The low anterior five-o'clock portal during arthroscopic shoulder surgery performed in the beach-chair position

Risk of Cephalic Vein Injury During the Creation of an Anterior Portal in Shoulder Arthroscopy

Background

There is a risk of cephalic vein injury during shoulder arthroscopy. However, limited data regarding its anatomic course are available.

Purpose

To analyze the positional relationship and factors affecting the distance between the coracoid tip and cephalic veins.

Study design

Case series; Level of evidence, 4.

Methods

A total of 80 contrast-enhanced computed tomography images from 80 patients (mean age, 49.6 ± 20.3 years; 61 men) were retrospectively analyzed. The distance between the center of the coracoid tip and the vertical line through the cephalic vein was measured in the axial (D1) and sagittal (D2) planes. The distance between 1 cm lateral to the center of the coracoid tip and the vertical line through the cephalic vein was measured in the sagittal plane (D3). Each distance was compared according to patient sex and laterality. Associations between each distance and the patient's age, height, weight, and body mass index were investigated.

Results

The mean D1 was 18.4 ± 7.3 mm in 59 patients. The mean D2 was 23.4 ± 11.6 mm, and it was within 10 mm in 10 patients (12.5%). The mean D3 was 33.7 ± 12.2 mm. There was no significant difference in D1, D2, and D3 according to patient sex or laterality. A positive correlation was observed only between D3 and patient height (r = 0.320; P = .034).

Conclusion

The cephalic vein was found to travel a mean of 23.4 mm distal and 33.7 mm distal to 1 cm lateral to the coracoid tip. Therefore, Care should be taken to avoid cephalic vein injury when creating an anterior inferior portal or 5-o'clock portal around these areas.

Curved-guide system is useful in achieving optimized trajectory for the most inferior suture anchor during arthroscopic Bankart repair

BACKGROUND

A curved-drill guide system was recently introduced to achieve a better trajectory for a low anteroinferior anchor during arthroscopic Bankart repair. However, the clinical performance of such a device remains unclear. The purpose of this study was to evaluate the trajectory and position of the low anteroinferior suture anchor with use of the curved-guide system in clinical cases.

METHODS

We enrolled 41 cases of arthroscopic Bankart repair in this study. Of these cases, 9 were repaired using the curved drill guide whereas 32 were repaired using a conventional straight guide. Postoperative computed tomography scans were obtained, and 3-dimensional models of the scapula were reconstructed. Notable perforations of the opposite cortex by the most inferior anchors were recorded. The clock-face angle, insertion angle, and insertion distance were measured.

RESULTS

The anchor perforation rate in the curved-guide group (11%) was significantly lower than that in the straight-guide group (56%) (P = .02). The insertion distance in the curved-guide group was significantly shorter than that in the straight-guide group (4.0 ± 1.6 mm vs. 7.0 ± 2.4 mm, P < .01). The clock-face angle and insertion angle were significantly greater in the perforated straight-guide group than in the nonperforated groups. The percentage of anchors in the absolute safe zone (clock-face angle > 135° and < 165° and insertion angle < 100°), where no anchors perforated, was greater in the curved-guide group than the straight-guide group.

CONCLUSION

Compared with the conventional straight guide, the curved-guide system provides better placement of the most inferior suture anchor during arthroscopic Bankart repair.

Patient Positioning in Arthroscopic Management of Posterior-Inferior Shoulder Instability: A Systematic Review Comparing Beach Chair and Lateral Decubitus Approaches

PURPOSE

To analyze the available literature pertaining to clinical outcomes and complications of posterior-inferior shoulder stabilization performed arthroscopically in either the beach chair (BC) or lateral decubitus (LD) position.

METHODS

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 3 databases (PubMed, EMBASE, and Medline) were searched up to January 2018 for English-language studies on posterior shoulder instability. Descriptive statistics are presented. The Methodological Index for Non-Randomized Studies (MINORS) scale was used to assess quality.

RESULTS

Twenty-five studies were included, examining 1,085 patients (n = 140 BC; n = 945 LD), of mean age 25.0 years, 27.1% female, and mean 3.1 years of follow-up. MINORS scores for BC and LD were 11.2 and 9.8, respectively. Regardless of positioning, patients did not differ across numerous outcomes and various surgical factors (e.g., number of portals, anchors, anchor types, concomitant pathology, or postoperative rehabilitation protocol). Postoperative patient satisfaction ranged from 85% to 87.5% and 93% to 100% for patients treated in BC and LD positions, respectively. Although not reported for BC, overall and preinjury return-to-play (RTP) rates in LD patients ranged from 72% to 100% and 55% to 100%, respectively, returning from 3 to 7.6 months postoperatively. Failure rates in the BC and LD positions ranged from 0% to 9.4% and 0% to 29%, respectively. There were no differences in reported incidences of neuropraxia, stroke, nonfatal pulmonary embolus, vision loss, cardiac arrest, or other positioning-related complications.

