2
Clinical Safety of the 5 O’Clock Portal in Shoulder
Arthroscopy: A Prospective Study
3
4
Purpose: The purpose of this study is to determine the rate of clinically significant
5
neurovascular complications associated with the routine use of the 5 o’clock portal during
6
arthroscopic Bankart repair.
1
7
8
Methods: 34 patients underwent arthroscopic Bankart repair with the use of the 5
9
o’clock portal. These patients were followed at 2 and 6 weeks post-operatively for
10
subjective signs of neurovascular injury (numbness and tingling) as well as objective
11
signs (intraoperative bleeding, radial pulse, capillary refill, sensation, motor strength,
12
hematoma and edema).
13
14
Results: 2 of 34 patients (6%) experienced transient neurological symptoms in an ulnar
15
nerve distribution which resolved by 6 weeks. There was no occurrence of clinically
16
significant injury to the axillary nerve, axillary artery, musculocutaneous nerve, lateral
17
cord of the brachial plexus or cephalic vein.
18
19
Conclusions: No clinically detectable neurovascular injuries were associated with the
20
use of the 5 o’clock shoulder portal during Bankart repair.
21
22
23
Level of Evidence: Level II
24
Clinical Relevance: The 5 o’clock shoulder portal can be used safely with minimal risk
25
to neurovascular structures during arthroscopic Bankart repair.
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
Key Words: Shoulder, Arthroscopy, Bankart, Labrum, Complications
56
Arthroscopic repair of Bankart lesions has become a commonly performed and
57
accepted practice worldwide. The success of this procedure in eliminating shoulder
58
instability has been well documented, while the incidence of complications related to the
59
procedure remains low. Nevertheless, the potential for complications exists.
60
Neurovascular injury is one of the most feared complications that can occur during this
61
procedure. 1-8
62
Neurovascular injury may result from traction placed on the arm during the
63
procedure, or from direct trauma during portal placement. Some authors have advocated
64
the use of a 5 o’clock or trans-subscapularis portal during Bankart repair.9,10 This portal
65
allows for a more perpendicular angle of entry during inferior anchor placement. For this
66
reason, it may allow anchors to be placed more inferiorly than a traditional, mid-glenoid
67
anterior portal.
68
While desirable from a biomechanical perspective, the 5 o’clock portal may be
69
disadvantageous due to its close proximity to neurovascular structures. Cadaver studies
70
have demonstrated that the axillary artery and nerve, the musculocutaneous nerve and the
71
cephalic vein may all be at risk during portal placement.10-14 Many arthroscopists
72
continue to use this portal on a routine basis with few neurovascular complications
73
reported.
74
The purpose of this study is to determine the rate of clinically significant
75
neurovascular complications associated with the routine use of the 5 o’clock portal during
76
arthroscopic Bankart repair. We hypothesize that the rate of neurovascular complications
77
is insignificant, proving that the routine use of this portal is safe.
78
79
METHODS
80
81
Patient Selection
82
83
Thirty-four consecutive patients undergoing arthroscopic Bankart repair were selected for
84
the study. Patients were prospectively identified, interviewed and examined for pre-
85
existing subjective or objective signs of neurovascular compromise. To determine
86
whether pre-existing subjective symptoms of neurovascular injury existed, a standard
87
question was asked of all patients: “Are you experiencing any numbness or tingling in
88
your arm or hand?” Patients were instructed to reply with a yes or no response. Patients
89
were also examined to identify any objective signs of pre-existing neurovascular
90
compromise (Table 1). Patients with pre-existing objective or subjective signs of
91
neurovascular compromise were excluded from the study. The 34 patients enrolled
92
underwent arthroscopic Bankart repair with the routine use of the 5 o’clock portal
93
established using an outside-in technique. These patients were examined post-
94
operatively at 2 and 6 weeks for subjective and objective evidence of neurovascular
95
injury.
96
97
Portal Placement
98
99
All portals were established by the author (XXX). Arthroscopy was performed in the
100
lateral decubitus position with 10 to 15 pounds of traction placed on the arm in all cases.
