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Original Instruments and Implants of theAssociation for the Study of Internal Fixation –AO/ASIF

Surgical Technique

UHN/PHN Humerus Nailing System

SYNTHES 1

Indications 2

UHN – Retrograde insertion 4

Compression (optional) 12

UHN – Antegrade insertion 14

Proximal locking with bolts 20(standard locking)

Distal locking 18

Compression (optional) 24

Proximal locking with spiral blade 26

PHN – Antegrade insertion 32

Implant removal 40

Case studies 41

Bibliography 46


Table of contents

WarningThis description is not sufficient for immediate applicationof the instrumentation. Instruction by a surgeon experiencedin handling this instrumentation is highly recommended

Image intensifier control

2


Indications

UH

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UHN – locking with bolt or spiral blade

The “Solid Humerus Nail”, or UHN, can be inserted into thehumerus shaft in both antegrade or retrograde directions andcan be used universally for the left and the right humerus.

The special hole geometry of the nail ensures optimal posi-tioning of the locking holes in both approaches. The numer-ous locking options allow secure fixation of even short distalor proximal fragments. In the antegrade procedure using aspiral blade for proximal locking, better fixation can beachieved in osteoporotic bone. Locking with bolts offers theoption of interfragmental compression for enhanced stabilisa-tion of transverse and short oblique fractures.

The range of indications for the UHN includes humerus shaftfractures down to approx. 5 cm proximal to the olecranonfossa with closed epiphyseal plates for:

– stable or unstable fractures

– pathological fractures

– refractures, fractures with delayed healing andpseudoarthroses

SYNTHES 3

PHN – standard locking with spiral blade

The “Proximal Humerus Nail”, or PHN, is inserted into theproximal humerus shaft in the antegrade direction and can beused universally for the left and the right humerus. The spiralblade is normally used for proximal locking and producesadequate anchorage even in an osteoporotic humerus head.

The range of indications for the PHN includes humerus frac-tures in adults in the subcapital area excluding the surgicalneck (AO/ASIF classification: A2, A3), or with concurrentavulsion of the greater tuberosity (AO/ASIF classification: Extra-articular bifocal fractures B1, B2) for:

– stable or unstable fractures

– pathological fractures

– refractures, fractures with delayed healing andpseudoarthroses

In selected cases, joint fractures at the head of the humeruscan also be managed by this technique (AO classification:C fractures) if the domed head fragment is large enough andnot itself fractured.

PHN

4


UHN – Retrograde insertion

1Position patient

The patient is preferably placed in the prone position, sup-ported by pads, on the ipsilateral edge of the table. Positionthe fractured upper arm on an additional arm board orarm rest fastened to the table. The elbow is flexed at 90°. Ifnecessary, it should be possible to flex the elbow up to ap-prox. 120°. In this position, the surgeon has a good view ofthe operating field from the dorsal side. It must be possible toview the whole upper arm, including the elbow and humerushead, in two planes in the image intensifier. The hangingforearm usually adopts the correct rotation by itself.

If the patient's general condition or injuries prevent the adop-tion of the prone position, the operation can also beperformed with the patient in the lateral or supine positions.

If the patient is placed in the lateral position, the arm to betreated should be positioned over a foam wedge. It mustbe possible to bend the elbow joint up to approx. 120°. Thepatient must be adequately supported.

If the patient is supine, a position approximating the lateralposition should be achieved by the use of supporting pads.With the elbow flexed, the humerus is held under tension bythe assistant.

The ability to view the whole of the humerus in the imageintensifier should be checked preoperatively, bearing in mindthat this is much more difficult with the lateral and supinepositions than with the prone position.

UHN 2

SYNTHES 5

2Determine nail length

The approximate nail length can be determined preopera-tively. Measure the length of the unfractured humerusfrom its head to the olecranon fossa and deduct 5–6 cm fromthe measured distance.

The length can only be determined correctly on the fracturedarm if the fracture is correctly reduced.

Position the image intensifier for an AP view of the distalhumerus (position 1). Using long holding forceps, hold theRadiographic Ruler for UHN (358.590) parallel to the humerusso that the proximal locking holes symbolized on the ruler arelocated at the correct point against the distal humerus.Mark the skin over the distal humerus at the end of the ruler.

Position the image intensifier over the proximal humerus(position 2), place the distal end of the ruler next to themarked skin site and record an AP image. Check the reduc-tion and read off the nail length from the image of the ruler.

Note: The nail tip should only project a little way into thehumerus head.

3Determine nail diameter

Position the image intensifier for a lateromedial view of thedistal humerus. Hold the ruler parallel or at right angles to thehumerus so that the square “NAIL DIAMETER” marking (6.7,7.5, 9.5) is positioned over the medullary canal. The innersquare of this marking corresponds to the nail diameter. Selectthe nail diameter shown when the medullary canal/cortextransition is still visible at the sides of the square in the imageintensifier.

�

�

cortex

cortex

nail diameter

Position 1Position 2

6

5Mount nail on insertion handle

Mount the selected nail on the Insertion Handle (358.692),ensuring that the apex of the nail curvature points away fromthe insertion handle. Screw the Connecting Screw (358.540)through the insertion handle into the nail and tightenusing the Ratchet Wrench � 11.0 mm (321.200) or the Com-bination Wrench � 11.0 mm (321.160).

Note: If interfragmental compression with minimizing of thefracture gap is desired for transverse or short oblique frac-tures, the Compression Device (358.600) and the CompressionConnecting Screw (358.610) must be screwed onto theinsertion handle at this point (see page 13, Applying compres-sion).

