Section Outline
- Regeneration and Repair of Osseous Tissues
- Infections of Bones and Joints
- Inflammatory Rheumatoid Disorders
- Osteoarthrosis
- Avascular Necrosis of Bone or Osteonecrosis
- Common Metabolic Bone Disorders
- Common Generalized Congenital Deformities and Dysplasias in Orthopedics
- Localized Congenital Deformities (Anomalies) of Limbs
- Common Orthopedic Tumors
- Common Neuromuscular Disorders
HEALING OF FRACTURES AND OSSEOUS TISSUES
Most of the fractures would unite whether splinted or not due to an in-built mechanism of healing. Land-animals afterall have been walking after such fractures.
In clinical practice, fractures require stable immobilization to alleviate pain, ensuring adequate contact of fracture ends in near anatomical position, preventing excessive movements at fracture site, however, permitting early axial loading of the limb. Axial physiological loading permits healing by natural way by formation of external callus. Visible external callus will not form if the fracture is fixed rigidly. The progress of healing process by rigid fixation cannot be easily appreciated. The bones under rigid implants due to stress shielding become osteoporotic, fracture at the weakened bone is not uncommon after the implant removal.
An outline of “natural healing” of a fracture is described below. All the structures, periosteum, endosteum, cells contained within the broken bones and muscles and soft tissues contribute to the process of fracture healing. The injury itself triggers the cascade of healing process. The cascade of fracture or bone healing starts after traumatic fracture, osteotomies (controlled fractures), pathological fractures (except due to malignancies), or any operation on bone.
Throughout the process of fracture healing (from fracture hematoma (Fig. 1.1) till the end of remodeling), many growth factors like bone morphogenic proteins, cytokines and other growth factors continuously play a role in cascadal fashion. The cellular and molecular responses are practically uniform up to the stage of soft callus formation, further behavior of growth factors and cellular response would, however, depend upon the environments provided for the healing process. The pluripotent reparative mesenchymal cells under variable conditions may induce woven bone (fiber bone), chondrogenesis, endochondral ossification, lamellar bone; or fibrous tissue when environments are unfavorable (Figs. 1.2 and 1.3).
Fig. 1.1: Bone is essentially a vascular tree surrounded by mineralized tissue. This is the appearance of ‘bone’ after removal of all mineralized tissues.
Immediately after a fracture, in addition to the formation of fracture hematoma, there is intense vascular response in the injured area (not unlike in the Ilizarov's process). 4The vascularity increases at every level, medullary vessels, periosteal vessels, from capillaries to nutrient artries. With healing, the continuity of endosteal, periosteal and extra-osseous vasculature is re-established across the site of fractured area.
Fig. 1.2: Reparative mesenchymal cells can be induced to form any mesenchymal tissue depending upon the environments.
Figs. 1.3A to C: Cellular response in early stages of repair. (A) During first week—non-specific inflammatory cells; (B) Between 2nd to 4th week—osteoclasts and osteoblasts; (C) Between 3rd to 5th week—clump of osteoblastic cells.
BIOLOGY OF NATURAL FRACTURE HEALING (SECONDARY HEALING)
The fractures heal by various biological stages in a cascadal fashion. The stages generally described are for convenience 5and possible understanding. Fracture or any injury to the bone triggers following biological cascade of repair (Fig. 1.4).
Stage I: Fracture Hematoma: Blood collects around the broken bones, because there is rupture of endosteal and periosteal blood vessels and the vessels in the disrupted soft tissues around the site of broken bones. At the fracture ends, one to 2 millimeter of bone dies because of disruption of its blood supply.
Stage II: Soft Callus: Within about 8 hours of the fracture, the hematoma gets organized (formation of granulation tissues) and invaded by neocapillaries accompanied by endothelial and perithelial cells under the influence of many growth factors and cytokines (Figs. 1.5A and B).
Stage III: Mineralization of Callus: Calcium starts getting deposited around the neocapillaries (neo-osteogenesis), peripheral parts earlier than deeper parts.
The pluripotent mesenchymal cells of the granulation tissue, under the influence of bone morphogenetic agents and growth factors, differentiate into osteogenic, chondrogenic and osteoclastic cells. Osteoclasts remove the dead bone and dead tissues, thus, creating channels (cutter heads) for neocapillaries to spread across the fracture site.