CONCLUSIONS

Arthroscopic management of posterior-inferior shoulder instability has a successful track record and minimal complication profile. Although patient positioning appears to influence results, with those treated in the LD position experiencing marginally higher patient satisfaction and failure rates, the current data prevent any conclusions being made regarding the superiority of one approach over another. As the clinical relevance of patient positioning remains to be determined, larger, higher-level study designs with long-term follow-up are required.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III, and IV studies.

Single Working Portal Technique for Knotless Arthroscopic Bankart Repair

Arthroscopic Bankart repair is widely accepted as the method of choice in restoring the labrum to the glenoid rim. It has been shown to have comparable outcomes with open stabilization. This usually involves the use of 2 portals anteriorly: one anterosuperior accessory portal and another anteroinferior working portal. The aim of this Technical Note is to present a simple and reproducible technique for Bankart repair using a single working portal anteriorly without an accessory portal.

Clinical Safety of the 5 O'clock Portal in Shoulder Arthroscopy: A Prospective Study

Background

The present study aimed to determine the rate of clinically significant neurovascular complications associated with the routine use of the 5 o'clock portal during arthroscopic Bankart repair.

Methods

Forty-eight consecutive patients underwent arthroscopic Bankart repair with the use of the 5 o'clock portal. These patients were followed at 2 weeks and 6 weeks postoperatively for subjective signs of neurovascular injury (i.e. numbness and tingling) as well as objective signs (i.e. intraoperative bleeding, radial pulse, capillary refill, sensation, motor strength, haematoma and oedema).

Results

Two out of 48 patients (4.2%) experienced transient neurological symptoms in an ulnar nerve distribution, which resolved by 6 weeks. There was no occurrence of clinically significant injury to the axillary nerve, axillary artery, musculocutaneous nerve, lateral cord of the brachial plexus or cephalic vein.

Conclusions

No clinically detectable neurovascular injuries were associated with the use of the 5 o'clock shoulder portal during Bankart repair.

A Biomechanical Analysis of Anchor Placement for Bankart Repair: Effect of Portal Placement

During arthroscopic Bankart repair, penetration of suture anchors through the far cortex can compromise the initial biomechanical characteristics of anchor stability and repair integrity. This study compared the placement of suture anchors through a low anterior-inferior rotator interval portal (AI) vs a trans-subscapularis portal to evaluate the rate of anchor perforation as well as biomechanical strength. Ten matched pairs of cadaveric shoulders were randomized to an AI or a trans-subscapularis portal for placement of suture anchors at the 3 o'clock and 5:30 positions. The following measurements were obtained: (1) distance from the portal to the cephalic vein; (2) presence and length of anchor penetration through the inferior glenoid; and (3) ultimate failure strength of the anchors. The distance from the portal to the cephalic vein was significantly greater with the AI vs the trans-subscapularis portal across all specimens (29.9 vs 11.2 mm, P<.05). The rate of anchor penetration was significantly increased in the AI group vs the trans-subscapularis group at the 5:30 position (60% vs 10%, P=.014) but not at the 3 o'clock position (P=.33). Mean pullout strength of the anchors at the 5:30 position trended higher in the trans-subscapularis group, but the difference was not significant (132.8 vs 112.6 N, P=.18). The cephalic vein is closer to the trans-subscapularis portal than to the AI, but is at a safe distance. Both the rate and the degree of glenoid suture anchor penetration were lower with the trans-subscapularis portal compared with the AI at the 5:30 position. Placing anchors through the trans-subscapularis portal provides a safe alternative method, with improved positioning of the inferiormost anchor compared with the traditional AI.

Shoulder arthroscopy: the basics

Shoulder arthroscopy is a commonly performed and accepted procedure for a wide variety of pathologies. Surgeon experience, patient positioning, knowledge of surgical anatomy, proper portal placement, and proper use of instrumentation can improve technical success and minimize complication risks. This article details the surgical anatomy, indications, patient positioning, portal placement, instrumentation, and complications for basic shoulder arthroscopy.

Trans-subscapularis portal versus low-anterior portal for low anchor placement on the inferior glenoid fossa: a cadaveric shoulder study with computed tomographic analysis

PURPOSE

The purpose of this study was to evaluate the accuracy of inserting a glenoid anchor at the 5:30 clockface position using a trans-subscapularis (TSS) portal versus a low anterior (LA) portal.

METHODS

Five surgeons (T.D., J.C., C.V., D.J.O-H., J.S.T.) placed a single anchor in 20 fresh-frozen cadaveric shoulders. In each of 2 shoulders, surgeons used an LA portal to insert the anchor, whereas in 2 shoulders a TSS portal was used. Surgeons were directed to place the anchor at the 5:30 position at an angle 45° to the glenoid surface (axial plane) and passing perpendicular to the glenoid rim in the coronal plane. Shoulders were then dissected and computed tomographic (CT) scans obtained. Anchor position relative to the clockface was documented by 2 blinded assessors, as was the angle of insertion in the axial and coronal planes. Statistical significance was calculated with a Student t test for paired samples (confidence interval [CI], 95%; significance, P < .05).

