All of us are unique. We aren’t all the same. This can also be said of the limbs in our body. Our two arms and our two legs are unique - they aren’t exactly the same.
There are multiple factors that affect leg length from the length of your bones, to the surrounding soft-tissues, to pelvic anatomy. Add to that the influence from disease such as arthritis, scoliosis, hip dysplasia, degenerative discs, or a lumbar surgery; and we can see that there are numerous influences on our limb structure.
I want to address limb length discrepancies after total hip arthroplasty. I see this topic posted on websites and questions asked about what to expect after surgery. Is a difference in leg length normal or a cause for concern?
Total Hip Replacement removes the hip joint and replaces it with an artificial implant. The goal of surgery is to relieve hip pain, increase mobility, and achieve stability of the hip joint. Many times after surgery there will be a difference in leg length, but there is usually a difference in leg length whether you have had surgery or not. Most often, the difference is minimal and we experience no symptoms. Symptoms only show up when there is a larger discrepancy in limb length. How large is large? Well, that depends on the person. There is no set measurement that indicates when symptoms or complications will occur.
There are three main reasons patients may experience a limb length discrepancy after Total Hip Replacement:
- Arthritis: Arthritis leads to a breakdown in cartilage and even bone. Before surgery, arthritis may have already affected the leg length and the body has compensated for this discrepancy. However, after surgery corrects the problem, it can lead to a perceived lengthening of the leg. This perception will correct itself as the patient adjusts to proper alignment.
- Other Medical Conditions: As I stated before, other medical conditions can affect limb length such as degenerative discs, scoliosis, or a spinal fusion.
- Need for Stability: This is usually the main reason for limb length discrepancy after hip surgery. During surgery, the soft tissues surrounding the hip joint may have to be stretched to hold the joint tightly in place. These soft tissues are what give the hip joint its stability. Stability is crucial. If the hip is unstable, then it can easily dislocate leading to additional surgery and additional pain and cost to the patient.
The goal of surgery is to relieve pain, increase mobility, stabilize the hip joint and have equal limb lengths with proper alignment. But stability of the hip joint always takes priority over a limb length discrepancy. Often, the difference will be minimal and cause no symptoms. If a larger discrepancy occurs, using a shoe lift can help correct the problem.
New surgical techniques, such as robotic-assisted surgery, are helping improve surgical outcomes by increasing precision for the position and alignment of implants.
Dr. Paul Jacob is a leading hip and knee surgeon in Oklahoma City who pioneered robotic joint replacement surgery in an outpatient setting. Dr. Jacob has performed over 5000 robotic joint replacement procedures and actively participates in numerous research studies on robotic outcomes.