Comparison between the cross-sectional area of bone-patellar tendon-bone grafts and multistranded hamstring tendon grafts obtained from the same patients

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.

Chronological changes in cross-sectional area of the bone-patellar tendon-bone autograft after anatomic rectangular tunnel ACL reconstruction

PURPOSE

The purpose of this study was to evaluate the change in cross-sectional area (CSA) of bone-patellar tendon-bone (BTB) autografts up to 5 years after the anatomic rectangular tunnel (ART) anterior cruciate ligament reconstruction (ACLR). The changing pattern in CSA might be a potential indicator of the graft remodeling process.

METHODS

Ninety-six (62 males, 34 females, mean age 27.0 years) patients were enrolled in this study with a total of 220 MRI scans after ART BTB ACLR to evaluate the CSA of the ACL autografts. The patients with first time unilateral ACLR that consented to undergo MRI evaluations at postoperative periods were included in this study. Intraoperatively, the CSA of the graft was measured directly using a custom-made area micrometer at the midpoint of the graft. Postoperatively, using an oblique axial slice MRI that was perpendicular to the long axis of the graft, the CSA of the graft was measured with digital radiology viewing program "SYNAPSE" at the midpoint of the graft. The postoperative MRI scans were classified into seven groups according to the period from ACLR to MRI evaluation: Group 0-2 months (m.), Group 3-6 m., Group 7-12 m., Group 1-2 years (y.), Group 2-3 y., Group 3-4 y., and Group 4 y.-. The percent increase of the CSA was calculated by dividing the postoperative CSA by the intraoperative CSA.

RESULTS

The postoperative CSA was significantly larger than the intraoperative CSA in each group, with the exception of Group 0-2 m. The mean percent increase of the CSA in Group 0-2 m., 3-6 m., 7-12 m., 1-2 y., 2-3 y., 3-4 y., 4 y.- was 101.8 ± 18.2, 188.9 ± 27.4, 190.9 ± 43.7, 183.3 ± 28.9, 175.2 ± 27.9, 163.9 ± 19.8, 164.5 ± 25.4% respectively. The percent increase in Group 3-6 m., 7-12 m., 1-2 y., 2-3 y., 3-4 y., and 4 y.- was significantly greater than that in Group 0-2 m.

CONCLUSIONS

The CSA of the BTB autografts after the ART BTB ACLR increases rapidly by 3-6 months after ACLR, reached a maximum value of 190% at around 1 year, decreases gradually after that, and reaches a plateau at around 3 years. The current study might help clinicians to estimate an individual BTB autograft's remodeling stages when considering returning patients to sports.

LEVEL OF EVIDENCE

IV.

Cross-Sectional Area Measurement Techniques of Soft Tissue: A Literature Review

Evaluation of the biomechanical properties of soft tissues by measuring the stress-strain relationships has been the focus of numerous investigations. The accuracy of stress depends, in part, upon the determination of the cross-sectional area (CSA). However, the complex geometry and pliability of soft tissues, especially ligaments and tendons, make it difficult to obtain accurate CSA, and the development of CSA measurement methods of soft tissues continues. Early attempts to determine the CSA of soft tissues include gravimetric method, geometric approximation technique, area micrometer method, and microtomy technique. Since 1990, a series of new methods have emerged, including medical imaging techniques (e.g. magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound imaging (USI)), laser techniques (e.g. the laser micrometer method, the linear laser scanner (LLS) technique, and the laser reflection system (LRS) method), molding techniques, and three-dimensional (3D) scanning techniques.

Sex Differences in the Residual Patellar Tendon After Harvesting Its Central Third for Anterior Cruciate Ligament Reconstruction

OBJECTIVES

Some studies have found that sex can affect the clinical results after anterior cruciate ligament reconstruction. We hypothesized that sex would significantly affect the healing of the postoperative patellar tendon. This study evaluated the patellar tendon after bone-patellar tendon-bone autograft harvest, specifically with regard to sex-dependent differences.

