Posterior cruciate ligament

Purpose: Because a strong and stable knee is paramount to an athlete's or patient's success, an understanding of knee biomechanics while performing the squat is helpful to therapists, trainers, sports medicine physicians, researchers, coaches, and athletes who are interested in closed kinetic chain exercises, knee rehabilitation, and training for sport. The purpose of this review was to examine knee biomechanics during the dynamic squat exercise. Methods: Tibiofemoral shear and compressive forces, patellofemoral compressive force, knee muscle activity, and knee stability were reviewed and discussed relative to athletic performance, injury potential, and rehabilitation. Results: Low to moderate posterior shear forces, restrained primarily by the posterior cruciate ligament (PCL), were generated throughout the squat for all knee flexion angles. Low anterior shear forces, restrained primarily by the anterior cruciate ligament (ACL), were generated between 0 and 60°knee flexion. Patellofemoral compressive forces and tibiofemoral compressive and shear forces progressively increased as the knees flexed and decreased as the knees extended, reaching peak values near maximum knee flexion. Hence, training the squat in the functional range between 0 and 50°knee flexion may be appropriate for many knee rehabilitation patients, because knee forces were minimum in the functional range. Quadriceps, hamstrings, and gastrocnemius activity generally increased as knee flexion increased, which supports athletes with healthy knees performing the parallel squat (thighs parallel to ground at maximum knee flexion) between 0 and 100°knee flexion. Furthermore, it was demonstrated that the parallel squat was not injurious to the healthy knee. Conclusions: The squat was shown to be an effective exercise to employ during cruciate ligament or patellofemoral rehabilitation. For athletes with healthy knees, performing the parallel squat is recommended over the deep squat, because injury potential to the menisci and cruciate and collateral ligaments may increase with the deep squat. The squat does not compromise knee stability, and can enhance stability if performed correctly. Finally, the squat can be effective in developing hip, knee, and ankle musculature, because moderate to high quadriceps, hamstrings, and gastrocnemius activity were produced during the squat.

Purpose: Because a strong and stable knee is paramount to an athlete's or patient's success, an understanding of knee biomechanics while performing the squat is helpful to therapists, trainers, sports medicine physicians, researchers, coaches, and athletes who are interested in closed kinetic chain exercises, knee rehabilitation, and training for sport. The purpose of this review was to examine knee biomechanics during the dynamic squat exercise. Methods: Tibiofemoral shear and compressive forces, patellofemoral compressive force, knee muscle activity, and knee stability were reviewed and discussed relative to athletic performance, injury potential, and rehabilitation. Results: Low to moderate posterior shear forces, restrained primarily by the posterior cruciate ligament (PCL), were generated throughout the squat for all knee flexion angles. Low anterior shear forces, restrained primarily by the anterior cruciate ligament (ACL), were generated between 0 and 60°knee flexion. Patellofemoral compressive forces and tibiofemoral compressive and shear forces progressively increased as the knees flexed and decreased as the knees extended, reaching peak values near maximum knee flexion. Hence, training the squat in the functional range between 0 and 50°knee flexion may be appropriate for many knee rehabilitation patients, because knee forces were minimum in the functional range. Quadriceps, hamstrings, and gastrocnemius activity generally increased as knee flexion increased, which supports athletes with healthy knees performing the parallel squat (thighs parallel to ground at maximum knee flexion) between 0 and 100°knee flexion. Furthermore, it was demonstrated that the parallel squat was not injurious to the healthy knee. Conclusions: The squat was shown to be an effective exercise to employ during cruciate ligament or patellofemoral rehabilitation. For athletes with healthy knees, performing the parallel squat is recommended over the deep squat, because injury potential to the menisci and cruciate and collateral ligaments may increase with the deep squat. The squat does not compromise knee stability, and can enhance stability if performed correctly. Finally, the squat can be effective in developing hip, knee, and ankle musculature, because moderate to high quadriceps, hamstrings, and gastrocnemius activity were produced during the squat.