RESULTS

The average deviation from the 5:30 position was 48 minutes (standard deviation [SD], 31 minutes) for the LA portal (average position, 4:42 o'clock) versus 28.5 minutes (SD, 19 minutes) for the TSS group (average position, 5:02 o'clock) (P = .15). The average angle of anchor insertion in the axial plane was 67.2° (SD, 19°) for the LA portal versus 62.8° (SD, 14°) for the TSS portal (P = .49), whereas the average angle of insertion in the coronal plane was 31.3° (SD, 14°) of inferior angulation in the LA group and 14.3° (SD, 8°) of inferior angulation in the TSS group (P = .009). Of the anchors inserted, 9 of 20 (45%) showed evidence of far-cortical perforation. No difference in cortical perforation was seen between the 2 portals, with perforation more likely with anchors inserted greater than 45° in the axial plane (8 of 20) than with those inserted less than 45° (1 of 20) (P = .02).

CONCLUSIONS

The use of a TSS portal improves the angle of approach to the inferior glenoid rim in comparison with an LA portal, reducing the acuity of the angle of insertion in the coronal plane.

CLINICAL RELEVANCE

The TSS portal is an option for surgeons performing arthroscopic Bankart repair using anchors low on the glenoid rim.

A comparison of the lateral decubitus and beach-chair positions for shoulder surgery: advantages and complications

Arthroscopic or open shoulder surgery can be performed using the lateral decubitus or beach-chair position. Advantages of the lateral decubitus position include better visualization and instrument access for certain procedures and decreased risk for cerebral hypoperfusion. Complications associated with this position include traction injuries, resulting in neurapraxia, thromboembolic events, difficulty with airway management, and the potential need to convert to an anterior open approach. One advantage of the beach-chair position is easier setup from a supine to upright position, which allows the surgeon the option to convert to an open procedure if necessary. Although rare, patients in this position may experience cerebral hypoperfusion and complications that range from cranial nerve injury to infarction. Other complications related to this position include cervical traction neurapraxia, blindness, and cardiac and embolic events. The surgeon must be cognizant of the complications associated with both positions and take extra care in the initial patient setup and coordination with the anesthesiologist to minimize the risk of complications and morbidity.

Outcomes of arthroscopic anterior shoulder instability in the beach chair versus lateral decubitus position: a systematic review and meta-regression analysis

PURPOSE

This study aimed to systematically review the clinical outcomes and recurrence rates after arthroscopic anterior shoulder stabilization in the beach chair (BC) and lateral decubitus (LD) positions.

METHODS

The authors performed a systematic review of multiple medical databases using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All English-language literature from 1990 to 2013 reporting clinical outcomes after arthroscopic anterior shoulder stabilization with suture anchors or tacks with a minimum 2-year follow-up period were reviewed by 2 independent reviewers. Data on recurrent instability rate, return to activity/sport, range of motion, and subjective outcome measures were collected. Study methodological quality was evaluated with the Modified Coleman Methodology Score (MCMS) and the Quality Appraisal Tool (QAT). To quantify the structured review of observational data, meta-analytic statistical methods were used.

RESULTS

Sixty-four studies (38 BC position, 26 LD position) met inclusion criteria. A total of 3,668 shoulders were included, with 2,211 of patients in the BC position (average age, 26.7 ± 3.8 years; 84.5% male sex) and 1,457 patients in the LD position (average age, 26.0 ± 3.0 years; 82.7% male sex). The average follow-up was 49.8 ± 29.5 months in the BC group compared with 38.7 ± 23.3 months in the LD group. Average overall recurrent instability rates were 14.65 ± 8.4% in the BC group (range, 0% to 38%) compared with 8.5% ± 7.1% in the LD group (range, 0% to 30%; P = .002). The average postoperative loss in external rotation motion (in abduction) was reported in 19 studies in the BC group and in13 studies in the LD group, with an average loss of 2.4° ± 1.0° and 3.6° ± 2.6° in each group, respectively (P > .05).

CONCLUSIONS

Excellent clinical outcomes with low recurrence rates can be obtained after arthroscopic anterior shoulder stabilization in either the BC or the LD position; however, lower recurrence rates are noted in the LD position. Additional long-term randomized clinical trials comparing these positions are needed to better understand the potential advantages and disadvantages of each position.

LEVEL OF EVIDENCE

Level IV, systematic review of studies with Level I through Level IV evidence.

