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Osteochondrosis or Epiphysitis and Other Miscellaneous Affections
Legg-Calvé-Perthes Disease
The cause of Legg-Calvé-Perthes disease is unknown but has provoked considerable controversy. Previously, some authors thought that an inherited thrombophilia promoted thrombotic venous occlusion in the femoral vein, causing bone death in the femoral head and ultimately leading to Legg-Calvé-Perthes disease. More recent studies have not found an inherited hypercoagulability or a deficiency in protein C activity, however, indicating that inherited thrombophilia is not associated with the osteonecrosis of Legg-Calvé-Perthes disease. Although research continues, it seems that coagulation disorders are not conclusive etiologic factors in Legg-Calvé-Perthes disease. As noted by Hosalkar and Mulpuri, even after 100 years the etiology of Legg-Calvé-Perthes disease remains unclear and its treatment is still controversial.
Diagnosis
The initial diagnosis of Legg-Calvé-Perthes can be difficult if symptoms have not been present for some time. Children with Legg-Calvé-Perthes disease have symptoms present for an average of 6 weeks before the diagnosis is made. This may be longer if the pain is mild and patients delay initial evaluation. Legg-Calvé-Perthes disease occurs three times more frequently in boys than in girls, and the average age of patients with Legg-Calvé-Perthes disease is 7 years, although it can occur in children significantly younger. Radiographic changes of the femoral head (condensation and sclerosis) generally are delayed but occur 6 weeks after initial symptoms. Therefore, if a child presents early with hip pain and radiographs are normal, a follow-up radiograph should be obtained at 6 weeks if the child is still symptomatic. Radiographic findings of Legg-Calvé-Perthes have been described by Waldenström ( Table 32.1 ), with further modifications by the Perthes Study Group that show good intraobserver and interobserver reliability and may be used in further clinical study.
TABLE 32.1
Stages of Legg-Calvé-Perthes (Waldenström)
| Initial |
|
|
| Fragmentation |
|
|
| Reossification |
|
|
| Healing or remodeling |
|
|
Meyer dysplasia can be easily mistaken for Legg-Calvé-Perthes disease and lead to unnecessary diagnostic procedures and treatment. Meyer dysplasia has been found to be more common in boys younger than 4 years old and more likely to be bilateral. Characteristic findings included delayed or smaller ossification centers on radiograph, a separated or cracked epiphysis, cystic changes, and mild pain and limping. Condensation, subchondral fractures, fragmentation, and subluxation usually are not present with Meyer dysplasia.
Classification
When the diagnosis is established, the primary aim of treatment of Legg-Calvé-Perthes disease is containment of the femoral head within the acetabulum. If this is achieved, the femoral head can re-form in a concentric manner by what Salter has termed biologic plasticity.
Historically, Catterall et al. classified patients with this disease into groups according to the amount of involvement of the capital femoral epiphysis: group I, partial head or less than half head involvement; groups II and III, more than half head involvement and sequestrum formation; and group IV, involvement of the entire epiphysis ( Table 32.2 ). They noted that certain radiographic signs described as “head at risk” correlated positively with poor results, especially in patients in groups II, III, and IV. These head-at-risk signs include (1) lateral subluxation of the femoral head from the acetabulum, (2) speckled calcification lateral to the capital epiphysis, (3) diffuse metaphyseal reaction (metaphyseal cysts), (4) a horizontal physis, and (5) the Gage sign, a radiolucent V-shaped defect in the lateral epiphysis and adjacent metaphysis. Catterall recommended containment by femoral varus derotational osteotomy for older children in groups II, III, and IV with head-at-risk signs. Contraindications include an already malformed femoral head and delay of treatment of more than 8 months from onset of symptoms. Surgery is not recommended for any group I children or any child without the head-at-risk signs.
TABLE 32.2
Catterall Classification
| Group I |
|
| Group II |
|
| Group III |
|
| Group IV |
|
|
|
|
Salter and Thompson advocated determining the extent of involvement by describing the extent of a subchondral fracture in the superolateral portion of the femoral head. If the extent of the fracture (line) is less than 50% of the superior dome of the femoral head, the involvement is considered type A, and good results can be expected ( Table 32.3 ). If the extent of the fracture is more than 50% of the dome, the involvement is considered type B, and fair or poor results can be expected ( Fig. 32.1 ). According to Salter and Thompson, this subchondral fracture and its entire extent can be observed radiographically earlier and more readily than trying to determine the Catterall classification (8.1 months average). According to these authors, if the femoral head is graded as type B, probably an operation such as an innominate osteotomy should be carried out. The extent of the subchondral fracture line, when present, has been suggested to be more accurate in predicting the extent of necrosis than is the extent of necrosis seen on MRI. In our experience, however, subchondral fractures are present early in the course of the disease in only a third of patients, and although this classification is a reliable indicator in the group with fractures, it has little to offer in early treatment decisions for the other two thirds of patients.
TABLE 32.3
Salter-Thompson Classification
| Class A |
|
| Class B |
|
| Based on radiographic crescent sign | |
Presently, the most used classification is by Herring et al. ( Table 32.4 ). They described a classification based on the height of the lateral pillar: group A, no involvement of the lateral pillar; group B, at least 50% of lateral pillar height maintained; and group C, less than 50% of lateral pillar height maintained ( Fig. 32.2 ). A statistically significant correlation was found between the final outcome (Stulberg classification) and the loss of pillar height. Patients in group A had uniformly good outcomes; patients in group B who were younger than 8 to 9 years old at onset had good outcomes, but patients older than age 8 to 9 years had less favorable results; patients in group C had the worst results, with most having aspherical femoral heads, regardless of age at onset or type of treatment. Reproducibility of this classification system was confirmed by 78% of members of the study group who used it. A patient with a pillar group B may progress to a pillar group C or may be in a “gray” area and designated as pillar group B/C border. Herring et al. noted that the advantages of this classification are (1) it can be applied easily during the active stages of the disease and (2) the high correlation between the lateral pillar height and the amount of femoral head flattening at skeletal maturity allows accurate prediction of the natural history and treatment methods. Price has challenged the concept that a lateral pillar sign allows accurate prediction of the natural history and treatment. He noted that the sign may change from A to C in the course of the disease and that containment may no longer be beneficial. The lateral pillar sign may help guide treatment for some patients; however, a prognostic indicator to assist decision-making in the early stages of the disease may be necessary.
TABLE 32.4
Lateral Pillar (Herring) Classification
| Group A |
|
|
| Group B |
|
|
| Group B/C border |
|
|
| Group C |
|
|
|
||
Bilateral involvement
Reports in the literature indicate that those with bilateral Legg-Calvé-Perthes disease, which occurs in approximately 10% of patients, have more severe involvement than patients with unilateral disease because most have a Catterall III or IV or a Herring B or C classification, and 48% rate as a Stulberg 4 or 5 at skeletal maturity. Bilateral involvement can be confused with multiple epiphyseal dysplasia of the hip. Radiographs of the other joints and a wrist radiograph to determine bone age (which is delayed in Legg-Calvé-Perthes disease) help to distinguish the two. Concerning sex, boys and girls who have the same Catterall classification or lateral pillar classification at the time of initial evaluation can be expected to have similar outcomes according to the classification system of Stulberg, Cooperman, and Wallensten.
