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Delta Shoulder

Please note that information on this site was NOT authored by Dr. Frederic A Matsen III and has not been proofread or intended for general public use.  Information was intended for internal use only and is a compilation for random notes and resources.

If you are looking for medical information about the treatment of shoulders, please visit shoulderarthritis.blogspot.com for an index of the many blog entries by Dr. Frederick A Matsen III.

Delta Xtend Technique Guide

Equipment Needed

1. DePuy Delta Xtend tools
2. From DePuy Delta set - "Delta Extras" set
   1. Impactor handle with simulated wood grip
   2. Ball impactor head
   3. Cup impactor head
   4. Humeral cutting guide
   5. Forked Homan retractors x 2
3. Matsen special humeral reamer set
4. Cement
   1. 1.5 pack Simplex cement
   2. Cement gun
   3. Selection of narrow cement tips
   4. 2 grams vancomycin
5. Long tipped irrigator
6. Regular Matsen shoulder arthroplasty tools and supplies
7. Depuy Sounds cement restrictor set and set of restrictors

Setup

Place templated x-rays, clinic notes and progress note on x-ray box.

Prefill-out orders and setup pt in a beach chair position.  The operative arm should be able to hang off bed as shown below.

You should circumferentially wrap cloth tape around the patient's chest and table to prevent pulling the patient off of the table during the surgery.  This taping is in addition to use of the patient's normal safety belt.

You should NOT be using the old RA table of Beachchair attachment for this case.  If for some reason you are using these systems (such as to help with fluoro) DO NOT REMOVE THE SHOULDER SUPPORT!  Removing the shoulder support under the operative side may seem like a good idea but the patient will eventually migrate off of the table.

The anesthesia team and ortho team should work together to tape the patient's head down.  You may need to use a clipboard to support the head (if using the RA table or Beachchair attachment).  We do not secure the head in a brace as shown above.

A 1010 drape should be secured around the patients neck and the free end secured to the tape holding the patients head.  Securing the free end prevents it from falling onto the sterile field when prepping.

ROM of the operative shoulder should be measured and recorded on the board in the following order: FE, ER, IRA, ERA, CBA.

Double Prep

A member from the ortho team needs to wash and gown and prep the patient's operative side.  ChloraPrep is the prep of choice.

Prep from the middle of the chest out to the wrist, followed by armpit, followed by wrist, hand and fingers.  This should be done a total of three times.

The first drape is setup under the patients head, operative arm and over the patient's waist.  If possible, the drape should be tucked under the patient's belt.  This draping is done by the nursing staff or other member of ortho team.

The first set of gloves are removed and the second prep is performed in the same manner as the first.

The second drape is setup over the first in the same manner.

Draping

After the two initial drapes are placed under the head shoulder and over the waist, one drape is place over the chest and feet.  This should go from the patient's armpit to the patient's neck.

Another drape is placed over the head and overlaps across the chest drape.

The three corners where these drapes come together are stapled.  There is no need to staple the drapes directly to the patient.

The arm should be covered with a stockinet and a dry sponge placed in the patient's axilla.

The deltopectoral  interval should be blunt dissected with the surgeon's index finger, taking the vein laterally.  Make an effort to preserve as much deltoid muscle as possible.

The motion interface under the deltoid and pectoralis should be freed up and the conjoined tendon located.

Remember to free up the conjoined tendon on its lateral side so that the tendon can be retracted medially.  Incising into anything medial to the lateral border of the conjoined tendon can result in musculocutaneous nerve injury.

When the lateral border of the conjoined is freed up, use a medium Richardson retractor to pull the conjoined medially.  Use a Balfour to expose the rotator cuff /superior humerus.

Bursa should be removed to better visualize the subscapularis.  Identify the long head bicep tendon and plan to free the subscapularis as close to and medial to the biceps without cutting it.  If surgery is for rotator cuff arthropathy, it is likely that the long head biceps will not be in its anatomical position.

Free the subscapularis from the humerus and tag stitch it twice.  Once it has been sufficiently freed, the humeral head should easily dislocate.

