Monday, April 12, 2010

Spinal deformity

Spinal deformity

 Myung-Sang Moon1, Bong-Jin Lee2, Sung-Soo Kim2,
1 Department of Orthopaedic Surgery, Cheju Halla General Hospital, Jeju; Catholic University of Korea and Seoul, Korea
2 Department of Orthopaedic Surgery, Cheju Halla General Hospital, Jeju, Korea


Available fromhttp://www.ijoonline.com/text.asp?2010/44/2/123/61725

Full Text

The vertebral column is an aggregate of articulated, superimposed segments, each of which is a functional unit. The function of the vertebral column is to support a man in upright position, mechanically balance to conform to the stress of gravity, permit locomotion and assist in purposeful movements.

The head is located over the body of the sacrum, and the spine in an upright manner bears an axial load to support the body. Loss of this spinal balance produces a position that is at a biomechanical disadvantage. To stand upright and look forward while standing and walking, the patient with sagittal plane imbalance causes back muscle to strain to successfully or unsuccessfully reduce a patient's sideways tilt. The additional energy expenditure associated with standing and walking in patient with a spinal deformity leads to reduced functional capacity including pulmonary function and a poorer quality of life.

The definition and scope of spinal deformity continues to evolve. Certainly, the term spinal deformity includes conditions such as idiopathic adolescent scoliosis, congenital scoliosis, post-traumatic deformities and other adult spinal deformity including post-infective kyphosis. In our region, one of the most common severe deformities is the post-infective kyphosis particularly in the less privileged countries.

In ancient times, Hippocrates and his successors treated scoliosis by traction and counter-traction on his bench, and Ambroise Paré, in the 16 th century, was credited with describing the first use of bracing to treat scoliosis. The basic methods of treatment throughout the ages have consisted of traction, support and more or less vigorous redressent plus exercise and massage. In 1911, Hibbs [1] and Albee [2] introduced their spinal fusion for tuberculosis of spine, and then fusion method was adopted for scoliosis management. However, there was no steady progress in the management of spinal deformity until 1945 when Smith-Petersen [3] introduced a spinal osteotomy procedure which was modified by the several surgeons. One disadvantage for surgeons at the time was that internal fixation device for the osteotomy was not available. In 1955, Harrington introduced the hooks and rods system which revolutionalized the deformity correction surgery. Halo distraction apparatus, developed by Nickel and Perry in 1959 could be utilized for a severely deformed and rigid spine. [4]

Thereafter, Luque's segmental fixation system for scoliosis [5],[6] and Roy-Camille's pedicle screw and plate system for fracture fixation were introduced. [7] The improved Roy-Camille's system later developed into Cotrel and Dubousset (C-D) system (1984). [8],[9] Spinal deformity correction surgery, together with the development of new fixation devices, has seen remarkable technical evolution since early 1980. The indications for spinal osteotomy have been broadened for last 20 years to include patients with congenital kyphosis and scoliosis, adult scoliosis, and post-traumatic and post-infective kyphosis. More effective instrument-aided deformity correction and stabilization after osteotomy or spondylectomy could be possible by utilizing the Hartshill segmental stabilization system, [5] hook and/or pedicle screw system since early 1990. Since early 2000 the mono- and bi-plane spinal deformities could be successfully corrected by combined two stage anterior release and posterior osteotomy procedure or one-stage posterior spondylectomy.

Although the surgical deformity correction is well documented, controversy has arisen as to the true outcome of such an expensive, technically demanding, complication fraught procedure. Some would argue that the procedure is primarily a cosmetic one that mainly allows patients to look better by standing. In summary, most spine surgeons would argue that the procedure restores the sagittal balance as well as possibly correcting decompensated coronal balance that ultimately reduces the energy required by the patient to stand and walk.

A high level of patient satisfaction can be achieved if performed by experienced technically skilled surgeons, and a significant risk is understood to exist by the patient. The current authors' belief is that in the recent years the corrected spine not only improves the spinal column function but also the cosmesis and quality of life.

Post-infective spinal deformity is a preventive disease. However, if the disease is neglected it results in esthetically unacceptable deformity and needs surgical care. Non-paralytic young patients tend to have very high esthetic demands, and to drive decision making rather than pure surgical indications. This has led to the development of safe and effective corrective surgical procedures for unsightly kyphosis, but each patient must be considered individually.

Healed tuberculous kyphosis in an adult is very rigid and angled acutely. The spinal cord has poor tolerance to the traction. The objectives of the corrective surgery for severe rigid tuberculous kyphosis are: to meet the patient's esthetic demands by the surgical realignment of the spine from severe to normal without impairing neurologic function, to maintain the cord function by preventing late onset paralysis, to improve pulmonary function, and to promote social rehabilitation through better outlook.

