Morphology of the patellar tendon and its insertion sites using three-dimensional computed tomography: A cadaveric study

Risk factors of failure results after double-bundle reconstruction with autogenous hamstring grafts for isolated posterior cruciate ligament rupture cases

Posterior tibial translation (PTT) after double-bundle posterior cruciate ligament (PCL) reconstruction has sometimes occurred. Purpose of this study is to identify the risk factors for postoperative PTT after double-bundle PCL reconstruction with a hamstring autograft. Comparing the results of bilateral gravity sag view (GSV) at 12 months after surgery, over 5-mm PTT was defined as 'failure' in this study. Of 26 isolated PCL reconstruction cases, over 5-mm PTT was seen in 7 cases (group F: 9.57 ± 1.28 mm), and 19 cases had less than 5 mm (group G: 2.84 ± 1.29 mm). Age, sex, body mass index (BMI), preoperative GSV, posterior slope angle of the tibia, anterolateral bundle (ALB) and posteromedial bundle (PMB) graft diameters, and tibial tunnel diameter were evaluated. The two groups were compared with the 2 × 2 chi-squared test, the Mann Whitney U-test, and Spearman's rank correlation coefficient. Multivariate logistic regression analysis was also performed to determine the risk factor. Statistical significance was indicated as p < 0.01 for correlation with postoperative PTT, and as p < 0.05 for all other comparisons. Mean age (group G 31.8 ± 12.5 vs group F 34.9 ± 15.9 years), sex (male/female: 15/4 vs 3/4), BMI (25.6 ± 4.6 vs 24.9 ± 3.9 kg/m2), preoperative GSV (11.3 ± 2.2 vs 11.6 ± 2.9 mm), PMB diameter (5.37 ± 0.33 vs 5.36 ± 0.48 mm), and tibial tunnel diameter (9.32 ± 0.58 vs 9.29 ± 0.49 mm) showed no significant differences. ALB diameter was significantly greater in group G (7.0 ± 0.5 mm) than in group F (6.5 ± 0.29 mm; p = 0.022). There was also a significant difference in posterior tibial slope angle (group G 9.19 ± 1.94 vs group F 6.54 ± 1.45, p = 0.004). On Spearman rank correlation coefficient analysis, ALB diameter GSV (correlation coefficient: - 0.561, p = 0.003) and posterior tibial slope angle (correlation coefficient: - 0.533, p = 0.005) showed a significant correlation with postoperative PTT. Multivariate logistic regression analysis showed that ALB diameter (OR 19.028; 95% CI 1.082-334.6; p = 0.044) and posterior slope angle of tibia (OR 3.081; 95% CI 1.109-8.556; p = 0.031) were independently associated with postoperative PTT, respectively. In double-bundle PCL reconstruction with hamstring, smaller ALB graft diameter and lower (flatted) tibial slope angle were considered risk factors for postoperative PTT.

Editorial Commentary: Proper Anterior Cruciate Ligament Graft Choice Mitigates Against the Need for Anterolateral Ligament Reconstruction

It is not coincidence that fervor surrounding anterolateral ligament (ALL) reconstruction increased as double-bundle anterior cruciate ligament reconstruction (ACLR) enthusiasm cooled. But perhaps we shifted our focus too soon, or perhaps we shifted our focus too much. But we must remember that the ACL is primary. Increases in ACL graft diameter by 1 or 2 mm can significantly increase graft strength and decrease revision rate. Biomechanical and clinical evidence suggests that quadriceps tendon ACLR and patellar tendon ACLR demonstrates less pivot shift phenomena than hamstring ACLR. In addition, As biologically active suture tapes become more mainstream, augmented allografts are an increasingly attractive option. Proper ACL graft choice mitigates against the need for ALL reconstruction. Risk factors for anterolateral rotatory instability may include low body mass index and lateral meniscal pathology, in addition to the well-known risks such as age, gender, activity level, and revision cases. Perhaps lateral extra-articular tenodesis should be reserved for high-risk cases.

Morphology of the quadriceps tendon and its patella insertion site on three-dimensional computed tomography and magnetic resonance imaging: A cadaveric study

AIM

This study was conducted to clarify the morphological properties of the quadriceps tendon (QT) and its patella insertion site using three-dimensional computed tomography and magnetic resonance imaging.

METHODS

Twenty-one right knees from human cadavers were evaluated using three-dimensional computed tomography and magnetic resonance imaging. The morphologies of the QT and its patella insertion site were evaluated, along with intra-tendon differences in length, width, and thickness.

RESULTS

The QT insertion site on the patella was dome-shaped without characteristic bony features. The mean surface area of the insertion site was 502.5 ± 68.5 mm2 (range, 336.0-610.7). The QT was longest 2.0 mm lateral to the central width of the insertion and gradually became shorter toward both edges (mean length, 59.7 ± 8.3 mm). The QT was widest at the insertion site (mean width, 39.1 ± 5.3 mm) and gradually became narrower toward the proximal side. The QT was thickest 2.0 mm medial to the center (mean thickness, 11.4 ± 1.9 mm).

