Tibial tunnel area changes following arthroscopic anterior cruciate ligament reconstructions with autogenous patellar tendon graft

Tibial tunnel enlargement after anatomic anterior cruciate ligament reconstruction with a bone-patellar tendon-bone graft. Part 2: Factors related to the tibial tunnel enlargement

BACKGROUND

Factors related to tunnel enlargement after anterior cruciate ligament (ACL) reconstruction should be evaluated by multivariate analysis, because the phenomenon has multifactorial characteristics. The purpose of this study was to elucidate the factors related to the tibial tunnel enlargement rate after anatomic ACL reconstruction with a bone-patellar tendon-bone (BTB) graft using multivariate analysis.

METHODS

Eighteen patients with unilateral ACL rupture were included. The anatomic rectangular-tunnel (ART) ACL reconstruction with a BTB autograft was performed. 3D CT models of the tibia, the tibial tunnel, and the bone plug at 3 weeks and 1 year after surgery were reconstructed and superimposed using a surface registration technique. The cross-sectional area (CSA) of the tibial tunnel perpendicular to the tunnel axis was evaluated at the aperture. The CSA was measured at 3 weeks and 1 year after surgery, and the tunnel enlargement rate at the aperture was calculated. Multiple linear regression analysis was performed to detect the significantly related factors to the tibial tunnel enlargement rate at the aperture among potential factors consisting of preoperative demographic factors and predisposing factors with the tibial tunnel.

RESULTS

The tibial tunnel enlargement rate at the aperture was 21.9 ± 14.1% (mean ± standard deviation). Multiple linear regression analysis detected the tendon length inside the tunnel as a significantly independent factor related to the tibial tunnel enlargement rate at the aperture (standardized β = 0.726, P = 0.008). There was no significant relationship between the tibial tunnel enlargement rate at the aperture and postoperative side-to-side difference (SSD) of the anterior knee laxity or Tegner activity level scale under single linear regression analysis.

CONCLUSION

The greater tendon length inside the tunnel was independently related to the higher tibial tunnel enlargement rate at the aperture 1-year after anatomic ACL reconstruction with a BTB graft under multiple linear regression analysis.

Tibial tunnel enlargement after anatomic anterior cruciate ligament reconstruction with a bone-patellar tendon-bone graft. Part 1: Morphological change in the tibial tunnel

BACKGROUND

Three-dimensional (3D) computed tomography (CT) is reliable and accurate imaging modality for evaluating tunnel enlargement after anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the tibial tunnel enlargement including the morphological change after anatomic ACL reconstruction with a bone-patellar tendon-bone (BTB) graft using 3D CT models.

METHODS

Eighteen patients with unilateral ACL rupture were included. The anatomic rectangular-tunnel (ART) ACL reconstruction with a BTB autograft was performed. 3D CT models of the tibia, the tibial tunnel, and the bone plug at 3 weeks and 1 year after surgery were reconstructed and superimposed using a surface registration technique. The cross-sectional area (CSA) of the tibial tunnel perpendicular to the tunnel axis was evaluated at the aperture and 5, 10, and 15-mm distal from the aperture. The CSA was measured at 3 weeks and 1 year after surgery and compared between the two time points. The locations of the center and the anterior, posterior, medial, and lateral edges of the tunnel footprint were also evaluated based on the coordinate system for the tibial plateau and compared between the two time points.

RESULTS

At the aperture, the CSA of the tibial tunnel at 1 year after surgery was significantly larger by 21.9% than that at 3 weeks (P < 0.001). In contrast, the CSA at 1 year was significantly smaller than that at 3 weeks at 10 and 15-mm distal from the aperture (P = 0.041 and < 0.001, respectively). The center of the tunnel footprint significantly shifted postero-laterally with significant posterior shift of the anterior/posterior edges and lateral shift of the lateral edge (P < 0.001).

CONCLUSION

The tibial tunnel enlarged at the aperture by 22% 1-year after anatomic ACL reconstruction with a BTB graft, and the tunnel morphology changed in a postero-lateral direction at the aperture and into conical shape inside the tunnel.