The important precautions with surgical management are:

1. Careful preoperative patient's evaluation 

2. Delicate and careful cord exposure 
3.  Greatest care and delicacy should be paid in insertion of hooks, wires, and screws and the intrusion of screws should be minimal if possible 
4. In case of anterior surgery, the vessel ligation should be done only on one side and always on convexity 
5. Excessive distraction should never be done because inadvertant stretch and kinking can easily damage cord circulation 
6. Cord monitoring and/or wake-up test should be done during surgery 
7. Hypotension should be avoided during surgery to maintain the normal blood flow to the cord

Severe post infective deformity is not only a clinical problem but also a cosmetic problem; with increased deformity, pain appears and neurologic deficit may develop or increase if untreated. Surgical restoration of anatomic alignment reduces the rate of instrumentation failure, and increases the fusion rates.

O'Brien et al. [6] (1971) and Yau et al. [10] (1973) reported that a halo-pelvic traction as the safest and efficient method for the correction of the rigid kyphosis and scoliosis. However, later they concluded that their corrective procedure had a small reward for such a major undertaking, and the hazard of deformity correction outweighs the gain. Hence it should not be carried out for cosmetic gains.

A two-stage correction operation-anterior release and decompression and posterior correction has been commonly used for angular kyphosis and kyphoscoliosis of the thoracic and thoracolumbar spine. The single posterior approach has been used rarely until end of 1990. However, since Kawahara et al. [11] and Shimode et al. [12] reported that they successfully performed corrective en bloc spondylectomy for the severe kyphotic deformity, the procedure drew attention. Although the surgical performance was known to be technically laborious it offered good correction without jeopardizing the integrity of the spinal cord. The current authors, however, recommend only the decompression surgery for Pott's paraplegics with severe kyphosis, and not the total en bloc spondylectomy procedure. [13],[14]

For spinal stabilization after deformity correction in the past few decades, pedicle screw placement has brought in a genuine scientific revolution in the surgical care of the spinal disorders. There is still concern that thoracic pedicle screws carry more risk than wires or hooks do, but to date no reports have suggested the thoracic screw technique is associated with a higher rate of neurologic deficit.

Another complication unique to pedicle screw is the risk to the great vessel. The percentages of misplaced screws inserted under fluoroscopy were obtained and compared to the percentage of misplaced screws inserted under computer assisted image guidance reported in the literature. The result was that there was no significant difference between two techniques. The computer assisted image guidance system demonstrated the improved accuracy with the placement of screw. However, the learning curve was fairly steep, and major pedicle violations were initially 12.5% and then improved 7.5%. [15] It is the authors' review that robot and/or computer-based technology will result in more accurate and safe pedicle screw placement.


 Correct Pedicle Placement, Spinal Osteotomy and Deformity Correction


Debates exist regarding the optimum implant method of fixation. The use of thoracic pedicle screws results in potentially more correction than can be achieved with hooks and wires or with a hybrid construct of hooks and screws. It is debatable whether a 55 ~ 65% correction is of any clinical importance, but if the pedicle screw technique can allow the surgeon to avoid an anterior operation or save distal fusion segments, there is a substantial benefit. Also, the use of pedicle screw implants facilitates the treatment of severe deformity, defined as a scoliosis curve of >100o or sagittal kyphosis of >120°. In addition, halo-gravity and halo-femoral traction may have role, and vertebral column resection is an option for these severe deformities.

Although anterior release has been considered a necessary and helpful ingredient in the correction of large curves, there is currently a strong trend away from it and towards more reliance on posterior release (osteotomy and spinal shortening) techniques.

Those wishing to use the pedicle screw fixation must have adequate training, and if image guidance is used, it should be relegated to an adjunctive role than the primary means of determining an entry site and trajectory.


 Corrective Surgery and Neurological Complication


The reported incidence of neurologic deficits following pedicle subtraction or V-shaped osteotomy, and spondylectomy are known to be around 12% (range 0~15.2%). [7] Congenital scoliosis often associates with the small spinal cord that can increase the risk for neurological complication following osteotomy or spondylectomy. Thus, this information should be included in the treatment strategy.


 Spinal Osteotomy and Dural Stretch or Buckling


Lehmer et al. [9] recommended in their report on posterior transvertebral osteotomy that correction at any one level should not exceed approximately 35°. Otherwise dural buckling, which may require dural plasty may occur.


 Spinal Column Shortening and Cord Function


The ideal size of the longitudinal spondylectomy, en bloc hemi- or total spondylectomy in the correction of the spinal deformity in relation with the cord function has rarely been discussed, and there is no consensus view. In the normal spine, the cord length, spinal canal and anterior spinal column length are equal. Kawahara et al. [11] concluded that 20% column shortening in spinal tumor surgery might be safe, while Kobayashi et al, concluded that the safety limit for column shortening in dog was 12.5 mm (62.5%). [16]


 Ligation of Radicular Artery and Corrective Spine Surgery


The ligation of the radicular artery is the key procedure in carrying a safe and bloodless surgery, but can also affect the cord circulation. [11],[17] Therefore, Luque stressed the importance of leaving the segmental vessels intact for the blood supply of the spinal cord in the posterior decancellation technique for multiple vertebrectomy. [5] However, Kawahara and Tomita [9],[11] reported no neurologic complication in a series of total enbloc spondylectomy involving one to three segments after bilateral ligation of the radicular artery. No neurologic complication occurred in Kawahara et al's series. [11] Toribatake found, in a cat model, that ligation of the Adamkiewicz artery reduced spinal cord blood flow by approximately 81% of the control value, but such decreased blood did not influence spinal cord-evoked potential. [17] The spinal cord completely compensates for the ligation of one or two radicular arteries because of the abundant arterial network around both dura mater and the spinal cord.


