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Background Excessive posterior tibial slope in medial unicompartmental knee arthroplasty (UKA) has been implicated in early failure. The purpose of this study was to evaluate the relationship between preoperative posterior tibial slope and postoperative slope of the implant (PSI) on outcomes in patients with anterior cruciate ligament (ACL) intact and ACL-deficient knees after fixed-bearing medial UKA. Methods Patients who underwent a medial UKA between 2002 and 2017 with a minimum 3-year follow-up were included. Preoperative posterior tibial slope and postoperative PSI were measured. Outcomes measures included Knee Injury and Osteoarthritis Outcomes Score (KOOS) subscales, Lysholm, and VR-12. Failure was defined as conversion to total knee arthroplasty. Results Of 241 knees undergoing UKA, 131 patients (70 women, 61 men; average age of 65 ± 10 years (average BMI of 27.9 ± 4) were included. For all patients, survivorship was 98% at 5 years and 96% at 10 years with a mean survival time for UKA was 15.2 years [95% CI: 14.6-15.7]. No failure had a PSI >7°. There were no superficial or deep infections. There were no significant differences in outcome scores between the ACL intact and the ACL-deficient group; therefore, the data were combined for analysis. At mean 8-year follow-up, KOOS pain scores were better in patients with PSI ≤7° (87 ± 16) than those with PSI >7° (81 ± 15). 76% of patients with PSI ≤7° reached the Patient Acceptable Symptom State for KOOS pain; whereas, 59% of patients with PSI >7° reached PASS for KOOS pain (P = .015). Conclusion Patients with postoperative posterior slope of the tibial implant >7° had significantly worse postoperative pain, without conversion to TKA, and with maintenance of high function. In ACL deficient and intact knees, nonrobotically-assisted, fixed-bearing medial UKA had a 96% survivorship at 10 years.

Background The rates of athletic anterior cruciate ligament rupture (ACLRu) and subsequent surgical reconstructions are on the rise. Given the associated sub-optimal return to play (RTP) and re-injury rates, alternative management strategies, such and non-operative management, are being increasingly explored. Research demonstrates that there may be a subset of patients with ACLRu, who will benefit from non-surgical management. Objectives In this case report, we aim to detail the comprehensive management involved in a 26.5-week RTP program for an athlete whose ACLRu was rehabilitated without surgical reconstruction. Clinical features The patient suffered a left knee injury resulting in mild knee pain and effusion, with mild stiffness at the end range of knee flexion. On further examination, a slight left knee strength deficit with positive anterior drawer and Lachman's tests were found consistent with ACLRu, which was confirmed with MRI. Interventions and outcomes The patient was classified as an ACL deficient coper after an initial 8-week conservative rehabilitation approach to the injury. The patient completed their RTP protocol over a total of 26.5 weeks, inclusive of initial strength and neuromuscular control training, a gradual return to restricted non-competitive training, through to competitive unrestricted training and eventual RTP. The RTP was without incident, with the patient achieving sufficient limb strength and power symmetry (>90%), adequate patient-reported outcomes and psychological readiness score before RTP. Conclusion In select sportspeople, the non-operative ACLRu management may represent a viable and accelerated management strategy for successful RTP. However, more detailed guidelines are needed to guide the RTP process.

Objective The process of anterior cruciate ligament (ACL) injury-induced meniscal tear formation is not fully understood. Clinical studies have shown that ACL reconstruction (ACLR) reduces the development of secondary meniscal tears, but it is difficult to gain insight into the protective effects of ACLR from clinical studies alone. Using rat ACL transection (ACLT) and ACLR models, we aimed to reveal (1) the formation process of meniscal tears secondary to ACLT and (2) the protective effects of ACLR on secondary meniscal tears. Design ACLT surgery alone or with ACLR was performed on the knees of rats. Histomorphological and histopathological changes were examined in the posteromedial region of the meniscus in intact rats and in rats that received ACLT or ACLR up to 12 weeks postsurgery. In addition, anterior-posterior joint laxity was measured using the universal testing machine to evaluate the effects of ACLT and ACLR on joint laxity. Results AAnterior-posterior laxity was significantly increased by ACLT compared to the intact knee. This ACLT-induced joint laxity was partially but significantly reduced by ACLR. Meniscal proliferation and hyaline cartilage–like tissue formation were detected in the medial meniscus at 4 weeks post-ACLT. At 12 weeks post-ACLT, hyaline cartilage–like tissue was replaced by ossicles and meniscal tears were observed. These ACLT-induced abnormalities were attenuated by ACLR. Conclusions Our results suggest that ACLT-induced joint laxity induces secondary medial meniscal tears through meniscal proliferation and ossicle formation via endochondral ossification. Joint re-stabilization by ACLR suppresses meniscal proliferation and ossicle formation and consequently prevents secondary meniscal tears.

Consolidated foremost cruciate tendon remaking and average opening wedge high tibial osteotomy can create solid re-visitation of donning action. This system permits patients to recapture a steady knee at right around 10-year follow-up, with a re-visitation of wearing exercises in about 80%. A critical decline in brandishing level is not out of the ordinary, and patient guiding is significant as the preinjury movement level in the objective patient segment is high. The point of this examination was to play out a precise audit of ACL remaking and high tibial valgus osteotomy in the administration of ACL insufficient with varus knee. This survey was finished utilizing standard approach sketched out in the Cochrane Handbook and detailed the discoveries as per the Preferred Reporting Items for Systematic Reviews and Meta-examinations (PRISMA) articulation rules. The writing search were performed utilizing the accompanying hunt terms: ACL reproduction with valgus osteotomy in administration of ACL inadequacy with varus knee. Watchwords: ACL recreation, and Varus knee. This precise survey included 6 examinations Only one investigation was and the others were single armed.We inferred that consolidated front cruciate tendon recreation and average opening wedge high tibial osteotomy is a feasible choice in youthful patients influenced by foremost shakiness, with great midterm results if a right sign, preoperative arranging, and careful method are applied. Also, The bone-patella ligament bone join has a more grounded obsession With the least re tear rate. This joined system gives palatable emotional, unbiased and radiological outcomes, improves the capacity and diminishes the agony.

