Orthopedics - Oleksa A.P. 2006

Joint Diseases
Degenerative-Dystrophic Joint Diseases
Static Deforming Arthrosis

Static Deforming Arthrosis occurs As a result of uneven load distribution across the articular surfaces due to a disrupted axis of the limb segments. Axial deviations beyond the normal range most commonly affect the knee joint, and less frequently the elbow and ankle joints. Although axis deviation of a segment can occur in any plane, clinical practice most frequently encounters varus deformities of the knee and valgus deformities of the elbow, which are sometimes simultaneously combined with recurvatum or antecurvatum.

Varus deformities of the knee area (Fig. 339) can be caused by Achondroplasia, Blount's Disease, epiphysitis of the proximal Tibia, Rickets, etc.

Under METABOLISM/18.html">The Influence of strong Muscles during standing and walking in varus knee deformity, the primary load falls on the medial condyles of the tibia and Femur, while the lateral processes are simultaneously unloaded. When the axis deviates by 10°, the load per unit surface area of the medial condyle Cartilage triples. Due to overload and excessive friction, the articular cartilage of the medial processes softens, degenerates, becomes thinner and uneven, the joint space narrows, while on the opposite side of the joint the space widens along with the stretching of the lateral collateral ligaments, which leads to joint instability and arthrosis.

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Fig. 339. Valgus deformity of the knee: a - before surgery, b - after removal of a bone wedge and fixation of the tibia with a staple in the corrected position.

Table 6. Causes of secondary deforming arthrosis of the knee joint

This process develops very slowly over many years, and initially, varus deformity causes the patient no trouble other than a cosmetic defect. Subsequently, the patient begins to experience increased friction and crepitus in the joint, pain after limb overload, and a protective flexion contracture (incomplete extension).

As a result of marginal compensatory osteocartilaginous growths from the medial process, which increase the load-bearing area, joint deformation and restricted movement occur.

Radiological examination reveals disturbances in the axis of the limb and its segments, narrowing of the joint space on the side of increased load and its widening on the opposite side. Depending on the duration of the disease, varying degrees of arthrosis changes, marginal bone growths, and Osteoporosis of the lateral processes due to their underloading are detected.

A similar mechanogenesis occurs in Genu Valgum.

Treatment. Any disturbance of the limb or segment axis requires treatment, as it will inevitably and progressively lead to deforming arthrosis.

Clinical observations indicate that post-rickets lower limb axis disorders can be successfully corrected conservatively in early childhood while children are still growing. At night, a straight wooden board is bandaged to the outer surface of the child's leg, resting against the knee to straighten the leg. During the day, children use corrective orthopedic braces, undergo Muscle massage, and are recommended swimming and multivitamin intake. If conservative treatment is ineffective, varus deformities of any Etiology must be operated on during the pre-arthrotic stage, i.e., in preschool and school-aged children. Timely surgery prevents The Development of deforming arthrosis by restoring the limb axis and normal joint loading. To prevent recurrence, children should be operated on during the period following another growth spurt. However, parents of children operated on before the age of six should be warned about the possibility of recurrence in Blount's disease due to the child's growth.

In the Cytology/cytology/16.html">Early stages of arthrosis, Surgical treatment prevents its progression by increasing and balancing the contact load-bearing area of the processes, normalizing the function of the menisci and the Ligamentous apparatus of the joint, as well as restoring articular cartilage defects with fibrous elements and strengthening the Bone Structure.

Before surgery, radiographs should be used to determine the angles of limb axis deviation and which bone caused the curvature in the knee area. Most often, the cause of genu varus is Pathology of the upper end of the tibia.

Today, the levels for corrective osteotomy are well-established (Coventry M., 1985; Pawlas R., 1994; Witocski D., Zwierzchowski H., 1994).

Surgical technique. Under anesthesia, an incision is made along the lateral surface of the lower leg below the neck of the Fibula to avoid damaging the fibular nerve, which wraps around the neck from top to bottom and from back to front. The fibula is osteotomized subperiosteally in an oblique direction, and the wound is closed. Afterwards, subperiosteal osteotomy of the tibia is performed.

Two options for tibial osteotomy are currently used.

The first surgical option is used in children with an active epiphyseal cartilage and Varus deformity of the tibia with some medial rotation.