Imaging evaluation
In the past, diagnosis often was delayed because plain radiographic changes are not apparent until 6 weeks or more from the clinical onset of Legg-Calvé-Perthes disease. Scintigraphy and MRI can establish the diagnosis much earlier.
MRI seems to be superior to scintigraphy for depicting the extent of involvement in the early or evolutionary stage of Legg-Calvé-Perthes disease. Perfusion MRI has been used at our institution to determine the extent of involvement, the classification, and treatment planning. A limitation of both the Catterall and lateral pillar classifications is that a definitive prediction cannot be made until well into mid-fragmentation stage, thus delaying treatment during this wait and see period (4 to 6 months). Gadolinium-enhanced subtraction MRI (perfusion MRI) has been used at the initial fragmentation (earlier) stage to determine the extent of lateral pillar involvement, thereby allowing initiation of constraint treatment ( Fig. 32.3 ). Although no serious complications have been reported with perfusion MRI for Perthes, approximately 50% of children have to be sedated or given general anesthesia. The Perthes Study Group reported promising results using MRI perfusion for early classification of lateral pillar signs. However, the routine use of perfusion MRI has been challenged by some authors (Schoenecker et al.) who believe that knowing early the extent of head and pillar involvement may not be that essential in treatment or ultimate results. A subsequent study of serial perfusion MRIs showed that during the active stage reperfusion of the femoral head progresses at a highly variable rate and in a horseshoe-type pattern, starting posterior and progressing to medial and lateral before converging anteriorly and centrally.
Treatment
Treatment depends on where the child is in the course of the disease. Most treatment is during the active process (early fragmentation). The problem again is to determine early the severity or ultimate involvement of the femoral head (Caterall II, IV, lateral pillar B/C, C, Salter-Thompson B). Treatment in the residual phase is reconstructive to prevent a malformed hip from progressing to osteoarthritis at an early age.
Many procedures have been described for both the active and residual phases of the disease. We have used a variety of treatments over the decades, including noncontainment treatments and containment-based treatments such as abduction orthoses, varus osteotomy, and Salter, Pemberton, or pelvic osteotomies when indicated, all with a vigorous hip range of motion program. Current consensus is that containment of the femoral head within the acetabulum throughout the disease process is the goal to allow remodeling of the femoral head.
In the early stage (active phase), our current treatment protocol for children age 4 years and older begins with explaining to the parents the natural history and expected duration of the disease (24 to 36 months). Children 2 to 3 years old can be observed and do not need aggressive treatment. Once synovitis resolves, a daily home physical therapy program, including active and active-assisted range-of-motion and muscle stretching exercises to the hip and knee, is recommended to try to maintain a normal hip range of motion.
Loss of motion at any time indicates a significant change in prognosis. If loss of motion is significant, and subluxation laterally is occurring, bed rest, skin traction, progressive passive and active physical therapy, abduction exercises, pool therapy, or bracing if possible, are indicated. If there is no improvement, we recommend closed reduction with the patient under general anesthesia and percutaneous adductor longus tenotomy, followed by an ambulatory abduction cast (Petrie) for 6 weeks or more.
If possible, we avoid surgery for Legg-Calvé-Perthes in the active phase of the disease because of the complications possible after major hip surgery, whether it be a varus derotational osteotomy or an innominate osteotomy; however, if containment of the femoral head in the acetabulum is at risk and the femoral head subluxes laterally, surgery may be indicated. Which procedure to use, however, is controversial. Historically, Salter, Thompson, Canale et al., Coleman, and others achieved “containment” by pelvic osteotomy above the hip joint, whereas Axer, Craig, Somerville, and Lloyd-Roberts et al. advocated varus derotational osteotomy. More recently, many studies have emphasized the importance of the timing and the indications for surgery, rather than the type of procedure, recommending that operative intervention be done in the early fragmentation stage before re-formation of a malformed femoral head can occur. Both varus derotational and innominate osteotomies have shown good outcomes at long-term follow-up, with patients who are older with more severe disease having worse outcomes.
Operative treatment may not produce better results than nonoperative treatment in younger patients, but, in general, better results have been reported in older children treated operatively than in children treated nonoperatively when femoral head involvement was severe (lateral pillar B, B/C).
Varus derotational osteotomy and innominate osteotomy have advantages and disadvantages. Varus derotational osteotomy theoretically allows more coverage; however, if too much correction (varus) occurs, and if the capital femoral physis closes prematurely as a result of the disease, excessive varus deformity may persist. Theoretically, a mild increase in length can occur with innominate osteotomy, whereas mild shortening may occur with a varus osteotomy. Compression of an already compromised femoral head also can occur with innominate osteotomy. A second operation to remove the implant is required after many procedures, and both have complications similar to any large operation on the hip. Neither procedure has been shown to accelerate the healing process of the disease. Although numerous authors recommend one procedure over the other, until there is conclusive evidence of superiority, it seems that the choice should be dictated by the surgeon’s familiarity and expertise with a particular procedure.
Shelf arthroplasty (lateral labral support) has been advocated for severe Legg-Calvé-Perthes disease (Catterall III or IV; lateral pillar B, BC, C) in the early stages (fragmentation), with incorporation of the shelf graft into the pelvis as a result of continued growth of the lateral acetabular structures. Although acetabular coverage and size may be increased in children younger than 8 years old, these changes are seen at short-term follow-up, and the amount of coverage at long-term follow-up is similar to that obtained by innominate osteotomy.
Distraction of the hip joint (arthrodiastasis) by an external fixator for an average of 4 months has been described in older children with active and severe Legg-Calvé-Perthes disease. Complications, such as pin breakage and pin track infections, have been reported with this procedure, and presently its use seems to be limited to the most severe cases.
MRI before surgery is indicated to determine (1) if any flattening of the femoral head is already present that would contraindicate most osteotomies of any type and (2) how much subluxation is present and how much surgical containment is necessary.
A combined osteotomy (pelvic osteotomy and varus femoral osteotomy) used as a salvage procedure for severe Legg-Calvé-Perthes disease has the theoretical advantage of obtaining maximal femoral head containment while avoiding the complications of either procedure alone, such as limb shortening, extreme neck-shaft varus angulation, and associated abductor weakness. Stevens et al. described guided growth of the trochanteric apophysis using a “tether” with an eight-plate and soft-tissue release as part of a nonosteotomy management strategy for select children with progressive symptoms and related radiographic changes ( Fig. 32.4 ).
In the residual-stage, indications for reconstructive surgery in Legg-Calvé-Perthes disease are (1) a malformed head causing femoroacetabular impingement or “hinge” abduction in which surgical hip dislocation or hip arthroscopy can be used for osteochondroplasty (cheilectomy) or a varus, valgus, or femoral head osteotomy can be performed; (2) coxa magna for which a shelf augmentation would provide coverage; (3) a large malformed femoral head with subluxation laterally, for which a pelvic osteotomy may be considered; and (4) capital femoral physeal arrest for which trochanteric advancement or arrest can be performed for relative lengthening of the femoral neck. External fixation across the pelvis and hip has been used to reduce the femoral head to avoid hinge abduction and persistent subluxation. All of these are procedures for an already malformed hip, and when used a high percentage of unsatisfactory results should be expected.
