REDUCTION OF THE FRACTURE

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Chapter 7

REDUCTION OF THE FRACTURE

7.1 Introduction

A meticulous clinical and radiologic examination (analysis of the fracture type), an anatomic reduction, a properly executed internal fixation and a correct rehabilitation (mobilization as early as possible with weight-bearing) are the most important parts for any head-preserving treatment of neck fractures.

We are in full agreement with authors who insist on the cardinal role of reduction (Parker and Pryor, 1993). According to Pannike (1996) the exactness of reduction is decisive for the success or fail- ure of internal fixation. Any error in reduction cannot be compensated by the implant(see Figs.

211 and 212). He also made it equally understood that a joint replacementwill always only be a sub- stitution. The current trend points toward a head- preserving intervention as achieved by an internal fixation. Problems nowadays encountered are due to the fact that major parts of the reduction maneu- vers have already been forgotten. The younger generation of surgeons has not anymore been exposed to a proper execution of a closed reduction.

In the majority of cases the immediate and earlyreduction is easier in fresh than in remote fractures. The normal muscle tone has not recurred, the caudal fragment is not displaced as much, the soft tis- sues are less swollen and the patient is still in a better mental condition (Weller, 1964). The closed reduction of remote fractures, particularly after one to two weeks, is seldom successful. In younger persons an open reductionis then preferable. In older patients who are in good health a joint replacement seems preferable. A minimally invasive internal fixation should be considered in high-risk patients as it facili- tates the postoperative care (Cserháti et al, 2000).

The exactness of reduction and the stability of internal fixation depend heavily on the fracture type. For this reason it is imperative to analyze carefully the radiographs before surgery allowing not only a proper execution of reduction but also an appropriate choice of the implant to be used.

Jagged and beak-like fracture surfacescan easily get jammed due to the displacement. Reduc- tion of these fractures is more difficult, but they remain stableafter proper reduction (Szabó et al, 1961b; Fekete et al, 1989b). In these instances it is of particular importance to execute the reduction maneuver properly starting with the abduction and to avoid breakingany beaks or asperities, as this will decrease the stability.

For other fracture types as smooth fracture surfaces, one or many intermediate frag- ments, comminuted fractures, the reduction is considerably easier but the proper assessment of reduction as well as the maintenance of reduc- tion are much more difficult. In the presence of smooth fracture surfaces and of predominantly oc- curring fractures with an avulsed fragment (mostly posterocaudal), the risk of over-rotation (erro- neous, exaggerated internal rotation) is smaller as the anterior (medial) cortex prevents slipping.

In multifragmentary fractures with a zone of comminution the instability is pronounced (also in rotation!). Care has to be taken in these fractures to avoid an over-rotation. An anatomic reduction is often impossible due to the defect. Conse- quently, we accept a compromise and do not force an anatomic reduction. We do not attempt to correct a slight displacement in valgus (up to 180º) nor an antecurvature (up to 160º). During internal fixation we recommend a cautious impactionfor better adaptation of the fracture surfaces. The necessary stability can be obtained with a properly chosen implant. Resorption of fragments does not occur when the reduction is perfect. To the contrary, the fragments contribute to a bony consolidation like cancellous bone grafts.

In respect to the reduction, Pauwels’ angleis of little importance. The danger of Pauwels-III fractures is not only the slipping but also the tilting in valgus. This can be avoided by inserting first the cranial screw during internal fixation. As the major part of Adam’s arch remains attached to the cranial

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fragment and thus one cannot rely on the 2nd but- tressing point, a reinforcement at the lateral cortex with an angle-stable plate is mandatory.

A reduction of Garden-I and -II fracturesthat are in a valgus position as seen in the a.-p. projection is not needed except in instances where the valgus angle exceeds 190º. The original Garden classi- fication has the disadvantage of assessing the fracture only in the a.-p. projection. It happens, however, not infrequently that a fracture judged in the a.-p. film as relatively undisplaced shows in the lateral view a marked antecurvature (< 160º),a position that must be reduced. We believe that these fractures should not be classified as Garden-I or -II fractures on the account of their instability (Man- ninger et al, 1992).

