of radial head fractures

Abstract

Background:
Surgical treatment of radial head fractures is increasingly performed arthroscopically. These fractures often feature concomitant injuries to the elbow joint, which may be under-diagnosed in the radiological examinations. Little is known about the diagnostic value of arthroscopy, the treatment options that arise from arthroscopically assisted fracture fixation and clinical results. We hypothesized that arthroscopy can detect additional concomitant injuries and simultaneously expands the therapeutic options. Therefore aim of this study was to compare arthroscopic and radiologic findings, to assess the distinct arthroscopic procedures and to follow up on the clinical outcomes.

Methods:
Twenty patients with radial head fractures were retrospectively included in two study centers. All patients underwent elbow arthroscopy due to at least one of the following suspected concomitant injuries: osteochondral lesions of the humeral capitellum, injuries of the collateral ligaments or loose joint bodies. Preoperative radiological findings were compared to arthroscopic findings. Afterwards, arthroscopic treatment options and clinical outcomes were assessed.

Results:
Arthroscopic findings led to revision of the classified fracture type in 70% (p = 0.001) when compared to preoperative conventional radiographs (CR) and in 9% (p = 0.598) when compared to computed tomography (CT) or magnetic resonance imaging (MRI). Diagnosis of loose bodies was missed in 60% (p < 0.001) of the CR and in 18% (p = 0.269) of the CT/MRI scans. Osteochondral lesions were not identified in 94% (p < 0.001) of the CR and in 27% (p = 0.17) of the CT/MRI scans. Percutaneous screw fixation was performed in 65% and partial radial head resection in 10%. Arthroscopy revealed elbow instability in 35%, leading to lateral collateral ligament reconstruction. After a mean follow up of 41.4 ± 3.4 months functional outcome was excellent in all cases (DASH-Score 0.6 ± 0.8; MEPI-Score 98.5 ± 2.4; OES-Score 47.3 ± 1.1).

Conclusions:
Elbow arthroscopy has a significant diagnostic value in radial head fractures when compared to standard radiological imaging. Although statistically not significant, arthroscopy also revealed concomitant injuries in patients that presented with an uneventful MRI/CT. Furthermore, all intraarticular findings could be treated arthroscopically allowing for excellent functional outcomes.

Trial registration:
Institutional Review Board University of Munich (LMU), Trial Number 507-14.

Full text

R E S E A R C H A R T I C L E Open Access
The value of elbow arthroscopy in diagnosing
and treatment of radial head fractures
Florian Haasters
1,2*
, Tobias Helfen
1
, Wolfgang Böcker
1
, Hermann O. Mayr
3
, Wolf Christian Prall
1,2
and
Andreas Lenich
4
Abstract
Background: Surgical treatment of radial head fractures is increasingly performed arthroscopically. These fractures
often feature concomitant injuries to the elbow joint, which may be under-diagnosed in the radiological examinations.
Little is known about the diagnostic value of arthroscopy, the treatment options that arise from arthroscopically
assisted fracture fixation and clinical results. We hypothesized that arthroscopy can detect additional concomitant
injuries and simultaneously expands the therapeutic options. Therefore aim of this study was to compare arthroscopic
and radiologic findings, to assess the distinct arthroscopic procedures and to follow up on the clinical outcomes.
Methods: Twenty patients with radial head fractures were retrospectively included in two study centers. All patients
underwent elbow arthroscopy due to at least one of the following suspected concomitant injuries: osteochondral
lesions of the humeral capitellum, injuries of the collateral ligaments or loose joint bodies. Preoperative radiological
findings were compared to arthroscopic findings. Afterwards, arthroscopic treatment options and clinical outcomes
were assessed.
Results: Arthroscopic findings led to revision of the classified fracture type in 70% (p= 0.001) when compared to
preoperative conventional radiographs (CR) and in 9% (p= 0.598) when compared to computed tomography (CT) or
magnetic resonance imaging (MRI). Diagnosis of loose bodies was missed in 60% (p< 0.001) of the CR and in 18%
(p= 0.269) of the CT/MRI scans. Osteochondral lesions were not identified in 94% (p < 0.001) of the CR and in 27%
(p= 0.17) of the CT/MRI scans. Percutaneous screw fixation was performed in 65% and partial radial head resection in
10%. Arthroscopy revealed elbow instability in 35%, leading to lateral collateral ligament reconstruction. After a mean
follow up of 41.4 ± 3.4 months functional outcome was excellent in all cases (DASH-Score 0.6 ± 0.8; MEPI-Score
98.5 ± 2.4; OES-Score 47.3 ± 1.1).