Objectives To report clinical and functional outcomes following Wxation of tibial posterior cruciate ligament (PCL) avulsion fractures through Burks and SchaVer's approach when combined with a rehabilitation programme, which emphasizes early range of motion. Design Retrospective study Setting Level 1 trauma centre, All India Institute of Medical Sciences (AIIMS), New Delhi Patients From December 2006 to June 2009, 18 cases of PCL tibial avulsion injuries presented to our institution and underwent surgical intervention. Patients were followed up for 10 to 16 months (mean 12 months). Intervention Fixation of tibial PCL avulsion fractures was with one or two 4-mm partially threaded cannulated screw and washer placed through a Burks and SchaVer's approach. Range of motion was begun on postoperative day 2. Main outcome measurements Range of motion, clinical stability, radiographic appearance, each patient's overall health-related quality of life (using the musculoskeletal functional assessment tool) and gastrocnemius muscle strength were evaluated at Wnal follow-up. Results Union was achieved in all the cases, and all of them were having clinically stable knee at the time of last follow-up. The average musculoskeletal functional assessment score was 14. (Musculoskeletal functional assessment scores range from 0-100, with higher scores indicating poorer function.

Background Previous approaches for medial collateral ligament (MCL) reconstruction have been associated with extensive exposure, risk of donor site morbidity with autografts, loss of motion, nonanatomic graft placement, and technical complexity with double-bundle constructs. Therefore, we implemented a technique that uses Achilles allograft, small incisions, and anatomic insertions to reconstruct the MCL. Description of Technique The MCL femoral insertion was identified, and a socket reamed over a guide pin. The Achilles bone plug was fixed in the socket and the tendon passed distally under the skin and fixed on the tibia, creating isometric reconstruction.

The treatment of isolated posterior cruciate ligament (PCL) injuries is controversial. This is partly because the natural history of the isolated PCL injured knee is unclear. It has been noted that many patients function well, even in high level sports, with a torn PCL. This is in direct contradistinction with the ACL injured knee. The reason for this difference is not clear, as the PCL is larger and stronger than the ACL.

Use of a dished polyethylene insert in 114 total knee arthroplasties, all with the posterior cruciate ligament resected or recessed, was retrospectively studied. Patients were evaluated at a mean follow-up of 8.3 years. Mean range of motion increased from 928 to 1118. Mean Knee Society pain and function scores increased from 35.2 and 39.7 to 91.3 and 74.7, respectively. WOMAC scores improved significantly in each category evaluated, including pain, stiffness, and physical function. Kaplan-Meier survivorship was 95% at 10 years (95% confidence interval, 82%-99%). The use of a dished polyethylene insert in primary total knee arthroplasty provides good to excellent midterm results regardless of whether the posterior cruciate ligament is recessed or sacrificed. Key words: dished polyethylene insert, total knee arthroplasty, outcome.

Background: High tension in an anterior cruciate ligament graft adversely affects both the graft and the knee; however, it is unknown why high graft tension in flexion occurs in association with a posterior femoral tunnel. The purpose of the present study was to determine the effect of the angle of the femoral and tibial tunnels in the coronal plane and incremental excision of the posterior cruciate ligament on the tension of an anterior cruciate ligament graft during passive flexion.

Y. Ishii et al.: Gait analysis after TKA ... Gait analysis after total knee arthroplasty. Comparison of ... Yoshinori Ishii1, Kazuhiro Terajima2, Yoshio Koga1, Hideaki E. Takahashi1, Joan E. Bechtold3, and Ramon B. Gustilo3 ... Departments of 1 Orthopaedic Surgery and 2 ...