In the presence of an anterior angulation (re- curvatum) the posterior retinacular vessels are under tension (risk of circulatory disturbance!).

Therefore, this displacement should be reduced.

The difference between Garden-III and Gar- den-IV fractureslies in the fact that no contact between the fragments remains in Garden-IV fractures. If one relies solely on a.-p. films, the su- perposition of the cranial over the caudal fragment is deceiving. The position of fragments seems acceptableas the fracture looks like a Garden-III.

The lateral view, however, reveals that the caudal fragment lies completely behind the cranial one and that after a few days the caudal fragment will be markedly displaced cranially.

On lateral films one can also observe the rare obliquely oriented fracture. Here the fracture line runs from anterocaudal to posterocranial (see Figs. 63d and 177). The bony spike remaining attached to the caudal fragment cannot find support on the femoral head fragment with the result that the diaphysis slips posteriorly.

7.2 Closed reduction of displaced neck fractures

If a spinal anesthesia has been performed, the patient is only transferred to the traction table once the anesthesia has taken effect. While grasping the leg with his handthe surgeon proceeds carefully with the reduction under continuous image intensifica-

tion. Once the reduction has been achieved the foot is attached to the foot holder. The advantage of the traction table lies in the fact that the limb is fixedin the reduced position and heldthere for the duration of surgery. The use of the traction table is not without dangers, when the reduction has not been carefully achieved before. If the limb is already attached, reduction with the fracture under traction can only be obtained with great force to overcome the muscle tension (Pannike, 1996). With such a maneuver the still intact retinacular vessels are at risk. Besides, the attempt at reduction may be unsuccessful. The same applies when during surgery a correction is attempted or the reduction maneuver has to be repeated. In this case it is advisable to grasp the limb again with the hand and start the reduction maneuver with careful abduction.

If an epidural anesthesia has been done, the limb must be very solidly fixed as the muscle tone is still preserved. Otherwise, muscle fasciculations may easily displace the fracture. On the other hand, if a general or a spinal anesthesia has been performed an overdistraction or a tilting of the fracture may occur given the complete muscle relaxation.

Once an overdistraction has happened, a revi- sion of reduction is extremely difficult!

Similarly, when dealing with a flaccid limb of a patient suffering from polio, hemiplegia or other neurologic diseases any strong trac- tion is contraindicated. The result may be an overdistraction or a displacement of the frac- ture(Fig. 175).

Of great importance are the sequential steps of the manipulation during the reduction.

First, the leg is carefully abducted (1) without exerting any traction, and then the leg is internally rotated (2) depending on the degree of exter- nal rotation. Starting with abductionof the externally rotated limb it is easy to fit the fragment anatomically by internal rotation. The success of reduction when internal rotation is done before abductionis uncertain as the fragments lying be- side each other or being jammed cannot be reduced without applying force. Under these circumstances the reduction can become difficult when jagged surfaces or beaks form an obstacle or multiple fragments render the assessment of reduction difficult.

The third step of the manipulation, the trac-

164 Chapter 7: Reduction of the fracture

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tion (3), is also achieved under image intensifica- tion. A traction is often unnecessaryfor fresh fractures as the adduction of the fracture is often already corrected by abduction (Ravasz, 1958). Should a displacement in varus or a shortening persist, increase in abduction combined with a careful traction on the limb fastened to the traction table will solve this problem. The manipulation must be followed on the monitor to avoid an overdistraction. If in Garden-IV fractures a marked displacement of the fragments has occurred, abduction combined with a slight traction should be done.

Abduction (and traction) correct the dis- placement in varus. The internal rotation around the longitudinal axis around the leg remedies the antecurvature. The displacement in varus will be carefully analyzed on the monitor in the a.-p. projection, whereas the antecurvature is checked in the lateral projection.

In particular, an exaggerated internal rota- tion must be avoided, otherwise the caudal neck stump will tilt posteriorly. This is seen in the lateral view as a translational (ad latus) displacement with an angle open anteriorly (recurvatum).A slight displacement can be tolerated whereas a major internal rotation is unfavorable as it leads to tension or rup- ture of the posterior retinaculum,thus increasing the risk of avascular necrosis. Particularly in the presence of comminuted fractures, this error is commonly made as the achieved position is difficult to assess due to the tilted posterior fragments (Fig. 176).