Inferior suture anchor placement during arthroscopic Bankart repair: influence of portal placement and curved drill guide

BACKGROUND

During arthroscopic Bankart repair, inferior anchor placement is critical to a successful outcome. Low anterior anchors may be placed with a standard straight guide via midglenoid portal, with a straight guide with trans-subscapularis placement, or with curved guide systems. Purpose/

HYPOTHESIS

To evaluate glenoid suture anchor trajectory, position, and biomechanical performance as a function of portal location and insertion technique. It is hypothesized that a trans-subscapularis portal or curved guide will improve anchor position, decrease risk of opposite cortex breach, and confer improved biomechanical properties.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty cadaveric shoulders were randomized to 1 of 3 groups: straight guide, midglenoid portal (MG); straight guide, trans-subscapularis portal (TS); and curved guide, midglenoid portal (CG). Three BioRaptor PK 2.3-mm anchors were inserted arthroscopically, with an anchor placed at 3, 5, and 7 o'clock. Specimens were dissected with any anchor perforation of the opposite cortex noted. An "en face" image was used to evaluate actual anchor position on a clockface scale. Each suture anchor underwent cyclic loading (10-60 N, 250 cycles), followed by a load-to-failure test (12.5 mm/s). Fisher exact test and mixed effects regression modeling were used to compare outcomes among groups.

RESULTS

Anchor placement deviated from the desired position by 9.9° ± 11.4° in MG specimens, 11.1° ± 13.8° in TS, and 13.1° ± 14.5° in CG. After dissection, opposite cortex perforation at 5 o'clock occurred in 50% of MG anchors, 0% of TS, and 40% of CG. Of the 90 anchors tested, 17 (19%) failed during cyclic loading, with a similar failure rate across groups (P = .816). The maximum load was significantly higher for the 3-o'clock anchors when compared with the 5-o'clock anchors, regardless of portal or guide (P = .021). For the 5-o'clock position, there were significantly fewer "out" anchors in the TS group versus the CG or MG group (P = .038). There was no statistically significant difference in maximum load among groups at 5 o'clock.

CONCLUSION

Accuracy in suture anchor placement during arthroscopic Bankart repair can vary depending on both portal used and desired position of anchor. The results of the current study indicate that there was no difference in ultimate load to failure among anchors inserted via a midglenoid straight guide, midglenoid curved guide, or percutaneous trans-subscapularis approach. However, midglenoid portal anchors drilled with a straight or curved guide and placed at the 5-o'clock position had significant increased risk of opposite cortex perforation compared with trans-subscapularis percutaneous insertion, with no apparent biomechanical detriment.

CLINICAL RELEVANCE

The findings from this study will facilitate improved understanding of risks and benefits of several techniques for arthroscopic shoulder instability treatment with regard to suture anchor fixation.

The low-anterolateral portal for arthroscopic biceps tenodesis: description of technique and cadaveric study

PURPOSE

Arthroscopic biceps tenodesis surgery is an important procedure for the correction of biceps tendonitis or in conjunction with rotator cuff repair with biceps symptoms. Recent trends have developed in placing the biceps tendon lower in the bicipital groove for a tenodesis. However, a more distal biceps tenodesis location is technically challenging when carried out arthroscopically with standard posterior and lateral portals. We aimed to establish the safety of a low-anterolateral portal location for direct access to the lowest aspect of the bicipital groove.

METHODS

An anatomical study design was used to examine portal to neurovascular structural measurements in 23 cadaveric shoulders. These shoulders had undergone low-anterolateral portal placement over the inferior most aspect of the bicipital groove as determined by palpation and direct arthroscopic visualization. No arthroscopic irrigation was performed. Following this, the shoulders underwent open dissection with the cannula in place to evaluate for any potential damage to any portion of the axillary nerve.

RESULTS

All of the resultant portals in this study provided direct access to the inferior most aspect of the bicipital groove, and the dissection revealed that the portal was touching a small distal axillary nerve branch on the undersurface of the anterior deltoid in nearly half of the shoulders.

CONCLUSIONS

The placement of a low-anterolateral portal for arthroscopic biceps tenodesis at the distal bicipital groove does not produce significant neurovascular damage; the portal trajectory comes close to distal anterior branches of the axillary nerve. Given these findings, this portal should be placed bluntly to best protect these underlying neurovascular structures.

Inferior anchor cortical perforation with arthroscopic Bankart repair: a cadaveric study

PURPOSE

The aims of this study were to evaluate the incidence of anchor penetration of the far cortex of the glenoid neck after arthroscopic Bankart repair and to compare the biomechanical properties of anchors in the 4- and 5:30- to 6-o'clock positions on the glenoid.

METHODS

Twelve (6 matched pairs) fresh-frozen human cadaveric shoulders were used to simulate arthroscopic Bankart repair in the lateral decubitus position. The most inferior anchor (5:30 to 6 o'clock) and that above it (4 o'clock) were inserted via the anteroinferior portal on the glenoid using the standard technique. After both anchor insertions, anchor perforation of the glenoid far cortex was identified. Biomechanical properties were measured to determine cyclic displacement of anchors at 100 and 500 cycles, stiffness, yield load, and ultimate failure strength.

