Arthroscopic single-bundle ACL reconstruction with modified double-layer bone-patellar tendon-bone allograft

Tubularization of Bone-Tendon-Bone Grafts: Effects on Mechanical Strength and Postoperative Knee Stability in Anterior Cruciate Ligament Reconstruction

Background and Objectives: The study addresses a significant limitation in applying bone-patellar tendon-bone (BTB) grafts in anterior cruciate ligament (ACL) surgery. By exploring the tubularization of grafts, the study extends the understanding of this surgical technique. The dual approach of the study-focusing on biomechanical properties using an animal model and postoperative outcomes in humans-offers a comprehensive perspective. Materials and Methods: The experimental cohort encompassed ten pairs of fresh porcine bone-tendon-bone grafts. One graft in each pair underwent modification through sutures that transformed the flat graft into a cylindrical structure. Testing determined the force required for the modified graft to rupture mechanically, expressed as N/mm2, compared to conventionally prepared bone-tendon-bone grafts. The second phase of the research involved a prospective randomized clinical trial comprising 120 patients undergoing operative ACL reconstruction. For half the cases, grafts were tubularized using a random selection process. Clinical evaluations preoperatively and 12 months postoperatively employed the Tegner, Lysholm, and IKDC scoring scales for knee assessment. Results: Experiments showed that ligaments made using the tubularized surgical technique have statistically significantly higher values of measured force and higher maximum elongation values than ligaments made using the classical method. The clinical study concluded that there was no significant difference between the two groups of patients in the average score on the Tegner, Lysholm, and IKDC scales before and after surgery. Conclusions: The study results showed that suturing the graft does not negatively affect its biomechanical properties, and tubularization significantly increases the values of force required to cause rupture and the values of maximum elongation during rupture. Given the possibility of the one-year follow-up period being insufficient, future investigations should extend this period to acquire objective functional insights post-surgery.

Better 4-year outcomes for anterior cruciate ligament reconstruction with double-layer versus single-layer bone-patellar tendon-bone allografts

PURPOSE

To evaluate the results of anterior cruciate ligament reconstruction using a double-layer bone-patellar tendon-bone (DBPTB) graft.

METHODS

Between 2010 and 2011, 98 patients underwent anterior cruciate ligament reconstruction with an allograft. Forty-seven of these patients received a DBPTB allograft and 51 received a traditional monolayer BPTB graft. Outcomes were evaluated at the end of a minimum 4-year follow-up in both groups using KT 1000 arthrometer measurements, Lachman and pivot-shift tests, the International Knee Documentation Committee form, and Lysholm scores.

RESULTS

One patient (1/47, 2 %) in the DBPTB allograft group and six patients (6/51, 12 %) in the traditional monolayer BPTB graft were lost during follow-up because of graft rupture (n.s.). The mean side-to-side differences in the DBPTB and monolayer BPTB graft groups 4 years post-operatively were significantly different at 1.4 ± 1.3 and 1.7 ± 1.6 mm, respectively (p < 0.05). The DBPTB group performed significantly better than the BPTB group on the Lachman test, International Knee Documentation Committee knee score, and Lysholm scores (p < 0.05).

CONCLUSIONS

The DBPTB allograft group achieved better outcomes than the traditional BPTB allograft group regarding success rate, anterior stability, and knee function.

LEVEL OF EVIDENCE

Level II.

Double-layer versus single-layer bone-patellar tendon-bone anterior cruciate ligament reconstruction: a prospective randomized study with 3-year follow-up

PURPOSE

To evaluate the clinical results of a randomized controlled trial of single-layer versus double-layer bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Fifty-eight subjects who underwent primary ACL reconstruction with a BPTB allograft were prospectively randomized into two groups: single-layer reconstruction (n = 31) and double-layer reconstruction (n = 27). The following evaluation methods were used: clinical examination, KT-1000 arthrometer measurement, muscle strength, Tegner activity score, Lysholm score, subjective rating scale regarding patient satisfaction and sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery.