Conclusions: Elbow arthroscopy has a significant diagnostic value in radial head fractures when compared to standard
radiological imaging. Although statistically not significant, arthroscopy also revealed concomitant injuries in patients
that presented with an uneventful MRI/CT. Furthermore, all intraarticular findings could be treated arthroscopically
allowing for excellent functional outcomes.
Trial registration: Institutional Review Board University of Munich (LMU), Trial Number 507–14.
Keywords: Radial head fracture, Arthroscopy, Associated injury, Elbow dislocation, Arthroscopic assisted fracture treatment
© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
* Correspondence: f.haasters@web.de
1
Hospital of General, Trauma and Reconstructive Surgery, University of
Munich (LMU), Nussbaumstr. 20, 80336 Munich, Germany
2
Department of Knee, Hip and Shoulder Surgery, Schön Klinik
Munich-Harlaching, Academic Teaching Hospital of the Paracelsus Private
Medical University Salzburg, Strubergasse 21, 5020 Salzburg, Austria
Full list of author information is available at the end of the article
Haasters et al. BMC Musculoskeletal Disorders (2019) 20:343
https://doi.org/10.1186/s12891-019-2726-6
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Background
Management of radial head fractures is still discussed con-
troversially, as there still is uncertainty and controversy
about when surgery is needed as well as what type of sur-
gical intervention is best. [1,2]Mostoftheisolated
(simple) fractures can be considered as stable and are suit-
able for a non-operative treatment. However, fractures as-
sociated with concomitant osseous or soft-tissue injury
(complex fractures) require different treatment strategies
to preserve and restore the integrity of the radiocapitellar
joint and elbow stability [2,3]. Multiple factors, such as
fragment number, fragment displacement, articular impac-
tion or radiocapitellar malalignment [4]aswellasosteo-
chondral lesions, loose joint bodies and elbow instability
should guide surgical treatment [5]. In order to assess
these factors, conventional radiographs (CR) in three
planes are still the diagnostic standard [4,6] while com-
puted tomography (CT) and magnetic resonance imaging
(MRI) are only occasionally applied to increase informa-
tion about complex or ligamentous injury patterns [7].
Based on radiographic findings fractures are most
widely classified according to the modified Mason classifi-
cation [8,9]. Type I fractures are defined as non-displaced
or minimally displaced fractures that do not block motion.
These fractures can be treated non-operatively [3,4,10].
Type II fractures are displaced fractures (> 2 mm) without
comminution and with or without mechanical block of
motion. The treatment recommendations are inconsistent
since recent data revealed no differences in the functional
outcome after surgical and non-operative treatment [2,
11]. Type III fractures are defined as displaced fractures
involving the entire radial head that are deemed not re-
pairable and should be either excised or replaced with a
prosthesis [2,9]. Johnston extended the classification sys-
tem introducing radial head fractures associated with
elbow dislocations (Type IV). [12] The accompanying
elbow dislocation is likely change the prognosis in com-
parison to a similar fracture without dislocation. Following
these classification systems, the question raises whether
radiological examinations adequately capture all relevant
injuries, or whether they are prone to miss injuries that
play an important role for clinical outcome and treatment
decision. Among these injuries, rotational block of mo-
tion, radial head fragments scattered into the posterior
compartment, osteochondral lesions to the postero-lateral
capitellum and postero-lateral instability may be under-
diagnosed. In this context, elbow arthroscopy may repre-
sent a useful diagnostic tool complementing radiological
findings and simultaneously allowing for minimally inva-
sive treatment of the identified injuries [13,14].
Elbow arthroscopy dramatically evolved within the last
decades and became an integral part of diagnosing and
an important assisting tool in treatment of a large variety
of elbow injuries [13–19]. However, only a few case
series reported on arthroscopically treated radial head
fractures, such as screw osteosynthesis of Type II frac-
tures or head resection after Type III fractures [20–22].
Therefore, aim of this study was to assess the signifi-
cance of elbow arthroscopy in diagnosing and treatment
of radial head fractures with associated injuries. Primary
objective was to compare preoperative imaging to the
arthroscopic findings. Secondary objectives were, wea-
ther all arthroscopic findings could be arthroscopically
addressed, and the assessment of the mid-term func-
tional outcomes. Our hypothesis was that elbow arthros-
copy provides a more accurate fracture classification, a
higher sensitivity for identification of associated intraar-
ticular injuries and allows for simultaneous arthroscopic
treatment of all lesions diagnosed.