Introduction: The most common ligament injured in knee is anterior cruciate ligament. This ligament is related to stability, prevention of excessive rotation and forward motion of knee. Accurate reconstruction should be done to achieve excellent functional outcome. Objectives: The main aim was to assess the functional outcome of arthroscopic ACL reconstruction using hamstring tendon auto graft. Also the study intended to describe early weight bearing and early mobilisation and rapid rehabilitation for good clinical recovery after surgery. Methodology: The study was done among 40 subjects who were between 18yrs to 50yrs, with ACL deficient knees, associated menisci injuries. The subjects excluded were having severe co-morbidities, multi ligament injuries and previously operated knee. The Patients were assessed with the IKDC score and single hop test preoperatively and after 6 months. Results: In the study 1 subject didn’t return to pre injury activity level and other 39 came back to pre injury activity level. In the study IKDC score and single hop test after 6 months showed a higher mean in comparison to pre operative evaluation. Conclusion: The technique of ACL reconstruction offers a normal or near normal function and pre and post operative outcome is improved by IKDC score or single hop test

No studies in ACL-D individuals have examined neuromuscular adaptations during landing from a jump where an unexpected mechanical event changes the pre-programmed course of movement. The purpose of this study was to compare pre- and post-landing muscle activation in ACL-D individuals and uninjured controls during normal and surprise landings. Nineteen ACL-D and 17 uninjured volunteered. Participants performed repeated single leg landings from 30 and 15 cm heights. During 15 cm landings, a single surprise landing was performed where participants unexpectedly fell through a false surface at 15 cm to the solid floor a further 15 cm below. Electromyography (EMG) amplitude from vastus lateralis (VL), lateral hamstrings (LH), and soleus (Sol) was recorded. Pre-landing (-60 to 0 ms), post-landing short latency (31-60 ms), and post-landing medium latency (61-90 ms) periods were examined. Comparisons in EMG amplitudes were made across limbs (ACL-D, ACL intact, and control) in 30 cm landings. Additionally, the ratio of EMG amplitude in surprise:30 cm normal landings was analyzed. Post-landing LH EMG was reduced in the ACL-D compared to control limbs at short latencies (P < 0.05). Post-landing VL EMG was reduced in the ACL-D and ACL intact compared to the control limb at both latencies (P < 0.05). Surprise landings notably increased post-landing EMG in all muscles, across all limbs (P < 0.001). However, the gain in VL EMG was significantly greater in ACL-D and ACL intact limbs (P < 0.05). These changes in neuromuscular control of ACL-D individuals during expected and surprise landings may have important implications for rehabilitation, instability, and the risk of secondary injury.

Aim: To compare the functional outcomes of double-bundle anterior cruciate ligament (ACL) reconstruction with and without use of dedicated zig for femoral and tibial tunnel preparation.Materials and Methods: Forty patients with ACL deficient knees fulfilling the inclusion criteria were selected and after careful alternate randomization, twenty each underwent ACL reconstruction surgery with and without using dedicated zig for tibial and femoral tunnel preparation respectively. Post operatively patients were followed up regularly with clinical evaluation based on IKDC (International Knee Documentation Committee) and modified Lysholm’s score and knee stability tests viz. anterior drawer, lachman’s and pivot shift tests. Final evaluation was done at 6 months and results were compared between the two techniques.Results: Forty patients ranging from 18 to 42 years, with mean age of 26.4 years in zig group and 24.6 years in freehand group with complete ACL tear included in study. All cases in both groups were males and sports injury being the most common mode of injury in both groups. Post operatively none of patient shows frank laxity in both groups. Average IKDC and modified Lysholm’s score at 6 month were 74.6/92.2 and 73.67/93.9 respectively. No major complication was noted and functional results were comparable between two groups.Conclusions: Functional results with both techniques are good and comparable and choice depends on surgeon’s skills and preference.

The purpose of the study was to determine the correlation between medial tibial slope (MTS) and anterior tibial translation (ATT) in female patients with an ACL-deficient knee. It was hypothesized that female patients with a greater medial tibial slope had an increased anterior tibial translation compared to males. MTS and ATT were analysed in 276 patients (138 females and 138 males) with a complete ACL rupture from 2012 to 2016. The mean age was 32 ± 12 years. Previous surgery or additional ligament injury was excluded. CT scan was used for measuring MTS. Meniscal findings were reported. Anterior tibial translation and side to side difference (SSD) were measured by bilateral Telos™ stress radiography with knee flexion of 20°. There was no significant difference in ATT between females (5.4 ± 3.9) and males (5.8 ± 4.2), nor was there a difference in MTS between females (9.8 ± 2.8) and males (9.8 ± 2.7). A positive correlation was found between MTS and ATT absolute (r = 0.35, p

The anterolateral ligament (ALL) has been suggested as an important secondary knee restrain on the dynamic laxity in anterior cruciate ligament- (ACL-) deficient knees. Nevertheless, its kinematical contribution to the pivot-shift (PS) phenomenon has not been clearly and objectively defined, and noninvasive sensor technology could give a crucial contribution in this direction. The aim of the present study was to quantify in vitro the PS phenomenon in order to investigate the differences between an ACL-deficient knee and an ACL+ALL-deficient knee. Ten fresh-frozen paired human cadaveric knees ( n = 20 ) were included in this controlled laboratory study. Intact, ACL-deficient, and ACL+ALL-deficient knees were subjected to a manual PS test quantified by a noninvasive triaxial accelerometer (KiRA, OrthoKey). Kinematic data (i.e., posterior acceleration of the tibial lateral compartment) were recorded and compared among the three statuses. Pairwise Student’s t -test was used to compare the single groups ( p < 0.05 ). Intact knees, ACL-deficient knees, and ACL+ALL-deficient knees showed an acceleration of 5.3 ± 2.1 m/s2, 6.3 ± 2.3 m/s2, and 7.8 ± 2.1 m/s2, respectively. Combined sectioning of ACL and ALL resulted in a statistically significant acceleration increase compared to both the intact state ( p < 0.01 ) and the ACL-deficient state ( p < 0.01 ). The acceleration increase determined by isolated ACL resection compared to the intact state was not statistically significant ( p > 0.05 ). The ALL sectioning increased the rotatory laxity during the PS after ACL sectioning as measured through a user-friendly, noninvasive triaxial accelerometer.

Background: The ACL deficient knee is predisposed to anterior translation and internal rotation of the tibia. Hypothesis/Purpose: To show that knee deformity in an ACL deficient knee will produce a more vertical orientation of the lateral collateral ligament (LCL), allowing for the entire length of the LCL to be visualized on a single coronal slice (coronal LCL sign) on MRI, and that this sign is indicative of a greater risk for graft failure after ACL reconstruction. Methods: Charts were retrospectively reviewed to create 3 separate cohorts: normal ACL and no pathology involving the collateral ligaments (control cohort), ACL reconstruction without evidence for graft rupture, and ACL reconstruction with graft failure. Tibial translation and femorotibial rotation were measured on MRI, and posterior tibial slope was measured on lateral knee radiographs. Imaging was reviewed for the presence of the coronal LCL sign. Results: Deficient ACL (n=153) compared with intact ACL (n=70) was associated with significantly greater displacement regarding anterior translation (5.8mm internal rotation vs 0.3mm external rotation, pConclusion: Our study shows that the coronal LCL sign correlates with the presence of an ACL tear and functions as a surrogate for the extent of axial and sagittal deformity. Further, we show that tibia internal rotation and posterior slope are independent predictors of ACL graft failure in adolescents. Whereas, the value of internal rotation could be improved with ACL reconstruction, the presence of the coronal LCL sign persisted over time and was predictive of graft rupture (without the need to make measurements or memorize values of significant risk). [Table: see text][Figure: see text]

» In anterior cruciate ligament (ACL)-deficient knees, treatment of medial compartment osteoarthritis (OA) that is refractory to nonoperative modalities is a controversial subject. » Currently available treatment options include unicompartmental knee arthroplasty (UKA) with or without ACL reconstruction (ACLR), high tibial osteotomy (HTO) with or without ACLR, and total knee arthroplasty (TKA). » Each treatment option has its own risks and benefits, and the evidence that is reviewed in this article suggests that patient characteristics guide treatment selection. » Future high-quality prospective studies that directly compare all 3 of the modalities are necessary to determine the best treatment option for different patient populations.