 Adult Spinal Deformity


Surgical treatment of spinal deformity demands a solid fusion, and a long construct from the thoracic spine to the sacrum is often needed. The results supported sagittal plane balance (not coronal plane correction/ balance) as the primary radiographic factor in determining the outcome. The current authors' view is that restoration of sagittal alignment together with coronal alignment is essential to minimize and/or delay the development of adjacent segmental disease.

Complications of adult spinal deformity surgery have been the focus of many presentations with additional data on catastrophic failure of the (1) proximal adjacent segment in pedicle screw construct, (2) women over the age of 60 years with sagittal imbalance, (3) obesity, (4) osteoporosis, and (5) substantial sagittal plane correction.


 Instrument-aided Deformity Correction in Children


Since the introduction of Harrington rods traditional surgical correction of spinal deformity has involved relatively long instrumentation and fusion techniques, producing a straighter but stiff spine. In the infant, this approach leads to a shorter trunk. Current surgical techniques may also have an adverse effect on pulmonary function. Non-fusion technique in the growing spine, to maximize or modulate future growth potential, is being explored. Their potential advantages include obviation of the need for early fusion and countering of the resultant relative axial shortening from the spinal arthrodesis.


 Is Prophylaxis of Deformity Progression Possible?


Congenital, natural attritional and/or disease-related spinal changes all may lead to cosmetically unacceptable deformity together with disability. Deformity correction surgery aims, primarily, not only to improve the spinal function but also to improve spinal cosmesis. However, it is generally believed by laymen that the main health care gain in the correction of idiopathic scoliosis and other acquired spinal deformities is cosmetic.

Postoperative assessment goal is to correlate the patient's outcomes with postoperative restoration of sagittal balance and complications. Residual coronal or sagittal imbalances were significantly associated with poorer patient satisfaction.

Computer aided or robot spine surgery is a hot and complex subject. The currently available image-guided surgery system has proved valuable in conducting safe pedicle screw placement. For this it is strongly recommended that all spine surgeons have a basic training on how to carry out the robot and/or computer guided surgeries in the coming years.

For early detection and care of the spinal deformities, national and/or community-based surveys by the school nurses and/or community healthcare personnel is recommended.

Successful surgeries can be attributed to the development of new upgraded surgical skill, surgical implants, robot and/or computer assistance and cord monitoring.

The symposium on this issue has 2 review articles on kyphosis in spinal tuberculosis by Jain AK and congenital scoliosis by Debonath U. An article on pedical morphometry in patients of adolescent idiopathic scoliosis (AIS) by upendra B discusses the variations in the size of pedicles on cancave and canvex side and by Rajasekaran, et al., the advantages of ISO-3CD navigation in placement of pedicle screw in thoracic and cervical spine. Canavese et al. discusses the use of vacuum assisted closure in post operative infection following instrumented correction of spinal deformity in children.

Through sowing we can harvest good crops. Let us lay down the fertile academic soil through exchange of thoughts. Continuous efforts should be made to upgrade the surgical technique.
References

1Hibbs RA. An operation for Pott's disease of the spine. J Am Med Assoc 1911;59:433-6.
2Albee FH. Transplantation of a portion of the tibia into spine for Pott's disease. J Am Med Assoc 1911;57:885-6.
3Smith-Petersen MN, Larson CB, Aufranc OE. Osteotomy of the spine for correction of flexion deformity in rheumatoid arthritis. J Bone Joint Surg 1945;27:1-11.
4Perry J and Nickel VL. Total cervical spine fusion for neck paralysis. J Bone Joint Surg Am 1959;41:37-60.
5Luque ER. Editor's commentary in: Luque ER ed Segmental spinal instrumentations Thorofare NJ Slack 1984;230-4.
6O'Brien JP, Hodgson AR, Smith TK, Yau ACMC. Halo-pelvic traction. A preliminary report of external skeletal fixation for correcting deformities and maintaining fixation of the spine. J Bone Joint Surg Br 1971;83B:217-19.
7Roy-Camille R, Berteaux D, Saillant J. Unstable fractures of the spine. IV. Stablization methods and their results. B. Surgical methods. 1. Synthesis of the injured dorso-lumbar spine by plates screwed into vertebral pedicles. Rev Chir Orthop Reparatrice Appar Mot. 1977;63:452-6.
8Moon MS. Tuberculosis of the spine-contemporary thoughts on current issues and perspective views. Curr Orthop Relat Res 2007;21:364-79.
9Lehmer SM, Kappler L, Buscup RS, Enker P, Miller SD, Steffee AD. Posterior transvertebral osteotomy for adult thoracolumbar kyphosis. Spine 1994;19:2060-7.
10Yau AMC, Hsu LCS, O'Brien JP, Hodgson AR. Tuberculous kyphosis; correction with spinal osteotomy, halopelvic distraction, and anterior and posterior fusion. J Bone Joint Surg (Am) 1974;56:1419-34.
11Kawahara N, Tomita K, Baba H, Kobayashi T, Fujita T, Murakami H. Closing-opening wedge osteotomy to correct angular kyphosis deformity by a single posterior approach. Spine 2001;26:391-402.
12Shimode M, Kojima T, Sowa K. Spinal wedge osteotomy by a single posterior approach for correction of severe and rigid kyphosis or kyphoscoliosis. Spine 2002;27:2260-76.
13Kim KD, Patrick Johnson J, Bloch BS O, Masciopinto JE. Computer-assisted pedicle screw placement: An intro feasibility study. Spine 2001;26:360-4.
14Oschowski J, Bridwell KH, Lenke LG. Neurological deficit from a purely vascular etiology after unilateral vessel ligation during anterior thoracolumbar fusion of the spine. Spine 2005;30:406-10.
15Pappou IP, Papadopoulos EC, Swanson AN, Mermer MJ, Fantini GA, Urban MK, et al. Pott disease in the thoracolumbar spine with marked kyphosis and progressive paraplegia necessitating posterior vertebral column resection and anterior reconstruction with a cage. Spine 2006;31:E123-7.
16Kobayashi T, Kawahara N, Murakami H, Fujita F, Tomita K. An experimental study on the influence of spinal shortening on the spinal cord. Jpn Orthop Assoc Congress book 2005; 3A-P9-1.
17Toribatake Y. The effect of total en bloc spondylectomy on spinal cord circulation (abstract in English). J Jpn Orthop Assoc 1993:67:1070-80.