Methods
In this retrospective case series we included all patients
who underwent arthroscopically assisted surgical treat-
ment following an acute (< 14 days) traumatic radial head
fracture with associated injuries between May 2013 and
May 2014. Inclusion criteria were any type of radial head
fracture in patients > 18 years in combination of one of
the following concomitant injuries: loose joint bodies,
(osteo-)chondral lesions to the humeral capitellum, and
injuries to the lateral or medial ligament complex (Figs. 1,
2and 3). Diagnosis of the concomitant injury was per-
formed according to radiological or clinical findings. CR
in three planes was conducted in all cases. If any of the de-
fined associated injuries was clearly diagnosed in plain ra-
diographs, arthroscopy was performed without additional
CT or MRI imaging. In case of insufficient visualization of
the extend of dislocation, capitellar lesions, suspicion of
loose joint bodies in CR a CT or MRI (if possible in full
extension) was performed. Furthermore, in patients with
an instability in the clinical examination or with a mech-
anical block of motion that could not be explained by CR
findings, MRI or CT was conducted.
Exclusion criteria were open fractures, fractures deemed
irreconstructable, radial neck fractures, accompanying frac-
tures at other locations, terrible triad injuries, neuro-vascu-
lar injuries, neurological disorders or substance abuse that
impaired postoperative compliance. Over the study period
a total number of n= 59 patients have been treated by
standard open reduction and internal fixation or radial
head replacement.
Fracture classification was performed after CR, CT/
MRI and during arthroscopy according to the Hotchkiss
modified Mason classification with the Type VI exten-
sion according to Johnston.
Patients underwent general anesthesia and were placed
in the lateral decubitus position. An examination under
anesthesia (EUA) was performed under fluoroscopic im-
aging in order to assess elbow stability in full extension
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and 30° flexion. The arm was supported by means of a
small arm holder allowing for a wide range of elbow mo-
tion. A tourniquet was inflated to 250 mmHg and the
pump was set at 30 mmHg. Before portal placement, the
joint was injected with 15 to 20 mL of saline solution
through the soft spot. All arthroscopic procedures were
performed by two senior surgeons. A standardized diag-
nostic evaluation for associated joint pathologies was
carried out with a 4 mm 30° arthroscope in every case
beginning from a posterolateral portal. A full-radius
blade shaver was used through the transtricipital portal
to remove hematoma and to allow for removal of loose
bodies in the dorsal recessus (Fig. 3d). The arthroscope
was then guided into the humeral radial joint thereby
carefully evaluating the posterior and postero-lateral as-
pect of the capitellum (Fig. 3g). Through the soft spot
portal the shaver blade was inserted to remove
hematoma and loose bodies. The forearm was now
Fig. 1 Mason Type II radial head fracture with traumatic capitellar chondral lesion und loose joint bodies. a-cCT scan showed a dislocation of 3
mm in coronal view. Loose bodies and capitellar injury were not identified (d) Arthroscopy revealed a large chondral loose body [LB] entrapped
between the capitellum [C] and the radial head [RH]. egrade IV chondral lesion to the capitellum. fAfter removal of fracture hematoma, (g)
chondroplastic and (h) microfracturing was performed at the capitellum humeri. iFracture reduction was carried out with a sharp hook and (j)
anatomic restoration of the radial head was achieved by screw osteosynthesis over the anterolateral portal. k,l Postoperative x-rays demonstrate
anatomic reduction and correct screw placement
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rotated in pronation and supination in order to explore
the radial head, to analyze the fracture pattern and to as-
sess an eventual mechanical block of motion (Fig. 1). An
anterolateral portal was then established to allow for
visualization of the anterior elbow joint. An additional
anteromedial portal was used if necessary. The “elbow
drive-through test”(Fig. 2g) was performed in order to
screen for posterolateral rotational instability (PLRI) as
described previously [15,16,23].
Depending on the fracture pattern the portals used for
visualization, fracture reduction and screw placement dif-
fered. However, in most cases the arthroscope was
switched to the posterolateral portal while reduction and
temporary fixation were performed with a sharp hook
using the soft spot and anterolateral portal (Fig. 1). Subse-
quently, 2.0 mm screws (Medartis, Switzerland or Depuy-
Synthes, USA) were placed via the anterolateral portal with
the elbow flexed between 45° to 90° and in different extend
of supination. Finally, fluoroscopic images were carried out
in anteroposterior, lateral and oblique views. The arm was
immobilized in a cast until the patient regained full con-
sciousness and pain or swelling decreased. A pain-guided
active-assisted physiotherapy was started at day one after
surgery without weight bearing for 6 weeks.