Background: Correction of high posterior tibial slope is an important treatment option for revision of anterior cruciate ligament (ACL) failure as seen in clinical and biomechanical studies. In cases with moderate to severe medial compartment arthritis, an additional varus correction osteotomy may be added to improve alignment. Purpose: To investigate the influence of coronal and sagittal correction high tibial osteotomy in ACL-deficient and ACL-reconstructed knees on knee kinematics and ACL graft load. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees were selected according to previous computed tomography measurements with increased native slope and slight varus tibial alignment (mean ± SD): slope, 9.9°± 1.4°; medial proximal tibia angle, 86.5°± 2.1°; age, 47.7 ± 5.8 years. A 10° anterior closing-wedge osteotomy, as well as an additional 5° of simulated varus correction osteotomy, were created and fixed using an external fixator. Four alignment conditions—native, varus correction, slope correction, and combined varus and slope correction—were randomly tested in 2 states: ACL-deficient and ACL-reconstructed. Compressive axial loads were applied to the tibia while mounted on a free-moving X-Y table and free-rotating tibia in a knee testing fixture. Three-dimensional motion tracking captured anterior tibial translation (ATT) and internal tibial rotation. Change of tensile forces on the reconstructed ACL graft were recorded. Results: In the ACL-deficient knee, an isolated varus correction led to a significant increase of ATT by 4.3 ± 4.0 mm ( P = .04). Isolated slope reduction resulted in the greatest decrease of ATT by 6.2 ± 4.3 mm ( P < .001). In the ACL-reconstructed knee, ATT showed comparable changes, while combined varus and slope correction led to lower ATT by 3.7 ± 2.6 mm ( P = .01) than ATT in the native alignment. Internal tibial rotation was not significantly altered by varus correction but significantly increased after isolated slope correction by 4.0°± 4.1° ( P < .01). Each isolated or combined osteotomy showed decreased forces on the graft as compared with the native state. The combined varus and slope osteotomy led to a mean decrease of ACL graft force by 33% at 200 N and by 58% at 400 N as compared with the native condition ( P < .001). Conclusion: A combined varus and slope correction led to a relevant decrease of ATT in the ACL-deficient and ACL-reconstructed cadaveric knee. ACL graft forces were significantly decreased after combined varus and slope correction. Thus, our biomechanical findings support the treatment goal of a perpendicular-aligned tibial plateau for ACL insufficiencies, especially in cases of revision surgery. Clinical Relevance: This study shows the beneficial knee kinematics and reduced forces on the ACL graft after combined varus and slope correction.

This study evaluated the relationships between anterior cruciate ligament (ACL) grading using the Oxford classification system and cartilage defects on the medial tibial plateau to clarify the validity of the system. We studied the location and size of a full-thickness cartilage defect of the medial tibial plateau in 154 knees (97 patients) treated by unicompartmental (113) or total (41) knee arthroplasty between April 2017 and January 2018, and analyzed their relationship to the anterior cruciate ligament (ACL) grade, Grade 1 (normal), Grade 2 (synovial damage), Grade 3 (longitudinal split), Grade 4 (friable and fragmented), and Grade 5 (absent). Significant trends in decreased posterior preserved cartilage, increased defect length, and posteriorized defect center were associated with increasing ACL grade. Multiple comparison analysis revealed that the measurements were significantly different between ACL functional (Grades 1–3) and ACL deficient (Grades 4 and 5). On the other hand, the anterior preserved cartilage was consistent among the Grades. The macroscopic Oxford ACL classification system well described the disease progression where the cartilage defect extends posteriorly with ACL damage. However, 38% of ACL deficient knees had well-preserved posterior cartilage with no evident tibial anterior translation.

While recreational running is popular, changes in tibiofemoral contact location after ACL injury can lead to early-onset knee osteoarthritis. Current treatments of bracing and reconstructive surgery do not fully restore tibiofemoral contact to pre-injury locations and, therefore, do not prevent early-onset osteoarthritis. This thesis investigated whether contact could shift back towards healthy, pre-injury locations by modifying a runner’s kinematics. One hundred running styles, with corresponding ground reaction forces, were synthesized using a Principal Component Analysis (PCA)-based regression model constructed from an existing running dataset. Tibiofemoral contact mechanics were estimated using the Concurrent Optimization of Muscle Activations and Kinematics (COMAK) approach with an ACL-deficient musculoskeletal model. Compared with baseline case with unaltered pre-injury kinematics after ACL rupture, several of the synthesized trials reduced deviation on contact relative to a healthy, pre-injury simulation. This study shows that in-vivo investigation should be done to study the effects of kinematics modifications on TF contact.

BACKGROUND: The intercondylar roof line is one of the indicators used during anterior cruciate ligament (ACL) reconstruction to see the relation to the position of the tibial tunnel. The tibial tunnel can be made posteriorly in the anteriorly subluxated tibia. During ACL reconstruction, the tibiofemoral relationship of the opposite or normal knee should be considered. The purpose of this study was to examine the radiographic tibiofemoral relationship of the sagittal plane in a standing position in ACL deficient knees. METHODS: In this study, 64 patients were evaluated for inclusion. Lateral radiographs of the injured and uninjured knee were obtained preoperatively in a standing position. The knee was fully extended with the opposite foot on a step, asking the patients to bear weight fully on one leg. The tibiofemoral relationship was evaluated in the radiographs. RESULTS: The mean value of anterior tibial subluxation was 1.2 mm in the injured side and −1.6 mm in the uninjured side. The tibia was located in a significantly anterior position in the injured knee (p

ACL insufficiency can be caused by different reasons. Elevated posterior tibial slope is a deformity which is discussed to have relevant influence on the outcome of ACL surgery. A increased posterior tibial slope of 12° or more leads to significant more ACL insufficiency. The surgical therapy of this pathology is a high tibial extension osteotomy. Publications ashowing a clinical follow up and results of this surgery are rare. In this video the technique of a closed wedge high tibial extension osteotomy is shown. Osteosynthesis is performed with two screws and an anklestable plate osteosynthesis. An arthroscopy with bone graft filling of the femoral ACL tunnel is performed first, followed by filling of the tibial tunnel in an open approach.Die Insuffizienz des vorderen Kreuzbandes (VKB) kann verschiedene Ursachen haben. Eine relevante knöcherne Deformität, die hier eine Rolle spielen kann, ist eine tibiale Slope-Erhöhung. Nachuntersuchungen großer Kollektive von VKB-Plastiken haben gezeigt, dass eine Erhöhung des posterioren tibialen Slopes auf 12° und mehr zu einem signifikant höheren Risiko für eine VKB-Insuffizienz führt. Die operative Therapie ist die tibiale Extensionsoteotomie. Publikationen zu klinischen Ergebnissen dieser Osteotomien sind bisher rar. Es wird hier die Technik der infratuberositär zuklappenden Tibiakopf-Extensionsosteotomie gezeigt. Die osteosynthetische Versorgung erfolgt mittels 2-facher Zugschraubenosteosynthese sowie additiver winkelstabiler Plattenosteosynthese. Vorgeschaltet ist eine diagnostische Arthroskopie, gefolgt von einer arthroskopischen Auffüllung des femoralen Bohrkanals sowie einer offenen Auffüllung des tibialen Bohrkanals.

