Good stability, few complications with femoral press-fit fixation

Researchers find better IKDC and Lysholm scores, and 69% of patients return to previous sports activity level.

The femoral press-fit fixation technique is a safe, alternative fixation method for bone-patellar tendon-bone graft, according to a recent Hungarian study, published in the American Journal of Sports Medicine.

Shown here are arthroscopic images of the bone-patellar tendon-bone graft at 24 months postop. Surgeons performed ACL reconstruction using femoral press-fit fixation

COURTESY: ATTILA PAVLIK

The technique provided good stability and prevented most femoral hardware-induced complications. The researchers found that 85% of patients had normal or nearly normal International Knee Documentation Committee (IKDC) scores at final follow-up. Mean Lysholm scores improved from 63.5 ± 12.7 points preoperatively to 93.5 ± 7.8 points (P<.01). Additionally, KT1000 Arthrometer (MEDmetric) results showed a side-to-side difference of 1.91 ± 2.1 mm in maximum manual strength tests, according to the study.

Of the 285 study patients, 197 patients returned to their previous level of sports activity, and only 13 abandoned sports participation, the study authors said.

Alternative ACL surgery

Interference screw fixation is a popular method for bone-patellar tendon-bone graft fixation, but can possibly damage the graft during screw insertion in cases of technical error, significantly decreasing fixation strength, the study authors said.

Attila Pavlik, MD, PhD, and colleagues at the National Institute for Sports Medicine and Semmelweis University in Budapest, prospectively evaluated femoral press-fit graft fixation as an alternative, hardware-free technique for anterior cruciate ligament (ACL) reconstruction. “Recently, the maximum tensile strength and stiffness of this method have been tested successfully by different studies,” the authors said in the study’s abstract. “With [a] careful operative technique, press-fit fixation is easy to perform, thus reducing the cost of surgery.”

From January 1998 to June 2002, surgeons performed 373 ACL reconstructions using bone-patellar tendon-bone autograft and an arthroscopic transtibial technique with femoral press-fit and tibial interference screw fixation.

Researchers examined 285 patients, including 201 men and 84 women, with a mean age of 29.1 years. Injury occurred in 169 right knees and 116 left knees. Follow-up averaged 35.8 months and included physical examinations and both subjective and radiological evaluations, according to the study.

Mostly normal results

At final final follow-up, 46 patients had normal IKDC scores, 195 patients had nearly normal scores, 39 patients had abnormal scores and five had severely abnormal scores. Additionally, patients had a mean final Lysholm score of 94.7 ± 5.5 points.

“All patients had a fair or bad score before the reconstruction, whereas 90% of them had excellent or good results postoperatively,” the authors wrote.

Ligament test results were negative in 93 patients and 1+ positive in 169 patients. Pain, swelling and giving-way sensations were slightly positive in 261 patients, and 281 patients experienced full or only minimally deficient ranges of knee motion. At their final evaluation, 269 patients (94%) had normal or nearly normal status for subjective assessments.

At a mean 8.5 ± 2.9 months postop, 69% of patients returned to their previous level of sports activity and only 4.6% quit sports participation. The remaining patients returned to sports at a lower activity level, the authors noted.

KT1000 Arthrometer measurements showed a mean side-to-side difference of 0.71 ± 1.2 mm at 67 N, 1.41 ± 1.7 mm at 89 N, and 1.91 ± 2.1 mm on the maximum manual pull test and 20° of flexion. At final follow-up, 66% of patients had a side-to-side difference of 2 mm or less and 84% had a side-to-side difference of 3 mm or less on the maximum manual pull test, according to the study.

Researchers found good stability and few hardware-related complications using femoral press-fit fixation for ACL reconstruction, as shown in this control radiograph at 12 months postop..

Few complications

Fifteen patients experienced donor site morbidity, including anterior knee pain, kneeling pain and painful crepitation. Another 99 patients had direct tenderness over the patella apex or tibial tubercle. However, the researchers noted: “These patients did not have any symptoms during everyday life, work or sports activity.”

For patients with loss of motion, surgeons performed manipulation under anesthesia or arthroscopic arthrolysis in the early postop period, including 13 reoperations for loss of extension and six reoperations for loss of flexion.

During surgery, femoral press-fit fixation was not stable in three patients, leading surgeons to switch to interference screw fixation during the manual checkup. Surgeons did not encounter any further complications with these patients during the postoperative period. In a patient with an intraoperative bone plug fracture, surgeons reversed and fixed the graft using interference screws and tibial suture post screws. Researchers excluded these patients from the study.

For more information:
Pavlik A, Hidas P, Tállay A, et al. Femoral press-fit fixation technique in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft. Am J Sports Med. 2006;34:220-225.