Innominate osteotomy
The advantages of innominate osteotomy ( Figs. 32.5 and 32.6 ) include anterolateral coverage of the femoral head, lengthening of the extremity (possibly shortened by the avascular process), and avoidance of a second operation for plate removal. The disadvantages of innominate osteotomy include the inability sometimes to obtain adequate containment of the femoral head, especially in older children; an increase in acetabular and hip joint pressure that may cause further avascular changes in the femoral head; and an increase in leg length on the operated side compared with the normal side that may cause a relative adduction of the hip and uncover the femoral head. Innominate osteotomy as described by Salter is included in the discussion of congenital deformities (see Chapter 30 ). Salter’s procedure includes iliopsoas release. Other pelvic osteotomies such as the Pemberton osteotomy ( Chapter 30 ), the Dega osteotomy ( Chapter 30 ), the Bernese osteotomy ( Chapter 6 ), or the Ganz periacetabular osteotomy ( Chapter 6 ) if needed in the residual phase can be used.
Innominate Osteotomy for Legg-Calvé-Perthes Disease
Technique 32.1
(CANALE ET AL.)
- ▪
Through a Smith-Petersen approach to the hip (see Technique 1.64), release the sartorius, tensor fasciae latae, and rectus femoris and expose the anterior inferior iliac spine.
- ▪
Release the psoas tendon from its insertion, and dissect subperiosteally on the inner and outer walls of the ilium down to the sciatic notch. Using retractors in the sciatic notch, with a right-angle clamp pass a Gigli saw through the notch. With the saw, carefully cut horizontally and anteriorly through the ilium as close as possible to the capsular attachment of the acetabulum.
- ▪
Maximally flex the knee and flex and abduct the hip to open the osteotomy. Use a towel clip to pull the distal fragment of the osteotomy anteriorly and laterally.
- ▪
Take a full-thickness quadrilateral graft 2 × 3 cm from the wing of the ilium according to the size of the space produced by opening the osteotomy (see Fig. 32.6 ). Predrill or precut the outline of the graft on the surfaces of the ilium to prevent fracture of the inner and outer cortices. Shape the quadrilateral graft carefully to fit the space produced, and impact it into the osteotomy site.
- ▪
Use one or more threaded pins for fixation, and leave the ends subcutaneous so that they can be removed later with local or general anesthesia.
- ▪
Use the center-edge angle of Wiberg in the weight-bearing position at this time to assess by radiography the coverage and containment of the femoral head.
Postoperative Care
The patient is immobilized for 10 to 12 weeks in a spica cast before the pins are removed. Range-of-motion exercises and full weight-bearing ambulation are started, and radiographic evaluation is repeated.
Lateral shelf procedure
Except in the active stage of the disease, lateral shelf acetabuloplasty can be used for older children who are not candidates for femoral osteotomy because of insufficient remodeling capacity and the likelihood that shortening of the femur would cause a persistent limp. Recently, it has been suggested to be indicated in the active early stages. Proponents of doing the labral support procedure early argue that it has three beneficial effects: (1) lateral acetabular growth stimulation, (2) prevention of subluxation, and (3) shelf resolution after femoral epiphyseal reossification. Advocates of the shelf procedure in active disease report results as good as those after varus osteotomy or innominate osteotomy of Salter. It is simple to perform (mini-incision with or without a dry arthroscope) and does not induce a permanent deformity in the proximal femur or acetabulum.
Lateral Shelf Procedure for Legg-Calvé-Perthes Disease
Technique 32.2
(WILLETT ET AL.)
- ▪
Make a curved incision below the iliac crest, passing 1.5 cm below the anterior superior iliac spine to avoid the lateral cutaneous nerve of the thigh. Strip the glutei subperiosteally from the outer table of the ilium to the level of insertion of the joint capsule. Mobilize and divide the reflected head of the rectus femoris.
- ▪
Create a trough in the bone immediately above the insertion of the capsule ( Fig. 32.7A ). Raise a bony flap 3 cm wide × 3.5 cm long superiorly from the outer cortex of the ilium.
- ▪
Cut strips of cancellous graft from the ilium above the flap, and insert them into the trough so that they form a canopy on the superior surface of the hip joint ( Fig. 32.7B ). Pack the web-shaped space between the flap and the graft canopy with cancellous bone graft ( Fig. 32.7C ).
- ▪
Repair the reflected head of the rectus femoris over the created shelf.
- ▪
Close the wound in the usual manner, and apply a spica cast.
Postoperative Care
The spica cast is worn for 8 weeks. Protective weight bearing in a single spica cast is continued for 6 additional weeks.
Varus derotational osteotomy
The advantages of varus derotational osteotomy of the proximal femur include the ability to obtain maximal coverage of the femoral head, especially in an older child, and the ability to correct excessive femoral anteversion with the same osteotomy ( Fig. 32.8 ). The disadvantages of varus derotational osteotomy include excessive varus angulation that may not correct with growth (especially in an older child), further shortening of an already shortened extremity, the possibility of a gluteus lurch produced by decreasing the length of the lever arm of the gluteal musculature, the possibility of nonunion of the osteotomy, and the requirement of a second operation to remove the internal fixation. Premature closure of the capital femoral physis may cause further varus deformity. Aksoy et al. reported poor results in children with pillar group C hips, especially after the age of 9 years. A varus derotational osteotomy is the procedure of choice when containment of the femoral head is necessary but cannot be achieved with a brace for psychosocial or other reasons, when the child is 8 to 10 years old and without leg-length inequality, when on arthrogram or MRI most of the femoral head is uncovered and the angle of Wiberg is decreased, and when there is a significant amount of femoral anteversion. An anteroposterior radiograph of the pelvis is taken with the lower extremities in internal rotation and parallel to each other (no abduction). If satisfactory containment of the femoral head is noted, derotational osteotomy alone is carried out. The degree of derotation is roughly estimated from the amount of internal rotation of the extremity, but further adjustments are made during the operation.
When internal rotation is seriously limited and remains so preoperatively after 4 weeks of bed rest with traction, varus osteotomy is carried out with the addition of extension that is produced by a slight backward tilt of the proximal fragment. When internal rotation is sufficient, abduction of the extremity brings about the desired containment of the femoral head. The degree of abduction is expressed by the angle formed by the shaft of the femur and a vertical line parallel to the midline of the pelvis. This angle represents the desired angle of the osteotomy (see Technique 32.2). Herring et al. stated that contrary to conventional belief greater varus angulation does not necessarily produce better preservation of the femoral head after osteotomy. Their recommendation was to achieve 0 to 15 degrees of varus correction for hips that are in the early stages of Perthes.