Purpose: The purpose of this study was to evaluate the clinical outcomes after arthroscopic single-bundle posterior cruciate ligament (PCL) reconstruction in patients with isolated grade III PCL injuries. Type of Study: Retrospective review. Methods: Twenty-one patients who underwent an isolated arthroscopic single-bundle PCL reconstruction for the treatment of a grade III PCL injury between 1989 and 1998 were included in the study. There were 15 male and 6 female patients with an average age of 38 years (range, 20 to 62 years). The length of follow-up was 5.9 years (range, 2.6 to 11 years), and the average time from injury to surgery was 4.5 years (median, 1.3 years; range, 2 weeks to 25 years). All patients completed a subjective evaluation and 14 patients returned for a physical examination and radiographs. One patient underwent an acute reconstruction (Ͻ3 weeks), 4 had a subacute (Ͻ3 months), and 16 underwent a chronic (Ͼ3 months) reconstruction. The anterolateral bundle of the PCL was reconstructed using an Achilles tendon allograft passed through femoral and tibial bone tunnels. Results: The overall average Activities of Daily Living Scale (ADLS), Sports Activities Scale (SAS), and SF-36 scores were 79.3, 71.6, and 98 points, respectively. There was a significant difference identified when the ADLS (91.3 v 75.6) and the SAS (90.4 v 65.8) scores of the subacute/acute group were compared with those of the chronic reconstruction group. Using the International Knee Documentation Committee (IKDC) subjective assessment, 57% of the patients had normal/near normal knee function, and 62% had a normal/near normal activity level. The average extension and flexion losses were 1°and 5°, respectively. Instrumented laxity examination revealed that 62% had less than a 3-mm and 31% had a 3-to 5-mm side-to-side difference in corrected posterior displacement. Radiographs at follow-up showed that 75% had normal/near normal findings according to IKDC guidelines. Conclusions: The clinical outcomes after arthroscopic singlebundle PCL reconstruction in this study produced a satisfactory return of function and improvement in symptoms. All patients in this study had improved laxity of at least 1 grade. When compared with chronic reconstructions, acute reconstructions had statistically significant better ADLS and SAS scores. Level of Evidence: IV, case series.

Loss of the posterior cruciate ligament (PCL) of the knee has a significant impact on joint stability and biomechanical function. Changes in joint biomechanics may result in mal-adaptive tissue degeneration and functional alteration of supporting ligaments. This study examines the effects of joint laxity on the vascular physiology of the intact anterior cruciate (ACL) and medial collateral (MCL) ligaments after PCL transection in rabbits. One-year-old female New Zealand white rabbits were assigned to control (n = 12). sham-operated (n = 12) or PCL transected (2. 6 or 16 weeks, n = 12 per time point) groups. Half of the animals (n = 6 per group) were used for ACL and MCL blood flow determination using coloured microsphere infusion (ml/min/100 g), and half were used for vascular volume determination (given as vascular index, pllg). In the MCL, PCL transection induced large, significant (4-S-fold) increases in blood flow (peak at 2 weeks) and vascular index (peak at 6 weeks) compared to sham-operated animals that returned towards control values by 16 weeks. In contrast, the ACL showed no increase in blood flow in lax joints, and a relatively small (2-fold) increase in vascular index at 6 weeks only. The wet weight and water content of both the MCL and ACL were significantly increased in PCL-deficient joints. We conclude that joint laxity (instability) subsequent to loss of the PCL in rabbits impacts the vascular physiology of intact supporting ligaments, inducing both vasomotor and angiogenic responses in the MCL. Changes in wet weight and water content of both the MCL and ACL demonstrate prolonged physiological adaptation of intact structures in lax joints.

Simulation of total knee replacement ͑TKR͒ is typically achieved by integrating sliding/rolling motions and loads between the implant's articulating surfaces during an activity cycle such as walking. Clinically, however, important variations in implant alignment and duty occur due to variability in patient anatomy/arthritic deformity, compounded by choices or errors in surgical installation. This study investigated the effects of the activity cycle severity, frontal plane alignment, relative femoral/tibial component rotational position, and the tightness of the posterior cruciate ligament ͑PCL͒. Seven different ͑four fixedbearing and three mobile-bearing͒ cruciate-retaining TKRs with different inherent constraints were tested on a force-control knee simulator. As well as the ISO standard wave forms for walking, an Enhanced Duty Cycle was used. The resulting anterior-posterior displacements and axial rotations were increased with the Enhanced Duty Cycle. Changing the line of action of the compressive force in the frontal plane ͑varusvalgus over/under-correction͒ did not appreciably change the kinematics. Rotating the tibial component shifted the rotational curves in the same direction as the misalignment. The PCL tightness produced the most noticeable effect on kinematics; a tight PCL reduced both displacements and rotations, and a loose PCL did the opposite.

