Surgical TechniqueE2%84%A2%20...scaphoid in its distal third. Note: The carpal resection guide handle shown in Figure 9 may be used to assist positioning. With the capitate and the

Surgical Technique

This brochure is presented to demonstrate the surgical technique utilized by:

James W. Strickland M.D.Andrew K. Palmer M.D.Thomas J. Graham M.D.

Biomet, as the manufacturer of this product, does not practice medicine and does not recommend this or any other system for use on a specifi c patient. The surgeon who performs any procedure is responsible for determining and utilizing the appropriate techniques for such procedure for use on a specifi c patient. Biomet is not responsible for selection of the appropriate surgical technique or products to be utilized for an individual patient.

1

Preoperative Planning and Surgical Approach

After the surgeon and patient have decided to proceed with total wrist arthroplasty, the surgeon should conduct preoperative planning using the templates provided and identify approximate sizes for each of the following components:

• Radial body• Radial stem• Capitate stem• Carpal plate• Carpal head• Radial and Ulnar screws

Estimate the amount of distal radius to be resected.

The patient is positioned supine on the operating table with the extremity placed comfortably on a hand table. Apply the pneumatic tourniquet to the upper arm and exsanguinate with an Esmarch bandage (Figure1).

Total wrist arthroplasty can be performed under general or regional anesthesia based on surgeon preference. Additionally, the administration of antibiotics is by preference of the surgeon and individualized to the patient.

Infl ate the pneumatic tourniquet.

Figure 1

2

Incision and Approach

Dissecting sharply against the underlying radius and carpus, elevate the overlying extensor compartments radially and ulnarward without violating their undersurface. Elevation and protection of the fi rst dorsal compartment tendons and the brachioradialis off the radius is also recommended.

Homan or large Gelpi retractors are used to displace the ulnar capsule and extensor tendons ulnarward and the radial capsule and radial wrist extensors, EPL, and fi rst compartment tendons radially, exposing the distal radius, the radioulnar joint capsule, the entire carpus, and the metacarpal bases.

Total wrist arthroplasty is performed through a dorsal incision placed slightly radial to the center of the hand and wrist and extending from three to four centimeters proximal to the distal radius to half way up the third metacarpal (Figure 2).

Dissect directly to the dorsal retinaculum without excessive undermining. Palpate Lister’s Tubercle and open the third dorsal extensor compartment, exposing the extensor pollicis longus tendon (EPL) (Figure 3).

Mobilize the EPL proximally and distally and displace it radially. Expose the dorsal wrist capsule and make a longitudinal capsular incision extending from the distal radius to the base of the third metacarpal (Figure 4).

Figure 4Figure 3

Figure 2

3

Carpal Resection Guide Assembly

Figure 6

Figure 5

placed, the ulnar wing of the guide should line up closely with the midcarpal articulation between the triquetrum and the hamate, while the radial wing bisects the scaphoid in its distal third.

Note: The carpal resection guide handle shown in Figure 9 may be used to assist positioning.

With the capitate and the proximal aspect of the third metacarpal exposed to facilitate alignment, the carpal resection guide is positioned so that the proximal apex of the guide allows visualization and subsequent resection of 2–3mm of the capitate head (Figure 5).

Two .062" K-wires are inserted through the guide — the fi rst wire is placed at the level of the capitate neck and the second in the metaphysis of the third metacarpal (Figure 6) with the guide parallel to the longitudinal axis of the third metacarpal. If properly

4

Figure 8

Figure 7

Fully loosen thumbscrew and insert the arm of the radial resection level guide into the slot on the carpal resection guide (Figure 7). Position the slot over the center of the radius and tighten the thumbscrew.

With the wrist in a neutral position, use a 5mm sawblade to score the center surface of the radius through the cutting slot (Figure 8). This will serve as a landmark for resection level of the distal radius later in the procedure.

Radial Scoring

5

Remove the radial resection level guide and insert the carpal resection guide handle to help stabilize carpal guide during resection. Keeping the sawblade fl ush

Figure 9

Figure 10

Carpal Resection

against the four edges of the carpal resection guide, cut through the scaphoid, capitate head, edge of the hamate, and triquetrum (Figures 9 and 10).

Guide Handle

6

Remove the carpal resection guide and remove the K-wires with either the K-wire Driver or the pin puller (Figure 11).