4Open medullary canal

With the elbow flexed at 90°, the lengthwise skin incisionbegins slightly distal to the olecranon. Split the triceps tendonwhere it extends beyond the distal humerus shaft. It shouldbe possible to view a bone area starting at the upper edge ofthe olecranon fossa and proceeding approx. 25 mm in theproximal direction. Do not open the elbow joint.

The insertion point in the medullary canal is located in thecentre of an imagined triangle between the medial and lateralsupracondylar edge and the roof of the olecranon fossa.

First drill three holes � 3.2 mm (Drill Bit � 3.2 mm [315.330])perpendicular to the medullary canal and then widen theholes with the Drill Bit � 4.5 mm (310.440). Lower the bit toan angle of approx. 30° (see illustration). Using the burrs,open up an entry portal 10 mm wide and 20 mm long. Theconical Burr � 8.5/3.5 mm (358.681) allows rapid reaming,while the cylindrical Projectile Burr (358.682) facilitates theshaping of the insertion point.

Chamfer and smooth down the distal edge of the insertionhole such that the nail can be introduced unhindered.

1 cm

2 cm

SYNTHES 7

6Insert nail

Insert the nail with slightly rotating movements of the inser-tion handle. It is not advisable to use a hammer wheninserting the UHN since this increases the risk of iatrogenicfissures or fractures at the insertion hole. Insert the nail up tothe fracture site, reduce the fracture and continue beyondthe fracture gap under image intensifier control. Proceedcarefully so as to avoid injury to the radial nerve, particularlyin fractures of the mid to distal third of the shaft.

If radial nerve paresis is present preoperatively, it may benecessary to explore the nerve through a short anterolateralincision at the transition of the mid and distal third of theshaft.

If the nail proves very difficult to advance, check whetherwidening of the medullary canal using the Hand Reamer forMedullary Canal (351.920/930/940) is indicated. This reducesthe risk of iatrogenic fractures. Under no circumstancesshould you knock the nail in with a hammer.

Continue advancing the nail until the tip projects slightly intothe humerus head. This allows the insertion of a latero-medial bolt in the humerus head distal to the rotator cuff.

Check the nail position under the image intensifier.

Note: Pressure against the humerus head when advancingthe nail prevents diastasis formation and possible associatedhealing problems.

UHN/PHN Humerus Nailing SystemUHN – Retrograde insertion

8

7Proximal locking

When the nail tip has reached its definitive position inthe humerus head, the nail is first locked proximally using theRadiolucent Drive (511.300) (pages 18–19, steps 7–10) orthe “freehand“ technique.

Check the position of the proximal fragment, since a fracturegap could have formed during nail insertion. Use Drill Bit� 3.2 mm (315.330) for the 3.9-mm bolts or Drill Bit� 2.7 mm (359.031) for the 3.4-mm bolts. Determine thelength of the locking bolt with the Depth Gauge for LockingBolts (355.790) or read the length directly off the ring markingon the calibrated drill bit.

Note: To avoid jeopardising the trunk or branches of theaxillary nerve after the skin incision, the underlying musclesshould be prepared by blunt dissection and spread apartcarefully.

SYNTHES 9

9Drill and determine length of locking bolt

Using the appropriate drill bit (� 3.2 mm for � 3.9-mm boltsor � 2.7 mm for � 3.4-mm bolts), drill through both corticesuntil the tip of the drill bit just breaks through the anteriorcortex. The required length of the locking bolt can be deter-mined either by reading it directly off the calibrated drill bit orby measuring with the Depth Gauge for Locking Bolts(355.790). If the depth gauge is used, add 2 mm to themeasured length to ensure that the locking bolt can penetratethe anterior cortex.


Distal locking

Distal locking is performed using the insertion handle withthe attached aiming arm. Normally, double-locking in parallelis performed at the distal end, i.e. both the static and com-pression hole are used.

8Mount aiming arm and insert trocar combination

Mount the Aiming Arm for Standard Locking (358.689) onthe insertion handle. Check the insertion handle/nail connec-tion and tighten if necessary. Likewise, check the reduction.

Insert the two-piece trocar combination (Protection Sleeve11.0/8.0 [355.700], Trocar � 8.0 mm [355.750]) through thedesired hole in the aiming arm, make a stab incision andinsert the trocar down to the bone. Remove the trocar andinsert the drill sleeve corresponding to the diameter ofthe bolt or drill (for � 3.9-mm bolts use Drill Sleeve 8.0/3.2[355.722], for � 3.4-mm bolts use Drill Sleeve 8.0/2.7[359.026]).

10

11Insert end cap into nail

The end cap protects the inner thread of the nail from tissueingrowth and facilitates subsequent implant removal. The endcap is available in four lengths (extension of 0, 5, 10 or15 mm) and can, if necessary, be used to extend the nail andthus allow freer placement of the locking holes in regionswith good bone quality.

Tighten the end cap using the hexagonal screwdriver (for the0 mm extension use the Small Hexagonal Screwdriver� 2.5 mm [314.240], for all other extensions use the LargeHexagonal Screwdriver � 3.5 mm [314.270]).

10Insert locking bolts

Insert a locking bolt through the protection sleeve andtighten using the large Hexagonal Screwdriver � 3.5 mm(314.270) until the bolt head rests against the posteriorcortex. The tip of the locking bolt should project beyond theanterior cortex by 1–2 mm.

Insert the second locking bolt in the same way.

Notes: Insert two locking bolts into each main fragment,particularly into short fragments.

The insertion of a locking bolt through the oblique lockinghole prevents the insertion of a second locking boltthrough the perpendicular holes and thus the application ofcompression.