RESULTS

All 12 suture anchors (100%) at 5:30 to 6 o'clock penetrated throughout the far cortex, whereas only 4 anchors (33%) at 4 o'clock did so (P = .005). The mean distance the anchor tip traveled into far cortex was significantly longer at 5:30 to 6 o'clock than at 4 o'clock (6.8 ± 1.6 mm v 2.0 ± 1.6 mm, P = .001). In terms of mechanical strength, anchors at 5:30 to 6 o'clock had greater 100- and 500-cycle mean displacements than those at 4 o'clock (3.0 ± 0.5 mm v 2.5 ± 0.3 mm, P = .018 for 100 cycles; 3.5 ± 0.7 mm v 2.8 ± 0.3 mm, P = .018 for 500 cycles), although no differences in ultimate failure strength after cyclic loading were found between 2 positions (133.4 ± 40.3 and 133.7 ± 29.2 N, respectively; P = .985).

CONCLUSIONS

For arthroscopic Bankart repair, insertion of the most inferior anchor via the anteroinferior portal with standard technique, in the lateral decubitus position, carries a high risk of perforating the inferior far cortex of the glenoid (100% in our study). This may result in mechanical weakness of the most inferior repair specifically in the early postoperative period.

CLINICAL RELEVANCE

Perforation of the glenoid far cortex by the most inferior anchor and its mechanical weakness should be taken into consideration. Further study is needed to improve surgical technique to place the most inferior anchor in an optimal position by arthroscopy.

Pathomechanisms and complications related to patient positioning and anesthesia during shoulder arthroscopy

The lateral decubitus and beach-chair positions each offer unique benefits to the shoulder surgeon with respect to visualization, efficiency, and ease during arthroscopic shoulder procedures. The purpose of this article was to comprehensively review the reports and studies documenting independent and dependent complications related to patient positioning and anesthesia during arthroscopic shoulder surgery. The lateral decubitus position has been associated with the potential for peripheral neurapraxia, brachial plexopathy, direct nerve injury, and airway compromise. The beach-chair position has been associated with cervical neurapraxia, pneumothorax, and the potential for end-organ hypoperfusion injuries (when deliberate hypotension is used). Potentially concerning are hypotensive bradycardic events, which may be relatively common in association with the use of epinephrine-containing interscalene anesthetics in beach chair-positioned patients. Irrigant complications (fluid spread, ventricular tachycardia) are avoidable risks not unique to either specific position. Although minor transient anesthetic- and position-related complications (neurapraxia, hypotension) may occur in as many 10% to 30% of patients, major complications such as end-organ damage or permanent impairments are exceedingly rare. Regardless of position, complications are almost uniformly avoidable if surgeon and anesthetist exercise care and prudent attention to position and anesthetic choices. The purpose of this article is to review the potential for position- and anesthesia-related complications and acquaint the shoulder surgeon with the proposed pathophysiologic mechanisms that can lead to them.

Arthroscopically assisted fixation of glenoid fractures: a cadaver study to show potential applications of percutaneous screw insertion and anatomic risks

BACKGROUND

Displaced glenoid fractures require reduction and internal fixation to avoid chronic instability or degenerative changes. Arthroscopically assisted percutaneous fixation has been performed successfully for such fractures, avoiding extensive surgical dissection. To assess the application of this new technique, our cadaveric study was designed to show 1) the safe zones of percutaneous screw insertion and 2) the position of bony obstructions to the glenoid.

METHODS

In 18 cadaver shoulders, we performed arthroscopically assisted percutaneous wire insertion into the glenoid using anterior, superior, and posterior approaches. After dissection, distances from wires to the relevant neurovascular structures were recorded, and 95% confidence intervals were calculated. A safe distance was defined as 15 mm. The entry point of each wire and angle of insertion relative to the glenoid clock face was also recorded.

RESULTS

Superior and posterior percutaneous approaches appear to be safe, with minimal risk to the suprascapular vessels and axillary nerve, respectively. The anterior approach injured the cephalic vein in 30% of specimens, and there was a clinically significant risk to the musculocutaneous nerve and inferior branch of the suprascapular nerve. The superior portion of the glenoid is accessible by percutaneous screw insertion between the clock times 7:40 and 2:50, apart from positions occupied by the coracoid (1:05-2:00) and acromion (9:35-10:55).

CONCLUSIONS

Arthroscopic fixation of complex glenoid fractures has had good outcomes in clinical case studies. This cadaveric study shows that percutaneous screw insertion is safe via superior and posterior approaches and feasible for a range of fracture configurations.

Complications in shoulder arthroscopy

Shoulder arthroscopy is generally a safe and effective method for treating a wide variety of shoulder pathology. Fortunately, complications following shoulder arthroscopy are rare, with reported rates between 4.6% and 10.6%.¹⁻⁷ These rates may be underestimated, as underreporting of complications and varying definitions of the term complication are likely. During shoulder arthroscopy, complications may occur at numerous points. The surgeon must be aware of potential problems and take necessary measures to prevent them. This article describes common complications after arthroscopic shoulder surgery. Although failure of treatment and postoperative stiffness are undesirable outcomes, they are not described.

