Knee Osteoarthritis (Gonarthrosis): Surgical Therapy

If the patient’s pain can only be controlled by continuously taking analgesics (painkillers) or if the patient’s lifestyle is severely impaired, then there is an indication for surgical therapy. There are numerous surgical options to alleviate the discomfort and consequences of gonarthrosis (knee osteoarthritis) and thus significantly improve the quality of life.

• Symptomatic surgical methods for joint preservation:
  • Lavage* (irrigation of the knee joint).
  • Shaving (technique to obtain replacement tissue).
  • Debridement* (rehabilitation of the wound bed by removing necrotic and fibrinous coatings).
• Bone stimulating surgical methods (marrow stimulation):
  • Pridie drilling – tapping of cartilage defects to break through the underlying bone layer and allow sprouting of blood vessels and thus regeneration of tissue by replacement cartilage (technique for obtaining replacement tissue).
  • Microfracturing – placing a small bone defect to trigger repair mechanisms in a joint with cartilage damage (technique for obtaining replacement tissue).
  • Abrasionplasty – in the course of an arthroscopy (arthroscopy of the joint), the residual cartilage in the defect area is removed with a cutter down to the subchondral bone layer (radiologically recognizable “hardening” of the bone under the cartilage surface of a joint). In this process, similar to microfracturing, there is a washout of mesenchymal stem cells (MSCs) from the bone marrow from the subchondral bone into the defect area; Indication: circumscribed cartilage damage.
• Advanced therapy options:
  • Joint surface restitution (for cartilage defects > 1 cm²).
    • autologous chondrocyte transplantation (ACT; synonyms: autologous cartilage transplantation; autologous chondrocyte cell transplantation) – in two surgical steps, the patient’s own chondrocytes (cartilage cells) are first harvested, cultivated ex vivo ((lat. “outside the living”), and then, in a second, open operation, implanted, i.e. The standard procedure is matrix-associated transplantation (M-ACI), in which the cultured chondrocytes are fixed to a collagen carrier substance in the laboratory and inserted into the cartilage defect zone.The procedure is traded as a so-called Advanced Therapy Medicinal Product (ATMP) as a drug. Approval has been granted by the European Medicines Agency (EMA) for the repair of symptomatic articular cartilage defects of the femoral condyle (distal articular process (condyle) of the thigh bone (femur)) and the patella (kneecap) up to 10 cm2 in size.Indications: traumatic or degenerative damage to articular cartilage; isolated cartilage damage with stable defect marginsSuitable parameters for patient selection are:
      • Size of the defect: > 2.5 cm² in young active patients, otherwise > 3-4 cm².
      • Defect type: isolated or focal cartilage damage.

      Negative predictors of outcome:

      • Female gender, older age, long-standing complaints, multiple prior surgeries, presence of multiple defects, patellofemoral location (compartment between patella and femoral fossa).
    • Osteochondral transplantation (OCT) – use of an autologous or an allogeneic graft (cartilage-bone graft) for defect treatment.
    • M-ACI shows at least comparable benefit with treatment alternatives such as microfracture or mosaicplasty.
  • Articular realignment osteotomy (synonym: corrective osteotomy) – surgical procedure in which a bone is cut (osteotomy) to restore normal anatomy of bones, joints, or extremities.
• Joint replacement* * (e.g., knee arthroplasty/partial knee arthroplasty/total joint arthroplasty (artificial replacement of the complete joint, i.e., the condyle and the socket); the complication rate as well as the mortality rate (death rate) after partial knee arthroplasty is lower than after total joint arthroplasty; the disadvantage of partial knee arthroplasty is that it must be replaced earlier than total joint arthroplasty)

Further notes

• * Numerous studies show that no benefit can be established for therapeutic arthroscopy with lavage and, if necessary, additional debridement compared with a nonactive comparative intervention (e.g., no efficacy documented for elderly patients with mild gonarthrosis (knee joint osteoarthritis)).A meta-analysis showed that arthroscopic surgery for the treatment of degenerative damage to the knee joint in middle-aged patients produces only a marginally better long-term pain-relieving effect than conservative treatment.
• * International expert panel – “Rapid Recommendations” section in the journal BMJ: Arthroscopic debridement (“knee joint toilet”) of the knee joint should no longer be part of the therapy in patients.
  • With degenerative knee joint osteoarthritis.
  • With meniscus tear
  • Purely mechanical symptoms
  • Absent or minimal signs of osteoarthritis on imaging
  • Sudden onset of symptoms not due to trauma
• Institute for Quality and Efficiency in Health Care (IQWiG): benefit for matrix-associated transplantation (M-ACI) procedure: a meta-analysis provided statistically significant effects in favor of M-ACI with regard to knee function and activities of daily living, although not of clearly clinically relevant magnitude.
• Billing note in the care of SHI-insured patients with gonarthrosis: As of spring 2016, arthroscopies may only be billed for patients with trauma, acute joint blockages, and meniscus-related indications in which the existing gonarthrosis is to be considered merely a concomitant disease. The method evaluation concluded that the procedures studied have no evidence of benefit compared to sham surgery or no treatment (IQWIG).
• Placebo therapy with an intra-articular injection (“into the joint cavity”) of saline showed the best effects compared with oral placebos (drug-free pills had the smallest placebo effect, invasive sham surgery the largest).
• * * Whether joint replacement is indicated is determined by the patient’s symptoms and level of distress, not by radiograph alone.