The manufacture recommends humeral reaming at this point, but this can be done later if the surgeon chooses to use the old Delta humeral cutting instead of the new complex cutting system.

Use the humeral cutting guide from the old DePuy Delta set to mark the cut angle on the humeral head.  Make sure you are holding the arm at 0° of retroversion.  After marking your cutting line with the bovi, remove the cutting guide.

Note: some surgeons may wish to start their cut with the cutting guide in place.  With this method, the cut is started and the cutting guide is later removed to allow the blade to complete its cut.

Use a saw to carefully cut the humeral head.  The trigger on the saw is configured for variable speed.  Careful trigger control will allow you to control the speed of your saw and allow for a more controlled and precise cut.

The fancy cut protector shown left may be used at the discretion of the surgeon.  This device may obstruct visualization of the glenoid but it allows for the DePuy Xtend forked Homan to lever on the humerus with less chance of crushing it.

Glenoid

Use Homan and double Homan retractors to expose the glenoid.

Determine where the spine of the scapula is and stick the double Homan retractor there to mark your spot.

Assemble the metaglene positioner by inserting and threading the internal rod into the positioner handle.  Do so by inserting the hex head tip of the handle in the corresponding plate hole (right or left depending on the shoulder being operated upon) and lock the assembly by tightening the internal rod.   For right shoulders, the positioner handle should be placed in the 2 o'clock hole.   For left shoulders, the postioner handle should be placed in the 10 o'clock hole.

Position the plate as low as possible so that its border follows the inferior edge of the glenoid.    The guide plate should be held perpendicular to the plane of the glenoid face. Make sure that the proximal handle of the instrument is not tilted superiorly. The guide pin should be inserted either perpendicularly to the glenoid face or with the distal tip of the guide pin in a slightly superior direction. This ensures that the glenosphere will either be perpendicular to the plane of the glenoid face or have a slight inferior tilt which may reduce the risk of scapular notching.

Remove the metaglene positioner, leaving the guide pin in place.

Ream the superior glenoid bone by hand, using the manual 42 mm glenoid reamer. This step is necessary to avoid any potential conflict between the glenosphere and the superior area of the glenoid bone.  Manual reaming should be carried out until the central part of the manual reamer is in full contact with the curved central glenoid surface.   Use the manual glenoid reamer to ream the glenoid anteriorly, posteriorly and inferiorly if necessary. A smooth surface without any remaining cartilage should be obtained.

Check the adequacy of the reaming by applying the glenoid reaming level checker on the glenoid surface. No space (except if due to bone erosion) should be seen between the instrument and the glenoid surface.

Assemble the internal rod of the metaglene holder in the metaglene holder main body. Insert the metaglene holder hex tip in the final metaglene implant central hole and tighten the assembly.

Place the metaglene on the glenoid bone and ensure that the metaglene is fully seated.  Apply bone graft if necessary to help fill surface irregularities between the metaglene and the glenoid bone.  Rotate the metaglene so that the inferior screw can be aimed toward the scapular neck.  The vertical metaglene marking should be aligned with the scapular neck inferiorly and with the base of the coracoid process superiorly (long axis of the glenoid bone).  The metaglene peg is 0.6 mm larger in diameter than the drill to enable a press fit.  With a mallet, gently impact in the proper orientation for inferior screw placement and then remove the metaglene holder.

Locking metaglene screws allow an angulation of ± 10 degrees around the optimal 17° screw positioning recommended by Professor Grammont.

Place the 2.5 mm drill guide in the metaglene inferior hole. The drill guide can be angled to ± 10 degrees but should always be seated fully in the metaglene hole. Palpate the scapular neck and aim into good bone. Using the 2.5 mm drill bit, start drilling through the subchondral bone to aproximately 10 to 12 mm deep. Then stop drilling and push gently on the drill bit to make sure that the drill is contained in the bone. Redirect and re-drill if uncontained. When a satisfactory drilling direction has been obtained, drill and push until the cortex is perforated.