Two senior surgeons performed evaluation of the pre-
operative radiological imaging independently. In case of
different results, a consensus was found by discussion.
Clinical results were assessed using the Disabilities of
Arm, Shoulder and Hand Questionnaire (DASH), the Ox-
ford Elbow Score (OES) and the Mayo Elbow Performance
Index (MEPI) [24–26].
Pearson’s chi-squared test (χ[2]) was used to test for
the association between categorical variables. The level
of statistical significance was defined as p< 0.05.
All procedures were performed in accordance with the
ethical standards of the institutional (votum no. 507–14)
Fig. 2 Mason Type I Fracture with loose joint body in the anterior compartment. a-cCT scan showed a mildly (< 2 mm) displaced radial head
fracture without blocking of motion and an osteochondral fracture fragment in the anterior elbow compartment. dThe loose joint body [LB] was
arthroscopically removed after identification between humerus [H] and coronoid process [CP]. eDynamic evaluation of unimpaired motion in the
proximal radioulnar joint [PRUJ] was arthroscopically confirmed. fExploration of the radial head in full supination. gPosterolateral rotational
instability was ruled out with a modified “drive through test”with a switching stick from the soft spot portal between ulnar [U] and humerus [H].
h, i Postoperative x-rays demonstrated correct alignment of the elbow joint and complete removal of loose bodies
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and national research committee and with the 1964
Helsinki declaration and its later amendments or compar-
able ethical standards. Informed written consent was ob-
tained from all individual participants included in the study.
Results
A total of 20 patients were included in this multicenter
case-series. The mean age was 42.9 ± 10.9 years and 13
of 20 patients were male. The mean follow-up was 41.4
(±3.4, range 35.2–46.6) months (Table 1). All 20 patients
received CR in three planes (anteroposterior, lateral and
radiocapitellar view). In eight patients CT imaging and in
three patients MRI scans were performed according to the
above mentioned criteria (Table 2). Based on CR fracture
were classified type I in 35%, type II in 35%, type III in 20%
and type IV in 10%. Classification changed due to CT/MRI
imaging in 7 of 11 (64%) cases (Table 3). In detail,
two type I fractures changed to type II, two type I
fractures changed to type IV, two type III fractures
changed to type IV and one type II fractures changed
to type IV (Table 2).
During elbow arthroscopy fractures were classified as
following: type I in 5%, type II in 20%, type III in 5% and
type IV in 70%. Comparing the fracture classification after
CR with the arthroscopic findings, the classification chan-
ged in 14 cases (70%). Comparing the classification based
on CT/MRI imaging and elbow arthroscopy, the classifica-
tion changed in one case (9%) (Tables 2and 3).
The changes in classification resulted from 1. the detec-
tion of a mechanical block of motion that was not found in
the clinical examination, 2. the detection of an anterior rim
fragment of the radial head trapped in the posterior com-
partment, 3. the identification of an varus or posterolateral
rotational instability (PLRI) detected during arthroscopy
(drive-through-sign) or EUA. In the second and third case
the findings revealed an occult dislocation and classifica-
tionwasconsequentlychangedtoatypeIVinjury.
Comparing the number of fracture fragments diag-
nosed by CR with the findings after CT/MRI and
Fig. 3 Radial head fracture classified as a type IV fracture due to an Osborne-Cotterill lesion [arrow] and displacement of the anterior rim
fragment of the radial head into the fossa olecrani [*]. a-c CT scans. dArthroscopic loose body [LB] removal. eResult after partial resection of
unstable anterior radial head [RH] fragments. fA second loose body was found at the dorsal capitellum [C] near the (g) Osborne-Cotterill lesion.
h, i Postoperative x-rays demonstrated correct alignment of the elbow joint and complete removal of loose bodies
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arthroscopy, a higher number of fragments was found in
36 and 40%, respectively (Table 3). In one case arthros-
copy revealed an additional fracture fragment that was
not diagnosed by the CT scan (Table 3, Fig. 1). Loose
joint bodies were diagnosed in 25% of all CR and in 85%
during all elbow arthroscopies. The examinations by
CT/MRI revealed loose bodies that had not been de-
tected by CR in 36% (4 of 11 cases). In one case arthros-
copy revealed loose bodies that were not diagnosed in
the CT examination. Analyzing the cases, where loose
bodies were identified, CT/MRI examination and arth-
roscopy revealed a higher number of loose bodies in 50
and 76% when compared to CR, respectively. In 60%
additional loose bodies could be diagnosed during elbow
arthroscopy that where not detectable with CT/MRI im-
aging. (Osteo-)chondral lesions of the capitellum humeri
were found in 80% during arthroscopic evaluation. These
lesions were missed by CR in 94% (15 of 16 cases) and by
CT/MRI in 27% (3 of 11 cases). Injuries to the lateral col-
lateral ligament complex were diagnosed during surgery
in 35%. In the cases where MRI was performed, all of
these injuries were identified prior to arthroscopy.
