Preoperative Psychological Competitive Ability Is Associated With Emotional States Six Months After Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: A Prospective Study.

Background Psychological state has been reported as one of the factors strongly related to a return to sports after anterior cruciate ligament (ACL) reconstruction. However, its relationship with the emotional state remains unclear. The aim of this study was to investigate whether patients who have undergone ACL reconstruction and have a higher preoperative psychological competitive ability have a better emotional status preoperatively and six months postoperatively. Methods Patients with a Tegner activity score of ≥6 who underwent ACL reconstruction between 2015 and 2020 were divided into two groups according to their grades on the Diagnostic Inventory of Psychological Competitive Ability for Athletes (DIPCA.3). The emotional states preoperatively and at six months postoperatively were assessed using the Profile of Mood States Second Edition (POMS2) and compared between the two groups. Furthermore, the possibility of returning to sports was compared between the groups based on participation in the entire practice at six months postoperatively. Results Eighty-four patients were included and divided into the high (DIPCA.3 grades ≥4, n = 23) and low (DIPCA.3 <4, n = 61) groups. Vigor-activity and friendliness were significantly higher in the high group than in the low group preoperatively. The difference was even greater at six months after ACL reconstruction. In addition, the high group showed significantly better results postoperatively for fatigue-inertia and total mood disturbance. Rates of return to sports did not differ significantly between the high and low groups (56.5% vs. 54.1%). Conclusions Those with a higher preoperative psychological competitive ability were in a positive emotional state preoperatively and six months after ACL reconstruction. However, the psychological competitive ability did not affect the rate of participation in the entire practice at six months postoperatively.

Blood flow signals through the bone cortex on ultrasonography can be used as a screening test for detecting bone marrow lesions on magnetic resonance imaging in patients with early knee osteoarthritis.

PURPOSE: Blood flow signals (BFSs) through the bone cortex on ultrasonography (US) and bone marrow lesions (BMLs) detected on magnetic resonance imaging (MRI) can be used to assess bone lesions; however, no studies have reported their relationship. Therefore, this study aimed to assess whether BFSs through the bone cortex on US can serve as a screening test for detecting BMLs on MRI in patients with early knee osteoarthritis (OA). METHODS: This study enrolled patients with knee joint pain who were diagnosed with early knee OA between January 2018 and January 2024. We targeted 77 patients who underwent MRI and in whom the presence or absence of BFSs through the bone cortex was confirmed on US. The association between BFSs and BMLs was evaluated using the chi-square test, and the sensitivity and specificity of BFSs for detecting BMLs on MRI were calculated. RESULTS: The chi-square test showed that BFSs and BMLs were significantly associated in the femur and tibia (femur: χ2 [1] = 52.9, p < 0.001; Tibia: χ2 [1] = 44.8, p < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of BFSs for detecting BMLs on MRI were 85.0%, 96.5%, 89.5%, and 94.8%, respectively, for the femur, and 84.0%, 92.3%, 84.0%, and 92.3%, respectively, for the tibia. CONCLUSION: BFSs through the bone cortex on US can be used as a screening test for detecting BMLs on MRI in patients with early knee OA.

One-Year Changes in Collagen Type in Semitendinosus Tendons: A Case Study Using Tissues Obtained From a Growing Patient.

Recently, there have been concerns about the high postoperative re-injury rate associated with the use of the semitendinosus tendon (ST) as an autograft for anterior cruciate ligament reconstruction in adolescent patients before the closure of the epiphyseal line. Our previous studies showed that this high re-injury is related to the histological and mechanical immaturity of ST in adolescent patients. Moreover, the overall structure of collagen fibers is strengthened with the application of traction force to tendon tissue. Therefore, it is assumed that, in vivo, bone growth and increased height increase the traction force applied to tendon tissue and the percentage of type I collagen, which has a remarkable physical strength. The present study aimed to investigate the changes in the content of ST's type I collagen in an adolescent patient over one year. The patient was an 11-year-old male with bilateral patellar dislocations. The orthopedic surgeon performed medial patellofemoral ligament reconstruction on the left knee using an ST graft, followed by a similar procedure on the right knee one year later. ST tissue that would have been discarded during each procedure was harvested and used. The bone of the patient's legs grew approximately 8 cm during the one-year period. The obtained tissues were immunostained and microscopically observed to evaluate the area content of type I and III collagen. The area content of type I collagen in STs collected from the patient was 66%. The area content of type I collagen increased rapidly to 95% one year later. A comparison of the two STs obtained from the patient in the first half of their 10th year showed that the type I collagen content of the STs increased rapidly over one year. This fact may provide a preliminary insight into the prevention of re-injury when selecting the autograft for anterior cruciate ligament (ACL) reconstruction in adolescent patients.

