Surgical Technique

COMPASS ELBOWUniversal Hinge

Compass™ Elbow Universal Hinge

Table of Contents

Introduction 3Design Rationale 6Design Features 7Surgical Technique 8Catalog Information 30

Nota Bene: The technique description herein is made available to the healthcare professional toillustrate the author’s suggested treatment for the uncomplicated procedures. In the final analysis, the preferred treatment is that which addresses the needs of the specific patient.

By: Robert N. Hotchkiss, M.D.Chief of Surgery, The Hospital for Special SurgeryAssociate Attending, The Hospital of Special SurgeryNew York, New York

3

Introduction

This technique defines the indication forapplication and use of the CompassUniversal Hinge on the elbow.

Flexion contractures in the elbow are quitecommon after trauma to the joint andrepresent one of the major challenges in thecare of these injuries. These disablingcontractures may also occur after burns orthe development of arthritis. Even minorcontractures (30° to 40°) can significantlyreduce function of the upper extremity.

However, regaining a functional range ofmotion after open release or distractionarthroplasty may be precluded by pain,swelling, and adaptive shortening of themuscle tendon unit on both sides of the joint.Until now, there was no effective method ofincreasing the motion of the elbow followingtrauma or contracture release. Neither earlyactive motion, comprehensive therapy,dynamic splints, nor CPM ensure success.

Early active motion, while reducing theseverity of contracture, requires the patient’sown strength and constant effort. Passivestretching by a therapist risks the formationof heterotopic bone and myositis ossificans.Dynamic splints are useful, but requirepressure on the soft tissues of the arm,reducing patient compliance. Finally, CPMdevices provide early motion gains, but donot allow the joint to reach the extremities ofmotion which are the areas of greatest need.

4

Introduction

The Compass universal hinge, however,addresses the challenge of maintaining oreven enhancing the range of position. Itallows both passive and active movement ofthe elbow through a kinematically normalrange of motion while stretching the softtissue capsule at the extremes of flexion andextension. The result is a significant reductionin joint contracture without the drawbacksinherent in the previously discussedmethods. In addition, patients with instabilityor massive injury following trauma may bemobilized early after repair and placement ofinternal fixation.

The Indications

The indications for use of the Compass Hingeinclude the following:

1. Acute trauma with instability.

2. “Cold” or delayed trauma to the elbow with subsequent instability.

3. Stiff elbow.

4. The arthritic elbow with posttraumatic arthritis with and without cartilage injury.

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6

Design Rationale

The elbow (ulno-humeral articulation) is oneof two joints which approximates a hinge(ginglymus). Only slight movement of theinstant center of rotation occurs at the elbowduring flexion and extension. Care must betaken, therefore, to locate the rotational axisof the elbow for proper treatment.

The Compass Universal Hinge uses theanatomic axis of the elbow as the mechanicalaxis of the device. The mechanical axes ofthe device’s bilateral hinges are alignedcoincident with the anatomic axis of the joint.The alignment can be verified throughout thecourse of application and treatment.

Once engaged, the Compass Hinge’sprecision worm gear permits passivemobilization of the elbow joint. Thismovement gently stretches the soft tissuecapsule and muscle tendon during flexionand extension. Stress, relaxation andelongation increase the range of motion andrange of position. Gentle, intermittent, passivedisplacement allows improvement ormaintenance of a maximal range of motion(ROM) during hinge wear. The worm gearmechanism may also be disengaged topermit the patient to exercise active ROM.

The Ilizarov method emphasizes incrementalpassive displacement to allow soft tissueaccommodation during limb lengthening andbone regeneration. With the CompassUniversal Hinge, those same principlesestablish and maintain a maximal range ofmotion after contracture release, distractionarthroplasty, or trauma.

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Design Features

Versatility. The Compass Universal Hingeoffers great versatility for use onthe elbow, the knee, or the ankle – and requires only a few simpleadjustments for any application.

Matching Axes of Rotation. The Compass Universal Hinge aligns its mechanical axis with the anatomicaxis of the joint – elbow, knee, or angle. This allows the hinge to work with the joint, gently moving itthrough a biomechanically normal range of motion. A choice of passive or active modes ensures thegreatest therapeutic value for each individual patient. As with the original design, radiolucentconstruction allows accurate alignment of the axes during hinge application. Once the hinge is placed,the axis reference pin is removed to reduce the likelihood of infection of the joint capsule.