CONCLUSION

The morphological properties of the QT and its insertion site were consistent. The characteristics of the QT graft depend on the harvested region.

Changes in patellar height after anatomical ACL reconstruction with BTB autograft with a focus on patellar tendon removal volume

BACKGROUND

Although anatomical anterior cruciate ligament reconstruction (ACLR) can provide satisfactory outcomes, little is known about how this procedure impacts patellar height. Since harvesting bone-patellar tendon-bone (BTB) autografts is a potential risk factor for decreased patellar height, we examined changes in patellar height after anatomical ACLR with BTB autograft with a focus on the size of the harvested graft.

METHODS

Subjects were 84 patients (49 males, 35 females; mean age, 23 years) who underwent primary anatomical ACLR with central third BTB autograft. Preoperative to postoperative Caton-Deschamps index (CDI) ratio was calculated using lateral knee radiographs before and 6 months after surgery. The length and cross-sectional area (CSA) of the graft were measured intraoperatively, and the CSA of the contralateral patellar tendon was measured by ultrasound 6 months postoperatively. The difference in graft CSA relative to the contralateral tendon CSA, expressed as a percentage (gCSA:ctCSA percentage), was also calculated.

RESULTS

Patellar height decreased slightly after surgery (preoperative CDI: 0.856 ± 0.113; postoperative CDI: 0.841 ± 0.113), with a mean difference between preoperative and postoperative CDIs of -0.015 (range: -0.293 to 0.101). Although the CDI of male subjects significantly decreased after surgery (preoperative: 0.852 ± 0.117; postoperative: 0.827 ± 0.115), no significant changes were noted in female subjects (preoperative: 0.862 ± 0.108; postoperative: 0.861 ± 0.108). Graft length and CSA did not significantly impact the CDI ratio (r = -0.138 and r = -0.038, respectively). Moreover, no significant relationship was observed between the gCSA:ctCSA percentage and CDI ratio (r = 0.118).

CONCLUSIONS

Although patellar height slightly, but significantly, decreased at 6 months after anatomical ACLR with BTB autograft, it was not affected by the length and CSA of harvested grafts. The decrease in postoperative patellar height was observed only in male subjects, suggesting the potential importance of sex differences in soft tissue healing during the postoperative period.

Clinical and Radiographic Outcomes of Double-Bundle Anterior Cruciate Ligament Reconstruction for Asian Patients with Bone-Patellar Tendon-Bone and Gracilis Tendon Grafts: A Matched-Control Comparison

For anterior cruciate ligament (ACL)-deficient patients, using a single bone-patellar tendon-bone (BPTB) graft for the double-bundle concept is one of the suitable approaches for acquiring better stability and reducing bone tunnel enlargement compared with the use of hamstring grafts. At least 10-mm width of BPTB autograft is needed to achieve this concept; however, it is larger than one-third of the patellar tendon width for small or middle physique patients. This study aimed to assess the clinical and radiographic outcomes of BPTB and gracilis (G) composite autografts for primary double-bundle ACL reconstruction in Asian athletes. Thirty-two Asian patients undergoing double-bundle ACL reconstruction with 7.0 to 7.5 mm of BPTB and 5.0 to 5.5 mm of G composite grafts were compared with 43 double-bundle ACL reconstruction with hamstring graft cases. The BPTB graft was used for the anteromedial bundle (AMB), with the G graft for the posterolateral bundle (PLB). Percentage of femoral bone tunnel enlargement compared with the original size was determined by computed digital radiographs on the first postoperative day and at 12 months in the anteroposterior (AP) and lateral views. Standard clinical evaluations, including the limb symmetry index (LSI), were also performed. Less PLB tunnel enlargement was found in the BPTB + G group than in the hamstring group in the AP (101.9 ± 22.9 vs.113.7 ± 20.6%, p = 0.031) and lateral views (104.4 ± 18.1 vs. 120.6 ± 23.4%, p < 0.01).There was no significant difference between the groups in 12-month postoperative clinical outcomes (Lysholm's score, Tegner's activity level scale, and International Knee Documentation Committee subjective knee evaluation score).The side-to-side difference was significantly less in the BPTB + G group (0.2 ± 1.3 vs. 0.9 ± 1.1 mm, p = 0.026). Despite the small sizes of the BPTB and G grafts, there was no significant difference in the knee extensor LSI between the groups (92.9 ± 10.1 vs. 93.3 ± 12.2%, p = 0.707), whereas the knee flexor LSI was significantly higher in the BPTB + G group (97.7 ± 14.8 vs. 90.1 ± 13.3%, p = 0.033). Double-bundle ACL reconstruction with a small size BPTB and G composite graft procedure provided good clinical outcomes and significantly less femoral bone tunnel enlargement than the hamstring procedure 12 months after surgery. It is thus a useful surgical option for ACL-deficient Asian athletes. This study reflects level of evidence III.