The purpose of the current study was to evaluate the correlation between the tibial slope and medial meniscus injury in anterior cruciate ligament deficient knees. A total of 223 patients with primary ACL injury admitted to Foisor Orthopedic Hospital between 2015-2016 were included in this study. The posterior tibial slope was evaluated on a lateral x-ray view of the knee and was defined as the angle between the line joining the tibial plateau and the line perpendicular to the longitudinal axis (the proximal tibial anatomical axis). Patients were divided into two groups depending on the posterior tibial slope ([9.9 and �10), and a Chi square test was used to evaluate if there is any correlation between this and internal meniscus injuries, and Fisher�s exact test was used to verify this. Overall medial meniscus lesions were found in 43.5% of the patients. The mean value of the posterior tibial slope was 11.19+/-2,685. After grouping patients in low and high group ([9.9 and �10), there were 66.8% in the high tibial slope group and 33.2% in the low group. In the high PTS group there were 93 patients with medial meniscus lesion (62.4%), and 56 (37.6%) without medial meniscus lesion. The mean posterior tibial slope was higher in the medial meniscus tear group (11.78 degrees), than mean PTS in the group without medial meniscus lesion (10.42 degrees). There was a strong correlation between high tibial slope and medial meniscus lesions (p=0.015). The main finding of the current study is that there is a statistically significant correlation between posterior tibial slope higher than 10 degrees and internal meniscus tears.

Background The location of the meniscus tear has been reported to influence kinematics in anterior cruciate ligament deficient (ACLD) knees. Medial meniscus posterior horn tear (MMPHT) often occurred after ACL rupture. Whether MMPHT influences the kinematics and kinetics in ACLD knees has not been reported yet. Research question The purpose of this study was to investigate three-dimensional (3D) kinematics and kinetics in ACLD knees with and without MMPHT (ACLD + MMPHT, ACLDs) during level walking. Methods Fifteen patients with isolated unilateral ACLD, ten with unilateral ACLD + MMPHT, and twenty-two healthy controls underwent gait testing between January 2014 and December 2016. Participant characteristics, as well as gait parameters, were compared among control, ACLDs and ACLD + MMPHT knees. Results Compared to the healthy controls, the ACLD knees with and without MMPHT showed significant extension deficiency at maximum extension (flexion: ACLDs: 7.83 ± 4.3°, ACLD + MMPHT: 11.09 ± 7.8°, control: 3.12 ± 4.6°, p = 0.005) and lower extension moments during terminal stance phase of gait. Compared with the healthy controls, significantly increased external tibial rotation during pre-swing phase and lower rotation moments at terminal stance phase were observed in the ACLD + MMPHT knees, but not in the ACLDs knees. No significant differences in gait parameters were observed between ACLDs and ACLD + MMPHT knees during stance phase of walking. Significance The ACLD knees with medial meniscus posterior horn tear exhibited extension deficiency, increased external tibial rotation, lower extension and internal rotation moments during the terminal stance phase compared to healthy control knees, presenting a combination of “stiffening gait” and “pivot shift gait” pattern. The ACLDs knees only presented extension deficiency and lower extension moments compared with healthy control knees, presenting a “stiffening gait”. Medial meniscus posterior horn tear did not significantly affect gait patterns during stance of walking in ACLD knees.

Arthroscopic anterior cruciate ligament reconstruction is standard procedure for ACL deficient knee with episodic or recurrent knee instability. Two described techniques one is transtibial and another one transportal (anteromedial portal) for femoral tunnel formation in Anterior cruciate ligament reconstruction are described. Present study is to identify differences in functional outcome and surgical analysis between both techniques in single bundle anterior cruciate ligament reconstruction with quadrupled semitendinosus and gracilis graft.

Maintaining anterolateral rotational stability of the knee requires a complex set of structures, most notably the anterior cruciate ligament. However, lateral knee structures such as the anterolateral ligament (ALL) also play an important role. There has been controversy over the role the ALL plays in an ACL deficient knee to maintain rotational stability. In this study, we examined ACL deficient knees with and without intact ALLs, for rotatory laxity using a pivot shift examination. This was graded using International Knee Document Committee (IKDC) criteria. MRI was used to view the ALL and its status. We found no statistically significant difference in rotational stability of ACL deficient knees, with or without intact ALLs. We did however find a statistically significant association between injury to the ALL and other concomitant lateral structures such as the lateral collateral ligament, biceps femoris tendon, and iliotibial band. This supports that the ALL works in concert with the other lateral structures in the knee and the ACL, to provide rotational stability. This suggests that as an isolated structure, the ALL's contribution to clinical rotational stability is not significant, even in the presence of an ACL tear.

Background Increased tibial slope has been shown to be associated with higher anterior cruciate ligament (ACL) reconstruction failure rate. Little is known about the correlation of tibial slope and anterior tibial translation in ACL deficient and reconstructed knees as well as the correlation of tibial slope and ACL reconstruction outcome. Purpose/Hypothesis The purpose of this study was to investigate the correlation of tibial slope with anterior tibial translation and ACL reconstruction outcome. It is hypothesized that increased medial tibial slope is associated with increased anterior tibial translation in the ACL deficient knee. Medial tibial slope is neither expected to affect anterior tibial translation in the ACL reconstructed knee nor short-term ACL reconstruction outcome. Materials and Methods A cohort of 104 patients with unilateral isolated ACL deficiency undergoing hamstring ACL reconstruction by a single surgeon between 2002 and 2004 was followed up prospectively. Preoperative data were collected including patient demographics, time to surgery, subjective and objective International Knee Documentation Committee (IKDC) outcome scores, as well as manual maximum anterior tibial translation measured with the KT-1000 measuring instrument. Medial tibial slope was assessed on long lateral X-rays using the method described by Dejour and Bonnin (1994). Intraoperative data were collected including meniscal integrity; postoperative data were collected at 1-year follow-up including manual maximum anterior tibial translation (KT-1000 measured), and subjective and objective IKDC scores. Results A significant positive correlation was seen between medial tibial slope in ACL deficient knees and KT-1000–measured anterior tibial translation (r = 0.24; p = 0.003). The positive relationship increased when meniscal integrity was factored in (r = 0.33; p Conclusion Increased medial tibial slope is associated with increased (KT-1000 measured) anterior tibial translation in ACL deficient knees. No significant correlation is found between increased medial tibial slope and poor short-term ACL reconstruction outcome.