Reliable information on acetabular containment of the femoral head, the size of the head, the flattening of the epiphysis, and the width of the medial joint space can be obtained from preoperative arthrography or MRI. The osteocartilaginous head of the femur should be covered adequately by the acetabular roof as the femur is abducted and the flattened segment of the femoral head is rotated into the depths of the acetabular fossa. We use a varus (medial closing wedge) osteotomy fixed with an adolescent or pediatric hip screw ( Fig. 32.9 ). According to the recent literature, fracture after plate removal for osteotomies is 5% in patients with Perthes. These data suggest that the time to implant removal should be extended beyond radiographic union to at least 6 months or more after the osteotomy.
Varus Derotational Osteotomy of the Proximal Femur for Legg-Calvé-Perthes Disease
Technique 32.3
(STRICKER)
- ▪
Place the patient supine on the operating table with image intensification, positioned in the anteroposterior projection; however, make sure with “scout” imaging, that the C-arm can obtain a lateral image of the hip. Prepare and drape the affected extremity, leaving it free to allow for intraoperative radiographs or imaging.
- ▪
Make a lateral incision from the greater trochanter distally 8 to 12 cm, and reflect the vastus lateralis to expose the lateral aspect of the femur.
- ▪
Identify the femoral insertion of the gluteus maximus, and make a transverse line in the femoral cortex with an osteotome to mark the level of the osteotomy at the level of the lesser trochanter or slightly distal ( Fig. 32.9A ). Correct positioning of the osteotomy site can be verified with image intensification.
- ▪
After the lateral portion of the trochanter and the proximal lateral femur have been exposed, place a guide pin outside the capsule, anterior to the neck. Using the fluoroscopic image, determine the direction of the neck. Set the adjustable angle guide to 120 degrees, and position it against the lateral cortex. Attach the guide to the shaft with the plate clamp. Insert the guide pin through the cannulated portion of the adjustable angle guide and into the femoral neck ( Fig. 32.9B ). Predrilling the lateral cortex with the twist drill can aid in placing the guide pin. Ensure that the guide pin is placed in the center of the femoral neck within 5 mm of the proximal femoral physis without violating it or the trochanteric apophysis ( Fig. 32.9C , inset 1 ). Verify guide pin placement in the anteroposterior and lateral views on the image.
- ▪
When the guide pin is placed within 5 mm of the physis, use the percutaneous direct measuring gauge to determine the lag screw length ( Fig. 32.9C , inset 2 ).
- ▪
Set the adjustable positive stop on the combination reamer to the lag screw length determined by the percutaneous direct measuring gauge. Place the reamer over the guide pin and ream until the positive stop reaches the lateral cortex ( Fig. 32.9D ). Do not violate the physis. It is prudent to check the fluoroscopic image periodically during reaming to ensure that the guide pin is not inadvertently advancing into the femoral epiphysis.
- ▪
Set the adjustable positive stop on the lag screw tap to the same length that was reamed. Tap until the positive stop reaches the lateral cortex.
- ▪
Insert the selected lag screw into the distal end of the insertion/removal wrench. Place it over the guide pin and into the reamed or tapped hole. The lag screw is at the proper depth when (1) the insertion or removal wrench’s first depth marking is flush with the lateral cortex ( Fig. 32.9E ), and (2) the handle of the insertion or removal wrench is perpendicular to the shaft of the femur, with the longitudinal key line facing proximally. This positioning ensures that the plate barrel and lag screw shaft are properly keyed for rotational stability ( Fig. 32.9F ). Remove the guide pin when the lag screw is at the appropriate length.
- ▪
With the lag screw in place, perform the osteotomy (20-degree transverse osteotomy is illustrated). Make the cut as proximal as possible, just below the lag screw entry point, because the proximal metaphyseal bone usually heals better than the cortical subtrochanteric bone. In addition, the correction of the proximal femoral deformity is best accomplished close to the deformity (i.e., as close to the femoral head as possible).
- ▪
Insert the barrel guide into the back of the implanted lag screw to help position the proximal femur. The desired correction can be accomplished by tilting the head into valgus or, in this case, varus, removing wedges to customize the fit if needed ( Fig. 32.9G ). Iliopsoas tenotomy or recession also may facilitate positioning of the osteotomy.
- ▪
Take the plate chosen during preoperative planning (100 degrees × 76 mm × 4 holes in this case), and insert its barrel over the barrel guide and onto the back of the lag screw ( Fig. 32.9H ). If necessary, insert the cannulated plate tamper over the barrel guide and tap it several times to seat the plate fully ( Fig. 32.9I ).
- ▪
Remove the barrel guide, and insert a compressing screw to prevent the plate from disengaging during the reduction maneuver. Use the slotted screwdriver for the pediatric compressing screw or the hex screwdriver for the intermediate compressing screw ( Fig. 32.9J ).
- ▪
Reduce the osteotomy, and secure the plate to the femur using the plate clamp. Check the rotational position of the lower extremity in extension.
- ▪
A range of 2.5 to 6.5 mm of femoral shaft compression is possible with the use of an intermediate osteotomy hip screw. To achieve 6.5 mm of compression, insert the drill guide end of the intermediate combination drill or tap guide into the distal portion of the most distal compression slot. Drill through to the medial cortex using the twist drill. If less compression is required, follow the same steps detailed previously in the distal portion of either the second or third distal slots for 2.5 mm of compression. If no compression is needed, follow the same steps listed previously except begin by placing the intermediate combination drill/tap guide in the proximal portion of the slot instead of the distal portion used for compression.
- ▪
Insert the tap guide end of the intermediate combination drill or tap guide into the slot, and insert the bone screw tap.
- ▪
Insert the depth gauge through the slot and into the drilled or tapped hole. Ensure that the nose of the guide is inserted fully into the plate’s slot. Insert the needle of the depth gauge, and hook it on the medial cortex. Read the bone screw length measurement directly off of the depth gauge.
- ▪
Select the appropriate length bone screw, and insert it using the hex screwdriver. Use the self-holding sleeve to keep the screw from disengaging from the screwdriver. In cases in which compression is being applied, the bone screw abuts the inclined distal aspect of the slot as it is being seated, forcing the plate and the attached proximal fragment slightly distally until resisted by compression of the osteotomy ( Fig. 32.9K ). Follow the same steps for the remaining two slots.
- ▪
In the most proximal slot, the intermediate combination drill or tap guide can be angled proximally so that the drill, and ultimately the bone screw, crosses the osteotomy line. Positioning the proximal bone screw in this way can provide additional stability at the osteotomy site ( Fig. 32.9L ).
- ▪
Irrigate the wound and close in layers, inserting a suction drain if needed. Apply a one and one-half spica cast.
Postoperative Care
The spica cast is worn for 8 to 12 weeks, until union is achieved. The internal fixation can be removed 12 to 24 months after the osteotomy if desired.
Lateral opening wedge osteotomy
Axer described a lateral opening wedge osteotomy for children 5 years of age and younger in which a prebent plate is used to hold the cortices apart laterally the measured amount. The defect laterally fills in rapidly in young children, but the open wedge may result in delayed union or nonunion in children older than 5 years. Because few children younger than 5 years are operated on for Legg-Calvé-Perthes disease in the United States, indications for this procedure are rare.
