Anatomy of the supraclavicular fossa portal in shoulder arthroscopy

Drilling through lateral transmuscular portal lowers the risk of suprascapular nerve injury during arthroscopic SLAP repair

PURPOSE

The aim of our study was to evaluate the risk of medial glenoid perforation and possible injury to suprascapular nerve during arthroscopic SLAP repair using lateral transmuscular portal.

METHODS

Ten cadaveric shoulder girdles were isolated and drilled at superior glenoid rim from both anterior-superior portal (1 o'clock) and lateral transmuscular portal (12 o'clock) for SLAP repairs. Drill hole depth was determined by the manufacturer's drill stop (20 mm), and any subsequent drill perforations through the medial bony surface of the glenoid were directly confirmed by dissection. The bone tunnel depth and subsequent distance to the suprascapular nerve, scapular height and width, were compared for investigated locations.

RESULTS

Four perforations out of ten (40 %) occurred through anterior-superior portal with one associated nerve injury. One perforation out of ten (10 %) occurred through lateral transmuscular portal without any nerve injury. The mean depth was calculated as 17.6 mm (SD 3) for anterior-superior portal and 26.5 mm (SD 3.6) for lateral transmuscular portal (P < 0.001).

CONCLUSIONS

It is anatomically possible that suprascapular nerve could sustain iatrogenic injury during labral anchor placement during SLAP repair. However, lateral transmuscular portal at 12 o'clock drill entry location has lower risk of suprascapular nerve injury compared with anterior-superior portal at 1 o'clock drill entry location.

A cadaveric analysis of the arthroscopic fixation of anterior and posterior SLAP lesions through a novel lateral transmuscular portal

PURPOSE

To compare the most commonly used portals with a novel, lateral transmuscular portal for the treatment of anterior and posterior SLAP lesions.

METHODS

Six paired cadaveric shoulders underwent arthroscopy to assess 3 different instrumentation portals: the anterior-superior lateral (AL) portal, the Neviaser (N) portal, and the Rothman-lateral (RL) transmuscular portal. After each portal was established, 5-mm cannulas were inserted followed by guidewire-assisted placement of implant fixation instruments. Each shoulder was then dissected to assess the relation of the instruments to the surrounding anatomic structures.

RESULTS

When the AL portal was used, instrumentation consistently passed through the rotator interval. When the N and RL portals were used, instrumentation penetrated the rotator cuff muscle belly at a mean distance of 25.75 and 7.67 mm, respectively, from the tendon. The mean angles of entry into the glenoid rim with respect to the glenoid articular surface were 32 degrees, 38 degrees, and -6 degrees for the AL, RL, and N portals, respectively. There was no violation of subchondral bone; however, 2 specimens showed weakened articular surfaces with use of the N portal. The RL portal was the only portal that allowed placement of instrumentation into all 3 zones of the superior glenoid rim (anterior superior, direct superior, and posterior superior) without violation of the subchondral bone and at the recommended 30 degrees to 45 degrees angle of entry.

CONCLUSIONS

The RL portal provides a safe and efficient method of arthroscopic fixation and knot tying of anterior and posterior SLAP lesions by use of a single instrumentation portal.

CLINICAL RELEVANCE

This novel, lateral transmuscular portal allows optimal angles of implant placement in all areas of the superior glenoid and provides a direct, simplified approach for arthroscopic knot tying.

The bony partial articular surface tendon avulsion lesion: an arthroscopic technique for fixation of the partially avulsed greater tuberosity fracture

The partial articular surface tendon avulsion (PASTA) is a common lesion that involves the supraspinatus tendon in most cases. We present an arthroscopic fixation technique for a previously undescribed lesion that may be considered a variant of the PASTA. The lesion involves a partial avulsion of the greater tuberosity with an intact deep insertion of the supraspinatus tendon into the fractured bone fragment and an intact superficial insertion of the supraspinatus into the unavulsed lateral aspect of the greater tuberosity: a "bony PASTA" lesion. The surgical technique involves the use of a 70 degree arthroscope to provide an "end-on" view of the pathology. A superior-medial transmuscular portal is used for anchor insertion and suture management; the portal avoids damage to the intact tendinous insertion of the supraspinatus, which can occur during transtendon anchor/screw insertion. Abduction of the arm to 50 degrees, after creation of the portal and passage of the cannula, permits an optimal "deadman" angle of anchor placement. An angled suture grasper is used to retrieve the 4 suture strands from the double-loaded suture anchor through the intact superficial and deep supraspinatus tendon fibers along the length of the fracture; these are tied as 2 mattress sutures over the tendon fibers in the subacromial space by use of sliding-locking knots. Adequacy of reduction is confirmed by intra-articular arthroscopic observation during movement of the extremity through its complete range of motion.