SYNTHES 11


12Postoperative management

Apply a sterile dressing with cotton wool padding postopera-tively; additional splinting of the arm is not required.

Check radial nerve function when the anaesthetic has wornoff.

Remove the Redon drain on the second postoperative day.

Active and passive movements and muscle-tensing exercises inthe shoulder and elbow can begin immediately, althoughrotational movements against resistance should be avoideduntil the fracture has healed.

13X-ray checks

X-rays checks are recorded immediately after the operation.Further X-ray checks are recorded after two, six and twelveweeks, and beyond, depending on the course of the healingprocess.

12

Compared to the femur and the tibia, the humerus is lessexposed to compressive stresses but more exposed torotational stresses. Thus, while dynamic loading will producefragment adaptation with certain fracture types in the femurand the tibia, healing problems can occur with correspondingfractures of the humerus shaft.

The application of compression facilitates the controlledjoining of the fragments with the aim of closing the fracturegap or exerting interfragmental compression.

Interfragmental compression is therefore indicated in thefollowing types of humerus shaft fractures:

– Transverse fractures

– Short oblique fractures

In view of the associated loss of length and possible disloca-tions, compression is contraindicated for the followingfracture types:

– Spiral fractures

– Long oblique fractures

– Lengthwise unstable fractures


Compression (optional)

SYNTHES 13

Applying compression

Screw the Compression Device (358.600) with the Compres-sion Connecting Screw (358.610) and insertion handle ontothe nail using the Ratchet Wrench � 11.0 mm (321.200) orthe Combination Wrench � 11.0 mm (321.160). Insert thenail into the medullary canal and lock distally in the compres-sion hole. Next, lock the nail in the proximal fragment underimage intensifier control. Tightening the nut on the endof the compression connecting screw moves the nail in thecompression hole and the corresponding distal fragment in aproximal direction (by a maximum of 8 mm). The moment inwhich the fragments come together must be checked underthe image intensifier, bearing in mind that when thefragments approximate, the base of the nail is located slightlymore distally (risk of impingement).

To secure the reduction, insert an additional bolt in the staticlocking hole. Then remove the compression device and insertan end cap into the end of the nail.

14


UHN – Antegrade insertion

1Position patient

Position the patient on his/her back with the upper bodyraised at an angle of 30°. Support the shoulder with pads.The operating table must be radiolucent in the shoulder area,or else it should be possible to remove the correspondingtable section. It must be possible to view the whole upperarm, including the elbow and humerus head, in two planes inthe image intensifier. Support the fractured arm on a siderest.

2Determine nail length

The approximate nail length can be determined preopera-tively. Measure the length of the unfractured humerus fromits head to the olecranon fossa and deduct 3–4 cm from themeasured distance.

On the fractured arm, the correct length can only be deter-mined correctly if the fracture is correctly reduced.

Position the image intensifier for an AP view of the proximalhumerus (position 1). Hold the Radiographic Ruler for UHN(358.590) parallel to the humerus so that the locking holessymbolized on the ruler are located at the correct pointagainst the proximal humerus. Mark the skin at the proximalend of the ruler.

Position the image intensifier over the distal humerus (posi-tion 2), place the proximal end of the ruler next to themarked skin site and record an AP image. Check the reduc-tion and read off the nail length from the illustration on theruler.

Note: The nail tip should be positioned at least 20 mm awayfrom the cranial boundary of the olecranon fossa.

�

Position 1Position 2

cortex

cortex

nail diameter

SYNTHES 15


Position the image intensifier for a lateromedial view of thedistal humerus. Hold the ruler parallel or at right angles to thehumerus so that the square “NAIL DIAMETER” marking (6.7,7.5, 9.5) is positioned over the medullary canal. The innersquare of this marking corresponds to the nail diameter. Selectthe nail diameter shown when the medullary canal /cortextransition is still visible at the sides of the square in the imageintensifier.


Make the initial incision anterolateral to the acromion processand split the deltoid muscle lengthwise. Palpate the greatertuberosity, identify – but do not expose – the supraspinatustendon and split the mid section lengthwise. Avoid anyadditional injury to the rotator cuff at all costs. The arm canbe adducted across the chest in order to gain better access tothe proximal humerus.

The antegrade insertion point for the UHN is located on theextended axis of the central humerus shaft at the bone-cartilage transition of the humerus head and not on thegreater tuberosity, otherwise the tendon attachment of thesupraspinatus will become involved. With the humerushead correctly positioned, the point is located just in front of,or below, the tip of the acromion process. Find this positionunder the image intensifier using a Kirschner Wire � 2.5 mmwith Trocar Tip (292.260). The orientation between an exces-sively ventral or dorsal position of the Kirschner wire can bedetermined where the line of the humerus head intersectsthe Kirschner wire. The Kirschner wire is located in the exactposition if it rests in the middle of the humerus head.

Using the cannulated Awl with T-Handle (351.120), advancethe Kirschner wire into the medullary canal. Check the posi-tion of the Kirschner wire under the image intensifier in boththe frontal and sagittal planes. Unscrew the Kirschner wireretention nut and open the medullary canal with the awl.

�

16


Mount the selected nail on the Insertion Handle (358.692),ensuring that the apex of the nail curvature points away fromthe insertion handle. Screw the Connecting Screw (358.540)through the insertion handle into the nail and tighten usingthe Ratchet Wrench � 11.0 mm (321.200) or the CombinationWrench � 11.0 mm (321.160).

Note: If interfragmental compression with minimizing of thefracture gap is desired for transverse or short obliquefractures, the Compression Device (358.600) and the Com-pression Connecting Screw (358.610) must be screwed ontothe insertion handle at this point (see page 25, Applyingcompression).