Figs. 1.5A and B: (A) Abundant neocapillaries formed at early stages of repair; (B) Neo-osteogenesis seen by tetracycline fluorescence around neoangiogenesis.
Earliest neo-osteogenosis is observed around the neocapillaries and vascular spaces (Figs. 1.5 and 1.6). Mineralization of callus is a diffuse process, external callus is radiologically visible, however, internal callus (medullary callus) is not easily discernable.
Stage IV: Callus Consolidation: The whole of callus is now mineralized spreading astride the fractured site. The fracture lines do not remain visible in the X-rays. The outer surface of callus is irregular (rough).
Stage V: Callus Remodeling: The bone laid down in the initial stages is as woven bone (fiber bone) or as endochondral bone. The restoration of the normal architecture occurs by the process of remodeling according to the Wolff's law (function determines the form of bone). The geometry, thickness and trabecular pattern of callus and bone are dependent upon the functional loading (probably the most important factor) and muscular action of the limb. Ultimately the trabeculae are laid (reorganized) in the direction of functional loading, woven bone or endochondral bone gets replaced by trabecular lamellar bone, the external callus gets resorbed (decreases in size), the medullary canal and medullary vessels get re-established. Radiologically the callus has normal mineralization and there is smoothening of the external surfaces.
TIMETABLE OF FRACTURE UNION
How long does a fracture take to unite and consolidate? No precise answer is possible because age, general health, status of soft tissue cover, blood supply, nature of fracture (closed or compound), the site of fracture and type of treatment, all influence the time taken. Approximate prediction may be possible for fractures of major bones in an adult (with optimum health) according to Perkin's timetable. A spiral fracture in the upper limb unites in three weeks, for consolidation (time to permit all activities without protection) multiply by 2; for lower limb, multiply all figures by 2; for transverse fractures, multiply all figures again by 2.
With optimum health and nutrition of the patient, having been offered a biologically sound treatment most of the fractures heal with optimum biological process. However, 5 to 10 percent of fractures undergo delayed union and non-union, many due to poorly understood causes. Optimization or enhancement of the healing process of such patients is being debated and tried.
Figs. 1.6A and B: Outer most layer of bone was laid about one month before harvesting this tissue, around a large vascular space. Successive layers of bone formed (as seen by tetracycline-fluorescence) in one month's time reducing the size of the vascular space to form an osteon.
We may not understand methods for enhancement of the process of fracture healing, however, causes of non-union or delayed unions are fairly well known.
Non-unions
If a fracture does not unite in double the expected time of union for that fracture, it is accepted to be called non-union. Common causes of non-union are:
- Distraction of fracture fragments, either as a result of interposition of soft tissues, or failure of soft tissues to hold the fragments in contact, or as a result of fixation of fragments in distraction (bipolar interlocking, plating).
- Excessive movements at fracture site.
- Severe damage to soft tissues (extent of trauma or iatrogenic).
- Poor local blood supply of bone.
- Infection (infected non-unions are most difficult to treat).
- Iatrogenic: Surgical intervention leading to excessive soft tissue stripping (damage), fixing the fracture with a gap between the fragments.
- Intracapsular fractures: Fracture line within the synovial fluid (fractures of femoral neck, scaphoid, talus).
Fracture line remains visible in X-rays after many months of treatment. Some operative intervention is indicated when a particular fracture is not expected to unite: The X-rays may show a gap of more than … mm, the bone ends are sclerosed, there is thinning of bone ends or the medullary canal is closed. Non-unions are classified as hypertrophic or atrophic or a mixed variety. In cases of difficulty or when the fragments are already fixed with implants, “stress X-rays” in various planes may help to reach the decision. Some non-unions especially in the elderly and located in upper limb may be managed by a suitable orthosis, which permits the patient function and ambulation without much pain. However, in general, the principles of open reduction, freshening of edges, internal fixation and barrel-stieve like copious autogenous bone grafting is mandatory. Post-operatively encourage active exercises and loading of the operated limb. When in doubt about the stability provided by the implant do not hesitate to use additional cast or orthosis. A few cm of shortening to achieve union is not much of a price to ensure union.