101
After establishing a posterior portal, a mid-glenoid, anterior portal was established using
102
an outside-in technique. Subsequently, a 5 o’clock portal was established approximately
103
1.5 cm inferior to the previously established anterior portal. The portal was positioned to
104
allow access to the 5 o’clock position on the glenoid face and was placed through the
105
subscapularis tendon. The initial stage of portal placement is localization with a spinal
106
needle confirming the correct position. After being localized with a spinal needle, the
107
Bio-SutureTack guide (Arthrex, Naples, FL) is advanced adjacent to the spinal needle
108
and into position and the spinal needle is removed. The Bio-SutureTack guide is left in
109
the joint until the inferior glenoid anchors are placed. Next, an anterior-superior portal
110
was routinely established and the remainder of the case was performed viewing from the
111
anterior-superior portal. Finally, the labrum and adjacent bony glenoid were prepared
112
and the labrum repaired using standard suture passing and knot tying techniques with a
113
Spectrum suture passing instrument (ConMed Linvatech, Largo, FL).
114
115
Patient Evaluation
116
117
All patients were evaluated in a clinic setting at 2 and 6 weeks post-operatively. To
118
determine the presence of subjective signs of neurovascular injury, a standard question
119
was asked of all patients: “Are you experiencing any numbness or tingling in your arm
120
or hand?” Patients were instructed to reply with a yes or no response. To determine the
121
presence of objective signs of neurovascular compromise, a standardized physical
122
examination was performed. Presence or absence of the radial pulse was documented.
123
Capillary refill at the finger tips was examined and documented as greater or less than 2
124
seconds. Radial, median, axillary and ulnar nerve distributions were examined to light
125
touch and compared to the contralateral extremity. Any decrease in sensation was
126
documented and further evaluated with two-point discrimination. Motor strength of the
127
radial, median and ulnar nerves was documented by grading the motor strength of the
128
extensor pollicis longus, opponens pollicis and interossei muscles, respectively, on a
129
scale of 0 to 5. The operative extremity was also examined for evidence of hematoma at
130
the portal sites or edema below the level of the elbow. In addition, any intra-operative
131
bleeding requiring exploration or prolonged pressure to be placed at the portal site was
132
documented at time of surgery.
133
134
RESULTS
135
136
All patients (34) were available for follow-up at 2 and 6 weeks post-operatively. A
137
number of patients underwent additional procedures at the same time as their Bankart
138
repair (Table 2). Two of the 34 patients (6%) exhibited subjective signs of paresthesias
139
in an ulnar nerve distribution at 2 weeks post-operatively. These patients had no findings
140
of decreased sensation on physical examination. Their symptoms had completely
141
resolved by 6 weeks post-operatively. No patients exhibited an absent radial pulse,
142
decreased capillary refill, decreased sensation, decreased motor strength, hematoma or
143
edema below the elbow. In addition, no occurrences of intra-operative bleeding requiring
144
exploration or the application of prolonged pressure were noted.
145
146
147
DISCUSSION
148
A robust repair of the labrum back to the glenoid is paramount to the success of restoring
149
stability during arthroscopic Bankart repair. In turn, accurate anchor placement is
150
necessary in order to achieve such a repair. While anchor placement in the superior and
151
mid portion of the anterior glenoid is possible via a traditional mid-glenoid portal,
152
inferior anchor placement is not always possible through this portal. For this reason,
153
many arthroscopists have advocated the use of the 5 o’clock portal to allow the consistent
154
placement of anchors inferiorly in the glenoid. This may potentially lead to a superior
155
Bankart repair, though this remains to be conclusively demonstrated.14 However, the
156
placement of the 5 o’clock portal also places the neurovascular structures at risk. If this
157
risk is found to be significant, the routine use of this portal may not be wise since its
158
benefit has not been proven definitively. The purpose of this study was to determine the
159
rate of clinically detectable neurovascular complications associated with the routine use
160
of this portal. In this prospective series, no clinically significant neurovascular
161
complications were found.
162
Two instances of transient ulnar nerve paresthesias were noted at the 2 week
163
follow-up. These likely represent neuropraxia that resulted from traction placed on the
164
arm at the time of surgery. It is possible that these symptoms were the result of the 5
165
o’clock portal placement but this seems unlikely. A 6% rate of transient neuropraxia has
166
been reported in series of shoulder arthroscopy which do not use a 5 o’clock portal.15-17
167
It is commonly believed that these neuropraxias are the result of traction being placed on
168
the arm during surgery and in turn traction being placed on the brachial plexus.16 The
169
possibility exists that the ulnar nerve or brachial plexus could have been injured during
170
placement of the 5 o’clock portal, but this seems to be a much less plausible explanation
171
due to the distance of the portal to these structures. Regardless of etiology, this 6%
172
neuropraxia rate does not represent a departure from the expected rate following shoulder
173
arthroscopy and all cases went on to complete resolution.
