All treatment procedures in patients with osteoarthritis of the hip and knee (hip and knee OA) should aim to reduce pain, improve function and mobility, and restore the impaired health-related quality of life. Depending on the stage of the disease, a variety of non-surgical treatment options, including a combination of pharmacological and non-pharmacological therapy as well as surgical procedures are available. Different clinical practice guidelines (CPG) serve as decision aids in order to identify the appropriate treatment for individual patients [[1], [2], [3], [4], [5]]. Nevertheless, there is currently no causal therapy for OA [6]. In addition to patient education and lifestyle adaptations, maintaining physical activity, exercise therapy as well as pharmacological therapy if needed, are particularly important during the initial stages of the disease. Evidence suggests that for mild to moderate symptoms it is possible to postpone surgery for some time by combining different types of non-surgical therapies [7,8].

Surgical procedures in hip and knee OA are considered if they either have the potential to alter the natural course in early degenerative stages (joint preserving surgery) or if conservative treatment is no longer effective in advanced degenerative stages (joint replacement). Joint preserving surgical procedures address structural deformities of the hip and knee joint and aim to delay OA progression through an improvement of congruency and/or load distribution. Hip and knee replacement are the ultimate treatment options in advanced OA stages with complete loss of articular cartilage and are irreversible surgeries [9,10]. When joint preserving surgery is no longer possible and conservative therapies become ineffective, joint replacement is one of the most successful and effective treatment options [[11], [12], [13]]. Recent data from the British National Joint Registry (NJR), which has been collecting patient-reported outcomes since 2009, show that 97% of patients reported an improvement in hip and 94% in knee pain and function 6 months after surgery [14]. According to a recent meta-analysis of pooled survival data derived from registry data [15], one can expect a total hip replacement (THR) to last 15 years at around 89% and a total knee replacement (TKR) in around 93% of patients.

Although different types of joint preservation surgery as well as a joint replacement have been shown to significantly improve pain, function, and health-related quality of life, their potential is still underestimated and utilization varies worldwide. Especially the high regional variability in joint replacement rates facilitates debates in many countries about appropriate decision-making for surgery based on explicit indication criteria [[16], [17], [18], [19]].

The aim of this chapter is to provide an overview of the principles of surgical treatment in hip and knee OA. Current evidence regarding indication criteria for different interventions (joint preserving surgery as well as joint replacement) shall be summarized and influencing factors on outcome be discussed.