Using a knife and ronguer, remove the proximal carpus and remaning distal scaphoid fragments (Figure 12). Insert a K-wire into the capitate at the apex of resection. The entry point should be placed in the center of the capitate. Confi rm positioning with the aid of fl ourscopy.

The 6mm cannulated capitate reamer is placed over the K-wire and carefully used to ream the center of the capitate

without cracking the cortical walls (Figure 13). Fluoroscopy should be used to determine the reamer placement, depth, and size within the capitate. The fl utes and stem should be inserted until they near the distal surface of the capitate.

The appropriate size trial capitate stem will be determined by the blue and green depth marks at the proximal margin of the capitate (Figure 14) and fl uoroscopic confi rmation of the position of the reamer. If only the fl utes are inserted past the articular surface, the silver trial is used. A 7.5mm capitate reamer can be used for large capitates and will require a cement mantle.

Carpal Canal Preparation

Figure 13 Figure 14

Figure 11 Figure 12

7

At this point, the reamer and K-wire are withdrawn from the capitate and trial carpal plate is provisionally determined by the curvature and width of the proximal carpal surface and the size of the radial defect resulting from the removal of the entire scaphoid.

Carpal plates are available in lengths of 37mm and 43mm with three separate scaphoid augment options for each length. In most instances, there is a radial defect proximal to the base of the trapezoid and one of the augmented carpal plates should be used. The appropriate carpal plate should lie fl ush with the hamate and proximal capitate surfaces and the scaphoid augment should hug the radial slope of the capitate and the base of the trapezoid.

Figure 15

Carpal Trial Placement

Assemble the previously chosen capitate stem to the appropriate carpal plate. The assembled carpal plate and stem are then inserted onto the proximal carpal surface and into the capitate using the insertion tool (Figure 15).

When fi tted correctly, the radial screw hole should lay straight below the second metacarpal, and the ulnar screw hole should be positioned so that an angled screw will be centered in the hamate. Any protruding bone that impedes congruous fi tting of the carpal plate should be trimmed.

Trial fi tting of the carpal plates together with the predetermined capitate stem and various radial augments is continued until observation and fl uoroscopy confi rms satisfactory plate position, radial augment size, and screw hole alignment. The carpal plate/capitate stem combination is then removed.

8

Radial Canal Preparation

Figure 18Figure 17

With the wrist held in near full palmar fl exion, the entire distal articular surface of the radius is visualized. Insert a .062" K-wire into the lower–radial corner of the dorsal ulnar quadrant of the scaphoid fossa of the radial articular surface.

Using these landmarks, the entry point for the K-wire should be near the center of the radius and immediately beneath the ulnar upslope of Lister’s Tubercle. The K-wire is then driven straight down the center of the medullary canal of the radius (Figure 16).

Flouroscopic confi rmation of the centered position of the K-wire in the radius should be demonstrated before proceeding and several placements of the K-wire may be required to achieve perfect centering. Drill over the K-wire with the cannulated drill bit to at least the 40mm mark (Figure 17).

Remove the K-wire and ream the radius beginning with the 4.5mm radial reamer. Continue reaming until the fl utes are inserted past the articular surface (Figure 18).

With the aid of fl uoroscopy, increase the radial reamer size until “chatter” of the reamer is encountered and the reamer fl utes fi ll the medullary canal of the radius.

Figure 16

9

Figure 21

Radial Resection Guide Assembly

Align the proximal-most margin of the resection guide with the initial score mark made on the dorsal cortex of the radius as shown in Figure 8 (Figure 20). Secure the resection guide to the radius using .062" K-wires (Figure 21).

Keep the last reamer used in the radial canal and remove the ratcheting handle from the reamer. Attach the radial resection guide boom to the shaft of the reamer. The resection guide is then slid over the boom (Figure 19).

Figure 19

Figure 20

10

Radial Cuts

Figure 23

Figure 22

guide directs the saw cut to exit at the juxta-articular margin of the radius platform and DRUJ thus maintaining the native anatomy on the ulnar side.

Complete the distal radial cut, remove the K-wires and the radial resection guide. Care should be taken when dissecting the distal fragment from the soft tissues including the pronator quadratus.