SYNTHES 17

6Insert nail

Insert the nail with slightly rotating movements of the inser-tion handle. It is not advisable to use a hammer wheninserting the UHN since this increases the risk of iatrogenicfissures or fractures at the insertion hole. Insert the nail up tothe fracture site, reduce the fracture and continue beyondthe fracture gap under image intensifier control. Proceedcarefully so as to avoid injury to the radial nerve, particularlyin fractures of the mid to distal third of the shaft.

If radial nerve paresis is present preoperatively, it may benecessary to explore the nerve through a short anterolateralincision at the transition of the mid and distal third of theshaft.

Check the nail position under the image intensifier.

Notes:– If the nail proves very difficult to advance, check whether

widening of the medullary canal using the Hand Reamer forMedullary Canal (351.920/930/940) is indicated. This re-duces the risk of iatrogenic fractures. Under no circumstancesshould you knock the nail in with a hammer.

– Pressure against the olecranon when advancing the nail pre-vents diastasis formation and possible associated healingproblems. Countersink the nail fully into the humerus headto avoid irritation of the shoulder structures, including duringabduction (impingement risk).

UHN/PHN Humerus Nailing SystemUHN – Antegrade insertion

18

If the fracture gap is well closed, distal locking can be imple-mented after proximal locking. Otherwise distal lockingshould be implemented first, once the nail tip has reached itsdefinitive position. The nail should then be knocked back and,finally, locked at the proximal end.

If a spiral blade is used, the nail must always be locked first atthe proximal end so that the spiral blade can be placed in theoptimal position.

Distal locking

Double-locking in parallel is normally performed at the distalend using the radiolucent drive or the “freehand” technique.

Distal locking with the Radiolucent Drive (511.300) is de-scribed below.

7Position insertion handle and adjust image

Check the insertion handle/nail connection and tighten theconnecting screw if necessary. In case of proximal locking witha spiral blade, swivel the insertion handle with aiming armapprox. 20° ventrally so as to respect the retrotorsion ofthe humerus head. Thus, the spiral blade will be positioned inthe centre of the humerus head.

Check the position of the distal fragment, since a fracture gapcould have resulted from nail insertion.

Align the image intensifier with the distal nail holes such thatthe holes appear perfectly round in the image.

8Perform incision

Determine the entry point on the skin and perform a stabincision with the scalpel.

Note: To avoid injury to the brachial artery or median nerve,perform blunt dissection down to the bone.

UHN/PHN Humerus Nailing System UHN – Antegrade insertion

Distal Locking

Incorrect Correct

SYNTHES 19

9Drill

Using Drill Bit � 3.2 mm (315.330) for the � 3.9-mm bolts orDrill Bit � 2.7 mm (359.031) for the � 3.4-mm bolts, insertthe corresponding bit into the radiolucent drive and introducethrough the incision down to the bone.

Incline the radiolucent drive such that the tip of the drill bit iscentered over the locking hole. The bit should almost com-pletely fill the circular locking hole. Holding the drill bit in thisposition, drill through both cortices until the tip just pene-trates the posterior cortex.

10Determine length of locking bolts and insert lockingbolts

If the calibrated drill bit is used, read the correct bolt lengthdirectly off the ring marking or else use the Depth Gauge forLocking Bolts (355.790). If the depth gauge is used, add2 mm to the measured length to ensure that the locking boltcan penetrate the posterior cortex.

20

11aMount aiming arm and insert trocar combination

Mount the Aiming Arm for Standard Locking (358.689) onthe insertion handle. Recheck the reduction.

Insert the two-piece trocar combination (Protection Sleeve11.0/8.0 [355.700], Trocar � 8.0 mm [355.750]) through thedesired hole in the aiming arm, make a stab incision andinsert the trocar down to the bone. Remove the trocar andinsert the drill sleeve corresponding to the bolt/drill diameter(for � 3.9-mm bolts use Drill Sleeve 8.0/3.2 [355.722], for� 3.4-mm bolts use Drill Sleeve 8.0/2.7 [359.026]).

Note: Only incise the skin and then perform blunt dissectionso as to avoid injury to the axillary nerve and its branches.

Proximal locking is performed using the insertion handle withthe attached aiming arm, which should be aligned precisely inthe mediolateral plane.

Single-hole oblique locking is considered to be the standardlocking method for antegrade insertion, since it does not interfere with the dome of the humerus and offers betterpurchase medially thanks to the stronger cortical bone.

For proximal locking with the spiral blade see page 26 ff., steps11b–17b.

UHN/PHN Humerus Nailing System UHN – Antegrade insertion

Proximal locking with bolt (standard locking)

SYNTHES 21

12aDrill and determine length of locking bolt

Using the appropriate drill bit (� 3.2 mm for � 3.9-mm boltsor � 2.7 mm for � 3.4-mm bolts), drill through both corticesuntil the tip of the drill bit just breaks through the medialcortex. The required length of the locking bolt can be deter-mined either by reading it directly off the calibrated drill bit orby measuring with the Depth Gauge for Locking Bolts(355.790). If the depth gauge is used, add 2 mm to themeasured length to ensure that the locking bolt can pene-trate the medial cortex.

13aInsert locking bolts

Insert a locking bolt through the protection sleeve and tightenusing the large hexagonal Screwdriver � 3.5 mm (314.270)until the bolt head rests against the lateral cortex. The tipof the locking bolt should project beyond the medial cortex by1–2 mm.

In case of double-parallel locking with two locking bolts,insert the second locking bolt in the same way.