Relationship between ultrasonographic findings and subscales of the Knee Injury and Osteoarthritis Outcome Score in patients with early knee osteoarthritis: a multicenter study.

PURPOSE: To characterize the ultrasonographic findings of patients with early knee osteoarthritis (KOA) and determine which findings were associated with the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale. METHODS: The study included 98 knees (35 men, 63 women, 60.3 ± 11.5 years) diagnosed with early KOA with no major deformity radiographically, but with pain during activity and tenderness in the medial knee. Synovial hyperplasia in the suprapatellar bursa, knee joint effusion, horizontal tear of the medial meniscus (MM), osteophytes of the medial condyle of the femur and tibia, blood flow signals in the synovium of the suprapatellar bursa, medial collateral ligament bursa, infrapatellar fat pad, MM extrusion (MME) in the supine and upright positions, and the amount of change in MME were observed using ultrasonography. RESULTS: Correlations (p < 0.05) were found between the presence of synovial hyperplasia of the suprapatellar bursa (r<-0.20) and amount of MME in the upright position (r< - 0.24) and all KOOS subscales. Presence of joint effusion and the four KOOS subscales except quality of life (QOL) were correlated (p < 0.05). Partial correlation coefficients showed correlations (p < 0.05) between knee joint effusion and symptoms (r = 0.299) and activities of daily living (ADL) (r = 0.254) of the KOOS subscales, and between MME in the upright position and symptoms (r= - 0.263), pain (r= - 0.256), and ADL (r= - 0.212). CONCLUSION: Quality and difficulty of life of patients with early KOA may be influenced by synovial hyperplasia in the suprapatellar bursa, joint effusion, and MME values in the upright position. Among them, synovial hyperplasia of the suprapatellar bursa and amount of MME in the upright position were independently associated with the KOOS subscales.

Collagen-Type Composition in the Semitendinosus, Quadriceps, and Patellar Tendons of a 22-Year-Old Patient: A Case Report.

Graft failure is a common postoperative complication after anterior cruciate ligament (ACL) reconstruction. Recently, a theory has emerged that histological and microstructural factors of autografts may be related to graft failure. We simultaneously collected the semitendinosus tendon (ST), quadriceps tendon (QT), and patellar tendon (PT) from a 22-year-old patient to provide insights into the differences in the collagen-type composition of the three tendons in skeletally mature patients. These findings may serve as a basis for selecting autografts for ACL to reduce graft failure rates. The patient was a 22-year-old female who required the removal of artificial ligament, screws, and washers and medial patellofemoral ligament (MPFL) reconstruction with an ST autograft after two surgeries for recurrent dislocation of the left patella. The ST, QT, and PT obtained during necessary intraoperative procedures were used as samples. The tissues were processed and immunostained; this was followed by confocal microscopy. Evaluation was performed by calculating the percentage of areas positive for collagen types I and III.The percentage of type I collagen in the ST, QT, and PT groups was 88%, 85%, and 88%, respectively.The collagen-type composition was examined following simultaneous collection of the ST, QT, and PT. The results revealed no significant differences in the content of physically strong type I collagen, which supports previous findings showing that the clinical outcomes after ACL reconstruction do not vary with the autograft used.

Knee flexor strength at 6 months after anterior cruciate ligament reconstruction using hamstring tendon can be predicted from that at 3 months.