Early weight-bearing after anterior cruciate ligament reconstruction with hamstring grafts induce femoral bone tunnel enlargement: a prospective clinical and radiographic study

BACKGROUND

Bone tunnel enlargement following primary anterior cruciate ligament (ACL) reconstruction with soft tissue graft might be a severe disadvantage for revision surgery. The postoperative rehabilitation protocol including the non-weight-bearing periods were different depending on the surgeon or institute. To determine the relationship between femoral bone tunnel enlargement and the postoperative non-weight-bearing period after double-bundle ACL reconstruction with hamstring grafts.

METHODS

Forty-two patients who underwent primary double-bundle ACL reconstruction with hamstring grafts were divided into two postoperative non-weight-bearing protocol groups: 1-week non-weight-bearing postoperatively (group A, n = 19); and 2-week non-weight-bearing (group B, n = 18). Five cases were excluded due to additional knee injury, pregnancy, and lost to follow-up. Bone tunnel enlargement was evaluated by computed digital radiographs (anteroposterior (A-P) and lateral views) taken on the first postoperative day and at 12 months. Each tunnel diameter was shown as a percentage to the maximum joint width of the proximal tibia in the A-P view, or a percentage of the maximum diameter of the patella in the lateral view. To determine the incidence of tunnel enlargement, percentage diameter changes of more than 10% were defined as an enlarged tunnel. The magnitude of tunnel enlargement and the standard clinical evaluation were also evaluated.

RESULTS

There were no significant differences between groups in the incidences of anteromedial and posterolateral bone tunnel enlargement, both in the A-P and lateral views (2 × 2 Chi-squared test). The magnitude of femoral posterolateral bone tunnel enlargement was significantly greater in group A in the A-P view (p = 0.01) and lateral view (p = 0.03) (Mann Whitney U-test). Twelve months after surgery, the Lysholm score and Tegner activity level scale were not significantly different between the groups.

CONCLUSIONS

This prospective, clinical and radiographical study showed that early weight-bearing protocol after double-bundle ACL reconstruction with hamstring grafts might have the potential risk of significant postoperative femoral bone tunnel enlargement of the posterolateral bundle. There was no significant difference in clinical outcomes by postoperative non-weight-bearing period. To reduce and prevent the femoral bone tunnel enlargement, the comprehensive management could be considered and required to establish the suitable early stage rehabilitation protocol after surgery.

TRIAL REGISTRATION

Trial registration number; UMIN000036212 . Scientific title: Prospective comparisons of femoral tunnel enlargement with two different postoperative non weight bearing periods after double-bundle anterior cruciate ligament reconstruction with hamstring grafts. Registered date: 15 Mar 2019 (retrospectively registered).

Bone tunnel change develops within two weeks of double-bundle anterior cruciate ligament reconstruction using hamstring autograft: A comparison of different postoperative immobilization periods using computed tomography

BACKGROUND

The purpose of this study was to evaluate bone tunnel changes following anterior cruciate ligament (ACL) reconstruction during the early postoperative period using computed tomography (CT), and to understand the impact of postoperative immobilization on these changes.

METHODS

Twenty patients who underwent double-bundle ACL reconstruction using hamstring tendon autografts were included. We subcategorized patients into two groups: patients who underwent isolated ACL reconstruction and had three days of knee immobilization (Group A, n=10); and patients with concomitant meniscus injuries who underwent ACL reconstruction and meniscus repair simultaneously (Group B, n=10) had their knees immobilized for two weeks after surgery. Bone tunnel enlargement was evaluated using CT imaging at one to three days, two weeks, one month, three months and six months after surgery. The cross-sectional area of the femoral and tibial tunnels was measured, and enlargement rate was calculated. The tunnel center location at two weeks after surgery was also evaluated.

RESULTS

The mean cross-sectional area adjacent to the joint space of the femoral and tibial tunnels significantly increased immediately after surgery, especially in the first month (P<0.01). However, after one to six months they were not increased (P>0.01). There was no significant difference in tunnel enlargement rate between group A and B. Tunnel center location changed even in the first two weeks.

CONCLUSIONS

Bone tunnel enlargement following double-bundle ACL reconstruction occurred at an earlier time point after surgery than anticipated. Postoperative immobilization could not prevent bone tunnel enlargement, but might prevent tunnel migration.

