Snapping elbow syndrome: a report of two cases
Keith K W Chan 陳國強, WK Wu 胡永強
HK Pract 2011;33:159-168
Summary
Snapping elbow syndrome is an uncommon clinical entity with snapping occurring either
at the medial or the lateral side of the elbow during certain motions of the elbow.
Patients sometimes presents sometimes present with pain or local tenderness instead
of snapping which may lead to the wrong diagnosis of the more common tennis or golfer's
elbow syndrome. While making the clinical diagnosis of snapping elbow is obvious
once the clinican is aware of the condition, to locate the cause of the snapping
and arrive at an anatomical diagnosis can be difficult although it is crucial to
successful treatment. In this article , we report two cases of snapping elbow syndrome,
one at the lateral side and one at the medial side of the elbow, and share our experience
with the use of musculoskeletal ultrasongraphy to arrive at an anatomical diagnosis
of the condition.
Keywords: Snapping elbow, medial, snapping elbow, lateral, musculoskeletal
ultrasonography, ulnar nerve subluxation, medial head of triceps subluxation, synovial
plica, real – time imaging, dynamic imaging
摘要
彈響手肘綜合症是一種不常見的病症,當手肘進行動作時,彈響會出現於手肘的內側或外側。但有些病人並無此典型病徵,只有痛楚或局部觸痛。因而易被誤診為較常見的網球手肘或哥爾夫球手肘綜合症。然而若能對這病症的存在保持警覺,診斷並不困難,但在判斷其成因和在解剖學上病變的位置時,則並不容易。而這些資料對於成功治療是很重要的。本文報告了兩個彈響手肘案例。一個發生在手肘外側及另一個在內則,並詳述我們在使用肌肉骨骼超聲波檢查作解剖學上診斷的經驗。
主要詞彙: 彈響手肘,內側,彈響手肘,外側,肌肉骨骼超聲波檢查,尺神經半脫位,肱三頭肌內側頭半脫位,滑膜皺襞,即時成像,動態成像
Introduction
Snapping elbow is a dynamic phenomenon where a snapping is a visible palpable or
audible during elbow joint movement, the condition is uncommon and generally poorly
understood by clinicians. It may be associated with pain 1 which makes
it easily misdiagnosed as other commonly encountered elbow conditions including
tennis elbow or golfer's elbow syndrome. Once the snapping is recognized, further
structural pathology of the snapping structures should be sought because precise
anatomical diagnoses determine potential for successful treatment. For example,
studies showed that ulnar nerve transposition surgery would fail with persistence
of symptoms if the associated snapping medial head of tricepts was unrecognized
and not property treated at the same time.2,3
To make an anatomical diagnosis of snapping elbow, ultrasonography and magnetic
resonance imaging (MRI) are usually advocated as investigation tools before arthroscopy.
The purpose of this article is to report two cases of snapping elbow syndrome with
a description of their diagnostic process and to review such clinical entity with
relevant literature.
Materials and methods
We studied two male patients with the complaints of snapping elbows (one at the
lateral side and one at the medial side). Both patients were assessed by the authors
and the snapping was confirmed clinically by history taking and physical examination.Musculoskeletal
ultrasonographic studies were then performed by the authors, both of whom received
prior relevant ultrasonography training. A phased array linear 12L-RS transducer
(LOGIQ-e, GE Ultrasound, USA) was used.
Case 1
Patient LWK, a 52-year-old male right-handed manual worker, presented to the author's
clinic with a painful lateral right elbow associated with snapping at his lateral
right elbow region during elbow region during elbow motions. The pain was localized
without radiation. He reported that his problems started insidiously about 6 months
ago after some weight lifting jobs. There was no history of overt sprain or contusion
over his right elbow at that time or in the past. The pain was gradually increasing
in severity and sometimes prevented him from prolonged weight lifting. Occasionally,
sudden pain with snapping during elbow motions would cause his arm to give way.
He denied associated numbness, tingling, burning or paresthesia over his right elbow
and arm. He did not have any other complaints over his left elbow.
Physical examination of his right elbow revealed no cubitus deformity and no erythema
or swelling around the elbow. Palpation elicited tenderness at the radiocapitellar
joint line, over the common wrist extensor tendon near its insertion. The right
elbow's range of motion (ROM) was full in all directions. By actively or passively
flexing and extending the pronated elbow back and forth, a visible snap was notices
over the lateral elbow at an angle of around 80-90 (Video Clip 1).4
No associated clicking or locking could be demonstrated. Further clinical examination
showed no ligamentous laxity or joint instability over the lateral elbow.
The clinical diagnosis was snapping lateral elbow. The offending structure could
be a hypertrophic synovial plica, but a torn annular ligament could not be ruled
out. The parient then underwent a musculoskeletal ultrasonogrpahy of his right elbow
to delineate the pathology (Figure 1).