Treatment of Posttraumatic Deformities in Children and Adolescents by Taylor Spatial Frame

Treatment of Posttraumatic Deformities in Children and Adolescents by Taylor Spatial Frame
By Mark Eidelman, MD; Michael Zaidman, MD; Alexander Katzman, MD
The Taylor Spatial Frame provides outstanding stability and computer accuracy and is a reliable and definite method for posttraumatic deformity correction.
Limb deformity may result from various traumatic sequelae. The most common cause is fracture malunion, but in growing children, shortening and angulation secondary to physis injury is also common. Correction of posttraumatic deformities can be done by various approaches. Each method has pros and cons, but a combination of limb shortening and angulation justify external fixator application.
Several external fixators are available. They can be divided into 2 groups: monolateral and circular. A monolateral external fixator may be more easily tolerated, but it is less stable and forgiving compared to the circular external fixator. The Ilizarov frame is a classic example of a circular external fixator. This frame allows excellent stability but has some disadvantages, such as a long surgeon learning curve and difficulty with rotational correction.The Taylor Spatial Frame (Smith & Nephew, Memphis, Tennessee) is a computerized external fixator with a virtual hinge and the ability to correct 6-axis deformities simultaneously. In contrast with the Ilizarov frame, there is no need for hinge application, multiple frame adjustments, or change of frame configuration to correct multiple plane deformities.
The purpose of this study was to determine the effectiveness of the Taylor Spatial Frame for treatment of complex posttraumatic deformities in children and adolescents.

Materials and Methods

Between 2003 and 2007, 18 patients with various posttraumatic deformities were treated with the Taylor Spatial Frame at our institution (Table). Average patient age at the time of frame application was 13.1 years (range, 8-17 years).
Table: Deformities, Treatment Approaches, and Complications
There were equal numbers of proximal, mid, and distal tibial malunions; 2 patients had combined distal and proximal tibial malunions. Seven patients had deformities secondary to growth arrest: 3 patients had growth arrest of the distal femur, 3 had proximal tibial growth arrest, and 1 had distal radius deformity secondary to physis injury.
Standing anteroposterior (AP) and lateral radiographs from pelvis to toes were obtained pre- and postoperatively and at final follow-up. Deformity analysis and measurements were made in all planes according to the principles described by Paley.1
Surgical technique was described in detail in several reports.1-5 All osteotomies were performed percutaneously by Gigli saw or the drilling and osteotome technique.1 All deformities were analyzed using the total residual correction program and were gradually corrected.
Minimum follow-up was 2 years after frame removal.