PURPOSE: This study aimed to identify factors influencing persistent muscle weakness in knee flexor strength after anterior cruciate ligament (ACL) reconstruction using the hamstring tendon and establish a clear cut-off value at 3 months postoperatively for the limb symmetry index (LSI) to exceed 90% at 6 months postoperatively. METHODS: One hundred forty-eight patients undergoing ACL reconstruction were included and categorised into two groups based on knee flexor strength at 6 months postoperatively: patients with LSI of 90% or greater (achieved group: n = 114) and patients with LSI less than 85% (nonachieved group: n = 34). Items with significant differences between the two groups (preoperative waiting period, LSI to body weight ratio of knee flexor and extensor strength at 3 months postoperatively and peak torque angle of knee flexor muscle) were included in the multiple logistic regression analysis. Additionally, a receiver operating characteristic curve was used to calculate the cut-off value of the LSI at 3 months postoperatively, which was required to achieve the LSI criteria for knee flexor strength 6 months postoperatively. RESULTS: Multiple logistic regression analysis extracted the preoperative waiting period and LSI for knee flexor strength at 3 months postoperatively. The cut-off value at 3 months postoperatively was 76.9% (area under the curve value, 0.82; sensitivity, 0.76; and specificity, 0.81) of the LSI. CONCLUSION: The LSI of at least 76.9% for knee flexor strength at 3 months after ACL reconstruction was an indicator for achieving the 6 months postoperatively. This is a criterion to aim for, considering the stress on the graft and the regeneration process of the semitendinosus tendon. LEVEL OF EVIDENCE: Level III.

Identifying unstable ramp lesions using ultrasonography.

BACKGROUND: Patients with suspected ramp lesions on magnetic resonance imaging (MRI) or ultrasonography (US) healed and showed no instability based on intraoperative arthroscopic findings. The purpose of this study was to assess the use of US in evaluating ramp lesions preoperatively and intraoperatively. METHODS: Eighty-two knees that underwent anterior cruciate ligament (ACL) reconstruction between January 2022 and June 2023 were included to assess the ramp lesion complication rate and instability using arthroscopic findings. The detection rate of ramp lesions using US at the initial visit and preoperatively was also investigated. The test-retest reliability was assessed using the intraclass correlation coefficient and analyzed using two-way random effects and absolute agreement. The patients were divided into two groups based on the presence or absence of ramp lesions, and these data were compared using Student's t-test. Statistical significance was set at p < 0.05. RESULTS: On ultrasound examination, 90.0% of the cases had a ramp lesion at the initial examination, of which 22.2% were poorly delineated on the day of surgery. In the cases where the ramp lesion was unstable at the time of surgery, it could be delineated using US. In the cases where the ramp lesion was stable, it was difficult to delineate the lesion using US. CONCLUSIONS: Unstable ramp lesions complicating ACL injuries could be detected using US.

Periarticular cocktail injection is more useful than nerve blocks for pain management after anterior cruciate ligament reconstruction.