During arthroscopy percutaneous screw osteosynthesis
was performed in 65%, a partial radial head resection in
10%, chondroplastic or microfracturing at the capitellum
humeri or the radial head in 85% and a mini-open collat-
eral ligament reconstruction at the humeral insertion
was carried out in 35% using suture anchors (3.5 mm
Bio Corkscrew or 2.9 mm Suture Tak, Arthrex, USA).
The final clinical outcome assessments resulted in an
OES 47.3 ± 1.1, a MEPI of 98.5 ± 2.4 and a DASH score
of 0.6 ± 0.8.
Discussion
To date, the evidence concerning arthroscopically assisted
treatment of radial head fractures is limited. There are
only a few small case-series available that mainly focus on
the feasibility of arthroscopic procedures. The present
study represents the largest case series of arthroscopically
assisted radial head fracture fixation and, for the first time,
it compares findings of preoperative imaging versus arth-
roscopy with special regards to associated lesions.
In clinical practice conventional radiographs (CR) rep-
resent the gold standard of radiologic examination and
provide an essential element for radial head fracture
classification [27]. Nevertheless, the sensitivity of plain
radiographs has been shown to be as low as 21%, at least
for simple elbow fractures in a cadaver study [28]. The
radiocapitellar view, as performed in our study, can add-
itionally detect radial fractures in up to 5% of patients
with no fracture seen in the two standard planes [29].
However, the interobserver reliability of the modified
mason classification is poor to moderate (k = 0.45–0.85)
and observers likely disagree about the grade of displace-
ment (Mason I vs. II) in plain radiographs [27]. In doubt,
some authors conclude that CT or MRI studies should
be conducted in addition. In our study, CT or MRI was
Table 1 Patient Data
Patient 1 2 34567891011121314151617181920total
Fracture type [Mason] after
arthroscopy
II II IV IV II IV IV I IV IV III IV IV IV IV IV IV II IV IV 1:4:1:14
Gender f f mmmff mf mmmmmmf mmmf f:m=1:
2.9
Age [years] 58 40 39 50 32 50 44 54 44 46 47 28 31 58 31 41 22 59 51 32 42.9 ±
10.9
Follow up [months] 47 46 45 45 44 44 44 43 43 41 41 40 40 40 39 38 37 37 36 35 41.4 ± 3.4
Loose bodies [n] 0 2 44013111121112102185%
Osteochondral lesions capitellum –++++–++++–++++++–+ + 80%
Injury to the lateral collateral
ligaments
–––––+––+–– ––+–++–+ + 35%
Screw osteosynthesis + + –+––––+++++–+–++++65%
Partial radial head resection ––+––––––––––+––––––10%
Loose body removal –++ + –++++++++++++–+ + 85%
Chondroplasty capitellum –++++–++++––––––––––40%
Lateral collateral ligament
reconstruction
–––––+––+–– ––+–++–+ + 35%
OES 48 47 47 48 47 48 48 47 48 45 47 48 45 45 48 48 48 48 47 48 47.3 ± 1.1
MEPI 100 95 100 100 100 95 100 100 100 95 100 95 95 95 100 100 100 100 100 100 98.5 ± 2.4
DASH 0 1 0 0 1.7 0 0 0.8 0 1 0 1 2 2 00001.700.6±0.8
ffemale, mmale, OES The Oxford Elbow Score, MEPI The Mayo Elbow Performance Index, DASH Disabilities of Arm, Shoulder and Hand Questionnaire
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Table 2 Detailed information of patients’fracture types and associated lesions after conventional radiographs (CR), CT/MRI imaging
and elbow arthroscopy (Scope)
X-Ray CT/MRI Scope X-Ray CT/MRI Scope
Classification [Mason] Patient 1 I II II Patient 11 III –III
Fracture fragments [n] 2 3 3 2 –2
Loose bodies [n] 0 0 0 0 –1
Capitellar osteo(chondral) lesions no no no no –no
Classification [Mason] Patient 2 I II II Patient 12 III –IV
Fracture fragments [n] 3 3 3 2 –3
Loose bodies [n] 0 0 2 0 –2