Objective To determine the relationship between preoperative static knee joint laxity and non-invasive quantitative pivot shift (QPS) in patients with anterior cruciate ligament (ACL) rupture. Methods Patients with an ACL injury participating in a multicentre trial were analysed if they had complete preoperative data on the following laxity tests: the rolimeter, the KT-1000 (134 N and manual maximum force), the Lachman, the anterior drawer and QPS. The QPS was assessed via a non-invasive inertial sensor system and an image analysis system for tibial acceleration and lateral tibial translation, respectively. Awake examination and examination under anaesthesia (EUA) were performed. Correlation between absolute values of static laxity and the QPS for each leg was assessed by Spearman’s rho. The Lachman and the anterior drawer were dichotomised into low- and high-grade, and differences between the groups in terms of continuous values of QPS were assessed. Results A total of 58 patients were included (41.4% women, mean age 27.1±9.8 years). Awake static laxity and QPS acceleration were negatively correlated in the ACL-deficient knee, meaning that a greater acceleration correlated to a lesser static tibial translation, and vice versa. The mean QPS acceleration correlated with the static tests as follows: the rolimeter r=−0.30 (P=0.024), the KT-1000 134 N r=−0.25 (P=0.06) and the KT-1000 manual maximum r=−0.37 (P=0.004). A negative correlation between awake QPS acceleration and the static tests was also shown for the non-involved knee. Patients with a high-grade Lachman’s test in the EUA had significantly greater QPS acceleration (P=0.0002) and QPS translation (P Conclusion Static anteroposterior and dynamic knee laxities, as presented by QPS, are poorly correlated in the ACL-deficient knee and should therefore be considered as separate entities of the knee examination. These findings strengthen the implementation of non-invasive technology for quantification of the pivot shift when establishing treatment algorithms for ACL reconstruction. Level of evidence Level III, prospective cohort.

CONTEXT: Anterior cruciate ligament (ACL) reconstruction has remained the gold standard for ACL injuries, especially for young individuals and athletes expose to high-level sporting activities aiming to return preinjury level of activity. Femoral cortical suspension devices have gained popularity. However, there are limited studies specifying a superior graft fixation technique. AIMS: To evaluate outcome of arthroscopic ACL reconstruction using fixed closed loop fixation (CLF) and adjustable loop fixation (ALF) techniques. SETTINGS AND DESIGN: Prospective case series. MATERIALS AND METHODS: 40 cases were included in the study, among of which 20 cases, underwent arthroscopic CLF and another group of 20, who were operated on using ALF. Clinical outcome was assessed using manual tests, i.e., Lachman and pivot shift, and results were graded using the International Knee Documentation Committee. Lysholm score was used to evaluate functional outcome up to 6 months. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS version 21. RESULTS: There were no significant differences in manual Lachman and pivot shift grading in both groups. One case (5%) in CLF group and 15% in ALF group were showed Grade B clinically laxity by Lachman, and one case (5%) in CLF group and 10% in ALF group were showed Grade 2 + rotatory laxities by pivot shift. The study found no statistically significant differences in functional score between the groups (P = 0.245). CONCLUSIONS: In femoral fixation of ACL graft both CLF and ALF techniques may provide secure fixation, equal reduction of graft laxity, and similar functional outcome in ACL deficient knee.

The anterior cruciate ligament (ACL) is not only a mechanical structure for knee joint stability but is also a source of sensory information which could be used in the control of standing posture. It has been shown that the center of pressure (COP) time series during normal standing may be decomposed into two components which are hypothetically governed by different neural mechanisms, namely rambling and trembling. The aim of the present study was to investigate to what extent an injury to the ACL structure would affect these two control mechanisms. In this study the balance of a group of ACL deficient (ACLD) patients during double and single leg standing was examined and compared with that of a group of healthy individuals. We not only calculated the traditional measures of COP, but also decomposed this complex signal to investigate if ACL deficiency would affect the rambling and trembling components differently. The results showed that rambling was not significantly different between the two groups; however the trembling component was significantly greater for the ACLD group in both the single leg and the double leg condition. Further, there was also a component (rambling/trembling) by direction (anterior-posterior/mediolateral) interaction for both groups, indicating that the rambling component exhibited differences between directions of sway whereas the trembling component did not. This study provided evidence that the two components of postural control are differently affected by ACL deficiency, and that the rambling component is influenced by direction of sway.

The anterior cruciate ligament (ACL) deficient knee has been subjected to various research and many conclusionshave been drawn to the loss of function in relation to it. ACL reconstruction is also very commonly done asthis ligament damage is the most common injury in sports. Muscle strength and proprioception have beenpostulated to be affected alongside this injury. We conducted a cross sectional study in 19 patients who haveruptured their ACL. We measured their muscle strength, thigh muscle bulk and proprioception in comparisonto their contralateral normal knee. The Biodex Isokinetic machine was used to measure the muscle strengthand proprioception. The thigh circumference was measured manually using a measuring tape. There wassignificant reduction of muscle strength and thigh circumference in the ACL deficient limb as compared to thenormal side, p

Anteroposterior knee joint laxity because of anterior cruciate ligament (ACL) insufficiency produces various degenerative changes in the joint, including intra-articular damage, meniscal tears and varus morphology leading to gradual thinning of the cartilage and resulting in posteromedial osteoarthritis (OA). Two different scenarios of medial OA and ACL tear need to be identified to ensure correct surgical planning and minimise the risk of poor surgical outcome. OA development of the medial compartment of the knee may be due to ACL failure or the ACL failure can be a consequence of the arthritic phenomenon within the knee. One of the most important causes of failure in unicompartmental knee arthroplasty (UKA) surgery is the absence of ACL and the majority of failures after UKA without ACL reconstruction occur because of tibial loosening, which tends to occur early. Patients eligible for combined UKA and ACL reconstruction are typically young adults with a history of previous trauma and untreated ACL rupture, joint instability, and consequent OA of the posteromedial part of the knee. In order to obtain a correct diagnosis, a detailed medical history, complete physical examination and detailed radiographic protocol are mandatory. ACL reconstruction combined with UKA is a technically demanding procedure and must be performed in well-defined steps. A significantly higher failure rate was noted in patients who did not undergo ACL reconstruction as compared with those who received a combined procedure. Unicompartmental knee arthroplasty combined with ACL reconstruction is an excellent surgical solution for posteromedial osteoarthritis secondary to ACL deficiency.

Purpose Posterior tibial slope (PTS) is a bony factor contributing to the anteroposterior stability of knee. It is believed that increased PTS has been associated with ACL injury. The aim of this study is to identify an increased posterior tibial slope as a possible risk factor for ACL injury in Indian population. Methods Prospective case control study was conducted in Bajaj orthopaedic sports clinic, Delhi. 55 patients were included, in which 27 patients with ACL tear were included in case group “A” and remaining 28 patients with intact ACL in control group “B”. Inclusion criteria: Age – 15–55 years, group “A” – patient diagnosed with ACL tear clinically and radiologically on MRI knee and presented within 3 months of injury, group “B” – patient with intact ACL and got their MRI knee done for other knee pathologies. Exclusion criteria: Age >55 years, poor quality MRI, advanced osteoarthritis classified as >grade 2 in Outerbridge classification, multiple ligamentous instability, non-Indian and Patient with ACL tear presenting >3 months after injury. Using MRI, PTS was calculated and compared individually for medial and lateral tibial condyle. Results The average PTS in case group was 3.95 and 4.74 for medial and lateral tibial condyle respectively. PTS in control group was less than case group with mean value of 0.03 and −0.38 for medial and lateral condyle respectively with statistically significant outcomes (p value Conclusion In Indian population, increased PTS can be concluded as a significant risk factor in ACL injury. Though, posterior tibial slope cannot be considered as an isolated risk factor.