Results

In all patients, restoration of the mechanical axis and length equalization was achieved with no or minimal difference compared with anatomical parameters of contralateral extremity. At last follow-up, all patients were pain free and had regained preoperative range of motion (ROM).
The frame was removed after a mean 12.3 weeks (range, 8-24 weeks). Average lengthening was 17.9 mm (range, 5-80 mm).
Eight patients had superficial pin tract infection, which resolved with oral antibiotics or a short course of intravenous administration. One patient had transient peroneal palsy. Another patient had delayed union and needed 2 additional cast immobilizations after fixator removal. The most serious complication was angulation of the regenerate after 40 mm of femoral lengthening (Figure 1). This complication was caused by unstable ring fixation. The fixation block was revised and angulation was successfully and gradually corrected by the total residual program. No patient had deep infection or nonunion.
Figure 1A: A segmented fracture of the femur Figure 1B: Damage of the distal femoral epiphysis Figure 1C: Distal femoral valgus, recurvatum, and external 
rotation Figure 1D: Distal femoral valgus, recurvatum, and external 
rotation
Figure 1E: A segmented fracture of the femur Figure 1F: Damage of the distal femoral epiphysis Figure 1G: Distal femoral valgus, recurvatum, and external 
rotation Figure 1H: Distal femoral valgus, recurvatum, and external 
rotation
Figure 1: Radiographs of a 13-year-old boy with a segmented fracture of the femur and damage of the distal femoral epiphysis (A, B). AP (C) and lateral (D) radiographs before frame application (1 year after trauma) showing distal femoral valgus, recurvatum, and external rotation. AP (E) and lateral (F) radiographs during correction showing regenerate of angulation. Note the distal fragment fixed with 1 ring and only 2 half pins. Radiograph after addition of the second ring and four 1.8 Ilizarov wires (G). Radiograph of normal femoral alignment after frame removal (H).

Discussion

Posttraumatic deformity correction in children with open physis can be a surgical challenge. Proximity of the growth plate restricts the use of intramedullary nail fixation, while shortening and pure soft tissue coverage restrict wide use of the plating technique. The obvious advantage of external fixator application in contrast to internal fixation devices is soft tissue preservation, which can be essential in posttraumatic conditions (Figure 2).
Figure 2A: Severe varus deformity Figure 2B: Pure soft tissue coverage of the medial side Figure 2C: AP radiographs before correction Figure 2D: AP radiographs after correction Figure 2E: Clinical appearance after correction
Figure 2: Photograph of 16-year-old boy with 80-mm shortening and severe varus deformity secondary to damage of the proximal and distal epiphysis (A). Note the pure soft tissue coverage of the medial side of the tibia (B). AP radiographs before (C) and after (D) correction. Clinical appearance after correction (E).
Several external fixators are available. They can be divided into 2 groups: monolateral and circular. A monolateral external fixator may be better tolerated but is less stable and forgiving.6 The stability of the circular frame allows early postoperative weight bearing and ROM maintenance, which can be essential for regenerate formation.2,3 The Ilizarov circular frame is the classic choice for deformity correction and allows correction of almost all possible deformities.7,8 However, correction of multiplanar deformities requires replacement of hinges and frequent frame readjustments. Successful use of the Ilizarov technique has a long learning curve, and correction of complex—especially multiplanar and rotational—deformities remains a difficult challenge, even for surgeons experienced with this technique.3,6
Manner et al9 compared the accuracy of complex deformity correction by Taylor Spatial Frame and Ilizarov circular frame on 208 deformities in 155 patients. They reported that deformity correction was achieved in 90.7% in the Taylor Spatial Frame group vs 55.7% in the Ilizarov frame group. They concluded that the Taylor Spatial Frame has better precision in deformity correction, in 2-, 3-, and 4-dimensional deformity corrections in particular. In most cases, orthopedic surgeons deal with multiplanar posttraumatic deformities.
We treated 18 patients with posttraumatic malunions. Most of our patients had multiplanar deformities and shortening. Despite complex deformities, all patients achieved precise correction of all deformities.
Another choice the surgeon faces is acute vs gradual deformity correction. Matsubara et al10 retrospectively examined clinical results of acute and gradual deformity correction in 2 groups of patients treated by Ilizarov frame or Taylor Spatial Frame. They concluded that gradual correction is a better approach with the use of external fixation.
We believe that gradual correction is a more forgiving and safe way to correct deformities in children. Almost all of our patients had some shortening; therefore, gradual correction with lengthening is the only way to resolve this problem, especially in children with deformities secondary to injury of the growth plate.
We observed relatively few complications in this study. The most common complications were superficial pin tract infections, which were treated with oral antibiotics. There were no deep infections or osteomyelitis. In our previous report,3 the most serious complications were fractures of the regenerate due to pure dynamization in 3 patients. In this study, 1 patient had angulation of the regenerate secondary to unstable fixation of the distal femur. Currently, we use 2 rings at the distal femur with at least one 1.8 Ilizarov wire and three 6-mm half pins.