Remove the reamer and guide boom from the radius, leaving the rounded resection guide secured in place by the K-wires.

Transect the radius along the proximal edge of the guide while keeping the blade fl ush against the arc of the guide (Figures 22 and 23). The contour of the radial resection

11

Figure 25

Figure 26

Figure 24

Based on the last radial reamer size used, insert the corresponding radial IM guide into the radial canal (Figure 24).

Attach the appropriate chisel guide to the modular handle. Select the chisel guide based on distal radius width.

Slide the chisel guide onto the radial IM guide until fl ush with the resected surface, ensuring proper orientation (lettering is always dorsal). If the chisel guide surface does not fi t fl ush with the distal radius, trim any prominent or

Figure 27

protruding bone to achieve a totally congruous fi t. Insert the appropriate size chisel into the chisel guide, tapping on the chisel until it is fully seated (Figure 25). Repeat on the other side of the chisel guide.

Remove the chisel, chisel guide, and IM guide and clean any remaining bone fragments from the chiseled triangular entrance into the distal radius (Figure 26).

Re-insert the IM guide into the medullary canal of the radius. Place the radial broach over the radial IM guide, ensuring proper orientation. Tap the broach until the cutting teeth are fully inserted (Figure 27).

Radial Broaching

12

Step 1 Assemble the previously fi tted capitate stem trial and carpal plate. Insert into the previously prepared carpus (Figure 28).

Step 2Select the appropriate radial stem and radial body for assembly. The radial stem size is based on the size of the last radial reamer used and the distal radial component trial is based on the size of the broach used to prepare the entrance into the distal radius. Connect the radial

Figure 30Figure 29

Figure 28

Step 2

Step 1

Step 3

stem and radial body and then insert into canal opening (Figure 29). Tap into place with the radial impactor until fl ush with the distal radius surface.

Step 3 Place the wrist in full fl exion. Be sure that the carpal plate remains properly oriented and fl ush with the carpal surfaces. Snap fi t the standard size carpal head to the carpal plate (Figure 30). Distract the wrist slightly and extend the hand to articulate the two components.

Snap Fit

Trial Component Placement

13

Figure 31

Trial Reduction

With all retractors removed, evaluate the motion and stability of the wrist. Approximately 2–3mm of joint separation should be possible during modest distraction (Figure 31).

If the wrist components are deemed to be too loose, replace the standard size carpal head with a +2 size or even a +4 size head and retest until the desired motion and stability under distraction are achieved.

Satisfactory radial and ulnar deviation and fl exion and extension of the wrist should be demonstrated at this point. Fluoroscopy should be used to further confi rm the positioning of the two components.

If soft tissue tension is too tight, further resect the radius. If the radial component will impinge the distal ulna, or if degenerative damage was present on preoperative x-rays, excise the distal ulna in a Darrach fashion.

Remove all trials from the wrist and irrigate with normal saline.

2-3mm

14

Carpal Implant Insertion and Screw Positioning

Figure 34Figure 33Figure 32

Drill longitudinally through the trapezoid and into the second metacarpal. Pin position and depth should be checked fl uoroscopically and, if necessary, the pins should be repositioned until the ulnar pin passes through the center of the hamate and the radial pin is in the second metacarpal medullary canal.

Drill distally over both K-wires with the cannulated drill bit using the larger hole on the drill guide (Figure 33).

Verify the drill depth and position with fl uoroscopy. The insertion depth can be determined by the score marks on the drill bit. Do not cross the fourth carpometacarpal joint on the ulnar side unless necessary for screw purchase.

Select the appropriate length ulnar screw (usually 15 mm) and screw into the hamate (Figure 34). The radial 5mm screw (usually 30mm or 35mm) is then introduced and screwed well into the second metacarpal base. Fluoroscopy is used to confi rm the screw position and both screws and tightened.

To assemble the distal component with the appropriate size capitate stem, plate, and carpal head, insert the capitate stem threads through the carpal plate center hole and into the carpal head. Ensure that the assembly is fully tightened by using the implant assembly tool and carpal driver (Figure 32).

Inject bone cement into the cavities of the capitate. Then insert the distal component pressing the stem into the capitate and the plate against the distally resected carpus using the carpal impactor.