Background Anterior cruciate ligament (ACL) reconstruction is a very common arthroscopic surgery. All around the world the commonest autograft preferred is hamstring tendon. Present trend is more in favor of retaining the native ACL stump as the available neuroreceptors in the stump might help in early recovery of proprioception after ACL reconstruction. Methods This is a prospective study done on 56 cases. We took biopsy samples from knee joints of patients who had undergone arthroscopic ACL reconstruction at our hospital from native ACL stump as well as the graft (Semitendinosus) and sent them for immunohistological examination using S-100 Protein and NFP (Neural filament protein). Results Chronicity of ACL deficient knee’s (injury to surgery more than 6 months) revealed poor positivity for neuroreceptors in sample A. After 3 months of injury there was a gradual decrease in positivity for neuroreceptors with persistence of these neural elements upto 6 months within remnant ACL stump. Conclusion The results suggest that complete or partial ACL tears should be addressed by early arthroscopic ACL reconstruction using remnant-preserving technique, as the number of mechanoreceptors gradually deteriorates with time following injury.

» Injuries to the posterior root of the lateral meniscus occur frequently in acute knee injuries with concomitant tearing of the anterior cruciate ligament (ACL). » The meniscofemoral ligaments (MFLs), consisting of the anterior MFL (ligament of Humphrey) and the posterior MFL (ligament of Wrisberg), as well as the osseous attachment of the meniscal root, stabilize the lateral meniscus, enabling appropriate load transmission and maintenance of contact forces within the lateral compartment of the knee during loading and range of motion. » In the setting of an ACL injury to the knee with osseous root injury of the posterior root of the lateral meniscus, the MFLs (when present) may stabilize the lateral meniscus against meniscal extrusion, thereby maintaining appropriate contact mechanics within the knee, decreasing the risk of subsequent chondral and meniscal injury and the development of premature osteoarthritis. » Additional study on the indications for posterior meniscal root repair during ACL reconstruction is warranted since the ideal management of lateral root injury in the MFL-intact knee remains unknown.

The purpose of this study was to clarify the relationship between knee biomechanics and clinical assessments in ACL deficient patients. Subjects included 22 patients with unilateral ACL rupture and 22 healthy controls. Knee kinematics and kinetics during walking and running were examined using a 3-dimensional motion analysis system. The passive knee joint laxity, range of motion of knee joint, and knee muscle strength were also measured. Correlations between the knee kinematic and kinetic data and clinical assessments were evaluated. In the ACL deficient patients, there were no significant relationships between tibial translation during walking and running and passive knee joint laxity. The correlations between knee kinematics and kinetics and range of motion of knee joint were also not significant. Additionally, there were no significant correlations between knee kinematics during walking and knee muscle strength. However, there were several significant correlations between knee kinematics during running and knee muscle strength. The results demonstrate the importance of knee muscle strength for knee kinematics and kinetics during running in ACL deficient patients. Patients with stronger knee muscle strength may demonstrate more nearly normal knee joint movement during dynamic activities such as running.

Meniscal tears are common concomitant injuries seen in up to 65% of anterior cruciate ligament (ACL) deficient knees. The goal of ACL reconstruction (ACL-R) is to restore mechanical stability to the knee and to prevent further damage to the menisci, which act as secondary knee stabilizers for both anterior-posterior translation and rotational laxity. Delayed ACL-R and chronic ACL insufficiency have been associated with secondary meniscal tears that are more likely to be complex tears. Excluding graft failure, another common cause of reoperation in ACL reconstructed knees is meniscal surgery. Therefore, addressing meniscal tears at time of primary ACL-R is important to restore joint mechanics, protect the ACL graft for successful healing, and prevent long-term osteoarthritis. Current management options include leaving tears in-situ, meniscectomy, or meniscus repair. However, inconsistent findings have identified the need for well-defined treatment recommendations. Surgical decision making is reliant upon multiple factors such as adequate understanding of meniscal anatomy, biomechanics, tear pattern, and patient factors. This review focuses on the impact of meniscus injuries in ACL deficient knees and addresses current surgical indications and outcomes.

PURPOSE: Little is known regarding movement strategies in the long term following injury of the anterior cruciate ligament (ACL), and even less about comparisons of reconstructed and deficient knees in relation to healthy controls. The present purpose was to compare trunk, hip, and knee kinematics during a one-leg vertical hop (VH) ~20 years post-ACL injury between persons treated with surgery and physiotherapy (ACLR), solely physiotherapy (ACLPT), and controls (CTRL). Between-leg kinematic differences within groups were also investigated. METHODS: Sixty-six persons who suffered unilateral ACL injury on average 23 ± 2 years ago (32 ACLR, 34 ACLPT) and 33 controls performed the VH. Peak trunk, hip, and knee angles during Take-off and Landing phases recorded with a 3D motion capture system were analysed with multivariate statistics. RESULTS: Significant group effects during both Take-off and Landing were found, with ACLPT differing from CTRL in Take-off with a combination of less knee flexion and knee internal rotation, and from both ACLR and CTRL in Landing with less hip and knee flexion, knee internal rotation, and greater hip adduction. ACLR also presented different kinematics to ACLPT and CTRL in Take-off with a combination of greater trunk flexion, hip flexion, hip internal rotation, and less knee abduction, and in Landing with greater trunk flexion and hip internal rotation. Further, different kinematics and hop height were found between legs within groups in both Take-off and Landing for both ACL groups, but not for CTRL. CONCLUSION: Different kinematics for the injured leg for both ACL groups compared to CTRL and between treatment groups, as well as between legs within treatment groups, indicate long-term consequences of injury. Compensatory mechanisms for knee protection seem to prevail over time irrespective of initial treatment, possibly increasing the risk of re-injury and triggering the development of osteoarthritis. Detailed investigation of movement strategies during the VH provides important information and a more comprehensive evaluation of knee function than merely hop height. More attention should also be given to the trunk and hip in clinics when evaluating movement strategies after ACL injury. LEVEL OF EVIDENCE: Prospective cohort study, Level II.

