A BIOMECHANICAL COMPARISON OF MATCHED FOUR-STRAND AND FIVE-STRAND SEMITENDINOSUS-GRACILIS GRAFTS

ABSTRACT Introduction: Recent studies have shown that the likelihood of semitendinosus-gracilis graft rupture is inversely correlated to its diameter. A graft can be prepared in a five-strand or four-strand fashion to increase its diameter. However, the biomechanical superiority of five-strand semitendinosus-gracilis grafts is still under debate. Objective: This study aimed to evaluate the biomechanical characteristics of matched four-strand and five-strand human semitendinosus-gracilis grafts. Methods: We evaluated semitendinosus-gracilis tendons harvested from ten fresh human male and female cadavers, aged 18-60 years. Four-strand or five-strand grafts were prepared with the tendons and fixed to wooden tunnels with interference screws. Each graft was submitted to axial traction at 20 mm/min until rupture; the tests were donor matched. Data were recorded in real time and included the analysis of the area, diameter, force, maximum deformation and stiffness of the grafts. Results: The diameter, area and tunnel size were significantly greater in the five-strand grafts than in the four-strand grafts. There were no significant differences in biomechanical properties. The area and diameter of the graft were positively correlated to stiffness, and inversely correlated to elasticity. There was no significant correlation between graft size and maximum force at failure, maximum deformation or maximum tension. Conclusion: Five-strand hamstring grafts have greater area, diameter and tunnel size than four-strand grafts. There were no significant differences in biomechanical properties. In this model using interference screw fixation, the increases in area and diameter were correlated with an increase in stiffness and a decrease in elasticity. Level of evidence V; biomechanical study.

A Unique Case of an Expanded Polytetrafluoroethylene Graft Rupture 14 Years after Abdominal Aortic Aneurysm Open Repair Managed with Placement of a Thoracic Endograft

We report a unique case of expanded polytetrafluoroethylene (ePTFE) tube graft rupture that occurred 14 years after abdominal aortic aneurysm (AAA) repair. Endovascular repair with a thoracic endograft was performed. Postoperatively, an increase in the size of the existing hematoma with active extravasation occurred and was managed with iliolumbar artery embolization. Τo the best of our knowledge, rupture of ePTFE graft used for AAA repair has not been reported in the literature.

Clinical outcomes of contemporary lateral augmentation techniques in primary ACL reconstruction: a systematic review and meta-analysis

Purpose The purpose of this investigation was to systematically review the contemporary literature to determine if a lateral augmentation (LA) added to an Anterior Cruciate Ligament Reconstruction (ACLR) provides better clinical and patient reported outcomes compared to an isolated ACLR. Methods A systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) criteria. Two authors independently conducted an electronic search using MEDLINE® and Embase® on February 6th, 2021 for level I-III randomized controlled trials (RCT) and prospective cohort studies without randomization, published after 2012 and with a minimum of two year follow-up. Publications were included when they reported on the objective knee stability examination, patient reported outcome scores, return to sports or graft rupture rate of any type of primary, isolated ACLR compared to ACLR combined with any type of LA. Results A total of 11 studies that reported on a combined total of 1892 unique patients were eligible for data extraction, including five RCTs and six prospective cohort studies. In 6 studies, an Anterolateral Ligament reconstruction (ALLR) was the LA of choice, while the 5 other publications used different types of Lateral Extra-articular Tenodesis (LET). A significant reduction in graft ruptures was found in patients treated with ACLR + LA (3%) compared to isolated ACLR (12%). Rotational laxity was significantly higher in isolated ACLR (14%) compared to ACLR + LA (6%). Addition of a LA reduced anterior translation when assessed via instrumented laxity testing. No significant difference was found in the patient reported outcome scores (IKDC and Tegner) between both patient groups, except for the Lysholm Score which was significant in favour of the ACLR + LA group. Conclusion Combination of a primary ACLR with a LA can significantly reduce the risk of graft rupture and provide better rotatory stability, without jeopardizing patient reported outcomes. Level of evidence Level III, Systematic Review of Level I, II and III studies.