Sonographic findings of patient LWK demonstrated that the snapping of his right
elbow occurred at the lateral elbow occurred at the lateral elbowbetween the capitellum
and the radial head in long axis view (Figure 2). The snapping
structure involved was a hypoechoeic structure (Figure 3) which
extruded gradually from the radiocapitellar joint when the elbow was flexed, pushing
the extensor carpi ulnaris (ECU) to flip with an associated snapping (Figure
4, Video clip 2).5 This most likely represented a posterolateral
hypertrophic synovial plica at the radiocapitellar joint.
Case 2
Patient NLF, a 23-year-old male right handed clerk, presented with snapping over
his medial left elbow during motion. The patient had a sprain injury to his left
elbow 2 years ago when he accidentally gave way during an overhead weight lifting
exercise. Immediately after the injury, he experienced pain and swelling at inflammation,
he started to notice snapping at the medial side of his elbow during elbow flexion
and extension. The snapping was sometimes associated with mild tingling sensation
at the ulnar side of his forearm and hand.
The physical examination of his left elbow revealed no cubitus deformity and no
edema or erythema around the elbow. Palpation did not elicittenderness but revealed
snapping on the medial elbow during flexion and extension to around 80. The snapping
was accentuated on resisted elbow flexion.Active and passive ROM of the left elbow
was full in all directions. No associated clicking or locking could be demonstrated.
Further clinical examination showed positive ulnar Tinel's sign at the cubital tunnel.
When the elbow was passively flexed and extended, the ulnar nerve could be felt
dislocating from its groove (cubital tunnel) at the posterior aspect of the humeral
epicondyle during elbow flexion. Otherwise, no ligamentous laxity or joint instability
could be found.
The clinical diagnosis was snapping medial elbow caused by the ulnar nerve subluxating
out of its cubital tunnel during flexion. A musculoskeletal ultrasonography of his
left elbow was then arranged to confirm the pathology of the snapping structure(Figure
5).
Sonographic examination demonstrated that the ulnar nerve was in the cubital tunnel
when the elbow was fully extended (Figure 6). On elbow flexion,
the ulnar nerve subluxed over the medial epicondyle carrying with it part of the
medial head of the triceps (Figure 7). When the elbow returned
from flexion to extension, the ulnar nerve reduced back to the cubital tunnel over
the tip of medial epicondyle. Such reduction was associated with a visible snapping
on the screen (Video Clip 3).6 The sonographic diagnosis
was ulnar nerve dislocation with subluxation of the medial head of triceps. The
diagnosis was later confirmed by findings at surgery (Figure 8, Video clip 4).7
Discussion
In 1970s, the terms "snapping elbow" has been regarded synonymous to slipping of
the ulnar nerve out of the cubital tunnel during elbow flexion.8 Reports
in recent several decades identified some other structures or conditions that can
contribute to snapping over the elbow. Extra-articular causes include ulnar nerve
dislocation with or without associated subluxation of the medial head of the triceps
9,10,11, and snapping brachialis muscle.12 Intra-articular
causes include intra-articular loose bodies 13, hypertrophic synovial
plica impingement at radio-humeral joint 14-16 and torn annular ligament.15-16
Other possible causes include tumors, previous surgery or trauma, articular degeneration
and inflammatory processes.
This case report demonstrated a case of medial snapping elbow caused by ulnar nerve
dislocation associated with subluxation of the medial head of the triceps. It is
one of the commonest causes of snapping elbow syndrome. Three differential diagnoses
for MEDIAL SNAPPING ELBOW are commonly quoted from literature:
1. Ulnar nerve dislocation (Table 1)
2. Subluxation of the medial head of the triceps (Table 2)
3. Snapping brachialis muscle (Table 3)
From literature, snapping elbows are most frequently related to medial anatomical
structures. Here, we also presented a case of lateral snapping elbow, where the
ECU tendon flicked over the hypertrophic synovial plica from the radiocapitellar
joint, resulting in snapping. Serveral recent reports brought LATERAL SNAPPING
ELBOW into the spotlight. Differential diagnoses include:
1. Synovial plica impingement (Table 4)
2. Torn annular ligament (Table 5)
3. Posterolateral rotator instability of elbow (Table 6)
To approach a patient with snappin gelbow, a detailed pain history of how and when
the snappings occur would give hints on the cause of the snapping. Once the snapping
phenomenon is clincially determined, its anatomical diagnoses should then be sought
as it is crucial for successful treatment.
