Total Hip Arthroplasty (THA):
What to expect

When is hip replacement indicated?

Total hip arthroplasty is typically recommended when hip osteoarthritis — or other conditions such as avascular necrosis, rheumatoid arthritis, or post-traumatic arthritis — causes significant pain and functional limitation that does not respond adequately to conservative treatment. Before considering surgery, most patients have tried physiotherapy, weight management, pain medication, and in some cases, corticosteroid or hyaluronic acid injections.

The decision to operate is based on a combination of imaging findings (usually weight-bearing X-rays), symptom severity, and the impact on your quality of life. There is no strict age cutoff — what matters is your overall health, bone quality, and what you want to be able to do after surgery.

The OCM approach — what makes it different

There are several ways to access the hip joint surgically. At my practice, I use the OCM approach (Orthopädische Chirurgie München — originally developed in Munich) for THA. This is an anterolateral, muscle-sparing approach performed with the patient lying on their back (supine).

The key principle is that the incision and tissue dissection are designed to avoid cutting through the major muscle groups that stabilise the hip — specifically the gluteal muscles. Instead, the interval between the tensor fasciae latae and the gluteus medius is used to reach the hip joint. This differs from the traditional posterior approach, which requires detachment and reattachment of short external rotators, and from direct lateral approaches that split the gluteus medius.

Practical advantages of the OCM approach

Because no major muscles are cut or detached, the hip's natural soft-tissue restraints are preserved. This allows most patients to bear full weight on the day of surgery, and the traditional "hip precautions" (avoiding bending, crossing the legs) that were standard with the posterior approach are generally not required. This simplifies rehabilitation considerably — particularly for patients living alone or traveling from abroad.

The supine position also allows for intraoperative fluoroscopy (X-ray guidance) to verify implant position, leg length equality, and cup orientation in real time. Fluoroscopic guidance has been shown to improve the proportion of implants placed within the optimal safe zone (80% with fluoroscopy vs 63% without, in one controlled study).

The implants

Modern THA implants are highly durable. The acetabular cup is fixed to the pelvis (typically press-fit cementless), and the femoral stem is placed into the thigh bone. The bearing surface — the part that actually moves — is most commonly ceramic-on-highly-crosslinked-polyethylene (ceramic/XLPE), which provides excellent wear characteristics and low friction over decades of use.

Implant choice is discussed individually based on bone quality, anatomy, activity level, and age. For most patients under 70 who are active, cementless fixation with a ceramic bearing is my preference.

Recovery timeline

Most patients walk with a frame or crutches on the day of or day after surgery. The majority of foreign residents and international patients are discharged within 2 weeks of surgery. The milestones below are approximate — individual recovery varies.

What the evidence says about outcomes

Total hip arthroplasty has among the best evidence for patient-reported outcomes of any surgical procedure. Studies consistently show substantial and durable improvement in pain, function, and quality of life at 10- and 20-year follow-up. Revision rates at 10 years with modern implants are typically below 5%.

Anterolateral and anterior muscle-sparing approaches have been shown to reduce the risk of posterior dislocation compared to conventional posterior approaches, though both share risks of femoral fracture and nerve injury with inadequate exposure — reasons why surgical experience and volume remain important.

If you are also considering knee surgery, see the article on knee replacement (TKA, UKA, and PFA).

Risks and complications

THA is safe but not without risk. The main risks include: infection (approximately 1%), deep vein thrombosis, dislocation (lower with muscle-sparing approaches), leg length discrepancy, nerve injury (femoral nerve at risk with the anterior approach), and implant-related complications over time. These are discussed in detail during your consultation — including their specific rates at the facility where we operate.