FRACTURE STABILIZATION—OPTIONS
Despite all the technological advances made in the operative treatment of fractures (open reduction and internal fixation– ORIF), surgical intervention is not free of complications, and many a time a second operation (re-operation) is indicated for implant removal. Non-operative management is a sound method of treating many fractures especially in places with moderate or compromised infrastructure available. Most of the fractures of upper end of humerus, humeral shaft, lower end of radius, fractures of forearm bones, fractures of tibia, fractures around the ankles, clavicle, carpal and tarsal bones, metacarpals and metatarsals can be effectively managed by non-operative treatment. Multiple Kirschner's wires fixation percutneously with biplanar and bicortical engagement under C-arm guidance can improve the stability around osteochondral fracture sites. Many fresh osteochondral fractures (less than 10 days duration) can be managed by closed reduction and insertion of Kirschner's wires under C-arm.
Other methods of achieving stability at the fracture site are plates, screws, external fixations, bridging plates, intra-medullary fixations. Rigid-internal fixation was advocated by AO–school in the second half of 20th century; however, at present, the preference and consensus is for stable 8fixations. Ideally one should prefer a fixation which permits early axial physiological loading, as during walking and while doing active muscle exercises.
Intramedullary nails with many of its modifications are used as a standard option for most of the diaphyseal fractures of bones. Reaming of the medullary canal for insertion of the nail is still controversial and debated. There are proponents for reaming to permit insertion of nails with larger diameter, we prefer minimal reaming to open the isthmic areas to permit a snug fitting nail, and there are some surgeons who insert nails without reaming especially while operating on a polytraumatized patient. Do not attempt extensive operations (to achieve “anatomical” reduction) which may lead to devascularization of bone. Basic goals of fracture treatment should be aimed at stable fixation (by any means) with least disruption of endosteal and periosteal circulation, respect to and restoration of soft tissue coverage with provision for relatively pain free movements of the adjacent joints. Micromotions do not impede the healing process. Prolonged non-weight-bearing can lead to local osteoporosis, soft tissue dystrophy and loss of cartilage nutrition. Some known substances that have inhibitory effect on bone healing are NSAIDs, tobacco (nicotine), diabetic state, rheumatoid disorders, malnutrition, osteoporosis, cytotoxic drugs and irradiation.
RIGID INTERNAL FIXATION
With rigid fixation, medullary circulation may get re-established early, the “cutter heads” may cross the fracture site, however, the so called “primary healing” or “osteon by osteon” healing takes place very slowly and means to accurately determine the progress (extent) of primary healing are unreliable. For early ambulation, casts or orthosis are still required to protect the limb during full weightbearing. Rigid fixation with plates results in stress shielding under the implant leading to cortical thinning, which may cause fracture at the ends of plate (site of stress concentration), or at the site of thinning of cortex. The reported incidence of such fractures is 10 to 15 percent (Table 1.1). The likelihood of refracture of bones that heal with external callus is extremely rare.
The classical diaphyseal fractures which are stable (transverse, or short oblique) can be managed by intramedullary nails without interlocking. However, unstable diaphyseal fractures, very oblique, long spiral, grossly comminuted segmental fractures, or fractures with loss of bone fragments, are candidates for interlocking (with screws). Early loading in cases of interlocking is inadvisable because the stress would be on screws, which are likely to bend or break. When one is using bipolar interlocking, dynamization must be done to avoid non-union. On an average dynamization for upper limb in recommended after 6 weeks, for the lower limb after about 9 weeks.
9
OSTEOTOMIES IN ORTHOPEDICS
Our ancestors in orthopedics evolved many osteotomies for a variety of orthopedic affections (conditions). These are essentially low technology but high biology procedures. If our patient selection is appropriate and the procedure is performed following the principles advocated by the exponents one can get a satisfactory result in a number of disorders for many years.