The goal is to have a sufficiently long screw inferiorly, usually 36 mm or more. The length of the screw is indicated on the drill bit by laser markings. The screw depth gauge can also be used to assess optimal screw length.

Use of the guide pin is optional and may or may not be used.  If used, insert the 1.2 mm guide pin through the drill guide and then remove the drill guide.  Slide the locking screw of the appropriate length onto the guide pin. Check that the internal tightening screw is unlocked (It should rotate freely).  Slide the locking screwdriver body on the guide pin and insert the tip into the 4 slots on the screw.   The manufacture does not recommend use of the internal screwdriver rod at this stage but it is difficult to control the screw without locking it to the driver.  You can lock the screw to the drive by sliding down the screwdriver sleeve completely to protect the screw head and tightening the internal screwdriver rod to lock it on the sleeve.  The internal screwdriver rod should be removed prior to handing tool to the surgeon.

Tighten the screw to compress the plate.

If used, remove the screw guide pin before final tightening to avoid stripping, making sure that the internal locking screw stays in place.

Repeat the same steps for the superior locking screw.   Drill the hole for the superior locking screw anticipating exit through the far cortex.  The superior screw should be directed at the base of the coracoid process and should have an anterior orientation to avoid the suprascapular nerve.   To obtain optimal compression of the metaglene plate on bone, alternate tightening of the superior and inferior locking screws.

The surgeon may use locking or non-locking screws in the anterior or posterior holes. Both types of screws will allow an angulation of up to ± 10 degrees, but not in a direction convergent to the central peg axis to avoid conflict with the central peg.     Use the 2.5 mm drill bit with the drill guide to set the most appropriate angle for ensuring that each screw is located in reliable bone stock.  The preferred position is usually chosen by palpating the anterior and posterior aspects of the scapula as well as examining the X-rays.

The surgeon may wish to use a guide pin to align the screw, or simply remember the angle of the drill prior to screwing in your screw.   Slide the corresponding screws onto the guide pin, if used, and tighten using the 3.5 mm cannulated hex screwdriver for non-locking screws (white handled driver) or the locking screwdriver for locking screws.   Follow the same procedure for the posterior screw, then alternately tighten both screws until they are fully tightened.

If you choose to lock your screws onto the driver, you will need to loosen the locking inner screws of each locking screw and retighten the outer screws.

Proceed with locking all variable angle screws used. Place the locking screwdriver main body in the head of the inferior screw.  Make sure that the screwdriver sleeve is in its upper position and not in contact with the screw head.  Slide the locking screwdriver internal rod into the main body. The tip of the internal rod will make contact with the screw head. Tighten it fully, locking the screw in place by expanding its head.   Repeat the same steps to secure the superior locking screw and anterior or posterior screws if variable angle screws have been used. The metaglene is left in place and the humeral preparation is then carried out.

Humeral Component

Continue to ream sequentially until the reamer just begins to bite on the cortical bone of the intramedullary canal of the humerus.  CTA bone is often on the soft side so make a note of not over reaming.

Select the appropriate proximal reaming guide size. For example, if a 12 mm intramedullary reamer and a 12 mm cutting handle were previously used, select the 12 mm proximal reaming guide.  Slide and screw the internal rod of the reaming guide holder into the holder main body. Then slide the reaming guide into the reamer holder and fasten the two parts together by firmly tightening the upper round handle.

Push the holder horseshoe plate fully down.

Slide the proximal reaming guide down into the intramedullary canal, rotating it if necessary to ensure that the horseshoe plate sits flat on the bone resection surface.  Drive the proximal reaming guide down until complete contact between the metal block and the resectioned bone surface is achieved.

Unscrew the upper round handle of the holder and remove the holder, leaving the proximal reamerguide in place.