Our case studies have demonstrated that musculoskeletal ultrasonography is a powerful
tool for making the anatomical diagnoses. Since the snapping elbow syndrome is a
dynamic phenomenon, musculoskeletal ultrasonography has the advantage of real-time
imaging as physicians can put the patients' elbows in motion to reproduce the snapping
and focus on that particular region inder real-time scanning . to find out the causative
structure or mechanism. MRI on the other hand has an inherent Limitation as a static
cross-sectional examination and therefore may be difficult in assessing the transient
snapping phenomenon.
The limitations of this study include the limited number of subjects as snapping
elbow syndrome is in general uncommon. In case 2, the sonographic diagnosis was
finally confirmed by intra-operative findings. Howeverm as the case 1 paritent refused
sugery, the sonographic diagnosis could not be confirmed operatively but the sonographic
findings of that case were further verified by one of the world experts in musculoskeletal
ultrasongraph to ensure accuracy.
Conclusions
This artical highlights 2 cases of snapping elbow synfrome, one snapping on the
lateral side from hypertrophic synoivial plica abutting on ECU, another one snapping
on the medial side from dislocation of ulnar nerve with subluxation of medial head
of triceps. Upon clinical examination of the elbow, snappin gwas evident in both
cases but the precise snapping structures could not be confidently delineated clinically
. Musculoskeletal ultrasonography was able to display realtime images of the causative
snapping structure(s) disputing that they are transient when the elbows were put
into motion. It is consifered that musculoskeletal ultrasonography can be the investigation
of choice to evluate snapping elbow syndrome.
Acknowledgements
I wish to thank Thomas B Clark, DC, RVT, an internationally renowned expert in musculoskeletal
ultrasonography for his help in verifying sonographic findings of the presented
cases. I also wish to thank Dr Yeung Sai Hung, a specialist in Orthopedics and Traumatology,
for preparing intro-operative photos and video clips of Case 2.
Keith KW Chan, MMPhysMed (Mu.sk)(Syd), FHKAM(FM), FRCGP(UK), FRACGP
Ricky WK Wu, PGDipMSM (Otago), FHKAM(FM), FRACGP, FHKCFP
Musculoskeletal Physicians and Specialists in Family Medicine
Correspondence to : Dr Keith KW Chan, The Hong Kong Institute of Musculoskeletal
Medicine, Room 1201, 12/F, City Landmark I, 68 Chung On
Street, Tsuen Wan, Hong Kong SAR.
References
- Silva HR, Simão MN, Júnior JE, et al. Imaging diagnosis in snapping syndromes. Radiol
Bras 2009;42(1):49-55.
- Haws M, Brown RE. Bilateral snapping triceps tendon after bilateral ulnar nerve
transposition for ulnar nerve subluxation. Ann Plast Surg 1995; 34:550-551.
- Rogers MR, Bergfield TG, Aulicino PL. The failed ulnar nerve transposition. Etiology
and treatment. Clin Orthop 1991; 269:193-200.
- Video clip 1: http://www.youtube.com/watch?v=raCKoWuWgfE
- Video clip 2: http://www.youtube.com/watch?v=QbvM-fWlZl0
- Video clip 3: http://www.youtube.com/watch?v=K7I2DmWN70Y
- Video clip 4: http://www.youtube.com/watch?v=fbn-avy9zwY
- Childress HM. Recurrent ulnar-nerve dislocation at the elbow. Clin Ortho 1975;108:168-173.
- Yiannakopoulos CK. Imaging diagnosis of the snapping triceps. Radiology. 2002;225(2):607-608.
- Spinner RJ, An KN, Kim KJ. Medial or lateral dislocation (snapping) of a portion
of the distal triceps: a biomechanical, anatomic explanation. ShoulderElbow Surg.
2001;10(6):561-567.
- Jacobson JA, Jebson PJ, Jeffers AW. Ulnar nerve dislocation and snapping triceps
syndrome: diagnosis with dynamic sonography – report of three cases. Radiology.
2001;220(3):601-605.
- Rudy BS, Armstrong AD. Atraumatic snapping brachialis in a 37-year-old woman. JAAPA
2007;20(1):48-51.
- Quinn SF, Haberman JJ, Fitzgerald SW, et al. Evaluation of loose bodies in the elbow
with MR imaging. J Magn Reson Imaging 1994;4:169–172.
- Tateishi K, Tsumura N, Matsumoto T. Bilateral painful snapping elbows triggered
by daily dumbbell exercises: a case report. Knee Surg SportsTraumatol Arthrosc.
2006;14(5):487-490.
- Huang GS, Lee CH, Lee HS, et al. MRI, arthroscopy and histologic observation of
an annular ligament causing painful snapping of the elbow joint. AJR 2005;185:397-399.
- Aoki M, Okamura K, Yamashita T. Snapping annular ligament of the elbow joint in
the throwing arms of young brothers. Arthroscopy 2003;19(8): e89-e92.
- Okamoto M, Abe M, Shirai H. Diagnostic ultrasonography of the ulnar nerve in cubital
tunnel syndrome. J Hand Surg 2000;25:499-502.