Background: High tension in an anterior cruciate ligament graft adversely affects both the graft and the knee; how- ever, it is unknown why high graft tension in flexion occurs in association with a posterior femoral tunnel. The purpose of the present study was to determine the effect of the angle of the femoral and tibial tunnels in the coronal plane

The role of the posterior cruciate ligament (PCL) remains controversial in total knee arthroplasty (TKA), with some surgeons who believe in PCL sacrifice and substitution and others who believe in PCL preservation for stability. Manufacturers have developed both cruciate-substituting/posterior stabilized (PS) implants typically used when the ligament is sacrificed and cruciate retaining (CR) implants designed for ligament preservation. However, studies demonstrate excellent clinical results with CR implants despite PCL sacrifice. This study sought to determine functional stability differences between PS and CR TKAs following PCL sacrifice. Eighteen (9 matched pairs) subjects with either a PS or CR TKA and sacrificed PCL and a normal contralateral knee were subjected to physical exam and gait analysis (walking, stair ascent and descent) using a staircase model, passive reflective arrays and an optoelectric system. No differences were detected between the two groups among any of the measured parameters (knee flexion angle, knee flexion moment, knee power absorption, pelvic tilt). PCL sacrifice in a well-balanced cruciate retaining TKA did not result in instability during stair descent based on gait parameters. The decision to use a posterior stabilized design when faced with an incompetent PCL intraoperatively should be based on factors other than anticipated instability.

Objectives: To present the original descriptions of common orthopedic physical examination maneuvers of the knee and then to review the literature to support the scientific validity of these tests. Data Sources: MEDLINE (1970-2000) searches were performed, as were reviews of various musculoskeletal examination textbooks that describe physical examination maneuvers of the knee. These references were then reviewed for additional references and crossed back to the original description (when possible) of these named tests. Study Selection: All articles that discussed the sensitivity and specificity of the physical examination maneuvers were extracted. This information was reviewed for accuracy and then summarized. Data Extraction: Multiple MEDLINE and text searches were performed by using the terms of the test maneuver, the joint tested, and the term physical examination. Any article with this information was reviewed until the article describing the original description was found. Articles dating from that original article to the present were reviewed for information on the sensitivity and specificity of the test. Data Synthesis: Literature reviewing the sensitivity and specificity of the tests reviewed is summarized in text and table form. The Lachman test seems to be very sensitive and specific for the detection of anterior cruciate ligament tears. For posterior cruciate ligament tears, the posterior drawer test is also very sensitive and specific and is enhanced with other tests, such as the posterior sag sign. For meniscal tears, the McMurray test is very specific but has a very low sensitivity, whereas joint line tenderness has fairly good sensitivity but lacks good specificity. Although collateral ligament testing seems to be sensitive and specific, there is a lack of well-designed studies that scientifically validate the sensitivity and specificity of these tests. Common tests for patellofemoral pain and patellar instability lack sensitivity when correlated with pathologic operative findings. Conclusions: Most physical examination tests could be referenced back to an original description, with variable information on the sensitivity and specificity along with other information about the validity of these tests in clinical practice. To standardize how physical examinations are performed and compared, they should follow the original description or agreed-on standards. In addition, the significance of a physical examination finding must be understood to ensure that patients with knee complaints are accurately diagnosed and properly treated.

Total knee arthroplasty (TKA) is today considered by most surgeons as a satisfactory treatment for end-stage osteoarthritis of the knee, with good subjective and objective results during the first 10-15 years after implantation. Despite these good results, however, it is clear that the functional status and the subjective feelings that are obtained after implantation of a TKA do not match those of the normal knee. Patients frequently report inconveniences after TKA, which may be considered as minor and relatively unimportant by the treating surgeon. One of the more consistent complaints by patients is certainly the inability to regain deep or maximal knee flexion, despite the fact that they may have had wellperformed surgery and excellent postoperative physiotherapy.