Unless you are using a size 8 stem, which only comes with a number 1 head.  The monobloc implant size should be chosen to match the initial distal reaming diameter.  Choose the most appropriate epiphysis size by placing a monobloc implant sizer disk in size 1 (Yellow) or 2 (Blue) on the proximal reaming guide. The most appropriate size will be the sizer disc that provides the best possible coverage of the bone resection surface.  The size chosen, epiphysis size 1 or 2, will determine proximal reamer and final implant sizes.

Select the appropriate proximal reamer for the monobloc implant, size 1 or 2, from the results of the previous trials. Ream the metaphysis using a hand reamer.  The manufacture recommends power reaming but CTA patients often have soft bone and power may be overkill and dangerous.

Trialing

Select the appropriate trial humeral implant. For example, if the initial distal reaming was carried out using the 12 mm reamer and proximal reaming was carried out using the size 1 proximal reamer, select monobloc humeral trial epiphysis number 1 with diameter 12 mm.

Mount the trial implant on the humeral implant driver and drive it down the intramedullary canal.  The implant orientation should be checked by making sure that the arm is held at 0 degrees of retroversion and face of the prosthesis is lined up with the axis of the body.

With everything aligned properly, drive the trial implant down.  Impact the trial implant by gently tapping the implant driver handle and remove the driver, leaving the trial implant in place. The driver is detached by pushing on the blue button.

The glenosphere implants are available in two diameters, 38 mm and 42 mm, and are either standard or eccentric spheres.  We generally use a 38mm standard sphere.

Fit the appropriate trial glenosphere to the the metaglene using the metaglene holder if necessary.   The surgeon may wish to use the cup impactor to set the trial.

For eccentric glenospheres, the vertical laser mark on the trial glenosphere should be aligned with the base of the coracoid superiorly and the scapular neck inferiorly.  The arrow indicates the position of the eccentricity and should be positioned inferiorly, aligned with the scapular neck.   The surgeon has the option of trialing the eccentric head in a direction other than directly inferior, but may create a situation where glenoid notching will become a larger concern later on.

An overlap of 3 to 5 mm is recommended by the manufacture to avoid conflict with the scapular neck.  Depending on the shape of the scapular neck, this overlap can be achieved by using a standard metaglene just by lowering the metaglene.  The largest 42mm glenosphere is recommended by the manufacture if the size of the joint (allows to increase both the overlap and the range of motion). The eccentric glenospheres are recommended by the manufactures for more transverse scapular necks.  We will generally use a 38mm gleonsphere.

Place the humeral trial cup (38 or 42 mm depending on the glenosphere size), with +3 mm of lateral offset, in the trial epiphysis.  The shoulder should then be reduced with longitudinal traction and assessed for a full range of motion.

Joint tensioning and stability assessment should be performed with particular care, using the following manufacture's guidelines:

• Tension within the conjoined tendon should be noticeably increased and detectable by palpation.
• With the arm in a neutral position, apply a longitudinal traction force to the arm while observing the movement of the shoulder with respect to the entire shoulder girdle as well as the trial prosthetic joint. Tension is appropriate if, in response to the longitudinal traction, the entire shoulder moves before detectable separation of the trial prosthetic surfaces.
• External rotation may appropriately demonstrate slight gapping between the glenosphere and articular surface (2 to 3 mm maximum).
• Positioning a hand or fist near the axilla to serve as a fulcrum, further adduct the arm and look for undesirable tendencies to sublux or dislocate laterally (a small opening of 2 to 3 mm is acceptable). Estimate the maximum forward elevation.
• Assess stability at 90 degrees, abduction with the humerus in neutral, maximum internal and maximum external rotation. Estimate the maximum forward elevation15.

• a thicker cup (+6 mm or +9 mm)
• a 42 mm glenosphere.
• a modular humeral lengthener or retentive cups in more extreme cases.

If unable to reduce the joint, the options include additional soft tissue releases and lowering the level of humeral resection. When the trials are satisfactory, the trial glenosphere should be removed using the extraction T-Handle so that final implant fixation can be performed.

Depending on space constraints, either the glenoid or humeral components can be secured next.

