In this report, surgeons from Brazil present the cases of four patients (all adult men) who had arthroscopic surgery to remove a tumor from the hip joint. In all four men, the tumor was a type called osteoid osteoma. The diagnosis was made with imaging studies including X-rays, CT scans, and MRIs.
Osteoid osteoma is the most common of the benign tumors involving bones. Most of the time, osteoid osteomas affect males between the ages of 5 and 24. A benign tumor doesn’t spread or metastasize like a malignant tumor can. But that doesn’t mean it isn’t symptomatic. Depending on the location of the tumor, intense pain and weakness are common.
Anti-inflammatory medications are used for first-line treatment. Sometimes removal of the tumor by surgery is necessary. It is now possible to perform this procedure using an arthroscope (long thin needle with a tiny TV camera on the end).
Arthroscopic surgeries are common in the knee but gaining access to the hip is a little bit trickier. With improved instruments and increasing experience with arthroscopy on the part of surgeons, it is now possible to successfully operate on the hip using this approach.
Instead of making a long incision to open up the hip and then dislocating the hip in order to get to the tumor, surgeons can now enter the joint with a long thin needle (the arthroscope). It’s called a scope because of the tiny TV camera on the end that allows the surgeon to see inside the joint.
The arthroscope makes it possible to magnify the area and project it onto a computer screen. This helps the surgeon make clean, clear cuts around the tumor without disrupting the rest of the bone and joint. This type of tumor removal is called en bloc resection.
With en bloc resection, the entire tumor is removed along with an edge of normal healthy tissue all around the tumor. Getting those clear margins helps ensure that the tumor won’t come back. In the case of a malignant tumor, en bloc resection prevents the tumor from spreading.
All four patients in this study presented in the physician’s office with hip, buttock, or groin pain that was worse with activities. Getting in and out of a car, going up and down stairs, and exercise were known aggravating factors (i.e., made the pain worse). The pain was also worse at night, which is a red flag symptom of tumors. In two of the patients, the tumors were in the socket side of the joint. The other two patients had tumors in the upper portion of the femur (thigh bone).
The results of surgery (measured at regular intervals) showed complete elimination of pain and improved function. There were no complications during or after the procedure. Patients could put full weight on the leg right away but the surgeons suggested partial weight-bearing with crutches for the first 30 days while the bone filled in the empty (weak) spot where the tumor used to be.
The authors conclude that osteoid osteoma of the hip is a rare condition. When the tumors are small, en bloc arthroscopic removal is possible. Full recovery has been demonstrated in these four cases. When the tumors are large or hard to reach without opening the hip up all the way, then radiofrequency ablation can be used. This heat treatment destroys the tissue making it possible to avoid surgery altogether.