Anterior cruciate ligament reconstruction tunnel size: causes of tunnel enlargement and implications for single versus two-stage revision reconstruction

Anterior cruciate ligament (ACL) reconstructions have increased over the past 25 years. The increased incidence of ACL reconstructions has translated into a larger number of graft failures and revision ACL procedures. It is important to understand the causes of graft failure when evaluating for a revision ACL reconstruction and to appreciate changes in tunnel anatomy over time prior to planning revision surgery. In this manuscript, tunnel size for ACL reconstruction and implications for single-stage versus two-stage revision ACL reconstruction will be discussed, as well as causes of tunnel enlargement, including mechanical and biological factors.

Anterior cruciate ligament reconstruction using a hamstring graft: a retrospective comparison of tunnel widening upon use of two different femoral fixation methods

PURPOSE

To compare femoral and tibial tunnel widening (TW) in patients undergoing anterior cruciate ligament (ACL) reconstruction using an interference screw (IS), or an EndoButton-Continuous Loop(®) on the femoral side, and an IS/staple on the tibial side.

METHODS

Between 2006 and 2009, at a single institution, 72 patients who underwent arthroscopic ACL reconstruction with quadrupled hamstring tendon grafting were retrospectively reviewed. Fixation was performed, and with the EndoButton-Continuous Loop(®) device (Group Ι) in 48 patients (mean age 29.1 ± 7.3 years) with a bioabsorbable IS (Group ΙΙ) in 24 patients (mean age 28.5 ± 8.4 years) on the femoral side. Evaluation included standardized anteroposterior (AP) and lateral radiography. The diameters of tunnels at the last follow-up visit (at a median time of 17 months postoperatively) were compared to those noted on radiographs taken 1 day postoperatively.

RESULTS

The two groups were similar in terms of age and gender distribution, the operated side, the size of the tunnel created, and the follow-up period (n.s.). Femoral TW at the proximal and middle levels (on both AP and lateral views) in Group ΙΙ was significantly greater than in Group Ι (p < 0.050 for all comparisons). No significant difference in femoral TW at the distal level was evident between the groups, and tibial TW at all levels was similar in both groups (n.s.).

CONCLUSION

Femoral TW is less after EndoButton-Continuous Loop(®) fixation and not reduced after IS fixation. Surgeons should be aware of TW when selecting a fixation device for hamstring graft.

LEVEL OF EVIDENCE

Therapeutic, retrospective comparative study, Level III.

Reliability of a semi-automated 3D-CT measuring method for tunnel diameters after anterior cruciate ligament reconstruction: A comparison between soft-tissue single-bundle allograft vs. autograft

BACKGROUND

Post-operative widening of tibial and/or femoral bone tunnels is a common observation after ACL reconstruction, especially with soft-tissue grafts. There are no studies comparing tunnel widening in hamstring autografts versus tibialis anterior allografts. The goal of this study was to observe the difference in tunnel widening after the use of allograft vs. autograft for ACL reconstruction, by measuring it with a novel 3-D computed tomography based method.

METHODS

Thirty-five ACL-deficient subjects were included, underwent anatomic single-bundle ACL reconstruction and were evaluated at one year after surgery with the use of 3-D CT imaging. Three independent observers semi-automatically delineated femoral and tibial tunnel outlines, after which a best-fit cylinder was derived and the tunnel diameter was determined. Finally, intra- and inter-observer reliability of this novel measurement protocol was defined.

RESULTS

In femoral tunnels, the intra-observer ICC was 0.973 (95% CI: 0.922-0.991) and the inter-observer ICC was 0.992 (95% CI: 0.982-0.996). In tibial tunnels, the intra-observer ICC was 0.955 (95% CI: 0.875-0.985). The combined inter-observer ICC was 0.970 (95% CI: 0.987-0.917). Tunnel widening was significantly higher in allografts compared to autografts, in the tibial tunnels (p=0.013) as well as in the femoral tunnels (p=0.007).

CONCLUSIONS

To our knowledge, this novel, semi-automated 3D-computed tomography image processing method has shown to yield highly reproducible results for the measurement of bone tunnel diameter and area. This series showed a significantly higher amount of tunnel widening observed in the allograft group at one-year follow-up.

LEVEL OF EVIDENCE

Level II, Prospective comparative study.

Three-dimensional analysis of bone tunnel changes after anatomic double-bundle anterior cruciate ligament reconstruction using multidetector-row computed tomography

BACKGROUND

The femoral and tibial bone tunnel enlargement after anatomic double-bundle anterior cruciate ligament reconstruction (ACL-R) has not been fully documented.