METHODS

At 6 months postoperatively, an ultrasonographic evaluation was performed. We measured the residual donor site gap width between tendon tissues and the thickness of newly formed nontendinous tissue in the gap. In addition, the cross-sectional area of tendon tissue was measured. The ratios between the operated and contralateral sides were calculated, and the sexes were compared. A paired Student t test was performed, with P < .05 considered statistically significant.

RESULTS

The population of 52 patients (32 male and 20 female) had a mean age ± SD of 23 ± 8 years. We observed no significant sex-dependent differences in the residual donor site gap and the thickness of newly formed nontendinous tissue when calculating ratios to the contralateral tendon. The mean cross-sectional area of tendon tissue was 101 ± 26 mm² (male, 114 ± 26 mm² ; female, 80 ± 16 mm² ). When the ratios to the contralateral tendon were calculated, male patients had significantly higher cross-sectional area ratios than female patients (male, 124% ± 20%; female, 100% ± 19%, P = .024).

CONCLUSIONS

We have reported a dramatic increase in the cross-sectional area of patellar tendon tissue during the first 6 months after anterior cruciate ligament reconstruction with a bone-patellar tendon-bone autograft, which was more prominent in male patients than in female patients. This difference might have contributed to the sex-dependent variation in clinical outcomes.

The cross-sectional shape of the fourfold semitendinosus tendon is oval, not round

BACKGROUND

The looped side of the semitendinosus tendon (ST) graft (i.e., the side inserted into the femoral tunnel during anterior cruciate ligament reconstruction) appears to be oval rather than round. The purpose of this study was to investigate the cross section of the fourfold semitendinosus tendon graft and, more specifically, the differences in pressure exerted by a rounded rectangular tunnel versus a round femoral tunnel.

METHODS

Seven STs were harvested from cadaveric knees and a fourfold ST graft was made. Aluminum cubes with round or rectangular tunnels containing four-way pressure-sensitive conductive sensors (vertically and bilaterally) were used. The area of both cubes was the same. The graft was inserted into the tunnels 15 mm from the looped edge. After measuring pressure, the graft was fixed using ultraviolet-curing acrylic resin and was cut at 7.5 mm and 15 mm from the lapel edge. The area, axes for the best fitting ellipse of the cross-section, and ellipticity of the axes were measured.

RESULTS

In the round tunnel, the mean contact pressure was 287.0 ± 136.7 gf at the bilateral sensor; there was no contact pressure detected by the vertical sensor. In the rounded rectangular tunnel, the mean contact pressure was 260.9 ± 186.4 gf at the bilateral sensor and 352.9 ± 49.5 gf at the vertical sensor. Ellipticity was 1.25 ± 0.13 at 7.5 mm, and 1.17 ± 0.07 at 15 mm from the lapel edge of the graft.

CONCLUSIONS

The cross-sectional shape of the fourfold ST graft was not round, but oval. Moreover, the rounded rectangular tunnel was more fitted to the graft than the round tunnel.

Acute augmentation for interstitial insufficiency of the posterior cruciate ligament. A two to five year clinical and radiographic study

BACKGROUND

there is need to ascertain clinical and imaging outcomes after posterior cruciate ligament (PCL) augmentation.

METHODS

we performed a retrospective analysis of clinical, imaging and functional data on 21 physically active males who underwent arthroscopic trans-tibial augmentation of the PCL for symptomatic grade III PCL insufficiency. The average follow-up time was 50 months (24-60 months). The Lysholm knee score was administered to all the patients, ligament laxity was evaluated with the posterior drawer test, the KT-1000 arthrometer, and the anteromedial tibial step-off. Standing antero-posterior, lateral and Merchant's view radiographs were taken preoperatively and at annual follow-up.