References

  1. Paley D, ed. Principles of Deformity Correction. Heidelberg, Germany: Springer-Verlag; 2002.
  2. Rozbruch SR, Fragomen AT, Ilizarov S. Correction of tibial deformity with use of the Ilizarov-Taylor spatial frame. J Bone Joint Surg Am. 2006; 88(suppl 4):156-174.
  3. Eidelman M, Bialik V, Katzman A. Correction of deformities in children using the Taylor spatial frame. J Pediatr Orthop B. 2006; 15(6):387-395.
  4. Eidelman M, Katzman A. Treatment of complex tibial fractures in children with the Taylor spatial frame. Orthopedics. 2008; 31(10). pii: orthosupersite.com/view.aspx?rID=31513.
  5. Taylor JC. Correction of general deformity with Taylor spatial frame fixator. J. Charles Taylor Web site. http://www.jcharlestaylor.com/spat/00spat.html. Accessed January 2010.
  6. Binski JC. Taylor spatial frame in acute fracture care. Tech Orthop. 2002; 17(2):173-184.
  7. Ilizarov GA, ed. Transosseous Osteosynthesis: Theoretical and Clinical Aspects of the Regeneration and Growth of Tissue. Berlin, Germany: Springer-Verlag; 1992.
  8. Birch JG, Samchukov ML. Use of the Ilizarov method to correct lower limb deformities in children and adolescents. J Am Acad Orthop Surg. 2004; 12(3):144-154.
  9. Manner HM, Huebl M, Radler C, Ganger R, Petje G, Grill F. Accuracy of complex lower-limb deformity correction with external fixation: a comparison of the Taylor Spatial Frame with the Ilizarov ring fixator. J Child Orthop. 2007; 1(1):55-61.
  10. Matsubara H, Tsuchiya H, Sakurakichi K, Watanabe K, Tomita K. Deformity correction and lengthening of lower legs with an external fixator. Int Orthop. 2006; 30(6):550-554.

Authors

Drs Eidelman, Zaidman, and Katzman are from the Pediatric Orthopedic Unit, Meyer Children’s Hospital, Rambam Medical Center, Haifa, Israel.
Drs Eidelman, Zaidman, and Katzman have no relevant financial relationships to disclose.
Correspondence should be addressed to: Mark Eidelman, MD, Pediatric Orthopedic Unit, Meyer Children’s Hospital, Rambam Medical Center, PO Box 96092, Haifa, 31906 Israel (eidelmanm@gmail.com).
doi: 10.3928/01477447-20100225-16

Excision of Proximal Fibular Tumors: A Newly Described Posterior Surgical Approach

The incidence of primary bone tumors in the fibula is 2.5%.1 The most common tumors found in the proximal fibula are osteochondromas, giant cell tumors, osteosarcomas, and Ewing’s tumors.2
Osteochondromas tend to grow eccentrically rather than centrifugally. Large osteochondromas that continue to grow after skeletal maturity have also been described.3 Osteosarcomas and Ewing’s tumors tend to grow in a centrifugal expansionist fashion, increasing in volume. It is therefore important to note the eccentric location of osteochondromas and their exact relationship to important anatomic structures such as the posterior tibial vessels and nerve, peroneal nerve, anterior tibial vessels, and fibular vessels.
A proximal fibular osteochondroma may distort the normal anatomical course of nerves and vessels and may lead to vascular compression syndromes and a pseudoaneurysm or peroneal nerve paralysis.4 The entrapment of a vessel in the cauliflower-like convolutions of an osteochondroma is also a possibility. A bursa may form about these lesions. An aggressive excision of these proximal tumors may lead to destabilization of the proximal tibiofibular joint.5 Careful staging and planning of the surgical approach and procedure is therefore of the utmost importance in dealing with proximal fibular tumors.
This article describes a surgical approach to deal with posteromedial growth of an osteochondroma that not only allows access and visualization at the posteromedial extension, but also at the anterior extension of such a tumor. At the same time, this approach allows for direct visualization and dissection of the posterior tibial vessels and for an extensive neurolysis of the peroneal nerve.

Case Report

An 18-year-old woman presented with a slowly enlarging posterior left calf mass. She reported exercise- and activity-induced pain with tingling and numbness in the sole of her foot. She had no previous history of tumors, and no one in her family had had any osteochondromas.
Clinical examination revealed a left calf greater in diameter compared to the right calf. The mass was present directly posterior in the calf and was firm in consistency. Both the dorsalis pedis and tibialis posterior pulses were palpable at the ankle. Muscle strength in the posterior tibial and peroneal nerve divisions was normal. No numbness was present during examination.
Radiographs revealed a large mass protruding from the fibula mainly posterior to the tibia (Figure 1). A diagnosis of a large osteochondroma was made. Magnetic resonance imaging (MRI) showed the mass to be extruding from the posteromedial surface of the fibula and extending medially and posteriorly (Figure 2). As this lesion was symptomatic and large, surgical excision was recommended. It was emphasized that nerve and vessel damage were possible. The patient elected to undergo surgery.
Figure 1: Lateral radiograph of an osteochondroma Figure 2: Axial MRI through the proximal fibular tumor
Figure 1: Lateral radiograph of an osteochondroma originating from the posterior aspect of the fibula and extending centrally into the calf muscles. Figure 2: Axial MRI through the proximal fibular tumor, demonstrating the dilemma of using a lateral or medial classic approach to the tumor.
The patient’s recovery was uneventful, with full neurological function without temporary nerve palsy postoperatively.