Capitellar osteo(chondral) lesions no no yes no –yes
Classification [Mason] Patient 3 I IV IV Patient 13 II –IV
Fracture fragments [n] 2 3 3 2 –2
Loose bodies [n] 0 3 4 1 –1
Capitellar osteo(chondral) lesions no yes yes no –yes
Classification [Mason] Patient 4 IV IV IV Patient 14 I I IV
Fracture fragments [n] 2 2 2 2 2 2
Loose bodies [n] 0 3 4 1 1 1
Capitellar osteo(chondral) lesions yes yes yes no no yes
Classification [Mason] Patient 5 II –II Patient 15 II –IV
Fracture fragments [n] 2 –31–2
Loose bodies [n] 0 –00–1
Capitellar osteo(chondral) lesions no –yes no –yes
Classification [Mason] Patient 6 IV IV IV Patient 16 II –IV
Fracture fragments [n] 1 1 1 2 –2
Loose bodies [n] 1 1 1 0 –2
Capitellar osteo(chondral) lesions no no no no –yes
Classification [Mason] Patient 7 I IV IV Patient 17 III IV IV
Fracture fragments [n] 2 3 3 3 3 3
Loose bodies [n] 0 1 3 0 0 1
Capitellar osteo(chondral) lesions no yes yes no yes yes
Classification [Mason] Patient 8 I I I Patient 18 II –II
Fracture fragments [n] 2 2 2 1 –1
Loose bodies [n] 1 1 1 0 –0
Capitellar osteo(chondral) lesions no no yes no no no
Classification [Mason] Patient 9 I –IV Patient 19 II IV IV
Fracture fragments [n] 1 –1223
Loose bodies [n] 0 –1112
Capitellar osteo(chondral) lesions no –yes no yes yes
Classification [Mason] Patient 10 III IV IV Patient 20 II –IV
Fracture fragments [n] 2 3 3 1 –1
Loose bodies [n] 0 1 1 0 –1
Capitellar osteo(chondral) lesions no yes yes no –yes
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conducted whenever the extend of dislocation was not
assessable on CR, associated lesion were suspected or in
case of discrepancy between CR findings and clinical
examination. Information gained by CT/MRI imaging
led to a change of fracture classification in 64%. Haapa-
maki et al. investigated 56 patients a with blunt elbow
trauma and found that CT revealed 13 fractures that
had been missed by plain x-ray study [30]. Acar et al.
demonstrated that CT revealed fractures in 12.8% of pa-
tients, with positive elbow extension test and normal x-
ray study [31]. In terms of interobserver reliability CT
examination revealed better results than CR concerning
radial head classification [32]. The clinical examination
represents another essential element in the Hotchkiss
modified Mason classification. The mechanical block of
motion is a crucial parameter that per definition is not
present in Mason I fractures. Furthermore, it indicates a
relevant dislocation or an associated lesions such as
loose bodies even if not detected in plain radiographs.
Unfortunately, clinical examination might be limited due
to unspecific symptoms, such as pain, swelling and joint
effusion. In our study, elbow arthroscopy including
examination under anesthesia and full visualization of
the radio-capitellar and radio-ulnar articulation led to a
change of fracture classification in 70% when compared
to CR. When comparing the fracture classification after
CT/MRI to the classification after arthroscopy, we only
revealed a discrepancy in one case. Taken together, arth-
roscopy does not seem to substantially contribute to a
better fracture classification when compared to CT/
MRI. Given the limitations of plain radiographs in terms
of accurate fracture classification, we recommend CT or
MRI scans in cases where clinical examination is hin-
dered and CR does not provide accurate visualization of
fracture pattern or fragment dislocation. Hotchkiss et al.
also recommended CT scans for additional information
on fracture fragment size and displacement [9].