An anatomic study of inferior glenohumeral recess portals: comparative anatomy at risk

PURPOSE

The purpose of this study was to describe the musculotendinous relations and neurologic structures at risk during establishment of posterior portals for access to the inferior glenohumeral recess (IGHR).

METHODS

Three 18-gauge spinal needles were used to establish 2 posteroinferior portals and 1 axillary pouch portal in 14 embalmed cadaveric shoulders, without joint distention and arthroscopic visualization. At dissection, musculotendinous structures traversed by the needles were recorded, and distances from the (1) axillary nerve (at the deltoid undersurface, quadrangular space, and capsule), (2) nerve to teres minor (at the inferior border of the teres minor muscle and at the capsule), and (3) suprascapular nerve were measured. Additional parameters studied included the vertical distances between the acromion and IGHR and between the acromion and axillary nerve. Statistical analysis (multiple comparisons procedure) was performed to compare relative portal safety.

RESULTS

The mean distance of the axillary pouch portal to the 3 nerves, at each level, was greater than that of the posteroinferior portals. In 1 specimen (7.1%), the posteroinferior portal tracts were in close proximity (within 2 mm) to the axillary nerve and its branch to the teres minor. The distance of the axillary pouch portal to the nerves was significantly greater (P < .05) at every level, except at the deltoid undersurface.

CONCLUSIONS

Our study suggests that posterior portal techniques described for access to the IGHR are safe; the risk of axillary nerve injury with posteroinferior portals is low, though possible. The axillary pouch portal is relatively farther away from the neurologic structures and provides safer access to the same region.

CLINICAL RELEVANCE

Arthroscopic procedures that require access to the IGHR can be safely performed with posteroinferior and axillary pouch portals. The axillary pouch portal may be used preferentially for this access because it is placed farthest from the neurologic structures.

The axillary pouch portal: a new posterior portal for visualization and instrumentation in the inferior glenohumeral recess

Arthroscopic access to the inferior glenohumeral recess is necessary in several surgical procedures on the shoulder. Posteroinferior portals described for access to this region may pose a theoretic risk to the posterior neurovascular structures (outside-in technique) and to the articular cartilage (inside-out technique). The first author (D.N.B.) has devised a new posterior portal that permits direct linear access to the entire inferior glenohumeral recess. The portal is placed higher and more lateral compared with the previously described portals; this places it further away from the posterior neurovascular structures and facilitates linear access to the axillary pouch. The portal is created via an outside-inside technique, with a spinal needle to ascertain the correct portal site and angulation. The portal is placed at a mean distance of 20.45 +/- 4.9 mm (range, 15 to 35 mm) directly inferior to the lower border of the posterolateral acromial angle and 21.3 +/- 2 mm (range, 20 to 25 mm) lateral to the posterior viewing portal. The spinal needle or cannula is angulated medially at a mean of 30.6 degrees +/- 4.7 degrees (range, 25 degrees to 40 degrees ) in the axial plane and slightly inferiorly (mean, 2 degrees ; range, 20 degrees superiorly to 20 degrees inferiorly). Use of 30 degrees and 70 degrees arthroscopes through the axillary pouch portal facilitates visualization of the entire recess and of the humeral attachment of the inferior glenohumeral ligament complex for evaluation of humeral avulsion of the glenohumeral ligament lesions. The portal also permits instrumentation in combination with the standard posterior or anterosuperior viewing portal for removal of loose bodies, synovectomy, capsular shrinkage, capsulotomy, and anchor placement in the posteroinferior glenoid rim.

Anatomic risks of shoulder arthroscopy portals: anatomic cadaveric study of 12 portals

PURPOSE

The purpose of this anatomic cadaveric study was to determine with trocars in situ the relationships of 12 shoulder arthroscopic portals frequently used with the adjacent musculotendinous and neurovascular structures.

METHODS

Twelve shoulders of embalmed cadavers installed in a beach-chair position were dissected. Twelve different portals were established by using their authors' description: posterior "soft point," central posterior, anterior central, anterior inferior, anterior superior, 5 o'clock portal, Neviaser, superolateral, transrotator cuff approach, Port of Wilmington, anterolateral, and posterolateral. Six of these portals were placed on each shoulder so that each portal was studied 6 times. Dissections were conduced with trocars in situ to take into account their volume. The distance to the adjacent relevant neurovascular structures at risk (axillar and suprascapular nerves, axillar and suprascapular arteries, and cephalic vein) were measured, arm at side, by using a calliper. Musculotendinous structures crossed by portals were noticed.

RESULTS

The cephalic vein was injured twice by anterior portals. The 5 o'clock portal is at most risk of neurovascular injury. It is located at mean distances to the axillar artery and nerve of 13 and 15 mm, respectively. Other anterior, posterior, superior, and lateral portals are safe with mean distances higher than 20 mm. No musculotendinous rupture nor large injury occurred.