Surgical technique. The tibia is exposed in the tuberosity area through a linear vertical tissue incision. Directly below the tuberosity, the periosteum is elevated using a raspatory, protectors are inserted, and the bone is cut with a shaped osteotome. After this, the lower limb axis is corrected, and the bone fragments are fixed with percutaneously inserted Kirschner wires.

In children, The Use of other fixators is inappropriate, and the wires are removed after three weeks by their ends protruding above the Skin. After closing the surgical wound, a long leg cast is applied. If difficulties arise during axis correction, postoperative external fixation (Ilizarov apparatus) can be used to gradually eliminate axial deviations over 5-7 days. The wound is sutured and drained for 24-48 hours.

The second surgical option is used in patients who have completed their growth and present with severe varus or valgus deformity of the knee area. High epiphyseal osteotomy above the tibial tuberosity is recognized by orthopedists as optimal, as it provides better postoperative ligament stability and improves knee joint function. Prior to surgery, the curvature angle and the dimensions of the wedge to be removed to straighten the limb axis are calculated from radiographs.

Under anesthesia, through a linear vertical incision along the medial edge of the patellar ligament, the tibia with its tuberosity is exposed. It is important not to open the knee joint cavity and not to cause hemarthrosis with all its ensuing consequences. The tuberosity is osteotomized and retracted upward along with the patellar ligament.

A standard subperiosteal transverse osteotomy of the tibial epiphysis is performed, and the limb axis is straightened. In varus deformity, only after transverse osteotomy and axis correction is a triangular gap formed, which is filled by impacting a wedge-shaped graft.

When using frozen homologous grafts, a loss of axis correction by several or sometimes more degrees occurs over time (Bieniek J., Sokotowski J., Mladzki Z., Olszowiec W., 1998). To prevent this, complete off-loading of the limb is necessary until the bone graft incorporates and remodels, which increases the duration of patient treatment.

Nowadays, ceramic grafts are used instead of bone grafts. Corundum ceramic with a porosity of 75% is compressive-resistant and biocompatible. Once such a graft is successfully invaded by normal tissue, its strength increases by 50-70 %.

As a rule, the required porous ceramic graft is shaped during surgery, carefully adapted to the spongy bone structure, and tightly wedged into place.

To achieve better wedge stabilization, Bieniek J. et al. (1998) leave the lateral cortical layer of the tibia intact, allowing it to fracture greenstick-style during correction. Plaster immobilization is applied for up to 6 weeks, followed by physical therapy. Weight-bearing on the leg is permitted after three months.

To avoid using grafts, a wedge is excised from the bone and removed. The fragments are then fixed using metal hardware.

Undoubtedly, any grafts require significantly more time for ingrowth and remodeling than the healing of well-adapted bone fragments following hemichelyotomy or wedge excision.

Most practicing orthopedic surgeons perform a high semicircular (epiphyseal) tibial osteotomy using a shaping osteotome. After axis correction, the fragments are secured with a T-shaped "AO" metal plate. This allows for knee mobilization after 3-4 weeks and graded weight-bearing on the limb in 6-8 weeks. If the limb axis is distorted by femoral condyle deformities, corrective osteotomy is performed at the level of the distal metaepiphysis.

To improve gliding mechanics and achieve decompression in gonarthrosis involving the Patella and femoral condyle, Novikov N.V., Popov V.A., and Ukrainets V.S. (1987) perform Procedures to correct muscle imbalance and ligamentous apparatus.

It is important to remember that lower limb axis malalignment must be corrected in the pre-arthritic stage; in cases of bilateral pathology, surgeries are performed at an interval of 6-8 months.

In advanced arthritic changes, The Scope of surgery is considerably greater, and the outcomes do not always satisfy patients and physicians.

Partial synovectomies and cheilotomies are still performed today, often combined with corrective osteotomies, but destructive Changes in the articular cartilage persist, and pain continues to trouble patients. Therefore, total joint replacement is currently the most justified Procedure for severe static gonarthrosis, whereas arthrodesis of the most affected knee joint is preferred for manual laborers.

The day before surgery, the patient is administered an intramuscular antibiotic, and the level and angle of bone resection are determined from radiographs to ensure that normal limb alignment is restored following arthroplasty.

There are several manufacturers that produce various endoprosthesis designs and instrument sets for joint replacement surgery.

Technique of knee arthroplasty. The surgery is performed under general anesthesia with Anesthetic Management. After preparing the operative field, the elevated lower limb is exsanguinated by applying an Esmarch bandage, starting from the FOOT. Once the tourniquet is applied to the upper third of the thigh, the operative field is prepped once again.

