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Quadriceps-sparing total knee replacement offers advantages over traditional surgery
Minimally invasive surgery for knee replacement can result in better rehabilitation, slightly less pain and short-lived ROM advantages.
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Minimally invasive total knee replacement surgery that avoids cutting into the quadriceps has benefits over traditional total knee replacement procedures, according to studies by Kenneth A. Gustke, MD, of Temple Terrace, Fla., and Prof. Francesco Benazzo, of Pavia, Italy.
Gustke describes what minimally invasive surgery (MIS) is and is not: “What it should not be is minimal incision surgery,” he said. “Even though a shorter scar is really all a patient can see, we all can do surgery through smaller incisions. Really, it is what you do inside that makes all the difference.”
He compared his first 50 patients receiving the MIS quadriceps-sparing, subvastus technique with a matched group receiving traditional TKR. Overall, he found significant differences in some parameters between the groups, with the greatest difference in rehabilitation, although, most gains made by the MIS group were compatable by three months postoperative.
“The most important thing is that the rehabilitation is much better, both to the physical therapist and to the patient. We found that 92% of the patients who had a mid-vastus approach could do a straight leg raise on the day of surgery, and this makes it a lot easier for them to transfer, and they don’t need to use the crutches as long.”
The other significant differences included length of incision (12 cm for the MIS group vs. 21 cm for traditional) and the average tourniquet time, which was nine minutes longer for the MIS group. There were no major differences between the groups in terms of blood loss or surgical time. Pain scores were significantly reduced for the MIS group, but only for the first three days postsurgery.
Surgical technique
Gustke, of the Florida Orthopaedic Institute, said that one of the important aspects of his surgical technique is keeping it as similar to the traditional surgery as possible. For this he makes his tibial and femoral bone cuts from the traditional frontal position using smaller, specially designed instruments. Keeping it close to the traditional techniques also makes the MIS easier to learn.
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“We thought that the better long-term results are much more important than any short-term advantages of accelerated rehabilitation. Therefore, you must be able to perform this reliably,” he said. “I feel that the best method is to perform the procedure in a manner closest to traditional techniques.”
He generally uses a 10- to 12-cm incision and leave patellar resection as an option. “After you have made your tibial and femoral cuts you can decompress the knee enough to allow partial eversion of the patella being able to prepare the patella from the side if you wish to resurface it. If you don’t wish to resurface the patella, you are not obligated to do that.”
Overall, Gustke called the advantages to the quadriceps-sparing technique short-term. “There really is no significant difference in the final range of motion,” he said. “Patients achieve it faster, but there is ultimately the same range of motion. The mini-incision subvastus quad sparing total knee does have slightly less pain initially, but physical therapists and the patients feel that the rehabilitation is easier and patients certainly like smaller scars.”
The Italian results
Like Gustke, Benazzo made his presentations at the 7th EFORT (European Federation of Orthopaedics and Traumatology) Congress. He offered his comparison of two matched groups, one receiving the MIS quadriceps-sparing approach and the other the traditional incision TKR surgery. Unlike the American experience, Benazzo and his colleagues at Clinica Ortopedica, Policlinicia IRCCS San Matteo saw a significant decrease in perioperative blood loss in the MIS group.
He too noted that shorter incisions should not be the aim of MIS, but “as the side beneficial effect and the natural consequence of a more conservative technique, sparing soft tissues such as the quadriceps tendon, the extensor mechanism and the suprapatellar pouch, as well as vascular tissue and nerve supply.”
He noted that his surgical technique is quite different from traditional TKR, but it has been facilitated by newer tools and implants. “We now have instrumentation available to make this technique easier for us.”
Real advantages
He compared a quad-sparing group of 30 patients to 26 people receiving traditional TKR. The groups were matched in terms of age, gender, Body Mass Index and radiographic evaluation.
Overall, he found that statistically significant differences in perioperative blood loss, less postoperative pain and a more rapid and better functional restoration in favor of the quadriceps-sparing group. Mean operative times showed the MIS to be 10 minutes longer; however, Benazzo said the length of the MIS decreased in the past six months.
For range of motion, Benazzo noted advantages in the short postoperative term, which was equal between the groups by three months postop.
“The supposed advantages to the QS (quadriceps-sparing) technique can be considered real, based on our statistical comparison,” Benazzo reported.
Since this investigation was initiated, Benazzo and colleagues have started to use different instrumentation that makes the procedure easier for the surgeons. Because of this, the number of patients undergoing MIS has increased from 15% to 34% of TKRs. Because of this, he concluded that “MIS can be considered an everyday surgical treatment.”
For more Information:
- Gustke K. Quadriceps sparing minimally invasive total knee replacement: initial experience and comparison to a matched set of non-MIS total knee replacements. #F245.
- Benazzo F. MIS quad-sparing technique in TKA. #F247. Presented at the 7th European Federation of National Associations of Orthopaedics and Traumatology Congress. June 4-7, 2005. Lisbon, Portugal.