Insert .062" K-wire into the ulnar screw hole using the small hole end of the drill guide. The pin will be directed obliquely into the central part of the hamate. In a similar manner, insert a .062" K-wire into the radial screw hole using the guide.

15

Figure 35

Figure 36

Radial Implant Insertion

Figure 37

to ensure it is fully seated. Articulate the wrist (Figure 36) and confi rm proper positioning of the components radiographically (Figure 37).

Assemble the radial stem to the radial body using the implant assembly tool (Figure 35). Inject bone cement into the radial cavity. Place the appropriate size radial component in the canal and use the radial impactor

16

Close the wrist capsule (Figure 38) and dorsal retinaculum using non-absorbable sutures and close the skin in the customary manner. The EPL may be left repositioned radially or included in the repair of the retinaculum and the use of a drain is at the discretion of the surgeon. If the distal ulnar was excised, a strong, stabilizing capsular closure should be carried out over the distal ulnar stump.

Apply a sterile bulky dressing incorporating a palmar splint. Defl ate the pneumatic tourniquet. Prior to removing the drapes and awakening the patient use fl ouroscopy to confi rm that the implant remains in a reduced position.

Figure 38

Early fi nger motion is encouraged. Remove the splint at one week and apply a cast or splint for an additional one to three weeks.

Note: If the distal ulna was removed, the forearm should be splinted in neutral rotation for three weeks before commencing rotational exercises.

Any drains are removed at 24 hours. The dressing and sutures are removed at 10–14 days. If the distal ulna was preserved, a short arm, removable splint is fashioned to maintain the wrist in neutral. Gentle active motion is permitted several times daily with the splint removed after 14 days. More vigorous active and passive motion are commenced at one month and the frequency of exercises and the amount of passive force applied to the hand is varied according to the patient’s progress and the discretion of the surgeon and therapist.

Closure Post-Op

17

Preparatory Instruments

A. Carpal Resection Guide

B. Resection Level Guide

C. Carpal Provisional Holding Forceps

D. Radial Resection Guide

E. Radial Guide Boom

F. Chisel Guide Handle

G. Chisel

H. Cannulated Capitate Reamer

I. Radial IM Guide

J. Radial Broach

K. Chisel Guide

L. Cannulated Drill Bit

M. Resection Guide Handle

N. Radial Reamer

O. Drill/K-wire Guide

P. Radial Provisional Extractor

Q. Pin Puller

B

A

DE

G

C

F

H

I

J

K

L

M

N

O

P Q

18

Assembly Instruments and Trial Components

B

A

L

GC

D

I

I

J

H

N

E

J

K

M

F

A. Radial Stem Trial

B. Radial Body Trial

C. Screw Depth Guide

D. Carpal Head Trial

E. Carpal Plate Trial

F. Capitate Stem Trial

G. Radial Impactor

H. Carpal Impactor

I. Impactor Handle

J. Implant Assembly Tool

K. Radial Assembly Wrench

L. Carpal Driver

M. Ratcheting Handle

N. Screw Hex Driver

19

Ordering Information

This material is intended for the sole use and benefi t of the Biomet sales force and physicians. It is not to be redistributed, duplicated or disclosed without the express written consent of Biomet.

Maestro™ is a trademark of Biomet Manufacturing Corp.

Carpal Plates

Part No. Size

180095 37mm

180096 43mm

180103 37mm with 6mm augment






Captitate Stems

Part No. Size

180120 12mm long

180121 15mm long

180122 18mm long

Radial Bodies

Part No. Size

180150 7.5 left

180151 7.5 right

180152 9.0 left

180153 9.0 right

Radial Stems

Part No. Size

180180 4.5mm dia

180181 6.0mm dia

180182 7.5mm dia

180183 9.0mm dia

Carpal Heads

Part No. Size

180063 std

180064 2mm

180065 4mm

Screws

Part No. Size

113843 5 x 15mm

113844 5 x 20mm

113845 5 x 25mm

113846 5 x 30mm

113847 5 x 35mm

113848 5 x 40mm

113861 5 x 45mm

113862 5 x 50mm

20

Biomet Orthopedics, Inc. 01-50-0904P.O. Box 587 Date: 06/0556 East Bell DriveWarsaw, Indiana 46581 USA

MAESTRO™ WRIST JOINT REPLACEMENT SYSTEMATTENTION OPERATING SURGEON

DESCRIPTIONBiomet manufactures wrist joint replacement prostheses intended for primary and revision joint arthroplasty for use in cemented applications. Wrist joint replacement components include: multiple piece radial and carpal components, and screws. Components are available with a MacroBond® Coat (a thin layer of titanium plasma spray) surface fi nish.