Precision Worm Gear.The Compass UniversalHinge incorporates aprecision worm gear thatprovides controlleddisplacement throughoutthe extremes of flexionand extension.

Range of Valgus. The self-telescoping designof the Compass UniversalHinge allows a full range of10° varus to 10° of valgus,allowing quick, easy andanatomically appropriateapplication to the knee,ankle, or elbow.

Displacement/Distraction.Distraction screws allow the surgeon

to distract the joint as needed.

Lower Profile. The Compass Universal Hinge is lighter in weightand lower in profile than the original design. Thisimproves patient comfort with the device and patientcompliance throughout the healing process.

Radiolucent Arcs. The Compass Universal Hinge isfully compatible with the Ilizarovsystem to provide a wide varietyof fixation options.

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Surgical Technique

Frame Assembly

The frame should be prebuilt to confirm thatproper ring size has been selected. It isimportant that the geared component isalways medial with the knob facing posterior.Before tightening the rings to the hingecomponents, place an axis pin through thecenter of the hinges (Figure 1). Then tightenthe rings to the connecting blocks with a 10mm wrench (Figure 2). Make sure thatcountertorque is applied to the hingecomponents to ensure that they maintainalignment on the axis pin.

When the frame has been assembled andappropriately adjusted, it is helpful to test thealignment of the frame relative to the axis pin.A properly aligned frame should slide alongthe axis pin (M/L and L/M) without significantimpingement (Figure 3). If the ring is too largeor too small, adjustments can be made at thispoint to switch to either a larger or smallerring bringing the hinge components eithercloser or farther away from the joint. Makesure that you allow for swelling in thepostoperative period, allowing at least 2 cm ofclearance from the skin to the hinge block atthe time of surgery and at least two fingerbreadths posteriorly at the level of the elbowwith the posterior portion of the ring. Makesure that the proximal ring is perpendicular tothe humerus from the later view.

The valgus angle of the hinge can beadjusted by loosening the set screw on thelateral component and rotating the 10 mmHex (Figure 4). Retighten the set screw whenring is perpendicular to the shaft of the bone.

Figure 1

Figure 2

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Surgical Technique

Preoperative Planning

Contracture Release

Before embarking on the surgical release,care should be taken to ensure that theinjured joint is scrutinized for the existencesof heterotopic bone. Loss of pronation andsupination must also be considered, as wellas the loss of flexion and extension. Lateralpolytomography and/or CAT scanning shouldbe performed to look for bone bridging the defect.

Once the determination is made that thepatient is suitable for contracture release and the use of the Compass Hinge, a longdiscussion with the patient concerning length of treatment should be undertaken. The patient needs to understand that he/shewill wear this device for at least six to eightweeks. There are frequently problemsassociated with the pins and proper care of these pins and earnest efforts by thepatient are required to make this procedure a success.

Figure 3

Figure 4

Surgical Technique

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Patient Positioning

For release of contracture and removal ofheterotopic bone, the patient should beplaced in the supine position with the arm ona radiolucent hand table. It is important toprep the patient all the way to the shoulderand axilla and a sterile tourniquet should beused. It is very important to position thepatient so that the proximal portion of thearm/humerus is as lateral as possible. Theshoulder should be at the very edge of theoperating table. A donut may be necessary tosupport the head. If this is not done, it isdifficult to visualize the proximal portion ofthe pins and their location in the humerus.

If the patient first requires a more extensiveexposure of the distal humerus for fracture orreconstructive work, it may be useful to beginthe operation with the arm over the chestwhen using one or more standard posteriorapproaches to the elbow, either olecranonostectomy or a triceps sparing exposure(Bryan/Morrey). Once the fracture work iscompleted, the patient can then be mademore supine and the hand table insertedunder the drapes and the patient placed inthe position as depicted in Figure 5, for theapplication of the Compass Hinge.

Figure 5

11Figure 8

Figure 7

Anterior Exposure of the Joint

The Modified “Over the Top” Exposure of the Elbow

Incision – The skin incision may bepredetermined from previous surgery. Theincision can vary from posterior to medial. Fornearly all applications, especially thosepatients who have contractures from traumaabout the elbow and who lack significantflexion, it is important to transpose the ulnarnerve (Figure 6). The skin incision must beextensive enough to allow exposure of theulnar nerve along its entire course, as well asexposure of the elbow and distal humerus.The most proximal portion of the incisionallows direct visualization of the distal-middlehumerus for placement of the medial pin.