Reversed or Closing Wedge Technique for Legg-Calvé-Perthes Disease
Technique 32.4
- ▪
After calculating from Table 32.5 the height of the base of the wedge to be removed, hold the extremity in in ternal rotation at the hip and mark a wedge. Close the wedge if a reverse wedge is being used.
TABLE 32.5Calculating Height of Base of Wedge to be Removed for Varus Osteotomy ∗Desired Angulatory Change (Degrees) Femoral Shaft Width at Osteotomy Site (mm) 10 12.5 15 17.5 20 22.5 25 27.5 30 32.5 35 37.5 40 10 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 15 2 3 4 4.5 5 6 6.5 7.5 8 9 10 10.5 11.5 20 3 4 5 6 7 8 9 10 11 12 13 14 15 25 4.5 5 6.5 7.5 9 10 11.5 12.5 14 15 16 17.5 18.5 30 5.5 6.5 8 10 11.5 12.5 14 15.5 17 18.5 20 22 23 35 6.5 8 10 12 13.5 14 17 18.3 21 22 24 26 27.5 40 8 10 12.5 14.5 16.5 18.5 20 23 25 27 29 31.5 33.5 Credited to Orkan and Roth. Data from A. Axer, personal communication, 1978.∗ The height of the base of the wedge in millimeters is read at the junction of the horizontal axis (desired degrees of angulatory change) and the vertical axis (width of the femoral shaft at the osteotomy site).
- ▪
Take a wedge half the height over the anterior surface of the femur with the base medially.
- ▪
Remove the wedge with an oscillating saw, rotate the distal fragment externally to the desired degree, turn the bone wedge 180 degrees, and insert it in the osteotomy with its base lateral or reversed. Because its base now is lateral, the varus angle obtained equals the angle that would be obtained with complete removal of a full-height bone wedge medially.
- ▪
Fix the bone fragments with the prebent plate as previously described with all cortices in contact. When the reversed bone wedge is not stable enough, fix it to the distal or proximal fragment with small Kirschner wires.
Postoperative care
A double spica plaster cast is applied and removed after 6 weeks or when union is confirmed by radiography. The child is encouraged to walk, in water initially if increased joint stiffness is noted. No restrictions are imposed on the child except for follow-up every 3 months in the first year.
Arthrodiastasis
The rationale behind arthrodiastasis is that distraction of the joint not only widens but also unloads the joint space, reduces the pressure on the femoral head, allows fibrous repair of articular cartilage defects, and preserves congruency of the femoral head. The articulated fixator allows 50 degrees of hip flexion. Recent reports have described significant complications with this procedure; it should not be taken lightly and used only for the most severely involved hips with severe subluxation.
Arthrodiastasis for Legg-Calvé-Perthes Disease
Technique 32.5
(SEGEV ET AL.)
- ▪
Place the patient supine on a transparent operating table. Obtain a hip arthrogram medially to assess cartilage architecture and the extent of hinged abduction.
- ▪
Tenotomize the adductor and iliopsoas tendons through a medial approach.
- ▪
Using image intensification, insert a 1.6-mm Kirschner wire into the femoral head at the center of rotation of the hip while keeping the leg in 15 degrees of abduction with the patella pointing forward.
- ▪
Using the articulated body for the hip Orthofix external fixation device (Bussolengo, Italy; Fig. 32.10 ), apply it onto the Kirschner wire and attach a standard model “kit body” to the hinge distally.
- ▪
Fix the proximal part to the supraacetabular area with a T-clamp using two or three 5- to 6-mm Orthofix screws. The procedure is done using a template that is replaced by the aforementioned parts.
- ▪
Immediately distract the joint space 4 to 5 mm under image intensification. Continue distraction at 1 mm per day until the Shenton line is overcorrected.
Postoperative Care
Flexion and extension exercises are encouraged with the fixator in place, and the patient is kept non–weight bearing. The fixator is left in place for 4 to 5 months until lateral pillar reossification appears. The fixator is removed in the operating room, and a hip arthrogram is obtained. After removal of the frame, the patient continues protective non–weight bearing and intensive physical therapy and hydrotherapy for an additional 6 weeks. At this stage, full weight bearing is allowed with continued physiotherapy for another 6 months.
Reconstructive surgery
Osteochondroplasty (Cheilectomy)
Hip arthroscopy and surgical dislocation of the hip have been used to treat certain types of femoral acetabular impingement (FAI) and other intraarticular lesions caused by Perthes disease. One type of FAI develops in the malformed femoral head; terms such as pincer and cam effect are now replacing terms such as hinge-abduction and “trench.” These newer techniques, surgical hip dislocation and arthroscopy, can eliminate intraarticular deformity and other lesions, such as labral tears, osteochondral or chondral lesions, loose bodies, or a torn ligamentum teres, and at the same time they can be combined with previously described extraarticular (extra capsular) procedures that provide coverage of the femoral head, increase acetabular coverage, or change the configuration of the femoral neck by advancing the greater trochanter.
Surgical dislocation of the femoral head has been used to treat FAI, and contrary to previous opinion can be done safely with few or no complications including osteonecrosis, myositis ossificans, or decreased motion secondary to soft-tissue reaction and scarring. Ganz and others popularized this technique and have performed chondroplasties, labral chondral tear or impingement excision, greater trochanteric advancement, and downsizing osteotomy of the mushroomed femoral head. Care must be taken, however, to protect the lateral epiphyseal arteries that are present in a narrow anatomic window on the femoral neck, but as noted by Millis, these are fewer in number in Legg-Calvé-Perthes disease.
Arthroscopy of the hip has become more refined and thus allows osteochondroplasty (cheilectomy) of the hip for FAI (cam and pincer lesions), loose bodies, and chondral and osteochondral defects (OCDs). Although arthroscopy is easier to perform than surgical dislocation and is less traumatic, it is not as extensive. Techniques for hip arthroscopy are found in Chapter 51 . A combined approach of hip arthroscopy and limited open osteochondroplasty by Clohisy and others is described in Chapter 6 .
Osteochondroplasty Surgical Dislocation of the hip
Ganz, after reviewing the anatomy of the medial circumflex artery, described a technique of surgical dislocation of the hip without compromising the blood supply to the femoral head. Surgical hip dislocation should probably not be carried out when the head is in the early fragmentation phase of the disease. Most of the pathology can be identified at surgery; however, MRI may be helpful as well as hip abduction, adduction, and flexion radiographs to assess for FAI and anterior coverage of the femoral osteotomy. A dynamic, three-dimensional reformation CT scan can be obtained to determine the extent of FAI. The approach for surgical hip dislocation as described by Ganz et al. is in Chapter 6 . Ganz’s algorithm for surgical treatment ( Fig. 32.11 ) offers a structured way to identify the problem and the surgical treatment to correct structural abnormalities.
Technique 32.6
(GANZ)
- ▪
Complete the approach for surgical dislocation of the hip (see Chapter 6 ), including an osteotomy of the greater trochanter.