Note: The insertion of a locking bolt through the obliquelocking hole prevents the insertion of a second boltthrough the perpendicular holes and thus the application ofcompression.

22

14aInsert end cap into nail

The end cap protects the inner thread of the nail from tissueingrowth and facilitates subsequent implant removal. The endcap is available in four lengths (extension of 0, 5, 10 or15 mm) and can, if necessary, be used to extend the nail andthus allow freer placement of the locking holes in regionswith good bone quality.

Tighten the end cap using the hexagonal screwdriver (for the0 mm extension use the small hexagonal Screwdriver� 2.5 mm [314.240], for all other extensions use the largehexagonal Screwdriver � 3.5 mm [314.270]).

Ensure that the nail and the end cap are fully countersunk inthe humerus head, so that shoulder function remains un-hindered, including during abduction. For this reason, an endcap without extension should be used where possible.

Note: If the compression device is used, bear in mind thatthe base of the nail will be located close to the surface ofthe domed head. It is preferable to insert the base of the naildeeper into the humerus head and, if necessary, to offset theexcessive distance from the dome surface with an appropriateend cap. Any nail projection could cause impingement andmust be avoided at all costs.

SYNTHES 23

UHN/PHN Humerus Nailing System UHN – Antegrade insertionProximal locking with bolt (standard locking)

16aX-ray checks

X-ray checks are recorded immediately after the operation.Further X-ray checks are recorded after two, six and twelveweeks, and beyond, depending on the course of the healingprocess.

15aPostoperative management

Apply a sterile dressing with cotton wool padding postopera-tively; additional splinting of the arm is not required.

Check radial nerve function when the anaesthetic has wornoff.


Active and passive movements and muscle-tensing exercises inthe shoulder and elbow can begin immediately, althoughrotational movements against resistance should be avoideduntil the fracture has healed.

24

Compared to the femur and the tibia, the humerus is lessexposed to compressive stresses but more exposed to rota-tional stresses. Thus, while dynamic loading will producefragment adaptation with certain fracture types in the femurand the tibia, healing problems can occur with correspondingfractures of the humerus shaft.

The application of compression facilitates the controlledjoining of the fragments with the aim of closing the fracturegap or exerting interfragmental compression.

Interfragmental compression is therefore indicated in thefollowing types of humerus shaft fractures:

– Transverse fractures

– Short oblique fractures

In view of the associated loss of length and possible disloca-tions, compression is contraindicated for the following fracturetypes:

– Spiral fractures

– Long oblique fracture

– Lengthwise unstable fractures

The compression device is designed primarily for the retro-grade procedure, since two parallel bolts are required at thebase of the nail. In the antegrade procedure, however, onlyone bolt is locked obliquely as a rule. Nevertheless, it isstill possible to use the compression device in the antegradeprocedure, although it should be borne in mind that the bonepurchase for these two bolts, now aligned in parallel, will bereduced as a result of the minimal cortical thickness andthat the compression bolt produces less compression in thecancellous bone compared to the retrograde technique.


Compression (optional)

SYNTHES 25

Applying compression

Screw the Compression Device (358.600) with the Compres-sion Connecting Screw (358.610) and insertion handle ontothe nail using the Ratchet Wrench � 11.0 mm (321.200) orthe Combination Wrench � 11.0 mm (321.160). Insert thenail into the medullary canal and lock proximally in the com-pression hole. Next, lock the nail in the distal fragment underimage intensifier control. Tightening the nut on the end ofthe compression connecting screw moves the nail in thecompression hole, together with the whole distal fragment, ina proximal direction. The moment in which the fragmentscome together must be checked under the image intensifier,bearing in mind that, when the fragments approximate, thebase of the nail is located slightly more proximally (risk ofimpingement).

To secure the reduction, insert an additional bolt in the staticlocking hole. Then remove the compression device and insertan end cap into the end of the nail.

26

Spiral blade locking can produce much greater stability in theproximal fragment compared to locking with bolts, particu-larly in the following cases: shaft fractures extending well intothe proximal section, combinations of shaft fractures withan ipsilateral, subcapital humerus fracture, and in patients withosteoporotic bone.

Note: The spiral blade cannot be combined with the UHN� 6.7 mm.


Proximal locking with spiral blade

11bMount aiming arm and insert trocar combination

Mount the Aiming Arm for Spiral Blade Locking (358.679) onthe insertion handle.

If starting with proximal locking, tighten the connectingscrew if necessary. Likewise, check the reduction. Swivel theinsertion handle with aiming arm approx. 20° ventrally soas to respect the retrotorsion of the humerus head. Thus, thespiral blade will be positioned in the centre of the humerushead.

Make a skin incision and insert the three-piece trocar combi-nation (Protection Sleeve 14.0/4.5 [358.688], Drill Sleeve4.5/2.0 [358.694], Trocar � 2.0 mm [358.686]) through thehole in the aiming arm marked “Spiral Blade” and insertthe trocar down to the bone.

Remove the trocar.


SYNTHES 27

13bAttach spiral blade to inserter

Insert the Connecting Screw (358.697) in the Inserter for SpiralBlade (358.696), mount the Spiral Blade (462.634–654) ofthe determined length on the cams of the inserter and tightenthe connecting screw. Check for a secure fit.

12bDetermine length of spiral blade and drill

Insert a Kirschner Wire � 2.0 mm (292.650) through the DrillSleeve 4.5/2.0 (358.694) into the humerus head and usethe image intensifier to check the definitive position at thetransition of the medial and lower third of the humerus head.The wire should extend almost to the cortex on the oppositeside, but should not perforate it down to the subchondralspace. Pass the Depth Gauge for Spiral Blades (358.698) overthe Kirschner wire and read off the length of the spiralblade on the scale. Remove the drill sleeve and depth gauge;the Kirschner wire must remain in the bone.

