A joint replacement (endoprosthesis) partially or completely replaces a joint damaged by wear and tear, injury, or fracture with an artificial joint made of metal, ceramic, and plastic. The joints most commonly replaced in older adults are:
- Hip joint: The most common endoprosthesis. Approximately 240,000 hip replacements per year in Germany.
- Knee joint: About 175,000 total knee replacements (TKR) per year. Technically more challenging, with a longer rehabilitation period.
- Shoulder joint: About 30,000 shoulder replacements per year; becoming increasingly common.
- Ankle, wrist, and finger joints: Less common, performed for specific indications.
The primary cause of joint replacement in older adults is osteoarthritis—the progressive wear and tear of the joint cartilage. Prevalence data:
- Radiologically confirmed knee osteoarthritis: over 40 percent of people over 65
- Symptomatic knee osteoarthritis: 15 to 20 percent
- Hip osteoarthritis: about 10 percent in older adults
In addition, there are secondary indications: consequences of previous fractures, rheumatic diseases, avascular necrosis of the femoral head, and following femoral neck fractures. In older patients with a fracture near the hip, joint replacement is often the standard approach—either in the form of a hemiarthroplasty or a total hip replacement.
→ Treatment following a fall resulting in a hip fracture: Femoral neck fracture in the elderly.
The indication for joint replacement is not primarily radiological—it is functional and based on the patient’s medical history. The decision-making framework is as follows:
- Is the pain significant?: At night, at rest, or has it increased over the past six months?
- Is function impaired?: Which activities have been lost? Which ones does the patient want to regain?
- Has conservative therapy been exhausted?: Physical therapy, weight loss, analgesia, hyaluronic acid injections?
- Is the patient resilient enough?: This is the key question for older adults—and the one that is often overlooked in the standard orthopedic assessment. For more on this, see “Surgical Risk in Older Adults.”
- Are the expectations realistic?: A prosthesis relieves pain and improves function. It does not turn a frail 85-year-old back into a 60-year-old.
In modern geriatric medicine, five dimensions are systematically assessed before any elective major surgery in patients over 70. This assessment is not bureaucracy—it is the foundation for an honest risk-benefit analysis. The tool used for this is the geriatric assessment:
- Frailty status: Clinical Frailty Scale (CFS) or Fried phenotype. Starting at a CFS score of 5, the risk of complications increases significantly. More on this: Frailty syndrome.
- Cognition: Preoperative MMSE or MoCA—prediction of postoperative delirium and POCD.
- Nutritional status: Mini Nutritional Assessment. Malnutrition in older adults is an independent risk factor for impaired wound healing and infections.
- Medication review: Based on PRISCUS and FORTA—with a focus on targeted deprescribing. Particularly relevant for joint replacement: anticoagulants, benzodiazepines, and anticholinergic agents.
- Social situation: Who will provide support after discharge? Is the home suitable for postoperative care?
→ For a detailed assessment of operability in older adults: Surgical Risk in Older Adults.
→ For frailty assessment: Frailty syndrome—understanding frailty in older adults.
The weeks between the diagnosis and surgery are not just a waiting period. Prehabilitation—structured preparation—can significantly improve postoperative recovery. Three components are particularly effective:
- Strength training: Progressive resistance training two to four weeks before the procedure. Building muscle before surgery pays off at every stage of postoperative recovery—especially in preventing sarcopenia.
- Nutritional Optimization: Protein intake of 1.2 to 1.5 g per kg of body weight. For malnutrition, provide liquid nutrition and nutritional counseling.
- Medication adjustment: Reduce or discontinue potentially risky substances before surgery—the geriatric medication review is a preoperative component, not part of postoperative care.
Randomized studies show that patients who undergo structured prehabilitation before hip or knee replacement surgery have shorter hospital stays, fewer complications, and return to their preoperative functional level more quickly. The investment of four to six weeks is well worth it.
The actual procedure for a total hip replacement (THR) usually takes 60 to 90 minutes; for a total knee replacement (TKR), it takes slightly longer. Modern anesthesia techniques—regional anesthesia or in combination with light general anesthesia—have significantly reduced the risks.
The first 72 hours are critical for the recovery process:
- Mobilization on the first postoperative day (fast-track approach)
- Consistent pain management without overmedication with opioids
- Delirium screening by nursing staff and physicians
- Thrombosis prophylaxis and respiratory therapy
- Nutritional monitoring and fluid management
→ What postoperative delirium is and how it is prevented: Delirium in older adults.
The acute phase is typically followed by:
- Early geriatric rehabilitation: in an acute care hospital, particularly for multimorbid patients with complex needs. More on this: Early geriatric rehabilitation.
- Follow-up rehabilitation (AHB): at a specialized rehabilitation clinic, typically lasting three weeks.
- Outpatient physical therapy: lasting weeks to months for further strengthening and gait training—particularly important for preventing falls in older adults.
The prognosis is good in most cases: hip replacements have a survival rate of 90 to 95 percent after 15 years, and knee replacements have similar rates. The revision rate—that is, the need for repeat surgery—is less than 1 percent per year.
→ For geriatric early rehabilitation: Geriatric Early Rehabilitation.
→ Specifically regarding hip replacements: Hip Replacement for Patients 80 and Older.
→ Specifically on knee replacements: Knee Replacement—What Older Patients Should Know.
Joint replacement is an orthopedic procedure. The selection of the implant, the surgical technique, and postoperative orthopedic follow-up—all of this falls within the core expertise of orthopedics. Geriatrics complements this expertise by considering the patient’s overall situation:
- Assessment of indications, taking frailty and life expectancy into account
- Optimization of the patient’s baseline condition (nutrition, medications, underlying medical conditions)
- Delirium prevention and postoperative care
- Structured rehabilitation planning
- Secondary prevention (osteoporosis, fall risk assessment)
Especially in specialized centers, this collaboration—often referred to as ortho-geriatrics or geriatric traumatology—is becoming standard practice. Leading Medicine Guide features a large number of experienced orthopedic surgeons and trauma surgeons whose expertise complements geriatric assessments well when dealing with complex cases.
→ For an overview of geriatric traumatology: Geriatric Traumatology — Trauma Surgery Care for the Elderly.
Not every joint replacement in older adults requires geriatric co-management. However, the following situations are clear indications:
- Age over 75 with five or more long-term medications — key term: polypharmacy in older adults
- Pre-existing cognitive impairment or suspected dementia in older adults
- Signs of frailty (fatigue, muscle weakness, weight loss)
- Repeated falls in older adults over the past twelve months
- Unclear operability from an internal medicine perspective
- Desire for a structured risk-benefit assessment that goes beyond a purely orthopedic perspective
→ How a comprehensive geriatric assessment is conducted: Geriatric Assessment.