Ideally any corrective osteotomy should be done nearest to the deformity. For genu varum, select proximal tibial osteotomy; for genu valgum, select distal femoral osteotomy; for cubitus varum or cubitus valgum, select distal humeral osteotomies. Proximal femoral osteotomies are generally indicated for fixed hip deformities or certain problematic fractures. Innominate osteotomies help provide ‘shelf’ for stability of hip joint. There are many methods of obtaining correction of deformities. It can be close-wedge osteotomy, it does not need bone grafting, however, the bone-wedge which one removes may be used as a bone graft to place over the osteotomy site before wound closure. If one opts for an open wedge osteotomy, one has to secure the correction by a suitable implant, most surgeons consider filling of the open wedge with bone grafts. Another method of achieving correction is by a dome-shaped (ball and socket) osteotomy. The convexity of the dome is generally towards the joint or broader end of the bone. After completion of the ball and socket osteotomy, the correction can be achieved in any direction—abduction, adduction, external rotation and internal rotation in isolation or in combination.
Once any of the above corrective osteotomies are completed, it is wise to correct all deformities, as planned preoperatively. The contralateral normal limb should be easily accessible for comparison of the achieved correction during surgery. The site of osteotomy can be fixed by any of the methods, plaster cast only, Kirschner's wires (K-wires) and plaster cast, tubular plates, screws and wires (like French osteotomy), angled blade plates, or external fixators. Depending upon the growth potential of the bone, one may do over-correction of the deformity by 5 to 10 degrees to negate the recurrence of deformity with growth. Basic priniciples of fracture healing must be observed during operation, fixation, postoperative immobilization, loading and rehabilitation.
Osteotomy performed by a surgeon should be considered a controlled fracture. While doing osteotomy if soft tissues are respected, while achieving correction bone ends are not treated roughly, raw surfaces at the osteotomy site are held in good apposition for at least 70% of the circumference, implants when used provide a stable fixation (without distraction) to permit axial loading in the lower limbs or active exercises (in the upper limb) 3 to 6 weeks after the osteotomy, non-union at the osteotomy site should be a rare complication. While using rigid implants for fixation of osteotomy, the surgeon must ensure the best desired position on the operating table. If one is using a semirigid implant (K-wires), the correction can be improved to the best desired at the time of stitch removal and application of definitive plaster around 2 to 3 weeks after the osteotomy. Most of the corrective osteotomies for joint problems provide adequate relief of pain, maintain functional mobility, retain natural bone stock and articular cartilage, provide proprioception and permit fairly high degree of activity for 10 to 15 years. Juxta-articular osteotomies do not necessarily compromise the later arthroplasty procedure.10
ILIZAROV’S (1950S) TECHNIQUE OF CORTICOTOMY AND DEFORMITY CORRECTION
Distraction osteogenesis is a form of tissue engineering founded on the principle of generation of new tissues in response to gradual increase in tension. The basis of the technique is to produce a careful fracture of bone or corticotomy, followed by a short wait (5 to 10 days) for young callus to form at the site of ‘fracture’. Distraction is now applied gradually via a circular or unilateral external fixator device (Fig. 1.7).
In corticotomy, the bony cortex is partially divided in a circumferential manner using sharp narrow osteotomes through small skin incisions. The break is completed by gentle manual force (osteoclasis), thus, leaving endosteal and periosteal blood supply intact. Alternatively, the site of osteotomy is exposed subperiosteally. Multiple drill holes are made all around the site of bone division in the cortex without going across the medullary canal. The osteotomy is completed using a sharp narrow osteotome.
One can understand the biological principles, however, mastery of the technique has a long learning curve. The operative technique is got to be tailored to each patient. Probably this method is best indicated in patients who have concomitant complex deformities like angulation, rotation, translation and shortening. The corticotomy or osteotomy must be completed by low energy technique (sharp, narrow osteotomes) to minimize necrosis and damage to endosteal and periosteal blood supply. Distraction osteogenesis has the best potential of “regeneration” at metaphyseal or metaphysio-diaphyseal junctional areas as compared to diaphyseal sites. A nearly ten-fold spatial increase in blood flow through neoangiogenesis following corticotomy (and possibly following osteotomy) has been observed. Neoangiogenesis is the precursor to neo-osteogenesis. Distraction is recommended at 0.25 mm four times a day. Distraction at this rate causes neovascularization, neo-osteogenesis, generalized cellular proliferation almost in all the tissues (most appropriately termed distraction histogenesis) under the effect of tension distraction. Ilizarov's corticotomy can be successfully used even in the presence of moderate active infection and local scarring of soft tissues.