Using the medial incision, the ulnar nerve canbe mobilized and will allow exposure of boththe anterior and posterior elbow joint (Figure7). After the ulnar nerve is mobilized and theintermuscular septum excised, the anteriordistal humerus and capsule are exposed byelevating the most proximal origin of theflexor muscle mass (the flexor carpi ulnaris[FCU]) is left attached to the medialepicondyle. Superior to the origin of thecapsule, the subperiosteal dissection iscarried out to the distal humerus and aBennett retractor or a blunt Hohmann can beinserted over the anterior surface of thebone.

With the flexor pronator muscle masselevated as depicted in Figure 7, the anteriormuscle of the brachialis and biceps can beseparated from the anterior capsule, therebyfully exposing the elbow joint (Figure 8 Inset).Heterotopic bone encountered at this timecan also be excised. The principle danger inthis exposure is excessive traction on themedian nerve and brachial artery which arebordering the lateral aspect of the muscularincision (Figure 8).

Figure 6

Surgical Technique

Tourniquet

Incision

Flexi CarpiRadialis Muscle

Pronator TeresMuscle

Biceps Muscle

Brachialis Muscle

Triceps MuscleMedial Head

IntermuscularSeptum

Ulnar Nerve

Medial Epicondyleof Humerus

ExposedAnteriorCapsule

Median Nerve &Brachial Artery

Protected

Brachialis Muscle

Biceps BrachiMuscle

Excised IntermuscularSeptum

Partially CutOrigin of Pronator

Teres Muscle

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Surgical Technique

There is usually a sufficient amount ofbrachialis muscle to protect the median nervefrom direct contact with the anteriorretractors. The most distal extent of themuscle split, at the flexor pronator origin,should not be lengthened withoutidentification of the branches of the mediannerve to the Pronator Teres. Once the capsuleis exposed, it can be excised from proximal todistal (Figure 9). The most superior portion ofthe elbow joint can be visualized at this pointand excision carried out from medial tolateral. Flexion of the joint itself relaxestension to the anterior structures and oftenaffords a better view. It is sometimesnecessary to use a headlight to see all theway across as the capsular excision isperformed. Each case is different and at thispoint the surgeon, using the medial exposure,must decide whether a full anterior releasehas been accomplished. If there is extensiveheterotopic bone or concern over further scarand contracture at the lateral side, it may benecessary to perform a lateral exposurethrough a supplementary incision along thesupracondylar ridge of the distal humerus.This need only be as extensive as necessaryto complete the capsular incision and removalof heterotopic bone.

Figure 9

Excised Anterior Capsule

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Figure 9

Posterior Exposure of the Joint

Once the anterior release is completed, thereis usually little gain in extension of flexionbecause of contracture and accumulated softtissue in the olecranon fossa posteriorly.Often heterotopic bone posterior to theolecranon also limits motion. The ulnar nervemust now be mobilized and transposedanteriorly. A vessel loop is usually used toaccomplish this; however, it is somewhatdangerous to apply a hemostat or clamp tothe loop for fear that inadvertent, suddenretraction could injure the nerve. With thenerve held anteriorly, the posterior exposurecan then be performed (Figure 10). Similar tothe anterior approach, a subperiostealdissection and retraction of the triceps at thedistal humerus is first performed withinsertion of a Hohmannn retractor posteriorlyseparating the distal humerus from thetriceps. In cases of posttraumatic adherenceand burns, there is often a great deal ofadherence all along the triceps to theexposure distally. Once the retractor is inplace, the capsule of the posterior elbow jointcan be exposed and excised (Figure 11). Theentire posterior portion of the collateralligament can be removed between thehumerus and ulna. The anterior portion of themedial collateral ligament is protected by theoverlying origin of the flexor carpi ulnarismuscle mass that has not been elevated.Once the capsule is exposed and excisedposteriorly, a complete excision of theheterotopic bone and impinging

Figure 10

Surgical Technique

Ulnar Nerve

Olecranon

Poesterior CapsularExcision

HererotopicBone

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portion of the olecranon must be achieved(Figure 12). It is sometimes difficult to see allthe way over to the lateral aspect of theolecranon for an adequate excision. Again, asupplementary lateral incision is occasionallynecessary. Once the entire capsular releasehas been achieved both posteriorly andanteriorly, the elbow usually exhibits improvedmobility. The anterior and posterior structurescan still be quite tense or tight. Excessive orforceful manipulation is ill-advised. However,gentle, sustained pressure can be appliedand manipulation of the elbow can beperformed to maximize flexion and extension.

