Predicting Diameter Increase Using a Quadriceps Tendon Augmentation for Undersized Hamstring Grafts in ACL Reconstruction

Background The failure rate for ACL reconstruction varies between 5 to 25% depending on the population. Recent studies found a higher failure rate with grafts of 8 millimeters in diameter or less. Various options are described when the graft’s diameter is inferior to the target value, but little literature helps us predict the final diameter during surgeries. Therefore, this study’s goal is to describe a new technique supplementing a hamstring graft folded in half with a quadricipital tendon band of partial width and thickness (4S+Q), and to predict the final diameter. Methods Thirty-three cadaveric knees were dissected in order to harvest semitendinosus and gracilis tendons (4S) along with a 6mm wide tendon band from the rectus femoris. Harvesting was done according to the usual surgical technique. Measures of length and diameter in 4S and 4S+Q configurations were performed separately by three evaluators. Results The threshold diameter of 8,5 mm was attained in only 30% of 4S grafts within our population in comparison with 88% when augmented with a quadriceps band. The average diameter increase with the 4S+Q configuration was 1,49 mm. A threshold of 7,5 mm was established for the applicability of this augmentation technique considering that 93% of the grafts measuring 7,5 mm or more reached the 8,5mm target. Conclusions The 4S+Q configuration offers a salvage option worth adding to one’s arsenal, significantly increasing the graft’s diameter. The width of the quadricipital tendon sample can be adjusted and will need further study.

Does Vancomycin Wrapping in Anterior Cruciate Ligament Reconstruction Affect Tenocyte Activity In Vitro?

Knee septic arthritis is a devastating complication following anterior cruciate ligament (ACL) reconstruction. To prevent this issue, intraoperative soaking of ACL grafts with vancomycin is often performed before implantation. Although vancomycin cytotoxicity has been reported several times, little is known about its biological effect on tenocytes. The aim of this study was to evaluate the in vitro effects of vancomycin on human primary tenocytes (hTCs). hTCs were isolated from hamstring grafts of four patients undergoing ACL reconstruction. After expansion, hTCs were treated with different concentrations of vancomycin (0, 2.5, 5, 10, 25, 50 and 100 mg/mL) for 10, 15, 30 and 60 min. In vitro cytotoxicity was evaluated measuring metabolic activity, cell toxicity, and apoptosis. hTC metabolic activity was affected starting from 10 mg/mL vancomycin and decreased markedly at 100 mg/mL. Cell viability remained unaffected only at a concentration of 2.5 mg/mL vancomycin. Vancomycin cytotoxicity was detected from 10 mg/mL after 15 min and at all higher concentrations. Cells died when treated with concentrations higher than 5 mg/mL. The use of this antibiotic on tendons to prevent infections could be useful and safe for resident cells if used at a concentration of 2.5 mg/mL for up to 1 h of treatment.

Effect of Time on MRI Appearance of Graft After ACL Reconstruction: A Comparison of Autologous Hamstring and Quadriceps Tendon Grafts

Background: After anterior cruciate ligament (ACL) reconstruction (ACLR), changes in the appearance of the ACL graft can be monitored using magnetic resonance imaging (MRI). Purpose: The purpose of this study was to evaluate and compare the MRI signal intensity (SI) of hamstring and quadriceps tendon grafts during the first postoperative year after ACLR. As a secondary aim, the relationship of SI to clinical and anatomic measurements was analyzed. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 78 patients who underwent ACLR with an autologous graft were reviewed; 55 received hamstring grafts and 23 received quadriceps tendon grafts. At 3 and 9 months postoperatively, 3-T MRI was performed using a dedicated knee coil, and the median SI of the intra-articular ACL graft was measured on sagittal-plane images. Postoperative lateral radiographs were analyzed to determine medial and lateral posterior tibial slope (PTS). Side-to-side difference in anterior knee laxity between injured and uninjured limbs was measured at 6 and 12 months postoperatively. Results: The median SI of quadriceps grafts was significantly greater than hamstring grafts at 3 months after ACLR ( P = .02). Between 3 and 9 months, the median SI of quadriceps grafts decreased ( P < .001), while that of hamstring grafts did not significantly change ( P = .55). The lateral PTS was significantly correlated with median SI measurements at 3 and 9 months such that greater lateral PTS values were associated with greater median SI. The side-to-side difference in anterior knee laxity decreased for the quadriceps group ( P = .04) between 6 and 12 months but did not change for the hamstring group ( P = .88). Conclusion: The median SI of quadriceps grafts significantly decreased on MRI between 3 and 9 months after ACLR, while the median SI of hamstring grafts did not significantly change. The change in MRI appearance of the quadriceps grafts was paralleled by a reduction in anterior knee laxity between 6 and 12 months after surgery. In the absence of standardized imaging techniques and imaging analysis methods, the role of MRI in determining graft maturation, and the implications for progression through rehabilitation to return to sport, remain uncertain.