Absence of an external rotation of the limb is rarely seen in displaced fractures. This clinical sign should remind the physician that no displacement in external rotation (no antecurvature) of the fracture exists. In this case an internal rotation should not be automatically done, as it will lead to an overcorrection in rotation (see Fig.

105f, g).

If after the trauma the foot lies in neutral or slightly internally rotated position, we may deal with the rare displacement with an anterior angle (recurvatum).It is corrected by external rotation.

However, when the limb is forcefully held in external rotation, the position of the neck as seen in the lateral view is not horizontal. Consequently, the aiming that must be done from posterior to anterior needs special attention. To circumvent these diffi- culties it may be helpful to place first a separate Kirschner wirethrough the fracture site into the head either anterior or posterior to the planned screw position. The wire holdsthe correct reduction in external rotation. Thereafter the limb can be internally rotateduntil the neck assumes a horizontal position without risking an exaggerated rotation.The typical steps of surgery can now follow. At the end of surgery the Kirschner wire is re- moved.

Major problems may be encountered, when the femoral head has turned around the neck axis.In this instance we are dealing with a real displace- ment in rotation of the femoral head (and the

Closed reduction of displaced neck fractures 165

Fig. 175. Faulty reduction in a polio patient.

a. 68 year-old woman, right Garden-IV neck frac- ture, delicate femoral diaphysis; b. Already a slight traction on the paralyzed leg resulted in a hypervalgus position and a slight translational displacement

a b

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neck). Not only is the diagnosis difficult (see Sect.

5.5) but also the reduction. The severe damages that cause the rotational displacement result in an al- most free mobility of the broken femoral head in the joint. This can be well recognized after arthrotomy with the patient on the traction table.

The cranial fragment, aptly called by Pannike an extremely mobile head fragment, rotates and tilts already under slight traction like a “tumbler”. It is impossible to steer the fragment with closed reduction.

Reduction can only be achieved after exposure of the fracture. This is mandatory in younger patients. Pannike (1996) recommends the removal of the obstructing bone spur or of the spikes to achieve a reduction. We do not share his opinion as our goal is a perfect adaptation. The prognosis of severe rotational displacement is poor from the onset on account of marked osseous and vascular damages. If the diagnosis of a displacement in rotation is without any doubt, a primary arthroplasty should be performed in older patients.

A posterior displacement of the caudal frag- ment caused by the weight of the limbmay occur on the traction table with the patient supine. It is seen in instances of unstable fractures(major intermediary fragments, comminution), in obese patients and in rare oblique fractures where the

fracture line runs from anterocaudal to posterocranial as seen in the lateral projection (Fig. 177).

This displacement can be corrected before under- taking the second step of the reduction maneuver (internal rotation) by lifting the trochanteric area by hand and supporting it. Thereafter the limb is placed in internal rotation; this usually allows main- taining the fragments in their impacted position. If the caudal fragment displaces again posteriorly, the fragment is lifted again and internally rotated: a well-padded support (exceptionally a crutch) at- tached to the traction table is placed under the trochanteric areato maintain the caudal fragment in the reduced position. Alternatively, a firm roll of towels or a small sandbag can be used. For slim persons we recommend to place also a smaller support under the opposite side as the pelvis may easily tilt toward the uninvolved side. This maneuver is espe- cially indicated as currently we do not apply any traction for neck fracture in the majority of our patients. This implies that the pelvis is not stabilized by horizontal traction. (Nevertheless, a certain degree of pelvic stability is obtained as we abduct and internally rotate the uninvolved lower limb).

Even with the above-described technique a reduction cannot always be maintained.The posterior translation of the caudal fragment can then

Fig. 176. Clinical examples of various degrees of exaggerated rotation.

a. Minimal exaggerated rotation with anterior step amounting to one cortical width (anterior arrow) and slight recurvatum; b. Modera- tely exaggerated rotation with greater anterior step (anterior arrow). The assessment is rendered difficult by the large fragment avulsed from the posterior cortex (posterior arrow); c. Major exaggerated rotation with anterior step measuring 1cm (the position of the poste- riorly avulsed fragment deceives the exactness of the reduction)

a b

c

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only be corrected by a small exposure of the frac- tureand by lifting the trochanter area with an in- strument(bone hook). In some instances it is necessary to hold continuously the caudal fragment during the internal fixationuntil the stability of reduction is assured after two guide wires have been inserted.