Closure – Before closing the entire wound,the ulnar nerve should be transposed andheld with a fascial sling (Figure 13). The fascialsling should be constructed in a way thatdoes not constrict the nerve and, duringflexion and extension of the elbow, does notallow the nerve to subluxate nor becomeentrapped. It is sometimes necessary tomake a small groove in the fascia of the flexor carpi ulnaris so that the nerve is not compressed.

This is also the time that the first medial pincan be placed with direct visualization. It isusually best placed posterior to the anteriorlytransposed ulnar nerve; however, itsometimes can be placed anterior to thenerve, depending on the extent of release.The level of the pin placement is determinedby placing the Compass Hinge first over theelbow and noting where it lies. Most of thewound can be closed leaving only theexposure of the distal humerus.

Figure 12

Figure 13

Surgical Technique

Excised PosteriorCapsule

UlecranonOstectomy

Transposed Ulnar Nerve

1st. Medical Pin

Fascial Sling for Ulnar Nerve

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Axis Pin Placement

There are two methods that can be used foraxis pin placement. The temporary axis pinaligns the hinge to the axis of rotation. Properplacement is crucial. Remember that thecenter axis pin is removed from the distalhumerus at the end of the case.

Method 1 (Single pin technique)

Where you can easily visualize the axis of thedistal humerus, the axis pin may be placedunder direct vision. This may be the case withan extensive contracture release or grossinstability. In these cases, it is not uncommonto have the entire distal humerus exposed.

In this setting, simply identify the startingpoint; usually this is easier on the lateral side.Imagine that the distal humerus is a spoolsitting on the end of a column. The goal is toplace the pin perfectly in the center ofrotation of that spool. The axis is distal toboth the medial and lateral epicondyles(Figure 14).

Take the 3.5 mm axis pin through either themedial or lateral side of the exposed joint,place the pin centrally and begin drilling tostart the hole in the alignment that is as closeto the axis as possible. Confirm the alignmenteither by C-arm in the A/P plane or by directvisualization at this time.

The alignment of the axis is crucial. It isimportant to take the time necessary toachieve perfect placement of this pin foralignment of the Compass Hinge at theelbow. Both an A/P and lateral should beviewed to ensure adequate placement(Figures 15A and 15B).

Figure 14

Figure 15A

Figure 15B

Surgical Technique

Axis of Rotation

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Surgical Technique

Method 2 (Two pin technique)

More commonly, the distal humerus isvisualized incompletely, but exposed on boththe medial and lateral sides. In this case thesurgeon must have a competent assistant tohelp with axis pin placement.

1. Preassemble the frame using the proper size rings. Make certain that the frame can rotate on its hinges. The gear portion is usually located on the medial side.

2. Both surgeons identify the center point on the distal humerus, medial and lateral, the axis of rotation.

3. The hinge is now brought into position and held by hand.

4. Starting with the medial side, the surgeon pushes the 3.5 mm axis pin through the frame, by hand, into the center of rotation as viewed from the medial side. This point is located just distal and anterior to the medial epicondyle (Figure 16). This medial pin is held at this point during the placement of the axis pin from the later side.

5. From the lateral side, the second surgeon carefully pushes a second 3.5 mm pin through the axis hole to the center of rotation, as viewed from the lateral position (Figure 17).

Figure 16

Figure 17

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6. The two axis pins must now be adjusted into alignment. Neither pin should be moved from their respective point of entry, as this reflects the axis of rotation, but rather the angle of entry adjusted until the frame itself can easily be slid medial to lateral, back and forth, assuringuniaxial alignment (Figure 18).

7. Once the two pins are coincident, entering at their respective centers of rotation, the lateral pin is driven in approximately 2 cm by power. Again, a check should be made that driving the lateral pin in did not cause the medial pin, held by hand, to shift. The frame should still be easy to slide from medial to lateral, back and forth, before driving in the pin from the medial side (Figure 18).

8. The medial pin is then drilled in, approximately 2 cm under power.

9. A check is made that the frame still can slide freely from medial to lateral.

10. An A/P fluoroscopic view is checked. A lateral may also be checked if desired, however, with experience, this becomes unnecessary since you have been able tovisualize both sides of the axis at the time of pin placement.