Surgical Technique

The patient is positioned in the right lateral decubitis position after a spinal anesthetic combined with conscious sedation. A tourniquet is applied on the upper thigh and elevated to 250 mm Hg prior to the incision.
A posterior longitudinal midline incision is used, starting at the flexor crease of the popliteal fossa laterally and extending 14 cm down the calf. Care is taken to preserve both the small saphenous and sural cutaneous nerves. The lateral portion of the incision is developed in the form of a large skin flap deep to the fascia to access the posterior and lateral compartments of the lower leg (Figure 3).
Figure 3: Lateral radiograph of an osteochondroma
Figure 3: Axial transverse anatomical illustration through the proximal third of the tibia with the surgical excision illustrated by dotted lines.
The median raphe of the gastrocnemius muscle is identified and cleaved. The lateral head of the gastrocnemius is carefully dissected loose from the soleus and mobilized laterally. The soleus is detached laterally and retracted medially, hence preserving its innervation on the medial side. The posteromedial part of the tumor can now be dissected free. The fibular attachment of the tumor cannot be accessed from this approach without damaging the lateral gastrocnemius. Therefore, the lateral border of the lateral gastrocnemius is now detached from the posterolateral intermuscular septum, allowing the muscle to be freed and able to be retracted medially or laterally to visualize and access the entire osteochondroma without damage to the lateral gastrocnemius muscle. Care is taken to preserve the proximal vascular supply and innervation of the gastrocnemius. The posterior vessels and nerve are visualized deep to the anterior border of the tumor.
The peroneal nerve is approached with the intent of mobilizing the common peroneal nerve and opening and exposing the common peroneal and deep peroneal nerve branch throughout the fibromuscular tunnel as described by Ryan et al.5 This is necessary to retract the peroneal nerve safely to a more anterolateral position to explore the tumor attachment to the fibula fully. It is imperative to ensure complete mobilization and release of the narrow part of the peroneal nerve through the fibrous tunnel to prevent postoperative compression on the nerve due to reactive swelling.
The next step is to carefully perform a subperiosteal dissection of the anterior periosteum of the tumor’s attachment of the fibula (the tumor stalk).
A curved Homan retractor is placed from superior around the stalk anteriorly to protect the anterior vessels. The tumor stalk is now carefully sectioned with a small oscillating saw. The stalk is retracted posteriorly and its anterior border can now be freed safely by dissection under visualization and protection of the posterior tibial vessels and nerve. Care is taken to remove the entire cartilage cap with its overlying membrane to minimize the possibility of a local recurrence. Sharp spikes of bone protruding from the fibula are smoothed, and visual inspection of the tumor bed as well as of the tumor on the back table is performed. The posterior tibial vessels and the peroneal nerve are inspected to ensure their free passage in the lower leg.
The tourniquet is released and all bleeders secured. The lateral gastrocnemius is sutured back posteriorly to the medial gastrocnemius. A soft drain is placed and the wound closed. A 3-way splint is applied with the ankle plantigrade (neutral) to prevent early muscle contracture and to help with pain management.

Discussion

Malawer2 described 2 types of excisions for tumors of the proximal fibula. The type I excision is wide but more conservative, saving the peroneal nerve and reconstructing the fibular collateral ligament. The type II excision, although also wide, is more aggressive and includes the anterior and lateral compartments, anterior tibial artery, peroneal artery, and proximal tibiofibular joint (en bloc). Both of these excisions are performed through a single incision curvilinear from above the knee, carving anterior to the tibial crest, and ending distal over the peroneal compartment. The flap is based on the posterior (medial) aspect of the skin. This is an excellent approach for centrifugally enlarging aggressive tumors where access to all 3 leg compartments is mandatory. The disadvantage of this incision is the large extent of the dissection to access the posterior compartment and its far medial extension to the medial border of the tibia.
It is for these medially protruding tumors not involving the lateral aspect of the fibula that the described surgical approach was developed. Krieg et al3 reported a case of extensive growth of an osteochondroma in a skeletally mature patient. Axial sections of the MRI showed a posteromedial extension of the tumor up to the medial border of the tibia. It would be difficult to access the entire tumor (similar to our case) from a lateral fibular approach without creating a large skin flap. A posterior midline approach in such cases allows the 2 heads of the gastrocnemius to be retracted sideways, exposing the medial and fibular (lateral) aspect of the tumor safely. If deemed necessary to reach the anterior compartment, it may be accessed by curving the incision anteriorly both at its superior and inferior extents (the reverse of Malawer’s2 skin incision) with its base anterior and lateral.
The incidence of iatrogenic peroneal nerve palsy after removal of fibular tumors is high (4 of 9 cases in the series of Erler et al6 and 3 of 6 type I excision patients of Malawer2). This shows the vulnerability of the common peroneal nerve and its branches after proximal fibular excisions. Palsy may follow excessive retraction or handling of the nerve with metal instruments, incomplete release of the fibular tunnel, and reactive postoperative swelling.
Ryan et al5 performed detailed anatomical dissections of the common peroneal nerve and its branches in the lower leg. They observed the most common site for compression to be the musculoaponeurotic arch at the entrance to the fibular tunnel. In cases of postoperative peroneal palsy, the entrance to the fibular tunnel is typically the area where the nerve is compressed. The deep peroneal nerve may be injured by procedures involving the lateral and anterior aspects of the proximal 8 cm of the fibula. It is therefore imperative to perform a complete release through the fibrous fibular tunnel and to retract the nerve only with soft instruments, eg, a rubber band to prevent iatrogenic peroneal nerve palsy. This is followed by applying adequate soft tissue coverage of the wound and by securing a 30° flexed position of the leg postoperatively.
Popliteal artery entrapment syndrome due to a fibular osteochondroma was described by Guy et al.4 Our patient had similar exertional symptoms due to posterior tibial artery compression. This diagnosis may be easily overlooked, and the claudication symptoms may be ascribed to muscle irritation and other mechanical causes of pain. Careful attention should be paid to preoperative MRI to assess any narrowing or compression of a segment of the posterior tibial vessels.
Tumor volumes >250 mL were reported by Erler et al6 as an indication to sacrifice the deep peroneal nerve to obtain a safe surgical margin. This applies to tumors with a high recurrence rate. Osteochondromas, even >250 mL, may be excised with sparing of the deep peroneal nerve with the caveat that a proper peroneal nerve release is performed.