If in younger adults– and in particular in ado- lescents and children – a perfect reduction with the above-described maneuver cannot be achieved, an open reductionthrough an arthrotomy is mandatory.

An internal fixation should never be un- dertaken when the initial displacement (exaggerated distraction or rotation, translation exceed- ing 0.5 cm, tilting in varus > 10º) has not been properly corrected. Open reduction in younger individuals does not present a problem whereas an inadequate reduction leads later to serious compli- cations. Forced maneuvers of reduction such as that recommended by Leadbetter(1933), traction in 90º of hip flexion, should be avoidedas it may damage the retinaculum and the retinacular vessels.

If the attempt at reduction has been un- successful,the leg should be gently externally rotated, the abduction decreased and the reduction maneuver repeated from the start!

The assessment of outcome of reduction de- pends greatly on the correct positioning of the image intensifier. Of decisive importance is the proper centering as well as the internal rotation in the sagittal plane and the direction perpendicu- lar to the neck axis in the lateral plane.Only a beam hitting the neck at 90º can show the femoral neck at its entire length.

In general, the fracture is well visualized when

the knee is in 10–20º of internal rotation. A small fragment avulsed from the posterior (or posterocaudal) neck is often seen. In this instance the posi- tion at the posterior site of the fracture gap can be barely assessed, even when the direc- tion of the beam in the lateral projection is correct. The posterior fragment may also be dis- placed or tiltedrendering the exact assessment of the translational displacement (ad latus) impossible. In such a case it is preferable to check the reduction on the anterior surface of the neck:the fragments should be on the same level without a for- mation of a step and without an anterior angulation (no recurvatum) (see Fig. 176c).

Particularly in the presence of a small pos- terior bone defect a small angle open posteri- orly(antecurvature < 160º) is better thanan exact reduction achieved by forced internal rotation.It leads to a better bony contact of the fracture surfaces without diastasis (Szabó et al, 1961b). If femoral head and neck move en block during internal and external rotation of the leg, the result should be acceptable even when the attempt to obtain a correct angle had been unsuccessful (see Fig. 239).

7.3 Open reduction of a displaced neck fracture

If two or three careful attempts at a closed reduction are unsuccessful, an open reduction is preferable as further manipulations may endanger the circula- tion in the femoral head. Fortunately this is rarely necessary in elderly patients who constitute the majority of our patients. Due to their osteoporosis in-

Open reduction of displaced neck fracture 167

Fig. 177. Intraoperative lateral radiograph of a posteriorly sagged cau- dal fragment.

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creasing proportionally with age, the fragments can usually be easily moved as compression and frag- mentation of bony spikes occur more often. Contrar- ily, in younger patients the jagged fracture surfaces prevent a reduction as described above.

If a large anterior spike exists, a small lateral incision, particularly in slim patients, should be made.

With the help of a periosteal elevator advanced to the anterior surface of the neck fracture exerting a pressure on the spike the desired position of the femoral head can be obtained; the fracture is stabilized by a Kirschner wire.

The posterolateral approach according to Gibson or Kocherhas only been used in hospitals where in addition to an internal fixation a pedicled bone-muscle transfer has been done.

An anterior approach according to Smith- Petersen (Smith-Petersen et al, 1931; Parker, 1993; Marti and Jacobs, 1993) is traditionally used for exposure of the neck. Through a 10 cm long longitudinal incision at the anterocranial third of the

thigh along the anterosuperior iliac spine the anterior surface of the joint capsule is reached lateral to the rectus femoris. The joint is open through a T-shaped incision and the capsular flaps are held by stay sutures. Retractors keep the wound open exposing the joint. The fracture can now be reduced with a periosteal elevator and gentle manipulations.