Figure 18

Surgical Technique

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Half-Pin Placement

Rancho Technique for Placement of Half-Pins

1. Determine the desired position of the pinlocation and angle.

2. Build a cube assembly that allows theparticular pin placement. This may be acube attached directly to a ring. It may behinged for proximal-distal angulation. Thehinged construct is built by attaching acube to a hinge or post with a bolt. A starwasher is used between the cube and postto resist rotation of the cube and possiblyloosening of the bolt. An 8 mm bolt shouldbe used, especially for the one hole cube,so that this bolt does not interfere with thelarge hole in the cube through which theguide sleeve and pin pass.

3. The drill guide is passed through the largehole. It should touch the skin and be in thelocation and direction desired for the pin.

4. Lift the guide so that an incision can be made.

5. Make an incision and separate the softtissues and periosteum so that the drillguide rests on bone. The drill guide has aconcave tip that reduces slipping.

6. Lightly lock the drill guide in place with aset screw or a bolt.

7. Using the appropriate size of drill andaccepted techniques for reducing heattransfer to the bone, drill carefully throughbone cortices. Bone thickness can bedetermined by reading the number ofmillimeters indicated on the drill shank atthe top of the guide.

Surgical Technique

8. Thickness from cortex to cortex can alsobe determined by hooking the tip of thedepth gauge on the outside of the farcortex and reading the number ofmillimeters at the top of the guide.

9. Choose the appropriate thread lengthdesigned by measurement and place thepin through the guide using the driver-extractor. Manual placement isrecommended. The Smith & Nephewhalf-pins are self-tapping.

10. Once the pin is firm in both cortices (X-ray verification is helpful), remove thedrill guide.

11. Slide the proper size of centering sleeveover the pin. Align the bold line on thehead to point to the threaded hole to beused to lock the pin. This allows the boltor set screw to impinge the pin directlyensuring a more secured lock.

12. Ensure all connections are tightened securely.

13. After each pin placement, checkalignment of elbow and hinge axis.

4 mm pins use a 2.7 mm drill5 mm pins use a 3.8 mm drill

Surgical Technique

19

20

Humeral Pin Placement

Two half pins are placed, one medial and theother lateral. The principle is to secure thehumerus in two places, without impaling any of the major muscle-tendon units orjeopardizing any neurovascular structures.

1. The medial pin is usually placed firstthrough a two-hole Rancho cube on the undersurface of the upper ring (Figure 19A).

2. The medial pin will be close to the ulnarnerve and should run along the medialintermuscular septum.

3. As this pin is drilled, care should be takento ensure that the upper 5/8 ring is notflexed or extended, but perpendicular tothe humerus (Figures 19B and 19C).

4. Both cortices should be engaged.

Figure 19A

Figure 19B

Figure 19C

Surgical Technique

21

The lateral pin is usually placed using a two-hole post and a single-hole Rancho cube.

1. The lateral flare of the humerus is used for placement.

2. The drill guide rests on the lateralsupracondylar ridge, directed anterior and distally. The radial nerve, at this level, is posterior to the pin.

It is helpful to envision and place theposterolateral humeral pin just anterior to thetriceps pin but directed from posterolateral toanteromedial. The radial nerve is now anteriorto this pin. A Rancho cube below the humeral5/8 ring is used to fix this pin (Figure 20).

At this time, assure that the alignment of theaxis is acceptable. Modifications of positionfrom anterior to posterior are possible usingthe sliding 5/8 ring attachment assemblies.

Surgical Technique

Figure 20

22

Placement of Ulnar Fixation

It is important at this point to assure that thedistraction component is well-seated. Againusing the Rancho System, two or three 4 mmpins are used in the ulna. The more proximalpin provides better control and can be placedup and through the coronoid. Spacing thepins along the subcutaneous border of theulna allows excellent rotational control. If theelbow is grossly unstable, it is quite importantto reduce the elbow before placing the ulnarpins. It is often helpful to place the elbow inapproximately 90° of flexion when applyingthe ulnar fixation. If a distraction arthroplastyis performed and the elbow is grosslyunstable, it is possible to have translated theulna on the humerus without knowing this. Itis therefore helpful, if there is any concernabout this, to view the joint under the C-armin the A/P plane before proceeding with ulnar fixation.

