Quadriceps-sparing TKA takes longer, has complications
By Carolyn Rogers
Early reports indicated less intraoperative blood loss, less pain, better early motion, shorter hospital stay, with an accuracy of implant alignment similar to standard-incision TKA
A standard arthrotomy approach, using as short a skin incision as possible, is superior to a quadriceps sparing (QS) approach when performing a total knee arthroscopy (TKA), according to scientific paper 505.
Researchers found that “despite no differences in most clinical and radiographic parameters between the standard and QS approach, the operative time for the TKA was longer and the early complication rate was higher when the QS technique was used.”
The mini-incision and quadriceps sparing (QS) approaches were developed to minimize the soft tissue damage of the knee joint and enhance early rehabilitation. Early reports indicated less intraoperative blood loss, less pain, better early motion, and a shorter hospital stay, with an accuracy of implant alignment similar to standard-incision TKA.
“We designed this prospective and randomized study in 120 patients who underwent bilateral simultaneous TKA to determine whether there was a difference in surgical parameters, component positioning, and safety of a QS technique compared with a standard arthrotomy,” the researchers said. “We also sought to determine the complication rate in each group.”
Between August 2004 and January 2005, primary bilateral simultaneous TKAs were performed in 132 consecutive patients. Each patient had the QS procedure in one knee and the standard arthrotomy in the other knee, with one side treated immediately after the other. Which technique was used first, and on what knee, was determined at random.
After 12 patients were lost to follow-up, the remaining 120 patients (93 women and 27 men) were followed for a mean of 21.5 months (range: 17 to 24 months). The average age of patients was 65.4 years (range: 43 to 88 years). Osteoarthritis was the preoperative diagnosis in 113 patients (94 percent), osteonecrosis was diagnosed in six patients (5 percent) and one patient (1 percent) had rheumatoid arthritis.
Clinical and radiographic evaluations were done at three months, one year, and two years after the operation. One researcher, who was blinded to the type of arthrotomy, analyzed the postoperative clinical and radiographic results. Each knee was rated preoperatively and postoperatively according to the Knee Society (KS) rating system. The patient subjectively evaluated pain in the knee with use of a 10-point visual analog scale.
QS takes longer
No significant differences were found with respect to the knee score, pain scale, range of motion, or radiographic results. The average intraoperative estimated blood loss, the average amount of drainage, and the average duration of the use of suction drains were also not significantly different between the two groups.
However, the average surgical time and tourniquet time were notably longer in the QS group. The early complication rate in the QS group was significantly higher as well. Complications—including anterior femoral notching, supracondylar femoral fracture, inadvertent quadriceps tendon laceration and superficial and deep infections—were notably more frequent in the QS group (p = 0.0468).
“We believe that the higher complication rate in the QS group was related to the limited visualization allowed by the limited medial prapatellar arthrotomy,” the authors stated. “Also, working through a small incision may result in both more pressure on the skin and soft tissues from stronger retraction and more abrasion of the skin edges from reamers and rasps, and may result in more wound complications and infections.”
All patients in both groups favored a short skin incisional scar.
“Despite there being no differences in most clinical and radiographic parameters between the two groups, the operative time was longer and the early complication rate was higher in the QS group,” the presenters said. “Therefore, we recommend a standard arthrotomy approach with as short a skin incision as possible for TKA.”
Due to the difficulty of placing a stemmed tibial component in the QS group, the quadriceps tendon was inadvertently lacerated in approximately one in four knees (31 knees, or 26 percent). Based on the negligible benefits and the higher rate of complications in the QS group, the authors suggest that “incision of quadriceps tendon 2 cm to 4 cm from the superior pole of the patellar should be done when using this approach.”
The lead researcher for Paper 505 is Youn-Hoo Kim, MD, of Seoul, Korea. Additional researchers are Keun-Soo Sohn, MD, and Jun-Shik Kim, MD—both of Seoul, Korea.