RESULTS

post-operatively, ligament laxity and Lysholm knee scores were significantly improved than at baseline. Sixteen patients (73%) returned to pre-injury sport activity level, 3 patients (14%) returned to a lower level, 2 had to stop. We found radiographic degenerative changes in 5 of 22 affected knees (23%), with evidence of a statistically significant association between the occurrence of degenerative changes and the interval time from injury to surgery and duration of the follow up.

CONCLUSIONS

arthroscopic transtibial single bundle autograft hamstring augmentation significantly improves the function of the knee, with an overall satisfactory outcome of 82% at 2-5 years from surgery.

Biomechanical analysis of medial collateral ligament reconstruction grafts of the elbow

BACKGROUND

There are no biomechanical studies evaluating different tendon grafts for elbow medial collateral ligament reconstruction.

HYPOTHESIS

Using a larger tendon for the graft will yield greater resistance to valgus load for medial collateral ligament docking technique reconstructions. The type of graft used for a medial collateral ligament docking technique reconstruction will have a significant effect on the resistance to valgus loads.

STUDY DESIGN

Controlled laboratory study.

METHODS

Cadaveric elbows from male donors were cyclically loaded to 3 and 5 mm elongation, both intact and after a docking technique medial collateral ligament reconstruction using palmaris longus, gracilis, semitendinosus, and patellar tendon grafts.

RESULTS

There was no significant difference in load to 3 or 5 mm elongation, number of cycles to failure, or stiffness between any tendon graft studied. Every tendon graft reconstruction tested was significantly weaker and less stiff than was the native medial collateral ligament.

CONCLUSION

There appears to be no biomechanical advantage to be gained by using a larger tendon graft instead of a palmaris longus graft.

CLINICAL RELEVANCE

The most readily available graft source with the lowest morbidity (often the palmaris longus tendon) should be used for medial collateral ligament reconstruction.

Bi-socket ACL reconstruction using hamstring tendons: high versus low femoral socket placement

To clarify the importance of the femoral socket location in bi-socket Anterior cruciate ligament (ACL) reconstruction. Subjects included 261 patients with an average age of 26 years who received ACL reconstruction via the high-femoral socket procedure (Group H) and 43 patients with an average age of 29 years who received ACL reconstruction via the low-femoral socket procedure (Group L) with a minimal follow-up of 24 months. In Group H, the femoral sockets were created at 1:00 or 11:00 and 2:00-2:30 or 9:30-10:00 of the intercondylar notch. In Group L, the two femoral sockets were drilled at 2:00 or 10:00 and 3:00 or 9:00. For the tibial side, a single tunnel was made at the center of the footprint. Evaluation was performed based on the IKDC Knee Examination Form. While 137 knees (52%) were graded as normal, 100 (38%) as nearly normal, 8 (3%) as abnormal, and 2 (1%) as severely abnormal with 14 (5%) re-injury in Group H, 38 knees (74%) were graded as normal, and 7 (16%) as nearly normal with 3 (7%) re-injury in Group L, showing a better subjective evaluation (P = 0.007). The average side-to-side differences in anterior laxity at manual maximum force with the KT-1000 were 1.1 +/- 1.6 mm for Group H and 1.0 +/- 1.6 mm for Group L without statistically significant differences excluding re-injured cases. There were 204 patients (83%) from Group H and 33 (83%) from Group L with values between -2 and 2 mm, while 228 (92%) patients from Group H and 38 (95%) from Group L had values distributed between -3 and 3 mm. While the bi-socket ACL reconstruction provided objectively satisfactory clinical outcomes in more than 90% of the patients, the low-femoral socket placement was found to subjectively achieve better outcomes.

