Endoscopic anterior cruciate ligamentreconstruction using doubled gracilis and semitendinosus tendons and endobutton femoral fixation

Bone tunnel enlargement on anterior cruciate ligament reconstruction

Objective:

To assess the presence of tibial bone tunnel enlargement after surgical reconstruction of the anterior cruciate ligament using quadruple graft of the flexor tendons and correlate the functional results in their presence.

Methods:

The studied lasted six months and included 25 patients, with ages ranging from 18 to 43 years old. Assessment was based on radiographs taken immediately postoperatively and at the third and sixth month of follow up in the anterior cruciate ligament reconstruction. Reconstruction of ligaments was performed with tendon grafts of the semitendinosus and gracilis muscle fixated in the femur with transverse metal screw and in the tibia with interference screws. Patients were evaluated objectively by tests ligament, graded from zero to four crosses and subjectively by the Lysholm method preoperative and after sixth month follow up.

Results:

Significant increase in the tunnels diameters were observed, 20.56% for radiographs in the anteroposterior view, 26.48% in profile view and 23.22% in computed tomography. Descriptive statistics showed significant improvement in subjective and objective clinical parameters.

Conclusions:

The bone tunnel enlargement is a phenomenon found in the first months after surgical reconstruction of the anterior cruciate ligament and it has no implications on clinical outcomes in the short term. Level of Evidence II, Prospective Study.

Biomechanical properties of porcine flexor tendon fixation with varying throws and stitch methods

BACKGROUND

The well-known suture technique configurations used for hamstring tendon autograft preparation in anterior cruciate ligament (ACL) reconstruction are the Krackow locking stitch and nonlocking stitch, such as a baseball stitch and a whipstitch. However, there are few data in the literature regarding biomechanical comparisons of suture techniques.

PURPOSE

The purpose of this study was to determine the properties of several current techniques of tendon graft suture employed in ACL reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Forty-two fresh-frozen porcine flexor digitorum tendons were used. Three stitch configurations (Krackow stitch [group K], baseball stitch [group B], and whipstitch [group W]) were assessed with varying suture throws (6 throws, group×6; 10 throws, group×10) using No. 5 Ethibond sutures. Each group was tested at 1500 loading cycles between 50 and 200 N. After loading cycles, the surviving tendons underwent a load-to-failure test.

RESULTS

During the loading cycles, 3 of 7 specimens in group B×6 and all specimens in group W×6 failed by suture pullout. Four of 7 specimens in group B×10 and all specimens in group W×10 showed partial tearing of the tendon. Elongation of group B×10 and group W×10 showed significantly greater elongation than other groups (P < .05). Maximum loads at failure showed significant differences between group K and the other groups (K×6, 436 ± 52 N; K×10, 419 ± 34 N; P < .05). Most specimens failed by rupture of the suture thread in group K. Pullout of the suture from the tendon was observed most in groups B and W.

CONCLUSION

The Krackow stitch was superior to other stitch methods. There was, however, no significant effect of the number of throws on the holding strength.

CLINICAL RELEVANCE

The Krackow stitch could prevent suture slippage by a locking mechanism. The whipstitch is not suitable for clinical application even with an increased number of throws.

Measurement of the graft angles for the anterior cruciate ligament reconstruction with transtibial technique using postoperative magnetic resonance imaging in comparative study

The aims of this study were to quantify the angle and placement of an anterior cruciate ligament (ACL) grafted with a single incision ACL reconstruction technique using postoperative magnetic resonance imaging (MRI), and to compare the results with those with a native ACL. Between February 1996 and May 2004, 96 consecutive patients, who had undergone postoperative MRI of the knee followed by an arthroscopically assisted ACL reconstruction with either a hamstring tendon or bone-patellar tendon-bone (BTB) autograft, were enrolled in this study. The femoral tunnel was drilled using the transtibial technique. The patients were divided into two groups; the hamstring tendon graft group (group H; 50 patients) and the BTB graft group (group B; 46 patients). All the patients including both groups in this study underwent postoperative MRI and were followed up for a minimum of 2 years. The control group (group C) consisted of 50 patients whose meniscus tear had been operated on by arthroscopy and whose ACL was intact. The orientation of the ACL ligament or graft was measured using three different methods: the sagittal ACL angle, the ACL-Blumensaat line angle, and the coronal ACL angle. The mean sagittal ACL angle in group C (58.7 +/- 3.8 degrees ) was significantly lower than in groups H (64.6 +/- 4.2 degrees ) and B (71.3 +/- 6.0 degrees ). The mean ACL-Blumensaat line angle in group C (8.6 +/- 3.6 degrees ) was also significantly lower than in groups H (12.8 +/- 5.2 degrees ) and B (18.0 +/- 5.3 degrees ). The mean coronal ACL angle in group C (65.9 +/- 4.4 degrees ) was lower than that in groups H (73.5 +/- 2.4 degrees ) and B (75.2 +/- 2.9 degrees ). The grafted ACL of the hamstring tendon and BTB grafts on the postoperative MRI showed a significant vertical angle in the coronal and sagittal plane compared with the native ACL. In the sagittal plane, the hamstring tendon graft was positioned more obliquely than the BTB graft, which had a larger angle of the tibial tunnel, in an attempt to prevent a graft-tunnel mismatch. The postoperative MRI study showed that the more horizontally the angle of the tibial tunnel can be placed in a single incision ACL reconstruction, the more efficiently it can produce a graft closer to the native ACL.

Quadrupled bone-semitendinosus anterior cruciate ligament reconstruction: a clinical investigation in a group of athletes

PURPOSE

The hypothesis of our study was that a quadrupled bone-semitendinosus (STB) graft could provide a clinically stable construct, allow recovery of normal limb strength, give high patient satisfaction with early return to active sports, and involve low donor-site morbidity.

TYPE OF STUDY

Outcomes study.

METHODS

Anterior cruciate ligament (ACL) reconstruction with an STB graft was performed on 80 athletes with isolated ACL injury from January 1996 to December 1999. Femoral fixation was obtained with EndoButton (Smith & Nephew, Andover, MA) and tibial fixation with Fastlok (Neoligaments, Leeds, England). At a mean follow-up time of 36 months (range, 24-52 months), patients were evaluated using standard knee scores (Noyes, Lysholm, Tegner, and International Knee Documentation Committee [IKDC] rating) and functional strength tests; postoperative pain rating; knee radiographs performed after surgery and at final follow-up; magnetic resonance imaging (MRI) at 3 to 6 months; isokinetic flexion-extension and internal-external rotation tests at 3, 6, and 12 months; and computed laxity analysis at final evaluation.

RESULTS

At final evaluation, subjective knee rating was 87%, kneeling test was positive in 7%, and Werner score was 44 of 50 (range, 30-48). Lachman test was negative in 90% at final evaluation. Sensory changes were present in 30% at 3 months, and 10% had definite hyposthesia. Computed laxity analysis revealed 90% with less than 3 mm side-to-side difference. Isokinetic testing showed normal hamstring and quadriceps peak torques at 12 months. The one-leg hop test and vertical jump were normal by 6 months. At final evaluation, average Noyes score was 88 (range, 65-100); Lysholm score, 91 (range, 70-100); postoperative Tegner rating, 6.5 (range, 5-9); and preinjury Tegner rating, 7.5 (range, 7-10). IKDC score showed 72 knees normal or nearly normal, 7 abnormal, and 1 severely abnormal. Sixty-five percent of patients returned to the same preinjury sports level.

CONCLUSIONS

The quadrupled bone-semitendinosus graft is a viable graft for ACL reconstruction and should be considered, especially for patients with extensor mechanism problems.