In contrast, arthroscopy revealed superior sensitivity for
identifying and quantifying loose joint bodies compared to
CT/MRI. While 60% of the loose joint bodies found dur-
ing arthroscopy were missed in CR, the vast majority was
detected by CT/MRI imaging. However, in 60% percent of
the cases arthroscopy revealed a larger number of loose
bodies than described in CT/MRI (Table 3). These
advantages might result from an inappropriate slice thick-
ness of standard CT and MRI scans or low sensitivity in
detecting chondral flake fractures. In our study we found
loose bodies in 85%. Respecting the fact that osteochon-
dral lesion of the capitellum were found in 80% of the
cases, the loose joint bodies not only originated from the
radial head fracture, but also from capitellar lesions. Fur-
thermore, injuries to the lateral collateral ligaments be-
came evident during examination under anesthesia and
arthroscopy in 35%. Loose joint bodies, osteochondral le-
sions of the humeral capitellum and lesions to the collat-
eral ligaments are known to be common injuries
associated with radial head fractures [10,12,33,34]. Our
findings go well in line with Itamura et al. who revealed
loose bodies in 22 of 24 (92%) MRIs of radial head frac-
tures [35]. Ward et al. found an incidence of 24% capitel-
lar lesions during open surgery on radial head fractures
[36]. Michels et al. found 14% capitellar cartilage lesions
during arthroscopic treatment of type II fractures [20]. In
our study, (oseto-)chondral lesions to the capitellum were
identified in a higher number, which might be due to the
high incidence of type IV fractures. Combinations of frac-
tures to the radial head and corresponding capitellar le-
sions might particularly affect the outcome since 60% of
the axial load at the elbow is transmitted through the
radiocapitellar joint [37]. Caputo et al. published a case
series of capitellar chondral lesions that have been trapped
between the fracture fragments of radial head fractures
[36]. They also stressed the importance of complete re-
moval of loose joint bodies. Van Riet et al. reported on less
good results in the patients with lesions of the capitellum
[34] and recommended fixation of larger displaced frac-
tures and excision of small fragments. According to these
recommendations we conducted removal of loose bodies
in 85% and a chondroplasty in 40%. In our series none of
the (osteo-)chondral fragments was suitable for refixation,
nevertheless we performed microfracturing in one case of
a larger chondral shear lesion (Fig. 1). Unfortunately, there
is a lack of literature on the management of traumatic car-
tilage lesions to the capitellum and evidence-based recom-
mendations are missing.
In our cohort, injuries to the lateral collateral ligament
complex (LCL) were found in 35%. This incidence seems
remarkably high. However, other studies demonstrated
Table 3 Differences in fracture classification, number of fracture fragments, identification of loose bodies and number of loose bodies
comparing conventional radiographs (CR) with CT/MRI imaging, CR with elbow arthroscopy as well as CT/MRI imaging with elbow
arthroscopy
Differences in
Classification
Differences in number
of fracture fragments
Differences in identification
of loose bodies
Differences in number
of loose bodies
CR -- > Arthroscopy 70% 40% 60% 65%
CR -- > CT/MRI 64% 36% 36% 36%
CT/MRI -- > Scope 9% 9% 18% 55%
Haasters et al. BMC Musculoskeletal Disorders (2019) 20:343 Page 8 of 10
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that the incidence of LCL injuries increases with the se-
verity of in radial head fractures [34,38,39]. Again, the
high percentage of type IV fractures in our study may
account for the high incidence of LCL injuries. On the
other hand, the routinely conducted combination of
EUA and diagnostic arthroscopy may allow for a higher
sensitivity for detection of PLRI. Elbow arthroscopy has
been shown to be a valuable tool in diagnosing and
management of elbow instability, such as PLRI [16,40].
Holt et al. suggested the anteromedial portal may be
used while performing a pivot shift maneuver. If PLRI is
present, the radial head may be seen rotating and trans-
lating posteriorly during this maneuver [40]. In our
study, we used a modified “elbow drive-through sign”
which originally is performed with the arthroscope in
the anterolateral portal. In patients with PLRI, the
arthroscope is easily driven through the lateral gutter
and into the lateral aspect of the ulnohumeral joint [15,
23,41]. In our modified technique the switching stick
from was introduced through the soft spot portal with
the arthroscope in the anterolateral portal. When the
switching stick can easily be advanced between ulnar
and humerus towards the coronoid process PLRI is
present (Fig. 3). Using this technique, injuries to the car-
tilage by the arthroscope itself can be minimized. Given
the importance of LCL complex restoration [16], we
conducted a mini-open repair of the LCL (mainly LUCL)
whenever PLRI was diagnosed.