Background: Anterior cruciate ligament (ACL) reconstruction is commonly associated with moderate-to-severe postoperative pain. Notably, various pain control strategies, a femoral nerve block (FNB) with a lateral femoral cutaneous nerve block (LFCNB), adductor canal block (ACB) with LFCNB, or periarticular cocktail injection (PI), have been investigated. However, no studies compare the effects of FNB with LFCNB, ACB with LFCNB, and PI for pain control after ACL reconstruction. This study aimed to evaluate the impact of FNB with LFCNB, ACB with LFCNB, and PI for pain relief in the early postoperative period after ACL reconstruction. Methods: This retrospective controlled clinical trial enrolled 299 patients who underwent primary ACL reconstruction at our hospital between April 2016 and October 2022. We categorized these cases into groups based on the use of PI (PI group), FNB with LFCNB (FNB group), and ACB with LFCNB (ACB group) for pain management. We selected 40 cases each, with matched age, sex, and body mass index (BMI) from each group, resulting in 120 cases for analysis. In the FNB and ACB groups, 0.75% ropivacaine 15 ml was injected under ultrasound guidance preoperatively. In the PI group, a mixture of 0.75% ropivacaine 20 ml, normal saline 20 ml, and dexamethasone 6.6 mg was injected half at the start of surgery and the rest just before wound closure. Patient demographics (age, sex, height, body weight, and BMI) and surgical data (the requirement for meniscal repair, operative time, and tourniquet inflation time) were analyzed. After ACL reconstruction, patients' numerical rating scale pain scores (NRS) (0-10) were recorded at 30 min and 4, 8, 12, 24, 48, and 72 h postoperatively. NRS were then compared among the three groups using analysis of variance. In addition, within each group, these data were compared between the NRS ≥7 and NRS ≤6 groups using a t-test. Results: There were no significant differences in patient demographics and surgical data. Pain scores were significantly higher in the PI group than in the FCB and ACB groups 30 min postoperatively, but they were lower at 12, 24, 48, and 72 h postoperatively. In the FNB group, there were no significant differences in the demographic and surgical data by NRS pain score. In the ACB group, the number of men was significantly higher in the NRS ≥7 group than in the NRS ≤6 group (p = 0.015). In the PI group, tourniquet inflation time was significantly longer in the NRS ≥7 group than in the NRS ≤6 group (p = 0.008). Conclusions: Following ACL reconstruction using a hamstring autograft, periarticular cocktail significantly reduced early postoperative pain compared with nerve block combinations.

The use of ultrasonography as an effective screening tool for chronic posterior cruciate ligament injuries.

PURPOSE: We aimed to explore the applicability and validity of ultrasonography for diagnosing chronic posterior cruciate ligament (PCL) injuries. METHODS: PCL thickness was measured at 2 cm proximal to the tibia insertion site. Using the same ultrasonography image, the angle tangent to the PCL from the tibia insertion site was also measured. These data were analyzed by plotting the receiver operating curve (ROC), and the sensitivity and specificity were calculated according to the optimal cut-off point. Ultrasonography data from the PCLinjured knee were compared with those from the contralateral uninjured knee of the same patient. RESULTS: Twelve men and six women, with a mean age of 28.8 ± 14.0 years, were included in this study. The mean time from injury to medical examination was 10.0 ± 6.7 months. The mean thickness of the PCL was 8.1 ± 1.9 mm on the affected side and 5.8 ± 1.2 mm on the uninjured side, with the affected side being significantly thicker. ROC analysis revealed that the optimal cut-off value for the thickness of chronic PCL injuries was 6.5 mm (sensitivity 83.3%, specificity 77.8%, area under the curve [AUC] = 0.87). The optimal cut-off value for the angle was 20° (sensitivity 88.9%, specificity 94.4%, AUC = 0.96). CONCLUSION: Ultrasonography is useful as a screening tool for chronic PCL injuries. The optimal cut-off point was 6.5 mm for thickness and 20° for angle. LEVEL OF EVIDENCE: IV.

Ultrasonographic diagnosis of medial meniscus posterior root tear in early knee osteoarthritis: a comparative study.

INTRODUCTION: This study aimed to detect medial meniscal posterior root tear (MMPRT) diagnostic methods with high sensitivity and specificity using dynamic ultrasonographic evaluation in patients with early knee osteoarthritis (OA) and demonstrate the usefulness of dynamic ultrasonographic medial meniscal extrusion (MME) evaluation in MMPRT diagnosis using a cutoff value. MATERIALS AND METHODS: Between 2018 and 2020, a total of 120 patients were diagnosed with early knee OA using clinical and radiographic findings. Dynamic ultrasonographic evaluations and magnetic resonance imaging were performed in all patients, and 47 patients who had and 73 patients who did not have MMPRT were classified into the MMPRT and non-MMPRT groups, respectively. Age, sex, femorotibial angle, MME of knee extension and flexion, and MME at weight-bearing were compared between the two groups. Additionally, the sensitivity and specificity of significant ultrasonographic findings were calculated using a receiver operating characteristic (ROC) curve. RESULTS: The MMEs under knee extension-flexion and weight-loading in the MMPRT group were significantly larger than those in the non-MMPRT group. ROC curve analysis for each ultrasonographic evaluation condition to diagnose MMPRT indicated that the sensitivity was 72-88% and the specificity was 66-85% when the cutoff values of MME under knee flexion at 0°, 90°, and weight-loading were set at 2.55 mm, 2.00 mm, and 3.55 mm, respectively. The highest sensitivity (88%) and specificity (85%) were exhibited upon > 2 mm MME at a knee flexion of 90° and were the most useful indicators for MME diagnosis. CONCLUSIONS: Ultrasonographic MME evaluations for MMPRT diagnosis showed relatively high sensitivity and specificity in patients with early knee OA. Dynamic ultrasonographic MME evaluation may lead to appropriate additional examinations, early diagnosis, and intervention for MMPRT in patients with early knee OA.