Gentamicin pre-soaking of hamstring autografts decreases infection rates in anterior cruciate ligament reconstruction

Aims Graft infection following anterior cruciate ligament reconstruction (ACLR) may lead to septic arthritis requiring multiple irrigation and debridement procedures, staged revision operations, and prolonged courses of antibiotics. To our knowledge, there are no previous studies reporting on how gentamicin pre-soaking of hamstring grafts influences infection rates following ACLR. We set out to examine this in our study accordingly. Methods This retrospective study included 2,000 patients (1,156 males and 844 females) who underwent primary ACLR with hamstring autografts between 2007 to 2017. This included 1,063 patients who received pre-soaked saline hamstring grafts for ACLR followed by 937 patients who received pre-soaked gentamicin hamstring grafts for ACLR. All operative procedures were completed by a single surgeon using a standardized surgical technique. Medical notes were reviewed and data relating to the following outcomes recorded: postoperative infection, clinical progress, causative organisms, management received, and outcomes. Results Superficial wound infection developed in 14 patients (1.31 %) receiving pre-saline soaked hamstring grafts compared to 13 patients (1.38 %) receiving pre-gentamicin soaked hamstring grafts, and this finding was not statistically significant (p = 0.692). All superficial wound infections were treated with oral antibiotics with no further complications. There were no recorded cases of septic arthritis in patients receiving pre-gentamicin soaked grafts compared to nine patients (0.85%) receiving pre-saline soaked grafts, which was statistically significant (p = 0.004). Conclusion Pre-soaking hamstring autographs in gentamicin does not affect superficial infection rates but does reduce deep intra-articular infection rates compared to pre-soaking hamstring grafts in saline alone. These findings suggest that pre-soaking hamstring autografts in gentamicin provides an effective surgical technique for reducing intra-articular infection rates following ACLR. Cite this article: Bone Jt Open 2021;2(1):66–71.

Comparing the Width of Hamstring Grafts Prepared Using Wet and Dry Gauze Methods in Anterior Cruciate Ligament Reconstruction Surgery

Background: The anterior cruciate ligament surgery commonly uses a hamstring tendon. The hamstring grafts are usually prepared by wrapping in a wet gauze under tension. Objectives: The placement of a hamstring tendon in a dry gauze affects the size of the graft, without any change in its collagen volume. The present study aimed to prove that the preparation method could affect the hamstring graft width. Methods: A total number of 32 patients who had undergone the anterior cruciate ligament reconstruction were enrolled in this analytical descriptive study. Initially, the width of the 4-layered extracted graft was measured using the sizer system, after placement under traction. Then, 16 patients were operated on, based on the dry gauze preparation method, and the other 16, based on the wet gauze preparation method. The grafts were remeasured after traction. Six months after the surgery, all patients received a clinical evaluation, in which the integrity of the graft was evaluated based on clinical criteria. Results: The Mean±SD width of the 4-layered extracted grafts was 7.44±0.54 mm and 7.41±0.33 mm in the dry gauze and wet gauze groups, respectively. However, these values did not significantly differ (P=0.96). After traction, the Mean±SD graft width of the dry gauze group was reduced to 6.97±0.62 mm. The traction led to no change in the graft width of the wet gauze group. The changes in the graft size significantly differed between the two groups (P=0.032). Moreover, 4 patients (25%) exhibited no certain endpoint in the Lachman test, also, the pivot shift-test was positive in 5 patients (31.2%). Conclusion: The hamstring graft preparation technique affects the tunnel graft size. Besides, the use of dry gauzes procures the need for a narrower tunnel in the tibia and femur.