- ▪
Reevaluate range of motion for intraarticular sources of FAI, such as femoral neck asphericity or acetabular rim prominence. Trim the head and neck as necessary, starting with the femoral head. Trim the acetabular rim if any FAI persists.
- ▪
Check for any impingement of the lesser trochanter (with the ischium or posterior acetabulum).
- ▪
Determine the exact location of the chondral damage on the femoral head by dividing the head into eight sections, four anterior, and four posterior ( Fig. 32.12 ). Include articular cartilage lesions, labral lesions, OCD lesions, and incongruent protrusions that were resected.
- ▪
Check functional radiographs intraoperatively to determine any joint incongruity and to determine if a proximal femoral osteotomy needs to be performed. Indications for a valgus osteotomy are a nonspherical femoral head with good congruency in an adducted view.
- ▪
Check the amount of correction that could be obtained by a pelvic acetabular osteotomy. An indication for a pelvic acetabular osteotomy is an associated secondary acetabular dysplasia (defined as a lateral center-edge angle of less than 25 degrees).
- ▪
Perform trochanteric advancement for relative lengthening of the femoral neck (see Technique 32.8).
- ▪
Perform a valgus osteotomy ( Fig. 32.13 ) or a pelvic acetabular osteotomy (Technique 32.1) as indicated.
- ▪
Reduce the hip and place in a neutral position in a soft splint.
Postoperative Care
Remove suction drains at 48 hours. Mobilize the patient with crutches and partial weight bearing (15 kg). Restrict active and passive abduction and adduction to protect the trochanteric osteotomy. Use low-molecular-weight heparin for 8 weeks to avoid deep vein thrombosis.
Valgus extension osteotomy
One residual of Legg-Calvé-Perthes disease is a malformed femoral head with resulting hinged abduction. Hinged abduction of the hip is an abnormal movement that occurs when the deformed femoral head fails to slide within the acetabulum. A trench is formed laterally, adjacent to a large uncovered portion of the deformed head anterolaterally. Raney et al. described valgus subtrochanteric osteotomy for malformed femoral heads with hinge abduction. All were classified Catterall III and IV with previous failed treatment. At 5-year follow-up, 62% had satisfactory results. We use a valgus extension osteotomy, as described by Catterall, fixed with a pediatric screw and side plate ( Fig. 32.13 ) to relieve this obstruction.
Valgus flexion internal rotation osteotomy
Kim and Wenger, using three-dimensional CT in Legg-Calvé-Perthes disease, noted “functional retroversion” rather than femoral anteversion. As a result, they recommended a valgus flexion, internal rotation femoral osteotomy plus a simultaneous acetabuloplasty in patients with severe femoral head deformity. The combined procedure (1) corrects the functional coxa vara and hinge abduction (valgus osteotomy); (2) establishes a more normal articulation between the posteromedial portion of the true femoral head and the acetabulum, while moving the anterolateral protruding portion of the femoral head away from the anterolateral acetabular margin (valgus-flexion osteotomy); (3) corrects external rotation deformity of the distal limb (internal rotation osteotomy); and (4) improves joint congruity and anterolateral femoral head coverage in hips with associated acetabular dysplasia.
Shelf procedure
If the hip is congruous, a Staheli or Catterall shelf augmentation procedure (see Chapter 30 ) is performed for coxa magna and lack of acetabular coverage for the femoral head.
Chiari osteotomy
We have used the pelvic osteotomy described by Chiari as a salvage procedure to accomplish coverage of a large flattened femoral head in an older child when the femoral head is subluxating and painful ( Fig. 32.14 ). It is described in detail in Chapter 30 .
Trochanteric overgrowth
Although trochanteric overgrowth can be caused by numerous conditions, including osteomyelitis, fracture, and congenital dysplasia, it occurs in Legg-Calvé-Perthes disease when the disease causes premature closure of the capital femoral physis while sparing the greater trochanteric physis. Whatever the mechanism, the result is the same: arrest of longitudinal growth of the femoral neck with continuation of growth of the greater trochanter ( Fig. 32.15 ). According to Wagner, the functional consequences are always the same: elevation (overgrowth) of the trochanter decreases tension and mechanical efficiency of the pelvic and trochanteric muscles; shortening of the femoral neck moves the greater trochanter closer to the center of rotation of the hip, decreasing the lever arm and mechanical advantage of the muscles, and impairing muscular stabilization of the hip; the line of pull of the muscles becomes more vertical, increasing the pressure forces concentrated over a diminished area of hip joint surface; and impingement of the trochanter on the rim of the acetabular roof during abduction limits range of motion. Macnicol and Makris described a “gear stick” sign of trochanteric impingement that is useful in the preoperative evaluation. This sign is based on the observation that hip abduction is limited by impingement of the greater trochanter on the ilium when the hip is extended but full abduction is possible when the hip is fully flexed. The “gear stick” sign is especially useful for differentiating between trochanteric impingement and other causes of limited abduction. Transfer of the greater trochanter distally restores normal tension to the trochanteric muscles and improves mechanical efficiency, puts a more horizontal pull on the pelvic and trochanteric muscle action to distribute forces over the hip joint more uniformly, and increases the length of the femoral neck to increase abduction and decrease acetabular impingement.
Premature closure of the proximal femoral physis often occurs after Legg-Calvé-Perthes disease and may limit abduction and produce gluteal insufficiency. Trochanteric advancement has been advocated for the late treatment of Legg-Calvé-Perthes disease and is thought to improve gluteal efficiency and increase the range of abduction, which was limited by impingement of the trochanter on the ilium. With surgical dislocation of the hip, the greater trochanter is routinely osteotomized. If trochanteric advancement is necessary, Ganz et al. have described an extended retinacular soft-tissue flap that protects the blood supply to the femoral head and allows for a relative lengthening of the femoral neck. The greater trochanter is advanced distally such that its tip is in line with the center of the femoral head. Fixation is secured with two or three 3.5- or 4.5-mm screws (see Technique 32.7). Alternative methods of treatment include abduction valgus osteotomy of the femur and trochanteric epiphysiodesis. Trochanteric epiphysiodesis does not appear to change the radiographic appearance but according to some authors reduces the Trendelenburg gait.
Trochanteric Advancement for Trochanteric Overgrowth
Technique 32.7
(WAGNER)
- ▪
With the patient supine, approach the hip through a lateral incision. Incise the fascia lata longitudinally and release the vastus lateralis from the greater trochanter.
- ▪
Retract the gluteus medius muscle posteriorly, and insert a Kirschner wire superiorly, parallel to the femoral neck and greater trochanteric physis and pointing toward the trochanteric fossa ( Fig. 32.16A ). Confirm the placement of the guidewire by image intensification. Internally rotating the hip slightly aids placement of the wire and allows better imaging.
- ▪
Make the osteotomy parallel to the Kirschner wire with a low-speed oscillating saw, completing it proximally with a flat osteotome ( Fig. 32.16B ). Pry open the osteotomy until the medial cortex fractures ( Fig. 32.16C and D ).