The advantage of the anterior approach lies in the fact that the important vessels in the posterior retinaculum are not damaged. The disadvantage of this approach is the impossibility to perform the internal fixation through the same approach. There- fore nowadays we use it primarily in revasculariza- tion surgery for implantation of the pedicled bone graft into the head.

More commonly used is the modified antero- lateral approach according to Watson-Jones.

This approach makes it possible to insert the im- plants through the same incision (Fig. 178).

In Watson-Jones’ original description the center

Fig. 178. Anterolateral approach to the femoral neck (Marti and Jacob, 1993).

a. Skin incision; b. Splitting of the fascia lata, division of the fibers of the tensor fasciae latae muscle and detachment of the gluteus me- dius with a cautery knife; c. The greater trochanter and the insertion of the gluteus minimus are shown, the latter is divided between two stay sutures to exposes the joint capsule; d. Insertion of the retractors: 1. caudal, 2. cranial to the neck, 3. at the anterior acetabular rim. The joint capsule is open in an inverted T-shaped fashion to expose the fracture

a b

c d

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Reduction of a Garten-I fracture impacted in hypervalgus 169

of the skin incision was placed over the tip of the greater trochanter. It extended caudally in a 7 cm long line and cranially it curved to the anterosuperior iliac spine. Today, we prefer a straight incision.

We split the fascia lata in the same direction as the skin incision posterior to the muscle belly of the tensor fasciae latae. The insertion of the gluteus medius is seen in the cranial part of the wound, whereas the muscle belly of the vastus lateralis is found caudally. The muscle fibers of the gluteus medius originating close to the capsule are detached with a cautery knife. The tendon of the subjacent gluteus minimus is divided 1 cm caudal to the tip of

the greater trochanter between two stay sutures. At the level of the lesser trochanter one retractor is inserted medial to the neck and one at the anterior rim of the acetabulum or posterior to the neck. Thus the capsule is visualized and incised in a T-shaped fashion exposing the fracture.

7.4 Reduction of a Garden-I fracture impacted in hypervalgus

In the majority of patients a reduction of simple Garden-I and -II fractures is not indicated. A reduc-

Fig. 179. Changes in the head/neck contours in various fracture types (modified and expanded schematic drawing according to Lowell 1981).

a, b. The contours of the intact femoral neck show in the a.-p. and lateral projection an S-shape corresponding to the convexity of the head and the head/neck junction. These contours change when the femur is turned around the diaphyseal or neck axes; c, d. To the contrary, in the presence of a valgus tilting after a neck fracture, a caudal straightening and a cranial sickle shaped kinking of the S is seen in the a.-p. projection. In the lateral projection the S is straightened anteriorly and kinked posteriorly; e, f. In the presence of a varus displacement or recurvatum the shape of the S is reversed

a

b

c

d

e

f

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Fig. 180. Clinical example of a femoral head necrosis after consolidation of an unreduced fracture in hypervalgus and stabilized with a delay.

This 46-year-old woman fell on the day before admission and injured her right hip. She was able to walk and presented herself on ac- count of hip pain at our institution for radiographs on the following day; a, b. In the a.-p. projection a hypervalgus position (alignment angle 190º) is seen, in the lateral view the fracture is undisplaced; c, d. Stabilization with two cannulated screws without reduction. The hypervalgus and the marked medial translation remain unchanged. Even an increase in impaction of the neck close to Claffey’s point is evident; e, f. Eight months postoperatively the screws were changed due to increasing hip pain. The “perforation” of the cranial screw however was not the consequence of a technical error but occurred secondarily to the collapse of the cranial pie-shaped head segment, the classical site of avascular necrosis. This segment is well seen anteriorly in the lateral view. Due to the progression of symptoms (see Fig. 186c) an uncemented total hip replacement was performed two months later

a

b

c

d

e

f

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Reduction of a Garten-I fracture impacted in hypervalgus 171

a

b

c

d

e

f

Fig. 181. Clinical example of a successful reduction of a hypervalgus fracture.