Conclusion

Excision of benign or malignant tumors of the fibula prove challenging due to the intricacies of the local anatomy with tricompartmental involvement and the proximity of important neuromuscular structures. Careful attention should be paid to the exact anatomical location of the tumor and its involvement of important neurovascular structures in selecting a surgical approach best suited to minimize complications.

References

  1. Unni K. Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases. Philadelphia, PA: Lippincot-Raven Publishers; 1996.
  2. Malawer MM. Surgical management of aggressive and malignant tumors of the proximal fibula. Clin Orthop Relat Res. 1984; 186:172-81.
  3. Krieg JC, Buckwalter JA, Peterson KK, el-Khoury GY, Robinson RA. Extensive growth of an osteochondroma in a skeletally mature patient. A case report. J Bone Joint Surg Am. 1995; 77(2):269-273.
  4. Guy NJ, Shetty AA, Gibb PA. Popliteal artery entrapment syndrome: an unusual presentation of a fibular osteochondroma. Knee. 2004; 11(6):497-499.
  5. Ryan W, Mahony N, Delaney M, O’Brien M, Murray P. Relationship of the common peroneal nerve and its branches to the head and neck of the fibula. Clin Anat. 2003; 16(6):501-505.
  6. Erler K, Demiralp B, Ozdemir T, Basbozkurt M. Treatment of proximal fibular tumors with en bloc resection. Knee. 2004; 11(6):489-496.

Authors

Drs Lindeque and Oren are from the Department of Orthopedics, University of Colorado Health Sciences Center, Denver, Colorado.
Drs Lindeque and Oren have no relevant financial relationships to disclose.
Correspondence should be addressed to: Bennie G. Lindeque, MD, PhD, Department of Orthopedics, University of Colorado Health Sciences Center, Mail Stop B202, 4200 E 9th Ave, Denver, CO 80262 (bennie.lindeque@ucdenver.edu).
doi: 10.3928/01477447-20100225-14

Thursday, April 1, 2010

Enzyme may provide quick and accurate diagnosis of periprosthetic joint infections

Posted on the ORTHO SuperSite March 18, 2010
NEW ORLEANS — A strip test indicating the amount of leukocyte esterase enzyme in knee joint synovial fluid following total knee arthroplasty may be a highly sensitive and specific indicator of infected joints, according to the results of a prospective study presented here.
Neutrophils in an infected knee joint secrete the leukocyte esterase enzyme and that the prevalence of this enzyme may be a marker for infection.
Jacovides presented the study at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons.
“We believe the leukocyte esterase strip test is a highly accurate test for diagnosis of infection,” Jacovides said. “It is a fast test. It takes 1 to 2 minutes, after which the results are immediately available.”
 They aspirated 1 cc to 2 cc of synovial fluid from 117 TKA cases undergoing revision surgery and applied the fluid to a strip that detected the presence of the leukocyte esterase enzyme. They sent the remainder of the aspirate to be checked for typical counts of leukocyte cells and cultured to determine whether the lab results correlated with the findings of the strip test.
If both tests were positive (++) or if one test was positive (+), the results with the new test were considered positive. All other results were deemed negative, Jacovides said. 
Reference:
Parvizi J, Jacovides CL, Azzam KA, et al. Diagnosis of periprosthetic joint infection: the role of a simple, yet unrecognized, enzyme. Paper #156. Presented at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons. March 9-13, 2010. New Orleans.

Staples significantly increase risk of postoperative infection

Posted on the ORTHO SuperSite March 31, 2010
The use of staples to close wounds following orthopedic surgery — especially hip surgery — is associated with a significantly greater risk of wound infection than traditional suturing, according to orthopedic researchers from Norwich, England.
The findings are available at the online home of the British Medical Journal.
Wounds closed with staples were more than three times as likely to develop a superficial wound infection compared to wounds closed with sutures.  In a subgroup analysis of patients undergoing hip surgery, the risk of developing a wound infection was found to be four times greater after staple closure than suture closure, according to the release. 
Staples not recommended
The researchers found no significant difference between staples and sutures in the development of inflammation, discharge, dehiscence, necrosis and allergic reaction.
Reference:
Smith TO, Sexton D, Mann C, et al. Sutures versus staples for skin closure in orthopaedic surgery: meta-analysis. BMJ. [Published online ahead of print March 16, 2010]