Differences in the microstructural and mechanical qualities of semitendinosus tendon grafts between skeletally immature and mature patients in anterior cruciate ligament reconstruction.

BACKGROUND: This study aimed to investigate the microstructural and mechanical properties of semitendinosus tendon graft tissues during anterior cruciate ligament reconstruction and the clinical outcomes in skeletally immature and mature patients. METHODS: Twenty-two patients who underwent primary anterior cruciate ligament reconstruction using a hamstring tendon graft were analyzed and divided into skeletally immature (n = 7) and mature groups (n = 15) based on magnetic resonance imaging findings of the epiphyseal plate of the distal femur. Tissue samples were collected from the mid-portion of the semitendinosus tendon. The collagen fibril diameter, maximum stress, and strain at maximum stress point in the semitendinosus tendon tissues were calculated for comparison of the microstructural and mechanical properties between the two groups. Postoperative outcomes were also assessed between the two groups. RESULTS: The mean and 60th and 80th percentiles of fibril diameters in the skeletally immature group were significantly smaller than those in the mature group (65.9 ± 13.0, 73.5 ± 19.3, and 91.3 ± 27.4 nm in the skeletally immature group; and 90.3 ± 14.7, 94.0 ± 18.4, and 125.3 ± 19.9 nm in the skeletally immature group; p = 0.001, 0.024, and 0.004, respectively). Additionally, the strain at maximum stress was higher in the skeletally immature group (237.2 ± 102.4% vs. 121.5 ± 51.9%, p = 0.024). However, there was no difference in maximum stress between the skeletally immature and mature groups (19.9 ± 14.3 MPa vs. 24.5 ± 23.4 MPa, p = 0.578). Strain was negatively correlated with the mean fibril diameter and the 60th and 80th percentiles of fibril diameters, whereas stress was positively correlated with the mean fibril diameter. The skeletally immature group had a higher pivot shift test-positive rate than the mature group at the last follow-up (p = 0.023). CONCLUSION: Semitendinosus tendon graft tissues differed microstructurally and mechanically between skeletally immature and mature patients. LEVEL OF EVIDENCE: Level Ⅳ.

Limited preoperative knee extension in anterior cruciate ligament reconstruction using a hamstring tendon affects improvement of postoperative knee extensor strength.

PURPOSE: This study aimed to determine the factors affecting knee extensor strength 6 months after anterior cruciate ligament (ACL) reconstruction using autograft hamstring tendon. METHODS: 144 patients who could undergo regular follow-up after ACL reconstruction were divided into 2 groups: those with greater than 90% (Group A: n = 95) and less than 85% (Group B: n = 49) isokinetic knee contraction at 60°/s 6 months post-ACL reconstruction. Basic information, injury status, limited preoperative knee extension, and knee extensor strength at 3 and 6 months postoperatively were compared between the groups. Multivariate logistic analysis was performed and included variables that showed statistically significant differences between the groups in the univariate analysis. In addition, the cut-off value for the limb symmetry index (LSI) at 3 months postoperatively needed to exceed an LSI of 90% at 6 months postoperatively was calculated using the receiver operating characteristics curve. RESULTS: Age, preoperative waiting period, limited preoperative knee extension, and knee extensor strength at 3 months postoperatively were significantly different between the two groups. The multivariate logistic analysis showed that all the variables affected the improvement in knee extensor strength at 6 months postoperatively. Limited preoperative knee extension was the most significant factor (odds ratio: 15.1, 95% confidence interval: 2.57-118.56, p < 0.01). The LSI cut-off value at 3 months postoperatively was 72.0%. CONCLUSION: Key factors in achieving the necessary knee extensor strength criteria for return to sports at 6 months post-ACL reconstruction include addressing limited preoperative knee extension and achieving an LSI ≥ 72% in knee extensor strength at 3 months postoperatively. LEVEL OF EVIDENCE: Level III.