This 64-year-old woman fell while disembarking from a streetcar; a, b. Left Garden-I hypervalgus fracture (a.-p. alignment angle 200º) without displacement in the lateral view. The a.-p. projection clearly shows a small fragment avulsed from Adam’s arch and an evident medial translation (arrows); c, d. Ten hours after the accident an internal fixation with two cannulated screws was done. A closed re- duction reduced the valgus angle to 180º and corrected also the medial translation. The patient was discharged home on day 5. At the three months follow-up she was symptom-free; e, f. Also three years later she had no symptoms; the radiographs did not show any evidence of avascular necrosis

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tion, however, is necessary when the by Lowell (1981) published radiologic signs indicating displacement or tilting of fragments are present (Fig.

179).

If a displacement in hypervalgus is not re- duced(a.-p. alignment angle > 190º), a high risk of avascular necrosis after consolidation of the fracture must be anticipated as the retinacular vessels entering at Claffey’s point are either kinked or incarcerated (Garden, 1971; Cserháti et al, 1996) (Fig. 180). Therefore this fracture type should be treated as an emergency as recommended by Lamare and Cohen(1986). Similar to the other displaced fractures reduction and sta- bilization should be done inside six hours af- ter trauma to decrease the risk of avascular necrosis(Fig. 181)!

The reduction of Garden-I hypervalgus fracture is differentfrom the reduction maneuver in Sect. 7.2. It is of cardinal importance not to put the limb in abduction.Any increase of the already precarious valgus angle will heighten the risks associated with abduction. Already a slight internal rotation of the extended leg is sufficient for re- duction. This maneuver not only corrects the ac-

companying antecurvature but also reduces the displacement in valgus. Should the displacement not being adequately corrected, the limb is carefully adducted without traction by using a fist or a rolled up towel placed proximally between the legs as a fulcrum.

In a.-p. projection we do not strive for an ex- act anatomic reduction. A remaining valgus of 180º does not constitute a risk for the head circula- tion. To the contrary, in respect to stability it is even more advantageous(Szabó et al, 1961b). A medial gap of 2 to 3 mm as seen on a.-p. radio- graphs is usually closed shortly after surgery by muscle contraction (Fig. 182). To obtain an immediate intraosseous drainage it seems however preferable to close such small gaps after release of traction by careful adaptation of the fracture surfaces already during surgery. Occasionally, a recurvatum is associated with a position in hypervalgus. As with displaced fractures, recurvatum is corrected by a maneuver of external rotation.

A defect of the femoral head may remain at the cranial site of impaction causing a risk of loss of correction during internal fixation reverting the head into the original position of hypervalgus. Exception-

a b

Fig. 182. Overdistraction of a Garden-I fracture.

a. After reduction of the valgus fracture a small medial (caudal) gap remained (slight overdistraction); b. In general, the gap closes once the muscle tone returns or during mobilization

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Guidelines for the assessment of reduction 173

ally, to avoid a recurrence of displacement it is advisable to insert first the cranial screw after predrilling (see Sect. 8.3.2.3).

7.5 Frequent errors of reduction

The majority of errors of reduction are caused by an inadequate positioning either of the injured limb or of the C-arm. This incorrect positioning leads to errors in the interpretation of the images. Incorrect positioning is caused by the following factors:

– The tube was not placed perpendicular to the neck in the a.-p. projection;

– The beam in the a.-p. projection was not centered on the neck;

– The beam in the lateral projection has not been aligned perpendicular to the neck axis (the neck is not displayed adequately, the greater trochanter is projected over the femoral head);

– Wrong positioning of patient (tilted pelvis, inter- ference by perineal post);

– Insufficient internal rotation of limb.

Other technical problemsindependent of positioning may interfere with the assessment of radiographs after reduction:

– Severe osteoporosis;

– Multifragmentary or comminuted fracture;

– Internal fixation in the presence of contracture or amputated limb;

– Morbidly obese patient (fat limb, soft tissue hanging over hip or abdomen;

– Use of a faulty image intensifier.

The surgeon must always check before surgery the positioning of the image intensi- fier and proceed with a correction, if neces- sary.