Distraction is usually applied through a circular or unilateral or bilateral external fixator. Depending upon the age of the patient and the health of the concerned bone, after 5 to 10 days of waiting period of osteotomy, graduated distraction generally forms a soft callus (regenerate) at the site of distraction in about 3 to 4 weeks. If distraction is too fast, the regenerate may be thin (poor) and has hour-glass appearance. If distraction is too slow, the regenerate shows a bulbous appearance and may undergo premature rapid consolidation defeating the purpose of the whole procedure. Ilizarov's principle of distraction histogenesis has also been used for distraction of the growth plate (chondrodiastasis), preferably in children close to the closure of the physis. Growth plate generally closes or is sealed after this procedure.11
Ilizarov's principle has also been used for correction of soft tissue contractures, like Volkmann's ischemic contracture in upper or lower limbs, and resistant club-foot deformities. Another indication for this technique is for filling of segmental defects in bone (bone-transport). Probably bone loss of more than double the diameter of tibia or femur would need the help of bone transport techniques. The gap is gradually filled by creating a “floating segment” of bone by performing a corticotomy (or osteotomy) proximal or distal (or bifocal corticotomy) to the site of bone gap. Ilizarov's technique offers a reliable method to correct complex deformities, overcome shortening, and bridge bone gaps. However, the complications in the hands of a general orthopedist remain high, therefore, for the best results, Ilizarov's technique should remain in the domain of especially trained and committed surgeons with adequately resourced infrastructure.
BONE GRAFTS AND GRAFT SUBSTITUTES
Bone grafts are needed in clinical orthopedics mostly for treatment of non-union of fractures, for filling large cystic lesions of bone and for reconstruction of large osteo-periosteal bone defects (Table 1.2). The best bone graft is autogenous, because it provides: (i) osteogenesis by the osteoinduction property of the graft inducing the reparative mesenchymal cells (from the host) into osteoprogenitor cells, (ii) it provides an ideal porous scaffold for penetration of vessels and cells, upon which the new bone can form, (iii) structural (mechanical) stability is provided minimally by cancellous, moderately by corticocancellous grafts and predominately by tubular bones, (iv) osteogenesis may also be brought about by a few surviving surface cells of autogenous grafts. Donor area morbidity is recorded, however, any orthopedic surgeon with moderate training would learn to obtain adequate amount of cancellous bone from the thickest part of iliac crest without serious complications. After subperiosteal exposure of the iliac crest and outer surface of the “harvest area,” one can remove adequate amount of cancellous bone as slivers. If one leaves the inner table intact and does a meticulous closure of muscles and skin, as a rule no complication is encountered. The most disturbing complication observed by us has been a sliding hernia through a major defect in the full thickness of iliac bone, this is, however, avoidable. The iliac bone provides a rich source of cancellous bone. Tricortical bone harvested from the thickest part of iliac crest constituted by the upper border, medial and lateral cortices of the bone can provide about 6 cm × 1.5 cm × 1.5 cm segment of bone for use as a structural graft. Cancellous autogenous bone grafts are best suited for non-unions, and for filling of “cavitory lesions”. For structural integrity, tricortical bone from iliac crest or a segment from distal half of fibula, or ribs when one is operating on spine would serve the purpose.
|
One may sometimes need to use both the structural grafts combined with cancellous bone. The limitation of autogenous bone grafts is the availability of sufficient quantity required especially in children. Cortical bones provide mechanical stability, however these are very slow regarding incorporation. Part of fibular grafts may still be radiologically visible 7 to 10 years after operation. Cancellous bone grafts provide poor mechanical stability however these get completely incorporated within 2 to 5 years after implantation.
Allografts: Earlier than 1965, fresh allografts generally donated by ‘mother’ of a child were used when no other material was available. Such grafts have no surviving cells, however, these cells have illicit antigenicity and induce an inflammatory response, which may lead to failure of the grafts. Slow penetration of neocapillaries in the transplanted fresh allogenic bone did not create a sudden surge of antigen-antibody reactions. Thus, the immune reaction was mild. However, since mid-sixtees clinical use of untreated allografts is not permitted.