Graft Rupture Rates After Combined ACL and Anterolateral Ligament Reconstruction Versus Isolated ACL Reconstruction: A Matched-Pair Analysis From the SANTI Study Group

Background: Clinical studies have demonstrated significant advantages of combined anterior cruciate ligament and anterolateral ligament reconstruction (ACL+ALLR) over isolated ACL reconstruction (ACLR) with respect to reduced graft rupture rates, a lower risk of reoperation for secondary meniscectomy, improved knee stability, and higher rates of return to sports. However, no long-term studies exist. Purpose/Hypothesis: The purpose of this study was to compare the outcomes of isolated ACLR versus ACL+ALLR at long-term follow-up. The hypothesis was that patients who underwent combined procedures would experience significantly lower rates of graft rupture. Study Design: Cohort study; Level of evidence, 3. Methods: Patients undergoing primary ACL+ALLR between January 2011 and March 2012 were propensity matched in a 1:1 ratio to patients who underwent isolated ACLR during the same period. A combination of face-to-face and telemedicine postoperative follow-up was undertaken. At the end of the study period (March 2020), medical notes and a final telemedicine interview were used to determine whether patients had experienced any complications or reoperations. The Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee score, Lysholm score, and Tegner score were collected for all patients. Graft survivorship was assessed using Kaplan-Meier analysis. Logistic regression was performed to account for the potential effect of activity level on graft rupture rates. Results: A total of 86 matched pairs were included in the study. The mean ± SD age was 32.2 ± 8.8 years (range, 22-67 years) in the ACL+ALLR group and 34.7 ± 8.5 years (range, 21-61 years) in the isolated ACLR group. The mean duration of follow-up was 104.33 ± 3.74 months (range, 97-111 months). Patients who underwent combined ACL+ALLR versus isolated ACLR experienced significantly better ACL graft survivorship (96.5% vs 82.6%, respectively; P = .0027), lower overall rates of reoperation (15.3% vs 32.6%; P < .05), and lower rates of revision ACLR (3.5% vs 17.4%; P < .05). Patients undergoing isolated ACLR were at >5-fold greater risk of graft rupture (odds ratio, 5.549; 95% CI, 1.431-21.511; P = .0132), regardless of their preinjury activity level. There were no significant differences between groups with respect to other complications or any clinically important differences in patient-reported outcome measures. Conclusion: Patients who underwent combined ACL+ALLR experienced significantly better long-term ACL graft survivorship, lower overall rates of reoperation, and no increase in complications compared with patients who underwent isolated ACLR. Further, patients who underwent isolated ACLR had a >5-fold increased risk of undergoing revision surgery at a mean follow-up of 104.3 months.

Augmentation of Primary ACL Reconstruction With a Modified Ellison Lateral Extra-articular Tenodesis in High-Risk Patients: A Pilot Study

Background: Lateral extra-articular tenodesis (LET) has been used to augment primary anterior cruciate ligament (ACL) reconstruction to reduce the risk of reinjury. Most LET procedures result in a construct that is fixed to both the femur and the tibia. In a modified Ellison procedure, the construct is only fixed distally, reducing the risk of inadvertently overconstraining the lateral compartment. Purpose: To evaluate the use of the modified Ellison procedure in a cohort of patients deemed to be at a high risk of further ACL injury after primary ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Included were 25 consecutive patients with at least 2 of the following risk factors: age <20 years at the time of surgery, previous contralateral ACL reconstruction, positive family history of ACL rupture (parent or sibling), generalized ligamentous laxity (Beighton ≥4), grade 3 pivot shift in the consulting room, a desire to return to a pivoting sport, and an elite or professional status. All patients underwent primary ACL reconstruction with an additional modified Ellison procedure. Postoperatively, patients completed the IKDC subjective knee evaluation form (International Knee Documentation Committee), KOOS Quality of Life subscale (Knee injury and Osteoarthritis Outcome Score), ACL–Return to Sport After Injury Scale, Marx Activity Rating Scale, and SANE score (Single Assessment Numeric Evaluation). Results: At 12-month follow-up, the mean outcome scores were as follows: SANE, 94/100; IKDC, 92/100; Marx, 13/16; ACL–Return to Sport, 85/100; and KOOS, 77/100. At 24 months, return-to-sport data were available for 23 of 25 patients; 17 (74%) were playing at the same level or higher than preinjury and 2 at a lower level. One patient (4%) sustained a contact mechanism graft rupture at 12 months. There were 2 (9%) contralateral ACL injuries, including 1 ACL graft rupture, at 11 and 22 months postoperatively. There was a further contralateral ACL graft rupture at 26 months. Conclusion: The use of the modified Ellison procedure as a LET augmentation of a primary ACL reconstruction to produce a low graft rupture rate appeared to be safe in a cohort considered to be at a high risk of reinjury. The procedure showed promise in terms of reducing further graft injuries.