Faults and errors during reduction as seen in the a.-p. projection:

– Persistence of a varus- or marked valgus malalignment(alignment angle under 160º or over 180º);

– Overdistraction of fracture: if slight: medial gaping and lateral translational displace- ment (ad latus)of the caudal fragment;

– If severe: enlargement of the entire fracture gap resulting in a serious diastasis;

– An overdistraction often results in a position of hypervalgus;

– Very rarely the traction is not strong enough.It is evidenced by a varus position, a lateral gaping of the fracture (medial impaction) and a medial translational (ad la- tus) displacementof the caudal fragment.

Faults and errors of reduction as seen in the lateral projection:

– During the correction of the initial external rotation the reduction of the originally present angle having a posterior opening (antecurvature) is exaggerated. The exaggerated internal rotation of the limb leads to an angle between femoral head and neck axes, that is open anteriorly (recurvatum).It is often accompanied by a posterior step. (This is the most frequent error!);

– Very rarely the internal rotation is insufficient. If the surgeon does not reduce adequately the initial external rotation, an antecurvature and the anterior stepremain;

– Due to the fracture type (zone of comminution or oblique fracture having the tendency to slide) or due to the weight of the limb (obese patient) the distal fragment sags posteriorly.

7.6 Guidelines for the assessment of reduction

Already during the first analysis of patients with femoral neck fractures seen between 1940 and 1955 our team paid special attention to the quality of reduction (Szabó et al, 1961b). We established criteria for good, satisfactory and poor reduction.

In addition, we analyzed the correlation between quality of reduction and early and late complica- tions. Our conclusions made then are still valid today.

The introduction of cannulated screws greatly influenced our practice. From the beginning we attempted to separate problems particular to the procedure from those caused by faulty execu- tion of the surgical technique.Consequently, we

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developed a prospective documentation. The clinical parameters of all patients were registered; the initial and postoperative radiographs were assessed as to the quality of reduction and internal fixation and analyzed in light of the outcome observed at the time of follow-up.

In the course of this work executed during the first years we elaborated criteria and border- line values that were later also used for the re- view of patients treated with cannulated screws in an attempt to prognosticate possible problems (Johansson et al, 1986; Cserháti et al, 1999). The detailed analysis listed below was foremost done for the establishment of a scientific compari- son.The resulting basic principles are also of use in daily practice.

To allow an exact assessment we established four categories to judge the quality of reduction:

1 = good, 2 = acceptable, 3 = faulty, 4 = poor (Table 5). For the determination of angles we used the Garden alignment angle values (in the a.-p. projection 160º, higher values define valgus and lower

values define varus; in the lateral projection 180º values below define antecurvature and higher values define recurvatum). A standard deviation of ± 5º was accepted. The value of the analysis is in- creased when those patients are excluded who could not be properly evaluated on account of missing data or poorly executed or exposed radiographic techniques. These exclusions are comprised of:

– Ill-defined contours precluding assessment;

– Underexposed radiographs with poor contrast;

– Poorly focused a.-p. radiographs (on the a.-p.

films of the pelvis crucial structures are missing or not clearly shown);

– A.-p. and lateral films were taken in marked external rotation of the limb;

– Poorly centered lateral radiographs, the tip of the greater trochanter is projected over the femoral head.

For each group we submit clinical examples (for the sake of better comparison all radiographs are shown as being left-sided) (Figs. 183–186).

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a.-p. projection lateral projection

1. good

– anatomic reduction (Fig. 183a, c) – anatomic reduction (Fig. 183b, d)

– valgus up to 180° – antecurvature up to 170°

2. acceptable

– valgus 180°–190° (Fig. 184a, b) – antecurvature 170°–160° (Fig. 184e)

– varus up to 150° – recurvatum up to 190° (Fig. 184f)

– too much or too little traction, – too much or too little rotation with translational displacement of max. translational displacement of max. 1/4 thickness of one cortex (Fig. 184c, d) cortical thickness (Fig. 184g)

– incomplete medial gap up to 3 mm

3. faulty

– valgus 190°–200° (Fig. 185a–c) – antecurvature 160°–150° (Fig. 185j) – varus 150°–140° (Fig. 185d, e) – recurvatum 190°– 200° (Fig. 185k) – too much or too little traction with translational – too much or too little rotation with

displacement varying between one cortical translational displacement up to 1/3 thickness and 5 mm (Fig. 185f, g) cortical thickness (Fig. 185l)