PURPOSE

To evaluate the region-specific bone tunnel volume changes and those transpositions using 3-dimensional multidetector-row computed tomography (MDCT) after anatomic double-bundle ACL-R.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Eleven patients who underwent unilateral double-bundle ACL-R with hamstring tendon autografts were included in this study. MDCT scanning of their knees was performed at 3 weeks and 1 year after surgery. The bone tunnel regions were extracted from the MDCT images, and the longitudinal axis of each bone tunnel was divided into 3 equal sections. The centroids of the outside and the articular thirds were then extracted from the bone tunnel position. Changes in the bone tunnel volume and the transposition of the articular third were calculated and compared.

RESULTS

At 1 year postoperatively, as compared with the 3-week postoperative value (set at 100%), the femoral bone tunnel volume of the anteromedial bundle (AMB) and posterolateral bundle (PLB) changed to 77.4% ± 15.3% and 102.3% ± 19.2% in the outside third and 122.3% ± 31.8% and 112.5% ± 34.4% in the articular third, respectively. The tibial bone tunnel volume of the AMB and the PLB changed to 108.6% ± 28.7% and 105.4% ± 22.6% in the tibial articular third and 54.9% ± 25.8% and 52.5% ± 26.9% in the outside third, respectively. The femoral outside third of the AMB and the tibial outside third of both the AMB and PLB were significantly reduced in bone tunnel volume. The centroid of the femoral articular third of the AMB moved 13°, 1.1 ± 0.6 mm posterodistally, and that of the PLB moved 35°, 0.8 ± 0.4 mm anterodistally. Furthermore, the centroid of the tibial articular third of the AMB moved 14°, 2.0 ± 1.6 mm posterolaterally, and that of the PLB moved 72°, 1.0 ± 1.3 mm posterolaterally.

CONCLUSION

Compared with 3 weeks postoperatively, the articular side outlets of the femoral and tibial bone tunnels at 1 year postoperatively had enlarged slightly but statistically maintained their volume, and they had moved a little in the direction that the grafts were pulled.

ACL reconstruction: effect of bone dowel on tibial tunnel enlargement

PURPOSE

To evaluate prospectively if the impaction of a bone dowel in the tibial tunnel prevents the tunnels from enlarging beyond their original diameter.

METHODS

Seventeen patients underwent arthroscopically assisted ACL reconstruction with hamstring autologous graft. All patients underwent CT of the knee on the day of surgery, at 3 months and 12 months post-op.

RESULTS

On the day of surgery, the median cross-sectional areas of the tunnels were 77.0 and 79.0mm(2), respectively at 15 mm and 20mm from the tip of the posterior wall of the tunnel. At 3 months, the median cross-sectional areas of the tunnels were 70.0 and 65.0mm(2), at 15 mm and 20mm. At 12 months post-op, the median cross-sectional areas of the tunnels were 69.0 and 69.0mm(2). The median enlargement of the tunnels between 3 months and 12 months post-op was 0.0mm(2) at 15 mm and -2.0mm(2) at 20mm.

CONCLUSIONS

The impaction of an autologous bone dowel in the tibial tunnel during hamstring ACL reconstruction keeps the tunnels from enlarging beyond their original diameter, and there is no further enlargement of the tunnels after 3 months post-op.

Comparisons of femoral tunnel enlargement in 169 patients between single-bundle and anatomic double-bundle anterior cruciate ligament reconstructions with hamstring tendon grafts

PURPOSE

Authors have hypothesized that the incidence and the degree of femoral tunnel enlargement after the hamstring ACL reconstruction may be significantly less in the anatomic double-bundle procedure than in single-bundle procedure. The purpose of this study is to test this hypothesis.

METHODS

Seventy-two patients who underwent single-bundle reconstruction (Group S) and 97 patients who underwent anatomic double-bundle reconstruction (Group D) were followed up for 2 years after surgery. The hamstring tendon grafts were used in each procedure. All of the 169 patients were examined with computed radiography, and the standard clinical evaluation methods.

RESULTS

In Group S, the incidence of femoral tunnel enlargement was 48.6 and 54.2% in the anteroposterior and lateral views. In Group D, the incidence of femoral anteromedial and posterolateral tunnel enlargement was 36.1 and 23.7%, respectively, in the anteroposterior view, and that of femoral anteromedial and posterolateral tunnel enlargement was 33.0 and 21.6%, respectively, in the lateral view. The incidence of femoral tunnel enlargement was significantly less in Group D than in Group S (P < 0.0133). Concerning the degree of the tunnel enlargement, a similar tendency with statistical significance was observed (P < 0.0001). In each group, there were no significant relationships between the degree of tunnel enlargement and each clinical measure.