- ▪
Mobilize the greater trochanter first cephalad, and with dissecting scissors remove any adhesions, joint capsule, and soft-tissue flush with the medial surface of the trochanter, sparing the blood vessels in the trochanteric fossa ( Fig. 32.16E ).
- ▪
When the greater trochanter is freed, transfer it distally and laterally. If excessive anteversion is present, it also can be transferred anteriorly.
- ▪
Using an osteotome, freshen the lateral femoral cortex to which the trochanter is to be attached. Place the trochanter against the lateral femoral cortex and check the position with image intensification. According to Wagner, the tip of the greater trochanter should be level with the center of the femoral head, and the distance between them should be 2 to 2.5 times the radius of the femoral head.
- ▪
When proper position is confirmed, fix the greater trochanter with two screws inserted in a cephalolateral to caudad direction ( Fig. 32.16F ). These screws, with washers, should compress an area of bony contact between the trochanter and femur. Bury the screw heads by retracting all soft tissues to prevent soft-tissue necrosis and local mechanical irritation from occurring postoperatively. Wagner uses a supplemental strong tension band suture that he believes helps absorb tensile forces from the pelvic and trochanteric muscles and prevents trochanteric avulsion; we have not found this suture to be necessary.
- ▪
No postoperative immobilization is required if the patient is compliant and the fixation is secure.
Postoperative care
Ambulation on crutches is begun at 7 days, but active exercises of the pelvic and trochanteric muscles are not permitted until 3 weeks. Sitting upright and flexing the hip also should be avoided because overpull of the gluteus medius muscle may cause loss of fixation.
Trochanteric Advancement For Trochanteric Overgrowth
Technique 32.8
(MACNICOL AND MAKRIS)
- ▪
Approach the greater trochanter through a straight lateral incision under lateral image intensification.
- ▪
With a power saw, divide the base of the trochanter in line with the upper border of the femoral neck. Mobilize the trochanteric fragment and the gluteal muscles from their distal soft-tissue attachment.
- ▪
Remove a thin wedge of bone from the posterolateral femoral cortex ( Fig. 32.17 ) to provide a cancellous bone bed for the transferred trochanter and to ensure that the trochanter does not project too far laterally. Any undue prominence would cause friction of the fascia lata and produce discomfort and bursitis.
- ▪
Fix the trochanter with two compression screws to prevent rotation of the fragment and to allow early partial weight bearing.
Postoperative Care
A spica cast is not used, but patients walk with crutches by the end of the first postoperative week. Exercises to promote movement are introduced gradually, but upright sitting, abduction, flexion, and internal rotation are not forced.
Greater Trochanteric Epiphysiodesis for Trochanteric Overgrowth
Technique 32.9
- ▪
Approach the physis of the greater trochanter through a lateral incision, and determine its location and orientation by inserting a Keith needle. If necessary, use radiographs to confirm its position.
- ▪
Use a small drill bit to outline the four corners of a rectangle that spans the lateral portion of the greater trochanteric epiphysis. Remove this lateral rectangle of cortical bone with osteotomies.
- ▪
Curet the physis, reverse the rectangle of bone, and replace it in its bed.
- ▪
Internal fixation is unnecessary.
Postoperative Care
Postoperative cast immobilization is not required unless curettage has been so vigorous that the physis of the greater trochanter has been excessively disrupted. Weight bearing is progressed as tolerated.
Osteochondrosis or Epiphysitis
The terms osteochondrosis and epiphysitis designate disorders of actively growing epiphyses. The disorder may be localized to a single epiphysis or occasionally may involve two or more epiphyses simultaneously or successively. The cause generally is unknown, but evidence indicates a lack of vascularity that may be the result of trauma, infection, overuse, vitamin D deficiency, or congenital malformation.
In some epiphyses, osteochondrosis is distinctive enough to be recognized easily as a distinct clinical entity. Osteochondrosis of some intraarticular epiphyses may closely resemble other diseases, however, and requires careful diagnostic study. Only disorders of the epiphyses that frequently present to the orthopaedist, or sometimes require surgical treatment, are discussed in this chapter.
Traction epiphysitis of the fifth metatarsal base (Iselin Disease)
In the German literature in 1912, Iselin described a traction epiphysitis of the base of the fifth metatarsal occurring in young adolescents at the time of appearance of the proximal epiphysis of the fifth metatarsal. This secondary center of ossification is a small, shell-shaped fleck of bone oriented slightly obliquely with respect to the metatarsal shaft and located on the lateral plantar aspect of the tuberosity ( Fig. 32.18 ). Anatomic studies have shown that this bone is located within the cartilaginous flare onto which the peroneus brevis inserts. It usually is not visible on anteroposterior or lateral radiographs but can be seen on the oblique view. It appears in girls at about age 10 years and in boys at about age 12 years; fusion occurs about 2 years later.
Iselin disease causes tenderness over a prominent proximal fifth metatarsal. Weight bearing produces pain over the lateral aspect of the foot. Participation in sports requiring running, jumping, and cutting, causing inversion stresses on the forefoot, is a common factor. The affected area over the tuberosity is larger on the involved side, with soft-tissue edema and local erythema. The area is tender to palpation at the insertion of the peroneus brevis, and resisted eversion and extreme plantar flexion and dorsiflexion of the foot elicit pain. Oblique radiographs show enlargement and often fragmentation of the epiphysis ( Fig. 32.19 ) and widening of the cartilaginous-osseous junction. Nonunion of the fifth metatarsal ( Fig. 32.20 ) has been reported in several adults as a result of Iselin disease and failure of fusion of the epiphysis.
The un - united epiphysis should not be mistaken for a fracture, and a fracture should not be mistaken for the epiphysis. This frequently can be determined clinically based on a history of trauma or the absence thereof, as well as tenderness to palpation over the base of the fifth metatarsal. Os vesalianum, a sesamoid in the peroneus brevis ( Fig. 32.21 ), and traction epiphysitis with widening of the epiphysis also must be distinguished from Iselin disease.
Treatment is aimed at prevention of recurrent symptoms. For acute symptoms, initial treatment should decrease the stress reaction and acute inflammation caused by overpull of the peroneus brevis tendon. For mild symptoms, limitation of sports activity, application of ice, and administration of nonsteroidal antiinflammatory medication usually are sufficient. For severe symptoms, cast immobilization may be required. Occasionally, for chronic symptoms, an arch support that wraps around the base of the fifth metatarsal is used. Internal fixation of the epiphysis is not indicated.
Osteochondrosis of the metatarsal head (Freiberg Infraction)
Freiberg infraction, also known as Freiberg disease, usually occurs in the head of the second metatarsal but also may occur in the third ( Fig. 32.22 ), fourth, and fifth metatarsals in adolescent patients. Surgery is not recommended during the acute stage, which may persist for 6 months to 2 years. It may be indicated later because of pain, deformity, and disability. Occasionally, a loose body is present ( Fig. 32.23 ), and simply removing it may relieve the symptoms. Other procedures used include scraping the sclerotic area and replacing it with cancellous bone (Smillie procedure), osteochondral plug transplantation ( Fig. 32.24 ), dorsal wedge osteotomy, temporary joint spacer, and total joint arthroplasty ( Fig. 32.25 ). The surgical treatment of this disorder is discussed in Chapter 84 .