A vertical tissue incision is made lateral to the rectus femoris tendon and patella, ending near the tibial tuberosity. After opening the knee joint cavity, it is dried, and The Nature and extent of the destructive process are assessed. If normal articular cartilage is found on the femoral condyles, while destructive changes with marginal osteophytes are present on the tibial articular surface, the procedure can be limited to tibial arthroplasty alone.

The lower leg is flexed to 90', or further if necessary. The menisci are carefully excised with a scalpel, and soft tissues are stripped from the articular margins of the tibia. A sizing template is secured at the required angle, and the articular end of the bone is resected. Next, a medullary canal is drilled for the endoprosthesis stem. The prosthesis is test-fitted to verify that the resection was performed correctly and that limb alignment has been restored, as adjustments can still be made. The bone canal is then dried and filled with bone "cement" prepared ex tempore, into which the tibial component of the endoprosthesis is inserted. Impacting the endoprosthesis compacts the cement and provides stable fixation. After the cement hardens, the wound is lavaged and closed in layers, with drainage maintained for 24-48 hours.

If destructive changes are found on the femoral condyles, total knee replacement is performed. In total arthroplasty, the articular end of the femur is mobilized first, and an alignment rod is driven from the intercondylar area into the medullary canal, upon which the template is placed. Using the template, the articular ends of the condyles are resected in three planes that precisely match the inner surface planes of the femoral component. Next, the stem canal is prepared, its placement is verified, and only then is it fixed with cement.

The procedure is completed with arthroplasty of the proximal tibial articular end, as described above. The limb is immobilized for 7-10 days using a plaster splint or a fabric brace with fasteners. To facilitate surgical exposure, the articular bone ends are resected first and then replaced with prostheses.

After suture removal, joint mobilization begins with active and passive exercises, accompanied by muscle massage. Patients are allowed to walk with crutches and bear partial weight on the leg after one month. Full weight-bearing while walking with a cane is possible in 3-4 months, which largely depends on the patient's activity level.

If the patient has bilateral knee involvement, the second surgery can be performed 6 months later, i.e., after the function of the previously operated leg has recovered.

Complications following knee replacement are similar to those after hip arthroplasty (early and late suppurations, prosthesis loosening, etc.). The management of these complications is likewise identical.

For static gonarthrosis in manual laborers who are forced to overload their lower limbs for extended periods, a stabilizing procedure should be considered optimal in cases of unilateral knee involvement.

Technique of knee arthrodesis. The surgery is performed under general anesthesia. Before applying the thigh tourniquet, the limb is exsanguinated with an elastic bandage, starting from the foot. Using Payr's incision with division of the patellar ligament and removal of fat pads, the knee joint cavity is exposed by retracting the patella proximally. The Joint Capsule is excised, and the articular bone ends are mobilized. Protectors are inserted to shield the popliteal neurovascular bundle, and the articular surfaces are economically resected at an angle to restore limb alignment with the lower leg flexed at 7-10', ensuring tight apposition of the cut surfaces.

Following the docking of the resected ends, they are bridged with the resected patella (Albrecht, Wreden, Turner), free bone grafts (Böhm G.), or more stably fixed with crossed impacted bone pegs (Michelman, Brittain) or metal rods (Zatsepin, Bogdanov, and others).

Nowadays, the resected bone ends are stabilized using the Ilizarov compression-distraction apparatus or a fixator system, which ensure ankylosis in the shortest possible time.

The surgical wound is closed in layers and drained for 24-48 hours.

Following the stabilization of the resected bones using the apparatus, graduated weight-bearing on the limb is recommended, with full weight-bearing introduced after 1.5 months. The device is removed once radiological confirmation of bony ankylosis is obtained.

A properly performed arthrodesis enables the patient to place full loads on the ankylosed knee joint, perform heavy physical labor, and reduce the burden on the contralateral leg, thereby preventing the onset or slowing the progression of degenerative-dystrophic changes within it.

In cases of bilateral static gonarthrosis in manual laborers, the more painful and functionally compromised joint is operated on first to achieve weight-bearing Stability of the limb through ankylosis. If the pathological process progresses In the second knee and surgical intervention becomes necessary, arthroplasty is performed, and the patient is referred to the medical and social expert commission (MSEK) for disability status determination.