– complete gap (diastasis) of max. 2 mm (Fig. 185h, i)

4. poor

– valgus > 200° (Fig. 186a–c) – antecurvature < 150° (Fig. 186g)

– varus 140° (Fig. 186d) – recurvatum > 200° (Fig. 186h)

– too much or too little traction with – too much or too little rotation with translational displacement > 5mm translational displacement > 1/3 of

(Fig. 186 e, f) cortical thickness

– complete diastasis > 2 mm

Table 5. Criteria for the assessment of reduction: 1 = good, 2 = acceptable, 3 = faulty, 4 = poor

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a b

c d

Fig. 183. Clinical example of a reduction judged as “good”.

a, b. Garden-IV neck fracture; c, d. Anatomic reduction in both projections. A small fragment of the posterior cortex is well seen in the lateral view (arrow)

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a b c

Fig. 184. Six clinical examples of reduction judged as “acceptable”.

(1) a. Fracture in hypervalgus (a.-p. alignment angle 200º). The fragment avulsed from Adam’s arch renders the assessment of the mar- ked medial translational displacement difficult (arrows) (see also Fig. 181). Surgery was done 10 hours after the accident; b. Follow-up radiograph after 3 years: after a successful reduction (a.-p. alignment angle 180º) there are no indications of necrosis. The patient is symptom-free;

(2) c. Slight overdistraction, medial gap measuring one cortical width (arrow);

(3) d. Slight inadequate longitudinal traction (one cortical width), medial impaction (arrow);

(4) e. Slight antecurvature (lateral alignment angle 160º);

(5) f. Slight recurvatum (lateral alignment angle 190º);

(6) g. Slight overrotation, the anterior translational displacement amounts to 1/4 of cortical width. A large posterior cortical fragment interferes with the assessment

d e f g

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a b c

d e

f g

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h i

i k l

Fig. 185. Seven clinical examples of a reduction judged “faulty”.

(1) a. Initially a marked displacement in valgus (a.-p. alignment angle 200º); b. The reduction was only partially successful (a.-p. align- ment angle 195º); c. Control after six months: evident resorption of neck and settling (the further course is unknown);

(2) d. Stabilization in 140º of varus, a fragment has been avulsed from Adam’s arch; e. Consolidation after one year with slight increase of varus, marked settling and limb shortening (patient has complaints!);

(3) f. Stabilization in malposition in valgus (a.-p. alignment angle 200º) and evident inadequate longitudinal traction; g. After six weeks displacement in varus and rotation;

(4) h. In addition to an error in internal fixation a marked gapping; i. Marked tilting in varus during the 4th postoperative week, loss of reduction (see also Fig. 211a, b);

(5) j. Due to an inadequate internal rotation an antecurvature of 150º persists;

(6) k. Patient shown in fig.105. Initially, no displacement was present. Unrecognized fracture that later displaced in varus. Faulty reduc- tion characterized by marked recurvatum secondary to exaggerated rotation (lateral alignment angle > 200º);

(7) l. This multifragmentary fracture was evidently stabilized in marked overrotation

(18)

a b c

d e f g

h

Fig. 186. Five clinical examples of a reduction judged “poor”.

(1) a. Initial displacement in hypervalgus (a.-p. alignment angle 200º) and marked translational displacement; b. The displacement was not corrected during surgery. To the contrary, the impaction near Claffey’s point is more pronounced; c. After one year the femoral head has collapsed (see Fig. 180);

(2) d. Stabilization in extreme varus position. Revision surgery;

(3) e. Exaggerated longitudinal traction. Hypervalgus, transitional displacement (probably the large fragment avulsed from Adam’s arch deceived the surgeon); f. Loss of reduction after one week;

(4) g. Exaggerated antecurvature (lateral alignment angle 120º). The femoral neck has been virtually fixed to the cartilaginous surface of the head. The anterior screw perforates the femoral head (see Fig. 212c–h);

(5) h. Similar outcome in an instance of recurvatum.

In all five patients a hemiarthroplasty became necessary