CONCLUSIONS

The present study shows that the trocars placement of the studied portals did not create, except for the cephalic vein, any lesion of the neurovascular adjacent structures.

CLINICAL RELEVANCE

This study suggests, except for the 5 o'clock portal, the safety of the shoulder arthroscopic portals tested regarding to the neurovascular adjacent structures.

A comparison of risk between the lateral decubitus and the beach-chair position when establishing an anteroinferior shoulder portal: a cadaveric study

PURPOSE

The purpose of this study was to assess, using a technique that minimally distorts the normal anatomy, the risk of injury when establishing a 5 o'clock shoulder portal in the lateral decubitus versus beach-chair position.

METHODS

The anteroinferior portal was simulated with Kirschner wires (K-w) drilled orthogonally at the 5 o'clock position in 13 fresh frozen human cadaveric shoulders. The neighboring neurovascular structures were identified through an anteroinferior window made in the inferior glenohumeral ligament. Their relations to the K-w and surrounding structures were recorded in both positions.

RESULTS

The median distance from the musculocutaneous nerve to the K-w was shorter in the lateral decubitus position than in the beach chair position (13.16 mm v 20.49 mm, P = .011). The cephalic vein was closer to the portal in the beach-chair position than in the lateral decubitus position (median 8.48 mm v 9.93 mm, P = .039). The axillary nerve was closer to the K-w in the lateral decubitus position than in the beach-chair position (median 21.15 mm v 25.54 mm, P = .03). No differences in the distances from the K-w to the subscapular and anterior circumflex arteries were found when comparing both positions. The mean percentage of subscapular muscle height from its superior border to the K-w was 53.03%.

CONCLUSIONS

This study showed the risk of injury establishing a transubscapular portal in either position. The musculocutaneous nerve and the cephalic vein are the most prone to injury. In general, the beach-chair position proved to be safer.

CLINICAL RELEVANCE

Inserting anchor devices orthogonally would permit stronger fixation but presents the risk of damaging neurovascular structures. This study focused on showing the neurovascular risk of performing full orthogonal insertion. Considering the good results reported with the usual superior-anterior portals, we do not recommend performing a transubscapular portal in routine shoulder arthroscopy.

The superior-medial shoulder arthroscopy portal is safe

PURPOSE

The superior-medial (SM) shoulder arthroscopic portal (Neviaser portal) is the portal anatomically closest to the suprascapular nerve, and any potential benefits of this portal would be mitigated if risk of suprascapular nerve injury were significant. The purpose of this study is to determine the safety of the SM arthroscopic shoulder portal. We hypothesize that the SM shoulder arthroscopic portal is safe.

METHODS

Twelve fresh cadaveric shoulders were securely positioned to simulate shoulder arthroscopy in the beach-chair position with the arm at the patient's side in neutral rotation. An SM portal was established 1 cm medial to the acromion and 1 cm posterior to the clavicle, and a 5.5-mm burr sheath was oriented toward the acromioclavicular joint. The skin and trapezius were resected, the supraspinatus was retracted, and the suprascapular nerve was identified. The distance between the sheath and the nerve was measured by 2 independent observers with calipers. A safe distance was defined as 10 mm.

RESULTS

The measured distances between the nerve and burr ranged from 18.5 to 35.7 mm, with a mean of 24.2 +/- 5 mm. The distance is significantly greater than the safe distance of 10 mm (P < .0001).

CONCLUSIONS

This study shows that the SM portal is safe. The distance between an instrument oriented toward the acromioclavicular joint via the SM portal and the suprascapular nerve was 18.5 mm or greater in all specimens.

CLINICAL RELEVANCE

Our study has clinical relevance because the SM portal is useful for arthroscopic rotator cuff repair, arthroscopic superior labrum repair, and arthroscopic distal clavicle excision.

The accessory posteromedial portal revisited: utility for arthroscopic rotator cuff repair

Arthroscopic rotator cuff repair is a technically challenging procedure. Accessory arthroscopic portals have been described that allow for optimal suture anchor placement, suture management, and knot tying. We describe here the usefulness of an accessory posteromedial portal that facilitates direct suture retrieval through the posterior aspect of a rotator cuff tear. This portal is created approximately 4 to 5 cm medial to the posterolateral corner of the acromion and 2 cm inferior to the scapular spine. The accessory posteromedial portal is especially useful when a retracted tear of the infraspinatus or teres minor is encountered. Because these tendons retract in a posterior and medial direction, the accessory posteromedial portal places the tendon-penetrating device in an ideal position for suture passage through the posterior portion of the rotator cuff tear. This portal also allows placement of margin convergence sutures for large U-shaped or L-shaped tears by permitting a direct "hand-off" of the suture to or from a second penetrating device that is placed through a standard anterior portal. If multiple suture anchors are required (as in the case of large or massive cuff tears, or when double-row fixation is employed), sutures can be pulled out through the accessory posteromedial portal to facilitate suture management.