CONCLUSION

Both the incidence and the degree of femoral tunnel enlargement after anatomic double-bundle reconstruction with the hamstring tendon grafts are significantly less than those after single-bundle reconstruction with the same graft.

LEVEL OF EVIDENCE

Prospective comparative cohort study, Level II.

Tibial tunnel widening after hamstring tendon anterior cruciate ligament reconstruction: the effect of supplemental aperture fixation with autogenous bone cores

BACKGROUND

Tibial tunnel widening is a common phenomenon seen with hamstring anterior cruciate ligament reconstruction. Concern exists that increased tunnel widening can lead to delayed graft incorporation, graft laxity, or difficulties in revision surgery.

HYPOTHESIS

Supplemental aperture fixation with autogenous bone cores or bioabsorbable interference screws will decrease tibial tunnel widening in hamstring anterior cruciate ligament reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

One hundred twenty-nine patients were divided into 3 groups based on type of aperture fixation: none, bioabsorbable interference screws, and autogenous bone cores. Tibial tunnel diameters were measured on plain radiographs at a minimum of 3 months postoperatively based on the timeline of tibial tunnel widening suggested by Simonian et al, and tunnel widening was quantified by the increase in tunnel diameters relative to initial reamer size.

RESULTS

Means for tunnel widening based on both anteroposterior and lateral maximum tunnel width measures were significantly different between the 3 groups (P < .05, 1-way analysis of variances); however, compared with the means for the group receiving no aperture supplementation, the means for the group receiving bioabsorbable interference screws were more than 0.8 mm wider, representing a significant increase (P < .05, Bonferroni-adjusted t tests), while the means for the group receiving autogenous bone cores were less than 0.6 mm wider than the group without aperture supplementation and not significantly different (P > .25, Bonferroni-adjusted t tests).

CONCLUSION

Tibial tunnel aperture supplementation does not appear to decrease tunnel widening in hamstring anterior cruciate ligament reconstruction and may actually increase the amount of tibial tunnel widening.

The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study

The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9-11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 +/- 0.05 (post-operative) to 9.30 +/- 0.8 mm (follow-up) in group A and from 9.04 +/- 0.03 to 9.94 +/- 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 +/- 0.04 to 10.01 +/- 0.80 mm in group A and from 9.04 +/- 0.03 to 10.60 +/- 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control group. Our results suggest that bone tunnel enlargement after ACL reconstruction using hamstrings autograft can be increased by an accelerated, brace free, rehabilitation protocol.

Bone tunnel enlargement after ACL reconstruction using autologous hamstring tendons: a CT study

PURPOSE

To evaluate prospectively the increase in the size of the tibial and femoral bone tunnel following arthroscopic anterior cruciate ligament (ACL) reconstruction with quadrupled-hamstring autograft.

METHODS

Twenty-five consecutive patients underwent arthroscopic ACL reconstruction with quadrupled-hamstring autograft. Preoperative clinical evaluation was performed using the Lysholm knee score, Tegner activity level, and International Knee Documentation Committee forms and a KT-1000 arthrometer (side to side). Computed tomography (CT) of the femoral and tibial tunnel was performed on the day after operation in all cases and at mean follow-up of 10 months (range 9-11 months).

RESULTS

All of the clinical evaluation scales performed showed an overall improvement. The postoperative anterior laxity difference was <3 mm in 16 patients (70%) and 3-5 mm in seven patients (30%). The mean average femoral tunnel diameter increased significantly (3%) from 9.04+/-0.05 mm postoperatively to 9.3+/-0.8 mm at 10 months; tibial tunnel increased significantly (11%) from 9.03+/-0.04 mm to 10+/-0.8 mm. There were no statistically significant differences between tunnel enlargement, clinical results, and arthrometer evaluation.

CONCLUSIONS

The rate of tunnel widening observed in this study seems to be lower than that reported in previous studies that used different techniques. We conclude that an anatomical surgical technique and a less aggressive rehabilitation process influenced the amount of tunnel enlargement after ACL reconstruction with doubled hamstrings.