Development of an educational three-dimensional anatomical structure replication tool and its application to medial open-wedge high tibial osteotomy.

BACKGROUND: With the standardization of surgical techniques and continuous development of plate fixators, medial open-wedge high tibial osteotomy (OWHTO) has become an option for the treatment of medial knee osteoarthritis. However, it is also associated with several complications. To reduce the risk of these complications, it is essential for surgeons to accurately understand the three-dimensional (3D) anatomical structures, including the surroundings of the surgical field. Gross dissection using a cadaver provides a large surgical field and is the best learning method for studying anatomical structures in three dimensions; however, it is not available at all medical institutions. METHODS: One female cadaveric knee, fixed using the Thiel method, was used in this study, and OWHTO was performed. A series of photographs was taken from approximately 60 different angles at each stage of the autopsy for digital photogrammetry to ensure that there was at least a 60% overlap between photographs. RESULTS: Each 3D object was created to be faithful to the original specimen and displayed on an augmented reality headset. It was created to capture the subtle nuances of irregular shapes and structures, highlighting the unique ability of photogrammetry to capture pathology. This method allows surgeons to visualize the location of neurovascular injuries in the intraoperative field of view. CONCLUSIONS: Using a technique that applies digital photogrammetry to create 3D objects from handheld photographs, this reports for the first time an educational tool that can reproduce the anatomy related to high tibial osteotomy in three dimensions.

Extrusion of the medial meniscus under a weight-loading condition in early knee osteoarthritis: an investigation using special upright magnetic resonance imaging.

BACKGROUND: Whether the medial meniscus morphology and movement occur under upright loading conditions in early knee osteoarthritis (OA) or medial meniscus posterior root tear (MMPRT) remains unknown. This study aimed to evaluate the medial and anteroposterior extrusion of the medial meniscus under unloaded and upright-loaded conditions in patients with early knee OA. METHODS: Twelve patients with early knee OA and 18 healthy adult volunteers participated in this study. Magnetic resonance imaging using special equipment was performed with the participants in the unloaded and upright-loaded conditions. Medial, anterior, and posterior extrusions of the medial meniscus against the tibial edge were evaluated and compared between the early knee OA and healthy adult control groups. Additionally, 12 patients in the early knee OA group were divided into 2 subgroups based on whether MMPRT was observed, and the extrusion of the medial meniscus was compared. RESULTS: The amount of medial extrusion of the medial meniscus in both the unloaded and upright-loaded conditions was significantly greater in the early knee OA group than in the control group (unloaded: 2.6 ± 1.0 mm vs 0.7 ± 0.5 mm; upright-loaded: 3.7 ± 0.9 mm vs 1.8 ± 0.8 mm). Similarly, the anterior and posterior extrusion of the medial meniscus in the upright-loaded condition was significantly larger in the early knee OA group (anterior: 4.6 ± 1.0 mm vs 3.7 ± 1.1 mm; posterior: -3.4 ± 1.1 mm vs -4.6 ± 1.6 mm). However, no difference was observed in meniscal extrusion between unloaded and upright-loaded conditions. The posterior extrusion of the medial meniscus in the upright-loaded condition was significantly greater in MMPRT cases than in non-MMPRT cases in the early knee OA group (MMPRT: -2.7 ± 1.1 mm; non-MMPRT -4.1 ± 1.5 mm). CONCLUSIONS: In early knee OA, significantly large meniscal extrusions of the medial meniscus in both unloaded and upright-loaded conditions were found compared with healthy adults. Among patients with early knee OA, those with MMPRT showed a large posterior extrusion of the medial meniscus in the upright-loaded condition compared with those without MMPRT. LEVEL OF EVIDENCE: Level IV.