When adequate amount of autogenous bone graft is not available to fill or bridge large defects, one has to depend upon allogenic bone. Currently the allografts are harvested under sterile conditions, the donor is cleared for malignancy, infection, and viruses (including HIV). The harvested bones are stored or preserved by deep freezing (at −70° C), freeze-drying or ionizing radiation. Osteoinductive potential of such grafts is, however, markedly reduced.
Demineralization (according to the principles of Urist, 1965) is another way of reducing antigencity, and increasing the porosity for better osteoconduction. Decalcified bone matrix retains sufficient osteoinductive agents (BMPs, growth factors) inducing the host mesenchymal cells to osteoprogenitor cells. The author has used such allogenic grafts between 1972 and 2013 for cavitory lesions, spinal fusions (in children) and for structural defects with impressive success comparable with the grafts from more sophisticated banking facilities (Figs. 1.8A and B). Preparation and maintenance of decalbone banks is simpler, less expensive and can be practised in hospitals with moderate facilities (Figs. 1.9A and B). Allografts are ideal for conditions like polyostotic fibrous dysplasia, generalized enchondromatosis, neurofibromatosis with pseudarthrosis and osteogenesis imperfecta. In such cases, the autogenous bone per se is inherently defective.
Allografts or bone graft substitutes can also be used as autogenous bone grafts expander. The process of incorporation of allografts is similar to that of autogenous grafts but slower.
Bone Graft Substitutes (Synthetics)
Synthetically produced graft substitutes are prepared from calcium phosphate, hydroxyapatites and calcium carbonate in various combinations. These graft substitutes act as osteoconductive agents for osteoprogenitor cells (accompanying neocapillaries) to penetrate in their pores and lay down bone. Mechanical strength and rate of resorpotion (one to 2 years) vary with different combinations.
Bone cement: Cementation may be used for filling-up benign cavities in bone if bone grafts or substitutes are not available. Cementation leads to exothermal reaction on the recipient wall. Probably the reaction eliminates the reparative potential from the host-bed (Figs. 1.8A and B). Once infected the infection persists. Metal implants at best provide stability to damaged bones. If the underlying damaged bone does not stabilize in the “critical” time the implant would break due to the accumulation of “metal-fatigue” (Figs. 1.10A and B).13
Figs. 1.8A and B: After curettage of giant-cell-tumor of proximal tibia, the cavity was filled with (A) cementation. The tumor recurred within 18 months after the operation; (B) The cement was removed, intralesional curettage of the tumor was performed and the cavity was compactly filled with allogenic bone graft. The biological activity of the host bone and the graft helped heal the osseous cavity.
Bone Morphogenetic Proteins (BMPs)
These bone inducing agents were earlier extracted from allogenic bones. The process was too complicated and the yield was too small (probably one mg from one kg of bone). At present, BMP-2 and BMP-7 are commercially prepared by recombinant techniques, these are available for clinical use, however, the cost is prohibitive (e.g. US dollars 400 for a single level disc fusion) for widespread use.
Fibula as a Bone Graft
Fibula is another source of autogenous bone graft especially for structural integrity. It provides an excellent mechanical stability, but has scanty cellular contents. The compact structure of fibula makes permeation by repairing mesenchymal cell and neocapillaries a slower process, delaying complete incorporation. The deepest part of fibular grafts may not get completely incorporated even after many years.14
Figs. 1.9A and B: (A) Synthetic bone graft substitute; (B) Decal-bone preserved in ethanol (prepared according to Urist's technique).
One can safely harvest about 15 to 20 cm of fibula. The distal cut should be at least one cm proximal to the inferior tibio-fibular joint. If one is impelled to obtain the upper end of fibula (as for reconstruction of distal end of radius), one must ensure the safety of the common peroneal nerve winding around the neck of fibula.