Materials:Radial Stems Titanium AlloyRadial Bodies Cobalt AlloyCarpal Heads Cobalt AlloyCarpal Plates Cobalt Alloy Capitate Stems Titanium AlloyBearing Surfaces Ultra-High Molecular Weight Polyethylene (UHMWPE) Radial Screws Titanium Alloy

INDICATIONSTotal Wrist IndicationsThe Maestro™ Total Wrist system is indicated for use as a replacement of wrist joints disabled by pain, deformity and/or limited motion caused by: 1. Non-infl ammatory degenerative joint disease including osteoarthritis, traumatic arthritis and avascular necrosis. 2. Rheumatoid arthritis. 3. Revision where other devices or treatments have failed. 4. Scapholunate Advanced Collapse (SLAC) and other functional deformities. 5. Trauma, including fractures of the distal radius and/or carpal bones.

Carpal Hemiarthroplasty IndicationsThe Maestro™ Carpal Hemiarthroplasty is indicated for use as a replacement of wrist joints disabled by pain, deformity and/or limited motion caused by: 1. Non-infl ammatory degenerative joint disease including osteoarthritis, traumatic arthritis and avascular necrosis. 2. Rheumatoid arthritis. 3. Revision where other devices or treatments have failed. 4. Scapholunate Advanced Collapse (SLAC) and other functional deformities. 5. Trauma, including fractures of the carpal bones.*

*Note: The Maestro™ Carpal Hemiarthroplasty is not indicated for fractures of the distal radius.

Patient selection factors to be considered include: 1) need to obtain pain relief and improve function, 2) ability and willingness of the patient to follow instructions, including control of activity levels, 3) a good nutritional state of the patient, and 4) the patient must have reached full skeletal maturity.

CONTRAINDICATIONSAbsolute contraindications include: infection, sepsis, and osteomyelitis. Relative contraindications include: 1) uncooperative patient or patients with neurologic disorders who are incapable of following directions, 2) osteoporosis, 3) metabolic disorders which may impair bone formation, 4) osteomalacia, 5) distant foci of infections which may spread to the implant site, 6) rapid joint destruction, marked bone loss or bone resorption apparent on roentgenogram 7) absent or insuffi cient wrist extensor tendons.

WARNINGS 1. Improper selection, placement, positioning, alignment and fi xation of the implant components may result in unusual stress conditions which may lead to subsequent reduction in the service life of the prosthetic components. 2. Malalignment of the components or inaccurate implantation can lead to excessive wear and/or failure of the implant or procedure. Inadequate preclosure cleaning (removal of surgical debris) can lead to excessive wear. Improper preoperative or intraoperative implant handling or damage (scratches, dents, etc.) can lead to crevice corrosion, fretting, fatigue fracture and/or excessive wear. 3. Thoroughly clean and dry connecting segments prior to attachment of components to avoid improper seating. Use clean gloves when handling implants. Laboratory testing indicates that implants subjected to body fl uids, surgical debris or fatty tissue has lower adhesion strength to cement than implants handled with clean gloves. 4. Do not modify implants. 5. The surgeon is to be thoroughly familiar with the implants and instruments, prior to performing surgery. 6. Properly align and securely assemble connecting components. Failure to properly align and completely seat the components together can lead to disassociation. Thoroughly clean and dry all connections prior to attachment of modular components to avoid improper seating. 7. Care is to be taken to assure complete support of all parts of the device embedded in bone cement to prevent stress concentrations that may lead to failure of the procedure. Complete preclosure cleaning and removal of bone cement debris, metallic debris and other surgical debris at the implant site is critical to minimize wear of the implant articular surfaces. Implant fracture due to cement failure has been reported with joint replacement implants.