RESULTS

Forty-eight subjects (24 in single-layer group and 24 in double-layer group) who were followed up for 3 years were evaluated. Preoperatively, there were no differences between the groups. At 3-year follow-up, the Lachman and pivot-shift test results were better in the double-layer group (P = 0.019 and P < 0.0001, respectively). KT measurements were better in the double-layer group (mean 2.9 versus 1.5 mm; P = 0.0025). The Tegner score was also better in the double-layer group (P = 0.024). There were no significant differences in range of motion, muscle strength, Lysholm score, subjective rating scale, graft retear, and secondary meniscal tear.

CONCLUSIONS

In ACL reconstruction, double-layer BPTB reconstruction was significantly better than single-layer reconstruction regarding anterior and rotational stability at 3-year follow-up. The results of KT measurements and the Lachman and pivot-shift tests were significantly better in the double-layer group, whereas there was no difference in the anterior drawer test results. The Tegner score was also better in the double-layer group; however, there were no differences in the other subjective findings.

Improved ACL reconstruction outcome using double-layer BPTB allograft compared to that using four-strand hamstring tendon allograft

BACKGROUND

This study compared the clinical outcomes of anterior cruciate ligament reconstruction using double-layer bone-patellar tendon-bone (DBPTB) allografts and four-strand hamstring (4SHS) grafts.

METHODS

This prospective randomized controlled trial included 101 patients. Of these, 50 patients received DBPTB allografts, and 51 received 4SHS grafts. Evaluations included KT-1000 arthrometer measurements, Lachman tests, pivot-shift tests, the International Knee Documentation Committee (IKDC) classification and Lysholm scores at three year postoperative follow-up.

RESULTS

Two DBPTB patients (four percent) and nine 4SHS patients (17.6%) had graft failures, which was significantly different (P=0.028). The DBPTB group had significantly better Lachman test, IKDC knee score and Lysholm score results than the 4SHS group (P<0.05). However, these differences were below the threshold for clinical significance.

CONCLUSIONS

DBPTB allografts had fewer graft failures at three years than 4SHS grafts for anterior cruciate ligament reconstruction; and there were statistically significant differences but not clinically significant differences between DBPTB and 4SHS grafts in terms of the KT1000 test, IKDC and Lysholm scores.

Arthroscopic single-bundle anterior cruciate ligament reconstruction with six-strand hamstring tendon allograft versus bone-patellar tendon-bone allograft

PURPOSE

The aim of this study was to compare the clinical outcomes of arthroscopic single-bundle anterior cruciate ligament (ACL) reconstruction with six-strand hamstring tendon (HT) allograft versus bone-patellar tendon-bone (BPTB) allograft.

METHODS

The prospective randomized controlled trial was included 129 patients. Sixty-nine patients received reconstruction with six-strand HT allografts (HT group), whereas 60 patients with BPTB allografts (BPTB group). Outcome assessment included re-rupture findings, International Knee Documentation Committee (IKDC) scores, Lysholm scores, KT-1000 arthrometer, Lachman test, pivot-shift test, range of motion (ROM) and single-leg hop test.

RESULTS

At a mean follow-up of 52 months, 113 patients (HT group, 61 patients; BPTB group, 52 patients) completed a minimum 4-year follow-up. Four patients in HT group and six in BPTB group experienced ACL re-rupture (6.2 vs. 10.3 %) and received revision surgery. Significant between-group differences were observed in KT-1000 outcomes and pivot-shift test 1 (1.2 ± 1.5 vs. 1.8 ± 1.3, p = 0.025; positive rate 6.5 vs. 18.9 %, p = 0.036), 2 (1.1 ± 1.4 vs. 1.6 ± 1.2, p = 0.044; 8.1 vs. 20.7 %, p = 0.039), 4 (1.1 ± 1.5 vs. 1.7 ± 1.4, p = 0.031; 9.7 vs. 25 %, p = 0.012) years postoperatively. The outcomes between the two groups were comparable in terms of IKDC scores, Lysholm scores, Lachman test, ROM and single-leg hop test.

CONCLUSIONS

Six-strand HT allograft achieved superior anteroposterior and rotational stability after single-bundle ACL reconstruction. It is a reasonable graft substitute for ACL reconstruction.