Change in the cross-sectional area of a patellar tendon graft after anterior cruciate ligament reconstruction

The purpose of this study was to clarify the change in the cross-sectional area (CSA) of a patellar tendon graft after anterior cruciate ligament (ACL) reconstruction, and its relationship with postoperative knee laxity. Forty patients (25 men and 15 women) were included in this study. Intraoperative CSA measurements were performed with an instrumented areamicrometer, while a magnetic resonance imaging (MRI) evaluation was utilized for the assessment postoperatively. For intraoperative measurement, the average CSA of a 10-mm wide patellar tendon graft was 32.3 +/- 7.0 mm2, while the average CSA measured at follow-up (mean: 14.8 months) was 48.8 mm2, showing a significant mean increase ratio of 49.4%. This value corresponded to 115% of the native ACL. The average CSA measured in 30 patients at 6 months was 49.7 mm2, almost equal to the value at the final follow-up (49.8 mm2) in the same patient group. Among potentially influential factors, postoperative notch width (available space for the ACL graft) had significant correlation with the CSA of the graft at follow-up. Finally, both intra- and postoperative CSA values did not correlate with postoperative knee laxity, indicating that a bigger graft does not guarantee a better laxity.

Arthroscopic posterior cruciate ligament reconstruction with hamstring tendon autograft: results with a minimum 4-year follow-up

This study prospectively evaluates the outcomes at a minimum 4-year follow-up after PCL reconstruction using quadruple hamstring tendon autograft with an arthroscopic double fixation technique. During 1996-1999, hamstring tendon autograft graft has been used in 57 patients. Data from 52 patients who had been followed up completely were analyzed. All patients suffered from a grade 3 or higher grade of posterior drawer test and posterior sag sign with MRI image confirmation. Twelve knees had combined posterior and posterolateral instability, which were simultaneously reconstructed. Clinical assessments included Lysholm knee score, International Knee Documentation Committee (IKDC) scores, KT-1000 instrumented test, thigh muscle assessment, and radiographic evaluation. The mean Lysholm score was 54 (40-65) and 91 (65-100) points (P<0.01) before and after surgery. Thirty (58%) patients could return to moderate or strenuous activity. The evaluation of AP translation has been performed with KT-1000. The average posterior displacement measured with KT-1000 was 11.69+/-2.01 mm preoperatively and 3.45+/-2.04 mm postoperatively. Forty-two (81%) patients demonstrated ligament laxity of less than 5 mm. Forty-two (81%) patients were rated as normal or nearly normal based on IKDC scores. Forty-six (88%) patients achieved a minimum of 80% recovery of extensor strength and 44 (85%) patients achieved a minimum of 80% recovery of flexor strength. Statistically significant differences existed in thigh girth, extensor strength, and flexor strength before and after reconstruction. Arthroscopic reconstruction for PCL with four-strand hamstring tendon graft produced satisfactory results. The semitendinosus and gracilis tendon graft is adequate in graft size, technically easier to perform and more reproducible, and had a satisfactory result.

Proteoglycan fragments in anterior cruciate ligament reconstructed knees: a comparative study of two different surgical techniques

Proteoglycan fragments (PF) as chondroitin sulphate were monitored and compared in two groups of patients who had anterior cruciate ligament reconstruction with either patellar tendon (PT) or quadruple semitendinosus tendon (ST) autografts. There were 20 ST and 21 PT reconstructions. No difference existed between the groups in terms of associated lesion and time from injury to surgery. Synovial sample was collected at 6 weeks, 3 months and 18 months after the operation. No difference was noted between the groups at 18 months in terms of activity level and functional scores. Both groups demonstrated a sudden increase of PF at 6 weeks with respect to preoperative quantities (p<0.0001). A significant decrease occurred in the PT group at 3 months (p<0.008). Even at 18 months, it was significantly below the preoperative values (p<0.004). However, the decrease in ST cases relative to 6 weeks was insignificant at 3 months and quantities did not drop below the preoperative levels at 18 month (p=0.79). These results confirm again a gradual decrease of PF values in PT-reconstructed knees depending on time and surgery. Reconstruction with quadruple ST does not seem to have the same effect until 18 months postoperatively. Achievement of almost the same level of activity and function in both groups does not necessarily reflect the molecular status.