Pass the Cannulated Drill � 4.5 mm for Spiral Blades(358.691) over the Kirschner wire and drill down to the stopunder image intensifier control.

28

14bInsert spiral blade

Introduce the spiral blade and inserter over the Kirschnerwire, through the aiming arm and down to the lateral cortex.

Align the T-handle of the inserter parallel with the aimingarm. Applying gentle hammer blows to the connecting screw,advance the spiral blade to the desired position. This willcause the T-handle to rotate through 90°. Check the positionof the spiral blade under the image intensifier.

Unscrew the insertion instruments for the spiral blade andremove the Kirschner wire.

If necessary, a transverse locking bolt can still be insertedthrough the proximal hole (shown in red in the illustration).

Remove the insertion handle.

Note: For fractures with avulsion of the greater tuberosity(B fractures), the latter must always be reduced and fixed aswell. This can be achieved either by means of a coveredtechnique or by extending the cranial incision. The tuberositycan be fixed with a cannulated titanium screw � 4.0 mm orwith tension-band wiring. In the latter technique, a suture orwire loop, for example, can be anchored in the speciallyprovided holes on the spiral blade or on the most proximallocking bolt.

SYNTHES 29

15bInsert end cap into nail

The end cap protects the inner thread of the nail from tissueingrowth and facilitates subsequent implant removal. Aspecial gold-coloured End Cap (462.660/665/666) is used tolock the spiral blade. During insertion, increased resistanceis encountered during the final few turns as a result of thenotch on the thread, which is designed to prevent looseningof the screw. Tighten the end cap securely.

The end cap is available in three lengths (extension of 0, 5 or10 mm) and can, if necessary, be used to extend the nailand thus allow freer placement of the locking holes in regionswith good bone quality.

Ensure that the nail and the end cap are fully countersunk inthe humerus head, so that shoulder function remains unhin-dered, including during abduction. For this reason, an end capwithout extension should be used where possible.

Note: When locking with a spiral blade, the End Cap(462.660/665/666) must always be inserted into the nail,otherwise the spiral blade will not be properly secured.

UHN/PHN Humerus Nailing System UHN – Antegrade insertionProximal locking with spiral blade

30

16bPostoperative management

Apply a sterile dressing with cotton wool padding postopera-tively; additional splinting of the arm is not required.Check radial nerve function when the anaesthetic has worn off.


Active and passive movements and muscle-tensing exercisesin the shoulder and elbow area can begin immediately,although rotational movements against resistance should beavoided until the fracture has healed.

UHN/PHN Humerus Nailing SystemUHN – Antegrade insertionProximal locking with spiral blade

17bX-ray checks

X-ray checks are recorded immediately after the operation.Further X-ray checks are recorded after two, six and twelveweeks, and beyond, depending on the course of the healingprocess.

cortex

cortex

nail diameter

32


PHN – Antegrade insertion

1Position patient

Position the patient on his/her back with the upper bodyraised at an angle of 30°. Support the shoulder with pads.The operating table must be radiolucent in the shoulder area,or else it should be possible to remove the correspondingtable section. It must be possible to view the humerus, includ-ing the humerus head, in two planes in the image intensifier.Support the fractured arm on a side rest.


Since it is not very long, the PHN usually occupies a relativelywide part of the medullary canal. Thus, the � 7.5-mm PHNis used as the standard nail and the � 8.0-mm PHN for osteo-porotic bone with a very wide medullary canal. In case ofdoubt, select the nail diameter according to the measuringprocedure used for the UHN.

Position the image intensifier for a lateromedial view of theproximal humerus. Hold the Radiographic Ruler for UHN(358.590) parallel or at right angles to the humerus so thatthe square “NAIL DIAMETER” marking (7.5 or 9.5 [corre-sponding to � 8.0-mm PHN]) is positioned over the medullarycanal. The inner square of this marking corresponds tothe nail diameter. Select the nail diameter shown when themedullary canal/cortex transition is still visible at the sidesof the square in the image intensifier.

�

SYNTHES 33


In certain cases after a closed reduction, the humerus headmay need to be fixed temporarily with an elevator or Kirschnerwire. The correct head position is visible in the AP view at themaximum humerus head diameter.

Perform an anterior incision in the region of the acromionprocess and split the deltoid muscle and rotator cuff.

Using the cannulated Awl with T-Handle (351.120), insert aKirschner wire at the appropriate insertion point in the proxi-mal humerus and advance in the medullary canal. Check theposition of the Kirschner wire under the image intensifierin both the frontal and sagittal planes. Unscrew the Kirschnerwire retention nut and open the medullary canal with the awl.


Mount the selected nail on the Insertion Handle (358.692),ensuring that the apex of the nail curvature pointsaway from the insertion handle. Screw the Connecting Screw(358.540) into the nail and tighten using the RatchetWrench � 11.0 mm (321.200) or the Combination Wrench� 11.0 mm (321.160).

34

5Insert nail

Insert the nail with slightly rotating movements of the inser-tion handle. Insert the nail up to the fracture site, reducethe fracture and continue beyond the fracture gap under theimage intensifier.

Proximal locking

After insertion, always lock the nail proximally first. To this end,the nail must be countersunk below the surface of thehumerus head so that it does not project above the domedhead even after the end cap is inserted and so that the spiralblade is not positioned too distally.