Glenohumeral arthroscopy portals established using an outside-in technique: neurovascular anatomy at risk

PURPOSE

The purpose of this study was to examine the neurovascular structures at risk during placement of glenohumeral arthroscopy portals using an outside-in technique.

TYPE OF STUDY

Anatomic cadaveric study.

METHODS

Five fresh-frozen cadaveric specimens were used in this study. Each shoulder was mounted on a custom-designed apparatus allowing shoulder arthroscopy in a lateral decubitus position. The following portals were established using an outside-in technique and marked using an 18-gauge spinal needle: posterior, posterolateral, anterior, 5-o'clock, anterosuperolateral, and Port of Wilmington. Each specimen was carefully dissected after the procedure, and the distance from each portal site to the adjacent relevant neurovascular structures (axillary nerve, musculocutaneous nerve, lateral cord of the brachial plexus, cephalic vein, and axillary artery) was measured using a precision caliper.

RESULTS

Except for the cephalic vein, all of the neurovascular structures were more than 20 mm away from all the portals evaluated. When creating either an anterior portal or a 5-o'clock position portal, the mean distance from the portal to the cephalic vein was 18.8 mm and 9.8 mm, respectively. In one anterior portal, a direct injury to the cephalic vein occurred.

CONCLUSIONS

Our study suggests that shoulder arthroscopy portals placed in an outside-in fashion are unlikely to produce neurologic injury. However, the cephalic vein is at risk during placement of an anterior or 5-o'clock position portal, although probably with minimal subsequent patient morbidity. Placing portals in an outside-in fashion guarantees the correct angle of approach, with minimal risk to adjacent neurologic structures.

CLINICAL RELEVANCE

This study shows the safety of standard and accessory glenohumeral arthroscopy portals.

Differential arthroscopic portal placement for rotator cuff repair

We report an effective technique of arthroscopic portal placement for rotator cuff repair of the shoulder. The differential portals are placed depending on the location of the tear. After the glenohumeral arthroscopic examination, the subacromial bursoscopy is performed through the same posterior skin portal. With the rotator cuff tear in view, a spinal needle is inserted to the center of the tear, 3 cm from the lateral margin of the acromion (middle working portal). Another spinal needle is then inserted into the posterior lip of the tear, 1 cm from the lateral margin of the acromion (rear viewing portal). The rear viewing portal provides a good downward en-face view of the tear, and the middle working portal allows better access to the anterior and posterior margins of the cuff tear than the usual posterior and lateral portals do. This differential portal placement with respect to the location of the rotator cuff tear ensures superior access for arthroscopic repair of rotator cuff tears.

The 7-o'clock posteroinferior portal for shoulder arthroscopy

BACKGROUND

Access to the inferior glenohumeral joint of the shoulder is very limited through the traditional 2- or 3-o'clock anterior portals.

HYPOTHESIS

The 7-o'clock posteroinferior portal offers an excellent alternative approach.

STUDY DESIGN

Descriptive anatomic study.

METHODS

Six paired cadaveric shoulders were used to arthroscopically develop and test a 7-o'clock posteroinferior portal. The distances between the portal and the subscapular and axillary nerves were measured with the arm in six different positions, combining flexion, extension, abduction, and adduction.

RESULTS

The distance from the 7-o'clock posteroinferior portal to the axillary nerve was 39 +/- 4 mm and to the suprascapular nerve was 28 +/- 2 mm. There was no statistically significant nerve-to-portal differential distance when the arm was placed in flexion, extension, abduction, or adduction. The inside-to-outside technique produced a 7-o'clock posteroinferior portal approximately 5 mm further from both the axillary and suprascapular nerves than did the outside-to-inside method. The angle of divergence from the 7-o'clock posterior portal skin incision to the axillary nerve was 47 degrees and to the suprascapular nerve was 33 degrees.

CONCLUSIONS

The 7-o'clock portal affords safe, direct working access to the inferior capsular recess of the glenohumeral joint.

CLINICAL RELEVANCE

The 7-o'clock portal is a safe and effective technique for use by shoulder surgeons.

The accessory posterior portal for shoulder arthroscopy: Description of technique and cadaveric study

As the indications for shoulder arthroscopy continue to expand, so too does the need for complete access to the glenohumeral joint. Specific regions of the joint, including the axillary recess, are often times difficult to access using traditionally described posterior and anterior portals. In this article, we describe a technique for the placement of an accessory posterior portal into the inferior hemisphere of the glenohumeral joint, effectively in the 8 o'clock or 4 o'clock position. To demonstrate the safety and effectiveness of this portal, 6 cadaveric specimens were dissected after the placement of a standard and accessory posterior portal. The proximity of the posterior portals to the axillary and suprascapular nerves was analyzed. Measurements were made in simulated beach-chair and lateral decubitus positions. The authors show that the accessory posterior portal is safe to use and may prove useful to the surgeon who wishes to gain access to the inferior recesses of the glenohumeral joint.