8. Biomet® joint replacement prostheses provide the surgeon with a means of reducing pain and restoring function for many patients. While these devices are generally successful in attaining these goals they cannot be expected to withstand the activity levels and loads of normal healthy bone and joint tissue. 9. Accepted practices in postoperative care are important. Failure of the patient to follow postoperative care instructions involving rehabilitation can compromise the success of the procedure. The patient is to be advised of the limitations of the reconstruction and the need for protection of the implants from full load bearing until adequate fi xation and healing have occurred. 10. Excessive activity, trauma and excessive load bearing have been implicated with premature failure of implants by loosening, fracture, and/or wear. Loosening of the implants can result in increased production of wear particles, as well as accelerate damage to bone, making successful revision surgery more diffi cult. 11. The patient is to be made aware and warned of general surgical risks, possible adverse effects as listed, and to follow the instructions of the treating physician including follow-up visits. Wrist joint replacement prostheses have not received FDA clearance for non-cemented application (USA).PRECAUTIONS 1. Specialized instruments are designed for Biomet® joint replacement systems to aid in the proper implantation of the prosthetic components. The use of instruments or implant components from other systems can result in inaccurate fi t, sizing, excessive wear and device failure. Intraoperative fracture or breaking of instruments has been reported. Surgical instruments are subject to wear with normal usage. Instruments that have experienced extensive use or excessive force are susceptible to fracture. Surgical instruments should only be used for their intended purpose. Biomet recommends that all instruments be regularly inspected for wear and disfi gurement. 2. Do not reuse implants. While an implant may appear undamaged, previous stress may have created imperfections that would reduce the service life of the implant. Do not treat patients with implants that have been, even momentarily, placed in a different patient. 3. Patient must avoid placing excessive loads on the implant. 4. Patient must avoid lifting more than 5 lbs with the operated arm after surgery. 5. Patient must avoid putting full body weight on the operated arm when rising from a seated position. 6. Patient must avoid sudden or strenuous pushing and/or pulling activities after surgery, as these can produce excessive stress on the operated arm. 7. Patients must avoid full wrist fl exion or extension under load bearing conditions.

POSSIBLE ADVERSE EFFECTS 1. Material sensitivity reactions. Implantation of foreign material in tissues can result in histological reactions involving various sizes of macrophages and fi broblasts. The clinical signifi cance of this effect is uncertain, as similar changes may occur as a precursor to or during the healing process. Particulate wear debris and discoloration from metallic and polyethylene components of joint implants may be present in adjacent tissue or fl uid. It has been reported that wear debris may initiate a cellular response resulting in osteolysis or osteolysis may be a result of loosening of the implant. 2. Early or late postoperative infection, and allergic reaction. 3. Intraoperative bone perforation or fracture may occur, particularly in the presence of poor bone stock caused by osteoporosis, bone defects from previous surgery, bone resorption, or while inserting the device. 4. Nerve injury is a concern in all joint replacement procedures. 5. Loosening or migration of the implants can occur due to loss of fi xation, trauma, malalignment, bone resorption, and/or excessive activity. 6. Periarticular calcifi cation or ossifi cation, with or without impediment of joint mobility. 7. Inadequate range of motion due to improper selection or positioning of components. 8. Undesirable shortening or lengthening of limb. 9. Dislocation and subluxation due to inadequate fi xation and improper positioning. Muscle and fi brous tissue laxity can also contribute to these conditions. 10. Fatigue fracture of component can occur as a result of loss of fi xation, strenuous activity, malalignment, trauma, non-union, or excessive load bearing. 11. Fretting and crevice corrosion can occur at interfaces between components. 12. Wear and/or deformation of articulating surfaces. 13. Intraoperative or postoperative bone fracture and/or postoperative pain.

STERILITYProsthetic components are sterilized by exposure to a minimum dose of 25 kGy of gamma radiation. Do not resterilize. Do not use any component from an opened or damaged package. Do not use implants after expiration date.

Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.

Comments regarding this device can be directed to Attn: Regulatory Dept., Biomet, P.O. Box 587, Warsaw, IN 46581, FAX: 574-372-1683.

The information contained in this package insert was current on the date this brochure was printed. However, the package insert may have been revised after that date. To obtain a current package insert, please contact Biomet at the contact information provided herein.

Documents

Surgical TechniqueE2%84%A2%20...scaphoid in its distal third. Note: The carpal resection guide handle shown in Figure 9 may be used to assist positioning. With the capitate and the