LEVEL OF EVIDENCE

II.

Systemic Review of Anatomic Single- Versus Double-Bundle Anterior Cruciate Ligament Reconstruction: Does Femoral Tunnel Drilling Technique Matter?

PURPOSE

To provide an up-to-date assessment of the difference between anatomic double-bundle anterior cruciate ligament (ACL) reconstruction (DB-ACLR) and anatomic single-bundle ACL reconstruction (SB-ACLR). We hypothesized that anatomic SB-ACLR using independent femoral drilling technique would be able to achieve kinematic stability as with anatomic DB-ACLR.

METHODS

A comprehensive Internet search was performed to identify all therapeutic trials of anatomic DB-ACLR versus anatomic SB-ACLR. Only clinical studies of Level I and II evidence were included. The comparative outcomes were instrument-measured anterior laxity, Lachman test, pivot shift, clinical outcomes including objective/subjective International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale and complication rates of extension/flexion deficits, graft failure, and early osteoarthritis. Subgroup analyses were performed for femoral tunnel drilling techniques including independent drilling and transtibial (TT) drilling.

RESULTS

Twenty-two clinical trials of 2,261 anatomically ACL-reconstructed patients were included in the meta-analysis. Via TT drilling technique, anatomic DB-ACLR led to improved instrument-measured anterior laxity with a standard mean difference (SMD) of -0.42 (95% confidence interval [CI] = -0.81 to -0.02), less rotational instability measured by pivot shift (SMD = 2.76, 95% CI = 1.24 to 6.16), and higher objective IKDC score with odds ratio (OR) of 2.28 (95% CI = 1.19 to 4.36). Via independent drilling technique, anatomic DB-ACLR yielded better pivot shift (SMD = 2.04, 95% CI = 1.36 to 3.05). Anatomic DB-ACLR also revealed statistical significance in subjective IKDC score compared with anatomic SB-ACLR (SMD = 0.27, 95% CI = 0.05 to 0.49).

CONCLUSIONS

Anatomic DB-ACLR showed better anterior and rotational stability and higher objective IKDC score than anatomic SB-ACLR via TT drilling technique. Via independent drilling technique, however, anatomic DB-ACLR only showed superiority of rotational stability. All clinical function outcomes except subjective IKDC score were not significantly different between anatomic DB-ACLR and SB-ACLR.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

Single-bundle modified patellar tendon versus double-bundle tibialis anterior allograft ACL reconstruction: a prospective randomized study

PURPOSE

The purpose of this study was to prospectively compare the outcomes of single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with modified bone-patellar tendon-bone (BPTB) allograft and double-bundle (DB) reconstruction with tibialis anterior allograft.

METHODS

With 94 patients enroled in the study, 43 subjects who had SB ACL reconstruction with modified BPTB allograft (group S) and 41 subjects of DB ACL reconstruction with tibialis anterior allograft (group D) were followed up for a minimum of 2 years. Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and the International Knee Documentation Committee (IKDC) classification, Lysholm and Tegner activity scores were compared between the two groups at the last follow-up.

RESULTS

The mean graft size of the group S, the anteromedial bundle and posterolateral bundle in group D were 9.9 ± 0.2, 7.5 ± 0.4 and 6.6 ± 0.4 mm, with statistically significant difference between the group S graft to either bundle of group D grafts (p < 0.001). At the last follow-up, there was no statistical difference between the two groups for the Lachman test, pivot-shift test and side-to-side difference. Substantial improvements in the subjective knee function scores were achieved in both groups, but without significant difference between the two groups.

CONCLUSIONS

After a 2-year minimum follow-up, SB ACL reconstruction based on modified BPTB allograft achieved similar clinical outcomes to DB reconstruction with tibialis anterior allograft in knee stability, both anterior-posterior and rotational, as well as knee function. The modified BPTB allograft was recommended as an ideal graft option for the SB ACL reconstruction.

LEVEL OF EVIDENCE

Therapeutic, randomized controlled study, Level II.