Outcome comparison of femoral nerve block and adductor canal block during anterior cruciate ligament reconstruction: adductor canal block may cause an unexpected decrease in knee flexor strength at 6 months postoperatively.

INTRODUCTION: Peripheral nerve blocks are frequently used in anterior cruciate ligament (ACL) reconstruction. While femoral nerve block (FNB) has been associated with knee extensor strength reduction in the early postoperative period, no consistent view of knee extensor strength several months after ACL reconstruction exists. This study aimed to compare the impact of intraoperative FNB and adductor canal block (ACB) during ACL reconstruction on knee extensor strength at 3 and 6 months postoperatively. MATERIALS AND METHODS: This retrospective study included 108 patients divided into FNB (70 patients) and ACB (38 patients) groups based on their postoperative pain management methods. Knee joint extensor and flexor strength were measured at 3 and 6 months postoperatively, using BIODEX at angular velocities of 60°/s and 180°/s. From these results, peak torque, limb symmetry index (LSI), peak knee extensor torque (time to peak torque and angle of peak torque), hamstrings-to-quadriceps (HQ) ratio, and amount of work were computed for two-group comparison. RESULTS: There were no statistically significant differences in peak torque, LSI of knee extensor strength, HQ ratio, and amount of work between the two groups. However, maximum knee extension torque at 60°/s occurred significantly later in the FNB than in the ACB group at 3 months postoperatively. Additionally, the LSI of the knee flexor at 6 months postoperatively was significantly lower in the ACB group. CONCLUSIONS: In ACL reconstruction, FNB may delay the time to peak torque for knee extension at 3 months postoperatively, which is likely to improve over the treatment course. In contrast, ACB may result in unexpected loss of knee flexor strength at 6 months postoperatively and should be considered with caution. LEVEL OF EVIDENCE: Level III.

Speed whip ripstop technique during anterior cruciate ligament reconstruction using quadriceps tendon results in higher fixation strength.

PURPOSE: To compare the biomechanical strength of different fixation configurations using a suspensory button in a soft-tissue quadriceps tendon graft for Anterior Cruciate Ligament (ACL) reconstruction. METHODS: Thirty fresh-frozen bovine Achilles tendons (10 mm wide, 50 mm long, and 4 mm thick) were used in this study. Tendons were assigned to three groups (n = 10 per group) with different suture configurations using adjustable loops with a suspensory button: group A, with the threads of an adjustable loop fixed by crossing at the tip of the loop and the entire loop; group B, continuous loops with hanging buttons were directly sutured to the tendon with eight simple sutures; group C, fixation was performed using the speed whip ripstop technique. Tensile tests with five cycles of preloading were performed at 50 N, held at 50 N for 1 min, and load-to-failure testing was conducted until rupture at 5 mm/min. The difference in the elongation and the maximum load-to-failure force were measured. RESULTS: The average elongation was significantly larger in group B (16.6 ± 2.2 mm) than in groups A (10.3 ± 2.4 mm) and C (10.0 ± 1.0 mm), (p < 0.001). The average load-to-failure force varied significantly between the three groups, 157.5 ± 33.4 N in group A, 253.4 ± 45.5 N in group B, and 337.7 ± 21.0 N in group C, (p < 0.001). CONCLUSION: Fixation using the speed whip ripstop technique to fix the suspensory button and soft-tissue transplant tendon resulted in minimal elongation and higher fixation strength. Simple devices that use this method have already been developed. Since it can be fixed using a relatively simple method, speed whip ripstop technique was shown to be advantageous for femoral fixation in ACL reconstruction using soft-tissue quadriceps tendon. The findings of this study could help surgeons reduce graft re-tear rates in ACL reconstruction using quadriceps tendons. LEVEL OF EVIDENCE: N/A, laboratory control study.