Once the joint is reduced and held inposition, the first proximal ulnar pin can beplaced using a two-hole post (Figure 21). Thisis tightened into place on the ringperpendicular to the ulna. A second pin canbe placed as well (Figure 22). Again, becauseof the size and the trefoil shape of the ulna, itis sometimes frustrating when placing thesepins and great patience may be necessary topredrill and achieve bicortical fixation of the 4mm pins. Once the first two pins are in place,ranging through flexion and extension andassuring reduction of the joint is important. If there is a tendency for the elbow tosubluxate, then alignment has not beenachieved and the bolts must be loosened and reduction achieved.

Figure 21

Figure 22

Surgical Technique

23

In summary, the assembly is as follows:

1. The axis pin is placed across the distalhumerus using a 3.5 mm pin.

2. The hinge – the medial gear block and thelateral hinge block are slid onto the axispin and using the ring of appropriate size,the hinge blocks are connected andaffixed firmly using the hinge blockconnectors through the bolts. If there isvalgus alignment, it needs to be adjusted.Loosen set screw on lateral componentand rotate 10 mm Hex until ring is inproper alignment. Tighten set screw.

3. The alignment of the hinge relative to tiltaxis pin is confirmed by sliding the framealong the pin. The proximal medial andthe proximal lateral half pin is placedusing the 3.8 mm drill and 5 mm half pin (in most adults).

The second pin is placed and then theoptional third pin is placed on the lateral side.

Surgical Technique

24

Surgical Technique

4. Before the axis pin is removed, confirmthat the hinge rotates appropriately.

5. The ulnar assembly, or the fixation of theulna is then performed. Ensure that thejoint tracks appropriately and that thedistractor blocks are flush at this zero position.

6. Next, the ulna is placed in the reducedposition at approximately 90° and the first 4 or 5 mm pins is placed proximallyfollowed by a second and/or third pin if needed. These are extended downdistally and kept on the subcutaneousborder of the ulna.

Again, the axis pin is kept in place if possible,taken through a range of motion to determinethat the hinge is functioning well actively andpassively. And finally, the axis pin is removed.All pin lengths should be checked by C-armto ensure proper length and alignment, andfinally, cut off at the appropriate length. Beforeleaving the operating room, confirm that allconnections are tightened including the halfpins to the frame.

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Application of Distraction

Once the joint has been reduced and all pins applied, distraction can then be applied to the system through the distractionmechanism. Distraction is achieved by turningthe bolts located on the ulnar ring fixationblocks (Figure 23). Both sides of the hingeshould be distracted an equal amount. Use of distraction should be done at the discretionof the surgeon.

Again it is helpful to check the entire range of motion of the elbow. It is often impossible to achieve full extension or fullflexion immediately on the table after thisrelease because of static and resting lengthcontracture of both the triceps and bicepsand brachialis muscle masses. It isnonetheless helpful to achieve as much as possible.

Immediate Postoperative Dressings

A light dressing is applied around theCompass Hinge in the wounds with spongesand clips over the pins. The axis pin can be removed at any point once the humeralfixation is achieved. If the patient’s principlelack of position has been extension, thenextension to the point of tightness is appliedand the patient goes to the recovery room in this position. It is important to ensure thatexcessive extension is not applied. Brachialblock anesthesia is helpful in creating apainless extremity, but does precludeexamination for any nerve function. Hemovacdrains are used and left in place for severaldays to reduce the amount of potentialhematoma formation. Ice packs around the elbow are also used to reduce swellingand inflammation.

Figure 23

Surgical Technique

26

Postoperative Mobilization

The first few days are spent graduallyimproving extension or flexion dependingupon the patient’s needs. CPM is not used,nor has it been found to be helpful in thissituation. Rather a slow, controlled passivestretch of the entire elbow is used togradually improve and overcome the restinglength of the biceps brachialis and triceps.Once the swelling and immediatepostoperative edema is resolved, the patientbeings cycling his/her motion from flexion toextension over a six- to eight-hour period. Forsix to eight hours, the patient works onachieving greater and greater extension,either alone or under the supervision of thetherapist. With the clutch engaged, gradualextension is applied increasingly inaccordance with the patient’s tolerance. Theyare usually left in extension overnight.

The following day, work is done to achieve asmuch flexion as possible, again on a gradualbasis over a period of hours with change inposition applied, as tolerated, as frequentlyas every 15-30 minutes. Again, rapid changesin position are not well tolerated in the earlypostoperative period.