The aim of this study was to quantify how abnormal dynamic tibiofemoral surface alignment affects the load bearing function of menisci in vivo. Using a sheep model of ACL deficiency, we tested the hypothesis that increased in vivo meniscal loads correlate with greater tibiofemoral surface alignment abnormality. Stifle kinematics were recorded using a bone-mounted instrumented spatial linkage in four sheep before, and at four and twenty weeks (w) after ACL transection. A parallel robotic manipulator was used to quantify stifle kinetics by reproducing each animal׳s in vivo kinematics and measuring tissue loads during gait. Meniscal resultant loads were estimated from the change in joint reaction force after sequentially removing load-bearing tissues. Tibiofemoral subchondral surfaces were then traced and modeled using thin plate splines. Proximity disturbance is a surface interaction measure used to quantify dynamic tibiofemoral surface alignment abnormality. ACL transection increased meniscal loads by 30-145% at 20w post-ACL transection, whereas the degree of dynamic tibiofemoral subchondral surface alignment varied between sheep. Positive and significant correlations between increased meniscal loads and proximity disturbance values >10mm were observed (R2=0.04-0.57; p≤0.05). Our results suggest that the proximity disturbance measure reflects abnormal meniscal loads following ACL injury; however given the range of R2 values, perturbations in dynamic tibiofemoral subchondral surface alignment do not explain abnormal joint kinetics entirely, and point to the presence of other dynamic compensatory mechanisms that may have a significant bearing on in vivo joint function and long-term joint health.

Some patients have continued rotatory instability following intra-articular anterior cruciate ligament (ACL) reconstruction, which limits their functional abilities. Advanced surgical techniques, such as double-bundle reconstruction and anteromedial portal drilling, have not solved this problem. This has led many surgeons to revisit the use of extra-articular procedures to control rotatory laxity. Multiple anatomic studies have confirmed the presence of an anterolateral ligament (ALL) that attaches to the tibia at the site of the Segond fracture. The biomechanical importance of this ligament is still being debated. Extra-articular reconstructions decrease the forces produced by intra-articular ACL grafts. Patients likely to benefit from additional extra-articular reconstruction are: (1) those with high-grade pivot shifts; (2) patients with previous failed ACL reconstructions without an obvious cause; (3) participants in contact sports and (4) patients in subgroups that have a high risk of failure (eg, generalised laxity). A variety of extra-articular reconstructions have been developed. Those techniques that have long-term follow-up data were described before most current orthopaedic surgeons were in practice. The available evidence suggests that performing an additional extra-articular reconstruction can improve rotational stability in patients undergoing intra-articular ACL reconstructions. Newer ‘anatomic' reconstructions of the ALL have recently been proposed but there are limited data on their effectiveness. Currently, there are no studies comparing different extra-articular procedures.

The purpose of this study was to evaluate the correlation between tibial acceleration parameters measured by the KiRA device and the clinical grade of pivot shift. The secondary objective was to report the risk factors for pre-operative high-grade pivot shift.Two-hundred and ninety-five ACL deficient patients were examined under anesthesia. The pivot shift tests were performed twice by an expert surgeon. Clinical grading was performed using the International Knee Documentation Committee (IKDC) scale and tibial acceleration data was recorded using a triaxial accelerometer system (KiRA). The difference in the tibial acceleration range between injured and contralateral limbs was used in the analysis. Correlation coefficients were calculated using linear regression. Multivariate logistic regression was used to identify risk factors for high grade pivot shift.The clinical grade of pivot shift and the side-to-side difference in delta tibial acceleration determined by KiRA were significantly correlated (r = 0.57; 95% CI 0.513-0.658, p 0.0001). The only risk factor identified to have a significant association with high grade pivot shift was an antero-posterior side to side laxity difference 6 mm (OR = 2.070; 95% CI (1.259-3.405), p = 0.0042).Side-to-side difference in tibial acceleration range, as measured by KiRA, is correlated with the IKDC pivot shift grade in anaesthetized patients. Side-to-side A-P laxity difference greater than 6 mm is reported as a newly defined risk factor for high grade pivot shift in the ACL injured knee.Level II.

Purpose The aim of the current study was (1) to provide an overview of common definitions and classification systems of ramp lesions (RL) and (2) to systematically review the available literature with regard to the diagnosis and treatment of RLs in anterior cruciate ligament (ACL)-deficient knees. Methods Following the PRISMA guidelines, MEDLINE and Scopus were searched for articles (1) reporting on acute or chronic ACL injuries, (2) with concomitant medial meniscus injury, (3) located at the posterior meniscocapsular attachment site (and red–red zone). Ex vivo studies, reviews and technical notes were excluded. Results Twenty-seven studies were included based on the criteria mentioned above. RLs are common in ACL-deficient knees with a prevalence ranging from 9 to 24%. RLs should especially be suspected in younger patients, patients with an increased meniscal slope and in patients with prolonged time from injury to surgery. The sensitivity of MRI for the detection of RLs ranges from 48 to 86% at a specificity of 79–99%. For arthroscopy, RLs are easily missed through standard anterior portals (sensitivity 0–38%). RL repair leads to a significant improvement of subjective knee scores, regardless of the specific fixation technique. For stable RLs, the literature suggests equivalent postoperative stability for trephination and abrasion compared to surgical RL repair. Conclusion Ramp lesions are frequently missed in ACL-deficient knees on standard arthroscopy with anterior portals only. If a RL is suspected, exploration via an additional posteromedial portal is indicated. In case of instability, RL repair should be performed. Level of evidence IV.

Bilateral ACL rupture is a relatively uncommon injury with an incidence of 2-4%. Most bilateral ACL rupture occurs at two different times, but few cases of single-staged bilateral ACL ruptures have also been reported. There have been reports of both single-staged, and two-staged reconstruction of bilateral ACL ruptures in the literature but without a clear consensus. We present a series of five bilateral ACL rupture cases managed by single-staged arthroscopic ACL reconstruction, using quadrupled hamstring grafts. All of them were young males, with an average age of 26.8 years (Range: 19-39 years). Three out of five of these cases (60%) had sustained the injury to both the knees simultaneously while playing sports. All the five patients had generalized joint laxity with significant hyperextension of their knees. All the ten knees (in five patients) were clinically stable, at their last follow-ups. None of the knees had any early or late complications. A single-staged bilateral ACL reconstruction is a safe, reproducible, and cost-effective procedure for patients with a bilateral ACL deficient knee, in experienced hands.

Background: There is increasing evidence that motor imagery performance (MIP) is impaired in conditions that have a component of movement dysfunction. However, MIP has not been investigated in people with chronic anterior cruciate ligament (ACL) deficiency who experience limited disability and function at high levels. Hypothesis: This study had three objectives: (1) to assess implicit MIP in individuals with a chronic ACL deficient (ACLD) knee compared with healthy controls (i.e., intact anterior cruciate ligament); (2) to determine if the location of ACL deficiency affects MIP (dominant versus non-dominant leg); and (3) to determine if impairment in MIP is specific to the side (injured versus non-injured) of ACL deficiency. Methods: Forty-five participants with chronic ACLD knee and 44 healthy controls completed a left/right judgement task of pictured knees using the “Recognise” app to evaluate implicit MIP. Accuracy and reaction time of judgements were compared between groups. Additionally, within the chronic ACLD knee group, we made comparisons between the dominant ACLD knee and non-dominant ACLD knee subgroups and between the injured knee and the non-injured knee of the ACLD group. Results: There were no differences in implicit MIP between the ACLD knee and the control group, the non-injured knee versus injured knee of the ACLD knee group, or the dominant ACLD knee versus non-dominant ACLD knee subgroups. Conclusion: Implicit MIP is not disrupted in high functioning individuals with chronic ACLD knee. Refereed/Peer-reviewed