PRE-OPERATIVE EXPECTATIONS FOR RETURN TO SPORTS AND OUTCOMES FOLLOWING ACL RECONSTRUCTION: A SURVEY OF ADOLESCENT PATIENTS AND THEIR PARENTS

Background: There is limited data regarding patient and parent expectations regarding return to sport (RTS) and outcomes following anterior cruciate ligament reconstruction (ACLR) in adolescent athletes. Purpose: To investigate RTS and outcome expectations of adolescent patients and their parents before ACLR and determine any differences between groups. Methods: For this cross-sectional study, sets of patients (aged 10 to 18 years) and parents were separately asked to complete the same questionnaire relating to knowledge and expectations regarding the patient’s upcoming ACLR. The custom survey consisted of 12 questions and was administered before being seen by a single sports medicine surgeon in the clinical setting of a tertiary care referral center from June 2019 through June 2020. Statistical analysis was performed to compare differences between patient and parent/guardian responses. Results: 28 sets of patients (53.6% female) and parents (64.3% female) completed the survey with average ages of 14.5 ± 2.0 years and 45.6 ± 7.0 years, respectively. 75% of families were Caucasian and 85.2% had private insurance. The most common sports played were basketball (25%) and soccer (17.9%). Overall, nearly 68% of consults were for a second opinion. 50% of patients and 82.1% of parents researched or read of ACL injuries and/or surgery prior to the visit. Most patients (46.4%) and parents (51.9%) expected the surgeon to consider full, unrestricted RTS/activities at 9 months. Only 7.1% of patients and 3.7% of parents believed full RTS would occur >12 months. 50% of patients and 67.9% of parents expected RTS at the same level. Both patients (53.6%) and parents (64.3%) believed fear of re-injury was the most common reason for not returning to sport or returning at a decreased level. There were no statistically significant differences in RTS expectations between patients and parents ( p>0.05). Most patients (38.5%) believed the risk of graft rupture in adolescent athletes was 5%, whereas most parents (37%) believed the risk to be at 25%, but the difference was not statistically significant ( p>0.05). Both patients and parents believed the risk of graft rupture was highest within the first 6 months (77.8% vs. 50%, respectively). More parents felt the risk of graft rupture was highest within the first year (39.3% vs. 22.2%), but the difference was not statistically significant ( p>0.05). Conclusion: Adolescent patients and their parents had similar knowledge and expectations regarding RTS and outcomes following ACLR. Further study is needed to better understand factors affecting those expectations.

Graft Failure in Adolescent Patients Undergoing Adult-Type ACL Reconstruction with Bone Patellar Tendon Bone or Hamstring Autograft

Introduction: Anterior cruciate ligament (ACL) injuries represent a quarter of high school knee injuries. Adult-type ACL reconstruction (ACL-R) is the treatment of choice for skeletally mature adolescent patients with a complete ACL tear. Graft choice is individualized to the patient, taking into account the patient’s anatomy, activity level, and athletic participation. This subset of patients is at perhaps the highest risk of failure due to demands on the reconstruction after surgery. Hypothesis/Purpose: The purpose of this study was to evaluate outcomes including graft rupture between bone-patellar tendon-bone (BTB) versus hamstring autograft in adolescent patients undergoing adult-type ACL reconstruction. Methods: A retrospective review of patients under the age of 21 undergoing primary adult-type ACL-R by a single surgeon using BTB or hamstring autograft between 2011 and 2019 was performed. Patient demographics, athletic participation, concomitant injuries, graft utilized, graft size, femoral and tibial fixation devices, compliance with rehabilitation protocol, complications, and rates of revision surgery were evaluated. Factors associated with graft failure were compared using Fisher’s exact test with statistical significance < 0.05. Results: 269 patients with an average age of 16.5 years (range 12.4-20.6) and an average follow-up of 2.1 years (range 0.4-6.6 years) were included. 52.5% of the patients were female. The overall graft rupture rate was 4.8%. There was no difference in average age, sex, compliance, and participation in high risk sports between graft type groups. Graft size was larger in patients with BTB autograft than patients with hamstring autograft (9.0 vs. 8.3; p<.001). There was no difference in the overall rate of re-operation between BTB and hamstring autografts (8.6% vs. 10.6%; p=0.81). There was no significant difference in rate of graft rupture with BTB and hamstring autograft (2.9% vs. 5.5%; p=0.26). Average time to revision surgery in those with ruptures was 1.7 years (range 0.7-4.7 years). 46% of patients had revision ACL-R with a different surgeon. There was no difference in age or participation in high risk sports between patients with and without graft tear. There was a higher percentage of documented compliance issues in patients with graft tear (46%) than without graft tear (29%), though not statistically significant (p=0.17). Conclusion: Rates of graft tear after ACL-R did not differ with BTB versus hamstring autograft. Rates of compliance and participation in high risk sports did not significantly differ in patients with and without graft tear. Many patients had a change in surgical provider for revision surgery.