Surgical Technique

27

Surgical Technique

Widening the range of position is the goalover the first week and analgesia isimportant. If an indwelling brachial block ispossible, this is often quite helpful. If not,patient controlled anesthesia with intravenousnarcotics, is often the best method.Nonetheless, it should be appreciated thatthis is not comfortable and adequateanalgesia must be given to achieve thedesired result. Indomethecin therapy is alsoinitiated immediately to reduce the frequencyand extent of heterotopic ossification that ispotential in all of these cases.

The patient’s hand and wrist are oftensomewhat unsupported so the use of an off-the-shelf wrist splint is sometimes helpful.Once the swelling and soreness have begunto resolve, the patient is comfortable with theCompass Hinge, and the family is taught themethod of gradual stretching and use of theCompass Hinge, the patient may bedischarged. At four to five days following thesurgery, the patient may shower with the armuncovered. Clean water is obviouslyimportant. A sterile dressing over the woundwith standard sponges over the pin site is thedressing of choice. Again, ice should be usedliberally for the first week, packed around theelbow during stretching sessions.

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First Two Weeks

The first and second weeks are often notnoted for extensive gains, but every effortshould be made to achieve as much range ofposition as possible. The patient’s medial pinoften drains serous fluid because of somemotion of the skin at that site.

Again, clean dressings around the pins andstandard pin care are used. If any of the pinsbecome irritated or inflamed, the patient mustbe inspected for excessive skin tension andthe skin released. Oral antibiotics aresometimes necessary for cellulites around thepin sites.

The first postoperative visit is usually at oneweek following discharge from the hospital.The patient is asked to keep a record ofhis/her range of position and the particulartimes a day. This gives the surgeon someinformation as to how well the patient is usingthe Compass Hinge. Again the use of atherapist to help supervise the range ofposition is also helpful. Sessions in a therapysetting with ice and stretching over a half-dayperiod can be quite beneficial in the earlystages. Again, the overall goal is to overcomethe resting tension in the muscle, both on theflexor and extensor surfaces of the elbow.

Surgical Technique

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Removal

Six to eight weeks following application,depending upon the patient’s overallprogress, removal of the hinge is generallydone in an outpatient surgery suite.

Gentle manipulation can be performed at the time. Physical therapy is usuallycontinued to maintain range of motion and to regain strength.

Surgical Technique

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Catalog Information

Description Cat. No. Qty.

40 mm Threaded Socket 10-0901 460 mm Threaded Socket 10-0911 4Nut 10-3300 40Thin Washer 10-2700 10Star Washer 10-2708 5Half Pin 4 x 20 12-2700 3Half Pin 4 x 30 12-2702 3Half Pin 4 x 40 12-2704 3Half Pin 5 x 20 12-2707 4Half Pin 5 x 30 12-2709 4Half Pin 5 x 40 12-2711 4Half Pin 5 x 50 12-2713 4130 mm 5/8 Ring 10-1363 2150 mm 5/8 Ring 10-1364 2180 mm 5/8 Ring 10-1366 2200 mm 5/8 Ring 7110-1362 213 mm / 10 mm Wrench L20-2002 29/64 x 9 (3.5 mm) Steinman Pin 12-8117 6

Description Cat. No. Qty.

Compass Universal SetCat. No. 7106-0000

Compass Universal HingeCat. No. 7106-0001

(Includes medial gear and lateral hinge assemblies only)

Compass Instrumentation Sterilization Case

Cat. No. 7106-0004

Tray Accepts:

1 Hole Rancho Cube 10-3451 22 Hole Rancho Cube 10-3452 23 Hole Rancho Cube 10-3453 14 Hole Rancho Cube 10-3454 15 Hole Rancho Cube 10-3455 15 mm Centering Sleeve 10-3405 5Set Screw 11-2727 10Hex Driver 11-2719 12.7 mm Drill 10-3044 13.8 mm Drill 10-30456 1Pin Driver Extractor 11-2716 1Drill Guide and Trocar 7103-1040 1Drill Sleeve Adapter 7101-1005 1Composite 1/2 Pin Arc 150 mm 7110-1555 2Composite 1/2 Pin Arc 180 mm 7110-1557 2Composite 1/2 Pin Arc 200 mm 7110-1558 28 mm Bolt 10-0550 1010 mm Bolt 10-3200 2016 mm Bolt 10-3201 1020 mm Bolt 10-3203 10

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Notes

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