6Mount aiming arm and insert trocar combination

Mount the Aiming Arm for Spiral Blade Locking (358.679) onthe insertion handle. Check the insertion handle/nail connec-tion and tighten the connecting screw if necessary. Likewise,check the reduction.

Swivel the insertion handle with aiming arm approx. 20°ventrally so as to respect the retrotorsion of the humerushead. Thus, the spiral blade will be positioned in the centre ofthe humerus head.

Make a skin incision and insert the three-piece trocar combi-nation (Protection Sleeve 14.0/4.5 [358.688], Drill Sleeve4.5/2.0 [358.694], Trocar � 2.0 mm [358.686]) through thehole in the aiming arm marked “Spiral Blade” and insertthe trocar down to the bone.

Remove the trocar.


SYNTHES 35

7Determine length of spiral blade and drill

Insert a Kirschner Wire � 2.0 mm (292.650) through the DrillSleeve 4.5/2.0 (358.694) into the humerus head and usethe image intensifier to check the definitive position at thetransition of the medial and lower third of the humerus head.The wire should extend almost to the cortex on the oppositeside, but should not perforate it down to the subchondralspace. Pass the Depth Gauge for Spiral Blades (358.698) overthe Kirschner wire and read off the length of the spiralblade on the scale. Remove the drill sleeve and depth gauge;the Kirschner wire must remain in the bone.

Pass the Cannulated Drill � 4.5 mm for Spiral Blades(358.691) over the Kirschner wire and drill down to the stopunder image intensifier control.

8Attach spiral blade to inserter

Insert the Connecting Screw (358.697) in the Inserter forSpiral Blades (358.696), mount the selected Spiral Blade(462.634–654) on the cams of the inserter and tighten theconnecting screw. Check for a secure fit.

UHN/PHN Humerus Nailing System PHN – Antegrade insertion

36

9Insert spiral blade

Introduce the spiral blade and inserter over the Kirschnerwire, through the aiming arm and down to the lateral cortex.

Align the T-handle of the inserter parallel with the aimingarm. Applying gentle hammer blows to the connecting screw,advance the spiral blade to the desired position. This willcause the T-handle to rotate through 90°. Check the positionof the spiral blade under the image intensifier.

Unscrew the insertion instruments for the spiral blade andremove the Kirschner wire.

The lateral cortex fragment can be further secured with anoblique bolt (shown in red in the illustration). Insert the boltas shown in steps 10, 11 and 12 on pages 37 and 38. Ensurethat the drill bit does not come into contact with the spiralblade during drilling.

Important: The obliquely inserted bolt should not be longerthan 50 mm, otherwise it will come into contact with thespiral blade.

Note: For fractures with avulsion of the greater tuberosity(B fractures), the latter must always be reduced and fixed aswell. This can be achieved either by means of a coveredtechnique or by extending the cranial incision. The tuberositycan be fixed with a cannulated titanium screw � 4.0 mmor with tension-band wiring. In the latter technique, a sutureor wire loop, for example, can be anchored in the speciallyprovided holes on the spiral blade or on the most proximallocking bolt.

SYNTHES 37

Distal locking

Check the reduction and, if necessary, close the fracture gapby compression. Distal locking is performed using the AimingArm for Spiral Blade Locking (358.679).

10Insert trocar combination

Insert the two-piece trocar combination (Protection Sleeve11.0/8.0 [355.700], Trocar � 8.0 mm [355.750]) through thedesired hole in the aiming arm, make a stab incision andinsert the trocar down to the bone. Remove the trocar andinsert the Drill Sleeve 8.0/3.2 (355.722).

11Drill and determine length of locking bolt

Using the Drill Bit � 3.2 mm (315.330) drill through bothcortices until the tip of the bit just breaks through the medialcortex. The required length of the locking bolt can be deter-mined either by reading it directly off the calibrated drill bit orby measuring with the Depth Gauge for Locking Bolts(355.790). If the depth gauge is used, add 2 mm to themeasured length to ensure that the locking bolt can pene-trate the medial cortex.

UHN/PHN Humerus Nailing SystemPHN – Antegrade insertion

38

12Insert locking bolts

Insert a locking bolt through the protection sleeve andtighten using the large hexagonal Screwdriver � 3.5 mm(314.270) until the bolt head rests against the lateral cortex.The tip of the locking bolt should project beyond the medialcortex by 1–2 mm.

Insert the second locking bolt in the same way.

13Insert end cap into nail

The end cap protects the inner thread of the nail from tissueingrowth and facilitates subsequent implant removal. Aspecial gold-coloured End Cap (462.660/665/666) is used tolock the spiral blade. During insertion, increased resistance isencountered during the final few turns as a result of the notchon the thread, which is designed to prevent loosening of thescrew. Tighten the end cap securely.

The end cap is available in three lengths (extension of 0, 5 or10 mm) and can, if necessary, be used to extend the nail andthus allow freer placement of the locking holes in regions withgood bone quality.

Ensure that the nail and the end cap are fully countersunk inthe humerus head, so that shoulder function remains unhin-dered, including during abduction.

After removing the connecting screw, leave the insertionhandle on the nail. Using the small hexagonal Screwdriver� 2.5 mm (314.240) place the End Cap 0 mm (462.660)in the proximal end of the nail through the insertion handle. Ifan end cap with extension is used, insert it directly using thelarge hexagonal Screwdriver � 3.5 mm (314.270).

Note: The End Cap (462.660/665/666) must always beinserted into the nail, otherwise the spiral blade will not beproperly secured.

