Hip resurfacing is a bone-conserving alternative to total hip replacement. Instead of removing the entire ball at the top of your thighbone, the surgeon trims and caps it with a smooth metal shell, then lines the hip socket with a matching metal cup. The damaged cartilage is removed, but most of your natural bone stays intact.
This distinction matters most for younger, active adults who may eventually need a second surgery decades later. Preserving bone now makes that future revision easier and more reliable.
How It Differs From Total Hip Replacement
In a traditional total hip replacement, the surgeon removes the entire head and neck of the thighbone and inserts a metal stem deep into the bone’s hollow center. A ball attached to that stem then fits into a new socket lining. The procedure works well, but it sacrifices a significant amount of healthy bone in the process.
Hip resurfacing takes a more conservative approach. The femoral head is reshaped rather than removed, then capped with a hollow metal dome. Because the natural anatomy of the hip is closely preserved, the procedure restores leg length and the mechanical offset of the joint more precisely. This also means the hip “feels” more like the original joint during movement, which is one reason it appeals to people who want to stay physically active after surgery.
The larger ball size used in resurfacing (matching your natural femoral head) also reduces the risk of dislocation compared to a standard replacement. In a randomized clinical trial comparing the two procedures, the total hip replacement group experienced three dislocations in the first two weeks, while the resurfacing group had one. That lower dislocation risk means fewer movement restrictions after surgery. Patients with standard replacements are typically told to limit certain positions for weeks, while resurfacing patients are generally allowed unrestricted movement sooner.
One area where the two procedures come out roughly equal is range of motion. At two years post-surgery, patients in the same trial averaged about 103 degrees of hip flexion after resurfacing and 107 degrees after standard replacement, a difference that was not statistically meaningful. Internal and external rotation were also comparable.
Who Is a Good Candidate
Hip resurfacing works best for active adults under 60 with good bone quality. The ideal candidate has hip arthritis severe enough to warrant surgery but enough healthy bone to support the metal cap. People who want to return to impact activities like running, cycling, hiking, or recreational sports tend to benefit most from the procedure, since the larger ball and preserved anatomy handle those stresses better than a traditional replacement.
Age is a practical consideration rather than a strict cutoff. The logic is straightforward: a 45-year-old with a total hip replacement will likely outlive the implant and need revision surgery. Starting with a resurfacing preserves bone stock so that a future conversion to a full replacement remains a clean, well-supported procedure. For someone in their 70s with lower activity demands and potentially weaker bone, a standard replacement is usually the better fit.
Several conditions can rule out resurfacing. Because the implant uses metal-on-metal bearings, people with known metal allergies (particularly to cobalt or chromium) are not candidates. Patients with kidney disease should also avoid the procedure, since the kidneys are responsible for clearing the metal ions that gradually enter the bloodstream from the implant. Poor bone density, large bone cysts in the femoral head, and certain hip deformities can also make it technically impractical to cap the bone securely.
The Metal-on-Metal Factor
Nearly all hip resurfacing implants use a cobalt-chromium alloy for both the ball cap and the socket cup. When those two metal surfaces glide against each other during walking, running, or any hip movement, they release microscopic metal particles into the surrounding tissue. Some of those particles break down further into metal ions that enter the bloodstream.
For most patients, the body clears these ions without problems. But in a subset of patients, the accumulation of metal debris triggers what the FDA calls an adverse reaction to metal debris. This can cause soft tissue damage around the joint, pain, implant loosening, and in some cases the formation of fluid-filled masses in the tissue (sometimes called pseudotumors). If the reaction progresses, it can damage bone, muscle, and nerves, potentially making a revision surgery more complicated.
This is the primary reason hip resurfacing fell out of favor with some surgeons in the early 2010s, when several poorly designed metal-on-metal total hip replacements (a different procedure from resurfacing) were recalled. Well-designed resurfacing implants with experienced surgeons have fared significantly better. The Birmingham Hip Resurfacing, one of the most studied implants, showed 96% survivorship free of any revision at 15 years in a long-term U.S. analysis, with 97.4% survivorship when counting only revisions due to implant failure rather than infection or trauma.
Patients with metal-on-metal implants are typically monitored with periodic blood tests to track cobalt and chromium levels, along with imaging if symptoms develop. Rising metal ion levels or new hip pain can prompt earlier investigation.
What Surgery and Recovery Look Like
The procedure itself takes roughly two to three hours under general or spinal anesthesia. The surgeon accesses the hip joint through an incision on the side or back of the hip, reshapes the femoral head, fits the metal cap, and lines the socket with the metal cup.
Recovery moves faster than many people expect. Most patients begin putting weight on the hip the day after surgery, using crutches or a walker for support. You can expect to use those walking aids for a few weeks as the muscles around the hip regain strength. Everyday activities like driving, light housework, and desk work are typically manageable around six weeks after surgery.
Returning to more demanding physical activities takes longer and varies by individual. Your surgeon will clear you for running, jumping, and sports based on how your hip is healing and how your muscle strength is progressing. Many resurfacing patients do return to high-impact activities, which is one of the procedure’s key selling points over traditional replacement. That said, the timeline for those milestones depends on your fitness before surgery, the complexity of the procedure, and how consistently you follow a rehabilitation program.
Long-Term Outlook
When performed by an experienced surgeon on a well-selected patient, hip resurfacing delivers durable results. The 15-year survivorship data for the Birmingham implant, at 96%, compares favorably with many total hip replacement implants over the same time frame. Surgeon experience matters more with resurfacing than with standard replacement because the procedure is technically demanding. Outcomes are consistently better at high-volume centers where surgeons perform the procedure regularly.
If a resurfacing does eventually fail, the conversion to a total hip replacement is generally straightforward precisely because so much bone was preserved in the original surgery. This is the core advantage of the “bone-conserving” philosophy: it keeps future options open. For a 50-year-old who gets 15 to 20 years from a resurfacing and then converts to a total replacement, the revision can be performed with standard techniques rather than the more complex reconstruction sometimes needed when revising a failed total hip replacement.