Glenoid Component Emplacement

Insert the 1.5 mm guide pin through the central hole of the metaglene.  Note - this is not the same pin used earlier to guide glenoid reaming.   Engage the 3.5 mm cannulated hex screwdriver in the final glenosphere. Slide the glenosphere on the 1.5 mm guide pin until it is in contact with the metaglene. Proper alignment between the glenosphere and metaglene is absolutely essential to avoid cross threading between the components.   Make sure that there isn't any soft tissue that may become trapped between the metaglene and glenoid sphere.

The arrow marked on the orientation guide should be aligned with the base of the coracoid process to position the eccentricity correctly.  Maintain the orientation guide in the required position and screw the glenosphere into place using the screwdriver until the glenoid bearing closes on the taper of the metaglene.

If the glenosphere seems difficult to thread onto the metaglene, do not force engagement but re-align the components. If necessary, remove the inferior retractor or improve the capsular release. It is also important to check that there is no soft tissue between the metaglene and glenosphere.

Tighten until the scapula begins to rotate slightly in a clockwise direction, meaning that the glenoid bearing is closing on the taper of the metaglene.

Gently tap on the glenosphere with the glenosphere impactor a minimum of three times.  Tighten the glenosphere central screw again.  Care should be taken to ensure that the glenoid bearing is fully locked onto the metaglene.  The gentle hammering procedure and screw tightening can be repeated, if necessary, until the screw is fully tightened.

Humeral Component Cementing

Remove the trial cups and trial implants using the humeral implant driver. Select the appropriate final monobloc humeral implant corresponding to the trial implant.

Determine the trial size of the cement restrictor and gauge the implantation depth.  Check that the trial restrictor is firmly seated in the canal, then remove trial.

Use pulsatile lavage and a nylon brush to clear the humeral canal of debris and to open the interstices of the bone ready for the cement. Place the definitive cement restrictor at the appropriate depth and check that it is firmly seated in the canal.

If you have a subscapularis to repair, drill and fill 6 number 2 Tevdex suture through the proximal humerus near the lesser tuberosity to enable secure reattachment of the subscapularis (if possible). You may wish to avoid re-attachment if unable to externally rotate the humerus to zero degrees.

Irrigate the canal, during a secondary cleaning, using pulsatile lavage to remove loose bone remnants and marrow. Some surgeons may wish to insert a one-inch gauze pre-soaked in an epinephrine (1:1,000,000 solution) or hydrogen peroxide solution to aid haemostasis and the drying of the humeral canal. 

Cement in the humeral implant as directed.  We use 1.5 packs of Simplex with 2 grams of Vancomycin.

Introduce the final implant in 0 degrees of retroversion in line with the long axis of the humerus, using the humeral implant driver.

Excess cement will extrude from the canal and should be removed before curing is complete.  Remove the driver by pressing on the blue button.  Inspect the exposed portion of the humeral component for cement and remove as necessary.

Place pressure on the component with your thumb until the cement is fully polymerized to avoid micromotion that could cause crack propagation.  Cement hardening takes about 10 minutes in the laminar airflow room and can be check by tapping on a test piece of cement.

Irrigate the wound thoroughly.  Place the trial articular surface and reduce the joint.  Confirm stability and dislocate the humerus.

Impact the final humeral cup using the cup impactor. When a humeral spacer is needed, impact it first on the epiphysis and then impact the final cup on it.

Note: All junction surfaces between the implant components should be clean and free of any tissue before impaction. Reduce the joint and carry out a final assessment of joint stability and range of motion.

Reduce the joint and carry out a final assessment of joint stability and range of motion.

Closing

Secure the subscapularis if indicated and assess ER ROM.

Close the delta-pectoral interval loosely.  Emplace a drain over deltoid and exit skin a good 7.5cm or more away from incision site.  Use staples to close the wound.

Postop

If iodine was used to prep the patient, this should be removed with alcohol immediately after dressing the incision site.

No CPM

Place Pt in sling

For PT - Axillary care and hand to mouth exercises.

Immediately post op, do a Grashey AP and Axillary view xray of the operative shoulder.