SYNTHES 39

14Postoperative management

Apply a sterile dressing with cotton wool padding postopera-tively. No immobilisation is required if the situation isstable (A fractures). Physiotherapy can be started immediately.Rotational exercises should not be initiated until the end ofthe third week. Immobilisation for three weeks is indicated ifthe greater tuberosity has also been fixed or if the bonequality is poor.

15X-ray checks

X-ray checks are recorded immediately after the operation.Further x-ray checks are recorded after two, six and twelveweeks, and beyond, depending on the course of the healingprocess.

UHN/PHN Humerus Nailing SystemPHN – Antegrade insertion

40


Implant removal

Routine nail removal is not absolutely necessary since the TANtitanium alloy (Ti-Al6-Nb7) should not corrode.

Experience has shown that the insertion hole and the nailbecome overgrown with callus. However, if removal ofthe nail is still desired, this callus formation will require carefuldissection.

1Remove end cap and locking bolts or spiral blade

Remove the ingrown tissue from the hexagonal recess of theend cap, the locking bolts and or the inner thread of thespiral blade. Remove the end cap with extension 0 mm usingthe small hexagonal Screwdriver � 2.5 mm (314.240).Remove the end cap with extensions 5–15 mm using thelarge hexagonal Screwdriver � 3.5 mm (314.270). Unscrewall locking bolts except one using the large hexagonal screw-driver and the Holding Sleeve (314.280).

In case of spiral blade locking, screw the inserter onto thespiral blade using the connecting screw for spiral blades andknock the blade out using a hammer.

Before removing the remaining locking bolt, fasten theConnecting Piece for Extraction of UHN (359.021) (a)to the nail using the Connecting Screw (358.540) (b) inorder to prevent the nail from rotating or sliding away.

Screw the Inserter/Extractor for UTN/CTN and UHN (356.490)onto the connecting screw.

2Nail removal

Unscrew the remaining locking bolt and knock the nail outwith gentle blows of the Slotted Hammer (332.200).

b

a

SYNTHES 41


Case studies

1a Short oblique fracture of the humerus shaft, a.p. and lateral

b Retrograde insertion of a � 7.5-mm UHN, interfragmentalcompression, static locking, postoperative, a.p. and lateral

c Bony consolidation after 13 weeks, a.p. and lateral

a

c

b

42

2a Spiral fracture of the humerus shaft after minor trauma in

a patient after many years of cortisone therapy, conspicuouslywide medullary canal, a.p. and lateral

b Retrograde insertion of a � 9.5-mm UHN, static locking,postoperative, a.p. and lateral

c Bony consolidation after 16 weeks, a.p. and lateral

a b

c

SYNTHES 43

3a Pathological fracture of the humerus shaft with metastatic

spread from a breast carcinoma, a.p.

b Antegrade insertion of a � 7.5-mm UHN, proximal obliquestatic locking, postoperative, a.p. and lateral

c Situation after 6 months, a.p. and lateral

a b

c

UHN/PHN Humerus Nailing SystemCase studies

44

4a Proximal humerus shaft spiral fracture with fracture outlier

extending to the greater tuberosity (accident views)

b Managed with a � 7.5-mm UHN and spiral blade (viewsrecorded immediately after operation)

c Healed fracture (5 months postoperatively)

a b

c

SYNTHES 45

5a Subcapital humerus fracture (accident views)

b Managed with PHN and spiral blade (views recorded immedi-ately after operation)

c Healed fracture (3 months postoperatively)

a

b c

UHN/PHN Humerus Nailing SystemCase studies

46


Bibliography

Blum J, Rommens PM, Janzing H, Gahr R, Langendorff H(1998) Retrograde Nagelung von Humerusschaftfrakturen mitdem UHN – Eine internationale multizentrische Studie. Unfallchirurg 100, 342–352

Blum J, Machemer H, Baumgart F, Schlegel U, Wahl D, Rommens PM (1999) Biomechanical Comparison of Bendingand Torsional Properties in Retrograde Intramedullary Nailingof Humeral Shaft Fractures. J. Orthop. Trauma 13, 344–350

Blum J, Högner M, Baumgart F, Schlegel U, Wahl D, RommensPM (1999) Die retrograde Eröffnung der Oberarmmarkhöhle.Biomechanische Untersuchung zur Stabilitätsänderung desHumerusschaftes. Unfallchirurgie 25, 207–214

Blum J, Rommens PM (2000) UnaufgebohrteHumerusnagelung – Klinische und biomechanische Unter-suchungen eines neuen Titan-Marknagelsystems zur Behand-lung von Humerusschaftfrakturen. Hefte zu Der Unfallchirurg279, Springer, Heidelberg

Blum J, Janzing H, Gahr R, Langendorff HS, Rommens PM(2001) Clinical Performance of a New Medullary Humeral Nail: antegrade versus retrograde insertion. J. Orthop. Trauma 15:342–349

Blum J, Rommens PM (2001) Interfragmentäre Kompressionbei der Humerusschaftnagelung mit einem speziellen Kom-pressionsgerät. Akt Traumatol 31: 90–94

Rommens PM, Blum J, Runkel M (1998) Retrograde Nailing ofHumeral Shaft Fractures. Clin. Orthop. 350, 26–39

Rommens PM, Blum J (1998) Retrograde Nailing of Fresh and Pathologic Humeral Shaft Fractures with a New Unreamed Humeral Nail (UHN). Techniques in Orthopaedics 13, 51–60

Rommens PM, Blum J (1999) Die retrograde Verriegelungs-marknagelung von Humerusschaftfrakturen mit demUnaufgebohrten Humerus Nagel (UHN). OperativeOrthopädie & Traumatologie, 11, 268–77

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