Osteochondrosis of the navicular (Köhler Disease)
Osteochondrosis of the tarsal navicular originally was described by Köhler in 1908. Ossification centers of the navicular appear between the ages of 1.5 and 2 years in girls and 2.5 and 3 years in boys. Abnormalities of ossification vary from minor irregularities in the size and shape of the navicular to gross changes indistinguishable from osteochondrosis. These abnormal ossifying nuclei are more common in late-appearing ossification centers of the navicular. The blood supply to the navicular consists of numerous penetrating vessels in children and adults. The development of the ossific nucleus is associated most frequently with a single artery, but the incorporation of other penetrating vessels as part of the vascular supply varies; occasionally a single vessel is the sole supply until the age of 4 to 6 years. Delayed ossification has been suggested to be the earliest event in the changes leading to irregular ossification because the lateness of ossification of the navicular subjects it to more pressure than the bony structures can withstand. Abnormal ossification may be a response of the unprotected, growing nucleus to normal stresses of weight bearing. If osseous vessels are compressed as they pass through the junction between cartilage and bone, ischemia results and leads to reactive hyperemia and pain. The diagnosis of Köhler disease is a clinical one requiring the presence of pain and tenderness in the area of the tarsal navicular associated with radiographic changes of sclerosis and diminished size of the bone, including collapse of the navicular ( Fig. 32.26 ). The appearance of multiple ossification centers without an increase in density should not be confused with Köhler disease, and radiographic findings similar to Köhler disease in an asymptomatic foot should be considered an irregularity of ossification.
Cast boot immobilization with protected weight bearing has been reported to produce quicker resolution of symptoms. This is a self-limiting condition, and operative treatment rarely is indicated.
Pain and disability rarely develop after osteochondrosis if the navicular becomes distorted and sclerotic, the head of the talus becomes flattened, the articular surfaces of the two bones become fibrillated, and osteophytes form along the margin of the articular surfaces. Though this is not common, surgery rarely may be indicated when disabling symptoms persist. In this case arthrodesis is the only operation of value, and the calcaneocuboid joint is included because most of its function is lost when the talonavicular joint is fused. The midtarsal joints (talonavicular and calcaneocuboid) can be arthrodesed by a technique similar to that used for deformities in poliomyelitis (see Chapter 34 ). The results of this operation usually are excellent; most patients become symptom free but may notice loss of lateral movements of the foot, though there are concerns about the long-term effects on adjacent joints. When symptoms arise from the naviculocuneiform joints also, these joints should be included in the fusion. Here arthrodesis is difficult to secure; metallic internal fixation and inlay grafts of autogenous cancellous bone are helpful.
Osteochondritis of the ankle
Osteochondritis of the ankle in adults is discussed in Chapter 90 . The natural history of this lesion in children with open physes seems to be similar to that of osteochondrosis of the knee in that, with immobilization, the lesion heals in most children. Bauer et al., in a long-term (≥20 years) follow-up study of 30 children with osteochondritis of the ankle, found that only one patient developed severe arthritis. Only minor radiographic changes occurred in the rest of the patients, in contrast to osteochondritis of the knee, in which osteoarthritis is frequent. Two of the lesions in their series were located on the joint surfaces of the distal tibia, a site previously unreported. Bauer et al. noted that the lesions in children are indistinguishable from those in adults; however, because the lesions in children heal, there may be some variance in ossification of the talus ( Fig. 32.27 ) . Regardless of the cause, the initial treatment should be nonoperative.
Apophysitis of the tibial tuberosity (Osgood-Schlatter Disease)
Osgood-Schlatter disease is an apophysitis of the tibial tuberosity that is the result of persistent traction on the apophysis of the tibial tuberosity caused by overuse. It occurs in boys aged 12 to 15 years and girls aged 9 to 13 years and frequently occurs in those who play basketball and volleyball, although it can also affect those who participate in other activities requiring frequent jumping and squatting. It typically occurs at the time that the apophysis has started to ossify but before it has fused to the remaining proximal tibial epiphysis and the remainder of the proximal tibia.
Clinically, patients complain of anterior knee pain and swelling over the tibial tubercle. Radiographs may show widening of the physis between the apophysis and the proximal tibia, irregularity of the tibial tubercle apophysis, or even fragmentation of the apophysis with separate ossicles.
A strong association has been noted between Osgood-Schlatter disease and patella alta, and, in particular, a shortened rectus femoris has been noted. The increase in patellar height may require an increase in the force by the quadriceps to achieve full extension, which could be responsible for the apophyseal lesion. It can be argued, however, that the patella alta is the result of chronic avulsion of the bony tuberosity. Robertsen et al. noted on histologic examination a pseudarthrosis covered with cartilage and no sign of inflammation. A pseudarthrosis may indicate the disease is traumatic in origin. They suggested that persistent symptoms of Osgood-Schlatter disease for more than 2 years warrant exploration. Krause et al. concluded that symptoms of Osgood-Schlatter disease resolve spontaneously in most patients and that patients who continue to have symptoms are likely to have distorted tibial tuberosities associated with fragmentation of the apophysis with ossicles on radiographs. Lynch and Walsh described premature fusion of the anterior part of the upper tibial physis in two patients with Osgood-Schlatter disease who were treated nonoperatively, and they recommended screening for this rare complication.
Surgery rarely is indicated for Osgood-Schlatter disease; the disorder usually is self-limiting or becomes asymptomatic with simple conservative measures, such as the restriction of activities, bracing, or cast immobilization for 3 to 6 weeks. Surgery may be considered if symptoms are persistent and severely disabling. Insertion of bone pegs into the tibial tuberosity (Bosworth procedure) is simple and almost always relieves the symptoms by causing fusion of the apophysis to the remaining tibia; however, an unsightly prominence remains after this operation and is rarely used. The bony prominence can be excised (ossicle resection and tibial tubercleplasty) through a longitudinal incision in the patellar tendon or arthroscopic removal of the ossicle and tibial tubercle debridement. Reported complications of Osgood-Schlatter disease whether treated surgically or not, include subluxations of the patella, patella alta, nonunion of the bony fragment to the tibia, and premature fusion of the anterior part of the epiphysis with resulting genu recurvatum. Because of the possibility of genu recurvatum, surgery should be delayed until the apophysis has fused. We have removed only the ossicle with satisfactory results; we believe the tuberosity should be excised only if it is significantly enlarged and the apophysis is closed. The amount to be excised (debrided) should be determined preoperatively as described by Pihlajamäki et al. ( Fig. 32.28 ).
Sinding-Larsen-Johansson disease is a clinical entity similar to Osgood-Schlatter disease except that the focus is the inferior pole of the patella ( Fig. 32.29 ). Symptoms are similar but pain is in the superior portion of the patellar tendon rather than over the tibial tubercle. Nonoperative treatment is similar and involves rest, stretching, and antiinflammatories.
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