Apart from the accompanying injuries, the actual radial
head fracture was treated by arthroscopically assisted per-
cutaneous screw osteosynthesis in 65% and by partial radial
head resection in 10%. The partial radial head resection
was conducted in cases of small-sized and shallow anterior
rim fractures that were not suitable for refixation. Rolla et
al. first described a standard approach for arthroscopic fix-
ation of radial head fractures with cannulated differential
thread screws in a case-series of six patients. The authors
particularly pointed out the benefits of simultaneous treat-
ment of associated lesions, such as chondral avulsion of
the capitellum. The authors found satisfactory short-term
preliminary outcomes [21]. Michels et al. [20] retrospect-
ively evaluated the results of arthroscopically assisted re-
duction and percutaneous fixation of radial head fractures
in 14 patients. The authors reported on eleven excellent
and three good results in their study population consisting
of Mason II fractures only. In contrast, our study focused
on radial head fractures with evidence of associated injur-
ies. Therefore, in our study population type III and IV frac-
tures were diagnosed in 75%. Despite this high ratio of
severe injuries we found excellent outcome scores in all
cases after a mid-term follow up of 41.4 ± 3.4 months.
Comparing these results to the outcomes after open reduc-
tion and internal fixation [42,43], arthroscopically assisted
fracture fixation led to similar or slightly superior results.
This study has its limitation due to a retrospective de-
sign, a lack of a control group and an incomplete dataset
of CT or MRI examination. Furthermore, we must
emphasize that arthroscopic radial head fracture reduction
and fixation is a technically demanding procedure. We do
not consider this procedure as a standard of care in gen-
eral trauma service, since it requires the skills of experi-
enced arthroscopists. However, a valuable point of
arthroscopy in diagnosing associated injuries is the possi-
bility to avoid treatment delay. MRI is costly which later
can affect patient decision that will delay the treatment.
Conclusions
Elbow arthroscopy has a significant diagnostic value in
radial head fractures. Our study demonstrates that elbow
arthroscopy features a high accuracy of fracture classifi-
cation and identification of relevant associated injuries,
such as loose bodies and capitellar lesions. Moreover, all
intra-articular lesions can be treated arthroscopically.
Arthroscopically assisted fracture reduction and internal
fixation reduces invasiveness and reliably allows for ex-
cellent clinical outcomes.
Abbreviations
C: Capitellum; CP: Coronoid process; CR: Conventional radiographs;
CT: Computed tomography; DASH: Disabilities of Arm, Shoulder and Hand
Questionnaire; EUA: Examination under anesthesia; f: Female; H: Humerus;
LB: Loose bodies; LCL: Lateral collateral ligament complex; m: Male;
MEPI: Mayo Elbow Performance Index; MRI: Magnetic resonance imaging;
OES: Oxford Elbow Score; PLRI: Posterolateral rotational instability;
PRUJ: Proximal radioulnar joint; RH: Radial head; U: Ulna
Acknowledgements
None.
Authors’contributions
FH, TH, WB, HOM, WCP, AL made substantial contributions to conception
and design, or acquisition of data, or analysis and interpretation of data;
have been involved in drafting the manuscript or revising it critically for
important intellectual content; have given final approval of the version to be
published. Each author should have participated sufficiently in the work to
take public responsibility for appropriate portions of the content; and agreed
to be accountable for all aspects of the work in ensuring that questions
related to the accuracy or integrity of any part of the work are appropriately
investigated and resolved.
Funding
No funding.
Availability of data and materials
All data generated or analysed during this study are included in this
published article.
Ethics approval and consent to participate
All procedures were performed in accordance with the ethical standards
of the institutional review board of the Ludwig-Maximilians-University of
Munich (LMU) (votum no. 507–14) and national research committee and
with the 1964 Helsinki declaration and its later amendments or comparable
ethical standards. Informed written consent and permission was obtained
from all individual participants included in the study.
Consent for publication
Written informed consent to publish was obtained from all individual
participants included in the study.
Haasters et al. BMC Musculoskeletal Disorders (2019) 20:343 Page 9 of 10
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Competing interests
The authors declare that they have no competing interests.
Author details
1
Hospital of General, Trauma and Reconstructive Surgery, University of
Munich (LMU), Nussbaumstr. 20, 80336 Munich, Germany.
2
Department of
Knee, Hip and Shoulder Surgery, Schön Klinik Munich-Harlaching, Academic
Teaching Hospital of the Paracelsus Private Medical University Salzburg,
Strubergasse 21, 5020 Salzburg, Austria.
3
Department of Orthopaedics and
Traumatology, Freiburg University Hospital, Albert-Ludwigs-University of
Freiburg, Hugstetterstrasse 55, 79106 Freiburg im Breisgau, Germany.
4
Department of Orthopedic Sports Medicine, University Hospital Rechts der
Isar, Technical University Munich, Ismaninger Str. 22, 81675 Munich, Germany.
Received: 12 November 2018 Accepted: 17 July 2019
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