The outcome of single-bundle anterior cruciate ligament (ACL) reconstruction depends largely on the anatomic placement of bone tunnel. The lateral intercondylar ridge (LIR) and bifurcate ridge (BR) are useful bony landmarks for femoral tunnel placement. The purpose of our study was to compare the bony landmarks of ACL footprint on femur by three-dimensional computed tomography (3D CT) scan and arthroscopy in chronic ACL-deficient knees. Fifty patients above 18 years of age who were diagnosed of having ACL tear were selected for the study. All the cases were more than 6 months old since the injury. Preoperative 3D CT scan of the affected knee was obtained for each of them. They underwent single-bundle anatomic ACL reconstruction. Measurements were done on the preoperative 3D CT and arthroscopy to quantify the position of the LIR and BR. The proximodistal distance of lateral femoral condyle was 21.41+/−2.5 mm on CT scan and 22.02+/−2.02 mm on arthroscopy. On preoperative 3D CT scan, the midpoint of the LIR was found to be located at a mean distance of 11.17±2.11 mm from the proximal margin of the lateral femoral condyle. On arthroscopy, it was at 10.18+/−1.52 mm from the proximal margin the lateral femoral condyle. The “bifurcate ridge”(BR) was not visible in any of the cases during arthroscopy or CT scan. We concluded that LIR is an easily identifiable bony landmark on arthroscopy in all cases. It can also be identified on CT scans. BR is not identified both on arthroscopy and CT scans in chronic ACL tears. The arthroscopic measurements of bony landmarks are quite close to those of CT scan. Midpoint of LIR is at 52.185% of the proximodistal distance on CT scan evaluation and it is at 46.21% on arthroscopic evaluation.

Background: Ramp lesions were initially defined as a tear of the peripheral attachment of the posterior horn of the medial meniscus at the meniscocapsular junction. The separate biomechanical roles of the meniscocapsular and meniscotibial attachments of the posterior medial meniscus have not been fully delineated. Purpose: To evaluate the biomechanical effects of meniscocapsular and meniscotibial lesions of the posterior medial meniscus in anterior cruciate ligament (ACL)–deficient and ACL-reconstructed knees and the effect of repair of ramp lesions. Study Design: Controlled laboratory study. Methods: Twelve matched pairs of human cadaveric knees were evaluated with a 6 degrees of freedom robotic system. All knees were subjected to an 88-N anterior tibial load, internal and external rotation torques of 5 N·m, and a simulated pivot-shift test of 10-N valgus force coupled with 5-N·m internal rotation. The paired knees were randomized to the cutting of either the meniscocapsular or the meniscotibial attachments after ACL reconstruction (ACLR). Eight comparisons of interest were chosen before data analysis was conducted. Data from the intact state were compared with data from the subsequent states. The following states were tested: intact (n = 24), ACL deficient (n = 24), ACL deficient with a meniscocapsular lesion (n = 12), ACL deficient with a meniscotibial lesion (n = 12), ACL deficient with both meniscocapsular and meniscotibial lesions (n = 24), ACLR with both meniscocapsular and meniscotibial lesions (n = 16), and ACLR with repair of both meniscocapsular and meniscotibial lesions (n = 16). All states were compared with the previous states. For the repair and reconstruction states, only the specimens that underwent repair were compared with their intact and sectioned states, thus excluding the specimens that did not undergo repair. Results: Cutting the meniscocapsular and meniscotibial attachments of the posterior horn of the medial meniscus significantly increased anterior tibial translation in ACL-deficient knees at 30° ( P ≤ .020) and 90° ( P < .005). Cutting both the meniscocapsular and meniscotibial attachments increased tibial internal (all P > .004) and external (all P < .001) rotation at all flexion angles in ACL-reconstructed knees. Reconstruction of the ACL in the presence of meniscocapsular and meniscotibial tears restored anterior tibial translation ( P > .053) but did not restore internal rotation ( P < .002), external rotation ( P < .002), and the pivot shift ( P < .05). To restore the pivot shift, an ACLR and a concurrent repair of the meniscocapsular and meniscotibial lesions were both necessary. Repairing the meniscocapsular and meniscotibial lesions after ACLR did not restore internal rotation and external rotation at angles >30°. Conclusion: Meniscocapsular and meniscotibial lesions of the posterior horn of the medial meniscus increased knee anterior tibial translation, internal and external rotation, and the pivot shift in ACL-deficient knees. The pivot shift was not restored with an isolated ACLR but was restored when performed concomitantly with a meniscocapsular and meniscotibial repair. However, the effect of this change was minimal; although statistical significance was found, the overall clinical significance remains unclear. The ramp lesion repair used in this study failed to restore internal rotation and external rotation at higher knee flexion angles. Further studies should examine improved meniscus repair techniques for root tears combined with ACLRs. Clinical Relevance: Meniscal ramp lesions should be repaired at the time of ACLR to avoid continued knee instability (anterior tibial translation) and to eliminate the pivot-shift phenomenon.

The purpose of this study was to investigate the isokinetic, eccentric and isometric hamstring/quadriceps (HQ) ratios in patients before and after ACL reconstruction (ACLR) using bone–patellar tendon grafts and to establish the relationships between HQ ratio and knee function. Forty-four patients (mean age of 26.6 years) underwent isokinetic testing of quadriceps and hamstring muscles before and after ACLR and HQ ratios were calculated. Lysholm, IKDC and Cincinnati Scores were used to assess function. Isokinetic concentric and eccentric peak torque (Nm/kg) was measured at three different speeds: 60, 120, and 180°/s. Isometric strength was tested at 30° and 60° of knee flexion. For the isometric tests, the HQ ratio between the involved and non-involved limb was not different for the ACLD knee (p = 0.28) at 30° knee flexion, but significant at the 60° flexion angle (p = 0.02) and for the ACLR knees at 30° and 60° (p = 0.02). For the isokinetic tests, the ratio between involved and non-involved limb was significant for ACL-deficient knees at both 60 (p = 0.039) and 120°/s (p = 0.05). There were significant differences between limbs for all speeds in ACLR knees (p = 0.0003–0.01). For the eccentric tests, the HQ ratio between the involved and non-involved limbs was not significant for both the ACLD (p = 0.19) and ACLR knees (p = 0.29) at the speed of 60°/s. At 120 and 180°/s, there were significant differences between limbs for both the ACLD (p = 0.02) and ACLR knees (p = 0.003). Linear regression did not reveal significant relationships between Cincinnati, Lysholm, and IKDC scores and HQ ratios in the ACLD (R2 = 0.35, p = 0.58; R2 = 0.34, p = 0.63; R2 = 0.38, p = 0.49). In contrast, there were significant correlations between the Lysholm and IKDC scores and HQ ratios in the ACLR knees (R2 = 0.84, p = 0.002; R2 = 0.86, p = 0.001). The findings of this study suggest that the HQ ratio in ACLD patients was not a predictor, but an indicator of patient-perceived knee function following ACLR. Level IV, case series.