174
This study contrasts with previous reports that suggest a higher complication rate
175
associated with the use of this portal. Davidson et al. performed a cadaveric study using
176
an inside-out technique to establish the 5 o’clock portal.11 They found the cephalic vein
177
to be less than 10 mm away from the portal in all cases and at significant risk of injury.
178
In a separate cadaveric study, Pearsall et al. also advised against the use of the 5 o’clock
179
portal due to its proximity to the cephalic vein.14 Lo et al. examined the 5 o’clock portal
180
using an outside-in technique and again demonstrated the close proximity, 9.8 mm, of the
181
5 o’clock portal to the cephalic vein.10 They noted the portal was a safe distance from the
182
axillary vein and artery, musculocutaneous nerve and lateral cord.
183
Recently, two additional cadaveric studies have again called into question the
184
safety of this portal. Gelber et al. examined the safety of the 5 o’clock portal in both the
185
beach chair and lateral decubitus positions in 13 cadavers.12 The authors advised against
186
the routine use of the 5 o’clock portal due to its proximity to the musculocutaneous nerve
187
and cephalic vein. These findings are inconsistent with the findings in the present study,
188
possibly due to the different methods of portal placement utilized. The authors placed a 2
189
mm Kirschner wire orthogonally in a posterior to anterior direction at the 5 o’clock
190
position. In contrast, our portal is not placed orthogonally at the 5 o’clock position. It is
191
placed at an inferiorly directed angle through the subscapularis to allow anchor placement
192
in the inferior glenoid, but not perpendicular anchor placement. By doing so, the anterior
193
structures are traversed more superiorly than in the study by Gelber et al. This may
194
account for the seemingly contradictory conclusions of these studies.
195
Meyer et al. also questioned the safety of the 5 o’clock portal.13 The authors
196
studied the risks associated with 12 different arthroscopic portals placed in 12 cadavers.
197
They found the 5 o’clock portal to be “unsafe” due to the risk of injury to the axillary
198
artery, axillary vein and cephalic vein. Specifically, they found the mean distances of the
199
trochar to the axillary artery, axillary vein and cephalic vein to be 13mm, 15mm and
200
17mm, respectively. Again, this study seems to be inconsistent with the findings of the
201
current study. However, when closely scrutinized there are differences in methodology
202
which may help to explain these differences. As in the study by Gelber et al., Meyer et al
203
also placed the portal at an orthogonal plane to the glenoid at the 5 o’clock position using
204
an outside-in technique. This contrasts to the portal placement in the current study which
205
is placed to allow adequate anchor placement at the 5 o’clock position, but not a 90
206
degree angle. In addition, Meyer et al. used a 12mm trochar in their study in comparison
207
to the no-trochar technique in the current study where only the drill guide for the anchor
208
is placed through the portal. Using a larger trochar would presumably increase the risk of
209
neurovascular injury during portal placement.
210
The current study has several important limitations. First, the sample size is not
211
large. It is possible that with a larger sample size more complications may have been
212
detected. Secondly, the follow-up time of 6 weeks is short. The sole purpose of this
213
study was to detect neurovascular injuries and it was thought that these would be
214
apparent in the immediate postoperative period. It is possible that certain complications
215
such as cephalic vein injury or axillary artery aneurysm may not present themselves in
216
the immediate post-operative period. Another limitation is that the cephalic vein may
217
have been injured but the injury may not have been clinically detectable. Imaging of the
218
cephalic vein itself would be necessary to determine the true rate of injury to this
219
structure. The purpose of this study was to determine the rate of clinically significant
220
neurovascular injury and for this reason no imaging was performed. Finally, these
221
procedures were performed by a fellowship trained sports medicine surgeon who
222
performs a high volume of arthroscopic shoulder cases. As such, these results may not be
223
an accurate representation of the expected outcomes of surgeons with less arthroscopic
224
shoulder experience.