- O'Driscoll SW, Horii E, Carmichael SW, et al. The cubital tunnel and ulnar neuropathy.
J Bone Joint Surg Br 1991;73:613-617.
- Vanhees MKD, Geurt GFAE, Van Riet RP. Snapping triceps syndrome: a review of the
literature. Shoulder & Elbow 2010;2(1):30-33.
- Spinner RJ, Goldner RD. Snapping of the medial head of the triceps and recurrent
dislocation of the ulnar nerve. Anatomical and dynamic factors. JBone Joint Surg
Am 1998;80:239-247.
- Watts AC, McEachan J, Reid J, et al. The snapping elbow: a diagnostic pitfull. J
Shoulder Elbow Surg 2009;18:e9-10.
- Spinner RJ, O'Driscoll SW, Davids JR, et al. Cubitus varus associated with dislocation
of both the medial portion of the triceps and the ulnar nerve. JHand Surg 1999;24:718-726.
- Dellon AL. Musculotendinous variations about the medial humeral epicondyle. J Hand
Surg 1986;11B:175-181.
- Fabrizio PA, Clemente FR. Variation in the triceps brachii muscle: a fourth muscular
head. Clin Anat 1997;10:259-263.
- Reis ND. Anomalous triceps tendon as a cause for snapping elbow and ulnar neuritis:
a case report. J Hand Surg 1980;5:361-362.
- Boon AJ, Spinner RJ, Bernhardt KA, et al. Muscle activation patterns in snapping
triceps syndrome. Arch Phys Med Rehabil 2007;88:239-242.
- Spinner RJ, Davids JR, Goldner RD. Dislocating medial triceps and ulnar neuropathy
in three generations of one family. J Hand Surg 1997;22:132-137.
- Spinner RJ, Wenger DE, Barry CJ, et al. Episodic snapping of the medial head of
the triceps due to weightlifting. J South Orthop Assoc 1999;8:288-292.
- Coonrad RW, Spinner RJ. Snapping brachialis tendon associated with median neuropathy:
a case report. J Bone Joint Surg 1995;77(12):1891-1893.
- Clarke RP. Symptomatic,
lateral synovial fringe (plica) of the elbow joint. Arthroscopy 1988;4:112-116.
- Steinert AF, Goebel S, Rucker A, et al. Snapping elbow caused by hypertrophic synovial
plica in the radiohumeral joint: a report of three cases and review of literature.
Arch Orthop Tauma Surg. 2010;130(3):347-351.
- Kim DH, Gambardella RA, Elattrache NS. Arthroscopic treatment of posterolateral
elbow impingement from lateral synovial plicae in throwing athletes and golfers.
Am J Sports Med 2006;3:438-444.
- Sakai K, Kanamori M, Kitano S. Extension restriction of the elbow caused by a synovial
fold: a report on 2 athletes. Acta Orthop Scand 1999;70:85-86.
- Commandre FA, Taillan B, Benezis C, et al. Plica synovialis (synovial fold) of the
elbow: report on one case. J Sports Med Phys Fitness 1988;28:209-210.
- Antuna SA, O'Driscoll SW. Snapping plicae associated with radiocapitellar chondromalacia.
Arthroscopy 2001;17:491-495.
- O'Driscoll SW. Classification and evaluation of recurrent instability of the elbow.
Clin Orthop Relat Res 2000; 370:34-43.
- O'Driscoll SW, Bell DF, Morrey BF. Postero-lateral rotator instability of the elbow.
J Bone Joint Surg 1991;73-A:440-446.
- McKee MD, Schemitsch EH, Sala MJ, et al. The pathoanatomy of lateral ligamentous
disruption in complex elbow instability. J Shoulder Elbow Surg 2003;12:391-396.
- O'Driscoll SW, Spinner RJ, McKee MD. Tardy postero-lateral rotator instability of
the elbow due to cubitus varus. J Bone Joint Surg 2001;83-A:1358-1369.
- Abe M, Ishizu T, Morikawa J. Postero-lateral rotator instability of the elbow after
post-traumatic cubitus varus. J Shoulder Elbow Surg 1997;6:405-409.
- Stanley JK, Penn DS, Wasseem M. Exposure of the head of the radius using Wrightington
approach. J Bone Joint Surg 2006; 88-B:1178-1182.
- Jensen SL, Olsen BS, Tyrdal S, et al. Elbow joint laxity after experimental radial
head excision and lateral collateral ligament rupture: efficacy of prosthetic replacement
and ligament repair. J Shoulder Elbow Surg 2004;86-A:975-982.
- Charalambous CP, Standley JK. Posterolateral rotator instability of the elbow. J
Bone Joint Surg 2008;90-B:272-279.
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