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.

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 new subclavian portal and modified Neviaser portal for arthroscopic rotator cuff repair

Shoulder arthroscopy and the introduction of suture anchors has provided the surgeon with the ability to repair rotator cuff tears through minimal incisions. Rotator cuff repair involves the use of several portals, such as the posterior portal, the anterior portal, the anterior superior portal, the anterior inferior portal, and the Neviaser portal. The authors have developed 2 additional portals, the new Subclavian portal and the modified Neviaser portal, to improve the safety and efficacy of rotator cuff repair and solve a number of problems associated with traditional repair techniques. The subclavian portal is located directly below the clavicle, 1 to 2 cm from the acromioclavicular joint, and instruments are aimed medial to lateral. The modified Neviaser portal changes the angle of insertion of the Neviaser portal. Instruments are aimed 20 degrees from the horizontal plane and 45 degrees anterior, directly at the suture anchor. Repair techniques using each portal were reviewed. Twenty cadaveric shoulders were dissected for each portal and the anatomy from each portal was documented. The cadaveric dissections showed that this portal passes greater than 6 cm from the brachial plexus, musculocutaneous nerve, and subclavian artery and vein, and 4.7 cm from the cephalic vein. The modified Neviaser portal was shown to be safer than the Neviaser portal because it passes on top of the supraspinatous muscle, thereby protecting the suprascapular nerve. These portals provide an optimal angle of approach to the rotator cuff tendon and suture anchor as well as improved safety and efficacy in the repair of rotator cuff tears.

An arthroscopic technique for confirming intra-articular subluxation of the long head of the biceps tendon: the ramp test

The purpose of this technical note is to introduce the ramp test and explain this arthroscopic technique. The ramp test is used to test the integrity of the soft tissue restraint to intra-articular subluxation of the long head of the biceps tendon. Injury to the soft tissue restraint, the hidden lesion, has been proposed as occurring in conjunction with a full-thickness rotator cuff tear. Both cadaveric dissections and arthroscopic patient assessments were conducted to develop the ramp test. In this study, 17 patients also presented with refractory anterior shoulder pain and underwent arthroscopy to further characterize the ramp test. An abnormal examination result showed that the long head of the biceps tendon translated medially and inferiorly across the humeral head. In addition, this subgroup of 17 patients all had an abnormal ramp test but did not have a full-thickness rotator cuff tear. The ramp test is now applied to all arthroscopic procedures by the senior author, and we recommend its use for arthroscopic confirmation of intra-articular subluxation of the long head of the biceps tendon. Thus, we advocate that an abnormal ramp test result indicates pathology and warrants the surgical removal of the long head of the biceps tendon from the glenohumeral joint.

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 use of the supraclavicular fossa portal in arthroscopic rotator cuff repair

SUMMARY

Advances in arthroscopic technology allow rotator cuff repair through a minimally invasive approach. However, fixation of the rotator cuff tendon to suture anchors can be tedious and time consuming. The supraclavicular fossa portal allows improved access to the tear for passing suture. The authors describe the relevant anatomy, positioning, and surgical technique for use of the supraclavicular fossa portal to simplify arthroscopic rotator cuff repair.

Acromial compromise with use of a transacromial portal: a biomechanical study

In an experimental evaluation with 14 paired cadaveric scapulae we found that the transacromial arthroscopy portal, used occasionally in the repair of superior labral lesions, will reduce the structural integrity of the acromion to approximately 60% (range 25% to 85%) of its original strength, thereby placing it at increased risk of fracture. These studies provide baseline biomechanical information and suggest that limited shoulder activity is indicated after use of this portal.

Complications in arthroscopic surgery of the knee and shoulder

Arthroscopy is a valuable technique used by the majority of orthopedic surgeons in practice. Complications in arthroscopy have been compiled on a formal basis since 1983. Several studies on complications are reviewed and summarized. A recent prospective study on complications is reviewed in detail. The most frequent type of complication encountered in arthroscopic surgery is hemarthrosis. The procedure with the highest complication rate is the lateral retinacular release. Technical considerations are discussed which would be useful in lessening the incidence of complications in arthroscopy.