Transfer of Vascularized Bone Graft (Taylor, 1975)
The commonest free vascularized bone graft used in clinical practice has been the fibula. This procedure, however, requires microvascular expertise and sound orthopedic principle with two operating teams working simultaneously at the donor-site and the recipient area. Besides the highly specialized expertise, the other limiting factors are scarring at the recipient area due to infection, soft tissue damage or radiation necrosis. This option may be considered only when simpler techniques have failed or judged to fail.
Muscle Pedicle-based Bone Grafts (Huntington, 1905)
Muscle pedicle-based bone grafts can be performed by most of the orthopedic surgeons, however, the limitation in this procedure is that the “pedicled bone” has a limited radius of excursion. The most popular (and successful) graft has been the transfer of muscle pedicled vascularized fibula to repair or replace large defects in the ipsilateral tibia.
Figs. 1.10A and B: Any metal-implant would fail due to accumulation of metal fatigue unless the underlying bone gets stabilized before implant failure (within critical time): (A) In the femur; (B) In the humerus.
Figs. 1.11A to C: Ipsilateral fibula is one of the most vital grafts available to reconstruct any large defect in the tibia. Distal half of tibia was lost after an open injury of this leg (A and B). Ipsilateral fibula was “tibialized” to bridge the gap with fusion of the ankle joint (C). Note hypertrophy and remodeling of the fibular graft, the proximal non-weight-bearing fibula has not hypertrophied
The author has used this technique (tibialization of fibula) successfully for repair of large tibial defects due to traumatic extrusion, extensive sequestration, oncological resection and congenital defects (Figs. 1.11A to C).
Many other muscle pedicled bone grafts have been innovated by orthopedic surgeons, a few examples are sartorius and tensor fascia lata based bone from anterior part of iliac crest, for neglected or nonunion of femoral neck fractures, and for avascular necrosis of femoral head in young patients. This would delay the need for total joint replacement by 10 to 15 years. Lumbosacral paravertebral muscle based bone from posterior part of iliac crest, for posterior or posterolateral fusion of lumbar or lumbosacral spine, and quadratus femoris based bone graft from ischeal tuberosity are other examples. Pedicled bone grafts provide the benefit of osteogenesis as of living bone, irrespective of the length of bone defect and condition of the recipient bed. These grafts are tolerant to moderate infection and are capable of hypertrophy according to the Wolff's law. For success, adherence to sound orthopedic principles for repair and regeneration of bone is mandatory.
REFERENCES
- Huntington TW. Case of bone transference. Ann Surg. 1944;26:455.
- Urist MR. Bone formation by autoinduction. Science. 1965;150:893–99.
- Companacci M, Zaanoli S. Double tibio fibular synostosis (fibula pro tibia) for non-union and delayed union of the tibia: End results review of one hundred seventy-one cases. J Bone Joint Surg. 1966;48–A:44–56.
- Illizarav GA. The tension-stress effect on the genesis and growth of tissues. Part II. The influence of the rate and frequency of distraction. Clin Orthop Relat Res. 1989;239:263–85.
- Ilizarov GA. Clinical application of the tension-stress effect for limb lengthening. Clin Orthop. 1990;250:8–26.
- Paley D, Chaudhry M, Pirone AM, Lentz P, Kautz D. Treatment of malunions and mal-nonunions of the femur and tibia by detailed preoperative planning and the Ilizarov techniques. Orthop Clin North Am. 1990;21:667–91.
- Sarmiento A, Latta L. The evolution of functional bracing of fractures. J Bone Joint Surg. 2006;88B:141–48.
- De long WG Jr, Einhorn TA, Koval K, et al. Bone grafts and bone graft substitutes in trauma surgery. A critical analysis. J Bone Joint Surg. 2007;89A:649–58.
- Kelly MP. Savage JW, Bentzen SM, et al. Cancer Risk from Bone Morphogenetic Protein Exposure in Spinal Arthrodesis. J Bone Joint Surg. 2014;96A:1417–22.
- Tuli SM. Tibialization of the fibula: A viable option to salvage limbs with extensive scarring and gap nonunious of the tibia. Clin Orthop Relat Res. 2005;431:80–4.
- Yadav SS. The use of a free fibular strut as a “Biological Intramedullary Nail” for treatment of complex non union of long bones. J Bone Joint Surg Open Access. 2018:e0050.