Digital Radiography’s Hip Factor
Until recently, the success of a total hip replacement could only be accurately evaluated after the surgeon left the operating room. Orthopedic surgeon Brad Penenberg, MD, is changing that. Software he designed helps measure placement accuracy during an operation. His program improves the functionality of digital radiography, enabling orthopedic surgeons to make adjustments as they operate based on real-time, low-radiation, X-ray image feedback. The benefits are improved implant longevity, lower occurrence of dislocation, and reduced rate of reoperation.
“Historically, the surgeon has relied on certain instruments and the ‘feel,’ tempered by experience, to achieve the desired result,” Dr. Penenberg explains. Unfortunately, optimal hip replacement requires the prosthesis to be placed at a precise angle. In general, using the standard 50-year-old techniques, surgeons have had only a 60 percent accuracy rate in positioning the cup in the hip socket. Inaccuracies resulting from imprecise instruments and estimates can also lead to a 5–15 mm difference in limb length—and a persistent limp in certain patients.
Dr. Penenberg’s program eliminates the guesswork— and the likelihood of a prolonged limp—by cutting down the difference to perhaps 0–3 mm. The software’s use can also extend the life of the new hip, as a properly positioned prosthesis has the potential to last 25 years or more, compared to the considerably shorter life expectancy of one that is poorly placed.
Cedars-Sinai’s new Advanced Health Sciences Pavilion allows for optimal use of Dr. Penenberg’s invention. The spacious size of the procedure rooms in the new facility makes it possible for surgeons to move seamlessly between the patient and the imaging equipment without having to exit the room, as is sometimes necessary in smaller ORs.
Although digital imaging dates back to the 1970s, the technology of digital radiography—in which X-ray sensors are used instead of film—is only five years old. Dr. Penenberg’s enhancements are sure to expand its use more widely, which will help increase the number of hip patients who return to normal mobility. Eighteen medical centers are already using the program, with more adopting it soon. The software can also be used for knee replacement surgery, spinal surgery, and trauma surgery.