225
226
CONCLUSION
227
In conclusion, this study demonstrates that the routine use of the 5 o’clock portal, as
228
described above, is associated with a low risk of clinically detectable neurovascular
229
injury. The 5 o’clock portal is safe and remains a useful tool in the armamentarium of the
230
arthroscopic shoulder surgeon.
231
232
233
234
235
236
237
238
239
REFERENCES
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
1. Bigliani LU, Flatow EL, Deliz ED. Complications of Shoulder Arthroscopy. Orthop
Rev. 1991;20:743-751.
2. Curtis AS, Snyder AJ, Del Pizzo W et al. Complications of Shoulder Arthroscopy.
Arthroscopy. 1992;8(4):395.
3. McFarland EG, O’Neill OR, Hsu CY. Complications of Shoulder Arthroscopy. J
South Orthop Assoc. 1997;6:190-196.
4. Nottage WM. Arthroscopic Portals: Anatomy at Risk. Orthop Clin North Am.
1993;24:19-26.
5. Rodeo SA, Forster RA, Weiland AJ. Neurologic Complications Due to Arthroscopy.
J Bone J Surg Am. 1993;75:917-926.
6. Segmuller HE, Alfred SP, Zilio G et al. Cutaneous Nerve Lesions of the Shoulder and
Arm after Arthroscopic Surgery. J Shoulder Elbow Surg. 1995;4:254-258.
7. Shaffer BS, Tibone JE. Arthroscopic Shoulder Instability Surgery. Complications.
Clin Sports Med. 1999;18:737-767.
8. Stanish WD, Peterson DC. Shoulder Arthroscopy and Nerve Injury: Pitfalls and
Prevention. Arthroscopy. 1995;11(5):458-466.
9. Ilahi OA, Al-Fahl T, Bahrani H et al. Glenoid Suture Anchor Fixation Strength:
Effect of Insertion Angle. Arthroscopy. 2004;20(6):609-613.
10. Lo IK, Lind CC, Burkart SS. Glenohumeral Arthroscopy Portals Established Using
an Outside-In Technique: Neurovascular Anatomy at Risk. Arthroscopy.
2004;20(6):596-602.
11. Davidson PA, Tibone JE. Anterior-Inferior (5 O’clock) Portal for Shoulder
Arthroscopy. Arthroscopy. 1995;11(6):519-525.
12. Gelber PE, Reina F, Caceres E et al. A Comparison of Risk Between the Lateral
Decubitus and the Beach-Chair Position When Establishing and Anteroinferior Shoulder
Portal: A Cadaveric Study. Arthroscopy. 2007;23(5):522-528.
13. Meyer M, Graveleau N, Hardy P et al. Anatomic Risks of Shoulder Arthroscopy
Portals: Anatomic Cadaveric Study of 12 Portals. Arthroscopy. 2007;23(5):529-536.
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
14. Pearsall AW, Holovacs TF, Speer KP. The Low Anterior Five-O’clock Portal
During Arthrocopic Shoulder Surgery Performed in the Beach Chair Position. Am J
Sports Med. 1999;27:571-574.
15. Andrews JR, Carson WG, Ortega K. Arthroscopy of the Shoulder: Technique and
Normal Anatomy. Am J Sports Med. 1984;12:1-7.
16. Klein AF, France JC, Mutschler et al. Measurement of Brachial Plexus Strain in
Arthroscopy of the Shoulder. Arthroscopy. 1987;3:45-52.
17. Skyhar MJ, Altchek DW, Warren RF et al. Shoulder Arthroscopy with the Patient in
the Beach-Chair Position. Arthroscopy. 1988;4(4):256-259.
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
Radial pulse
Capillary refill at the finger tips
Radial, median, axillary and ulnar nerve sensation
Radial, median and ulnar nerve motor strength
Hematoma
Edema
Table 1: Objective physical examination findings used to determine presence of
neurovascular compromise
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
Procedure
total
Isolated Bankart
Bankart and SLAP repair
Bankart, SLAP and posterior labral repair
Bankart and posterior labral repair
Bankart and rotator cuff repair
Bankart, SLAP, rotator cuff repair and
biceps tenodesis
Table 2: Procedures performed during the study
n
% of
19
7
4
2
1
1
56%
20%
12%
6%
3%
3%