From 1973 to 1987, 28 patients seen at our institution sustained isolated posterior cruciate ligament tears. Of these 28 patients, 25 were reevaluated at an average followup of 7 years and 1 month after secondary recon struction of the posterior cruciate ligament using the semitendinosus and gracilis tendons alone or with an extraarticular procedure. Subjectively, 22 of 25 patients related no restrictions regarding activities of daily living, with 14 of 25 patients being able to return to their previous competitive level in sports. Objective evaluation after reconstruction re vealed no change in the preoperative and postoperative posterior drawer examination in 13 of 25 patients, a finding confirmed by KT-1000 arthrometer measure ments. Radiographic evaluation revealed degenerative changes predominantly involving the medial and patel lofemoral compartments in 15 of 25 patients. Despite optimistic subjective reporting, this long-term retrospective study reveals that this procedure in...

Objective: The objective of this study was to evaluate the results obtained from posterior cruciate ligament (PCL) reconstruction with the double femoral tunnel technique, using quadriceps tendon and semitendinous autograft, in patients with isolated PCL tears or PCL tears associated with other ligament lesions, 2 years after surgery. Methods: The study included 14 patients with isolated PCL lesions and 20 with combined ligament lesions, who underwent PCL reconstruction using the double femoral tunnel technique and were evaluated 24 months after surgery using the International Knee Documentation Committee (IKDC) and Lysholm scores, a KT-1000 arthrometer, and the graduation of the posterior drawer test. Results: Knees were considered normal ("A") or nearly normal ("B") in 92.9% of patients with isolated lesions and in 95.0% of patients with combined tears, according to the IKDC score. Good or excellent results were obtained in 100% of patients in both groups according to the Lysholm score. Absence or outstanding reduction of posterior tibial translation was seen in 92.9% of patients with isolated lesions and in 100% of patients with combined ligament tears, in the posterior drawer evaluation. Conclusion: The PCL double femoral tunnel reconstruction technique using autografts was effective in restoring posterior knee stability, in isolated and/or combined PCL tears, showing remarkable clinical improvement in all patients. Level of evidence: 2C.

Purpose: To evaluate the results of our method of surgical treatment of traumatic knee dislocation with injury to the posterolateral corner by use of a standardized protocol. Methods: Twenty-five consecutive patients presented with a grossly dislocated or reduced knee. Five of these patients were not included in this series. The remaining 20 patients were treated by primary arthroscopic reconstruction. The anterior cruciate ligament (ACL) was reconstructed using gracilis tendon reinforced with artificial ligament (Ligament Augmentation and Reconstruction System [LARS] ligament); the posterior cruciate ligament (PCL) was reconstructed with semitendinosus tendon and reinforced with LARS ligament; and the posterolateral corner was treated using the gracilis and semitendinosus tendons from the uninjured knee. Twenty patients returned for subjective and objective evaluation at a minimum of 24 months after surgery. Early mobilization through continuous and active exercise was started on the fourth day postoperatively. Results: At a mean follow-up of 44 months, the mean Lysholm score was 90 points, the mean score on the survey of daily activities was 90 points, and the sports activities score on the knee outcome survey averaged 80 points. By the rating of Meyers et al. the results were excellent in 6 patients, good in 10 patients, fair in 3 patients, and poor in one patient. The final International Knee Documentation Committee (IKDC) rating was not normal in any knee. The mean loss of extension was 2 (range, 0 to 3) and loss of flexion was 12 (range, 10 to 15). Conclusions: By using the described method of arthroscopically assisted reconstruction of the cruciate ligaments and the posterolateral corner, 80% of the patients had good subjective results and functional stability, and according to the IKDC scale, 45% of knees were nearly normal, 45% were abnormal, and 10% were severely abnormal. No patient's rating returned to normal. Level of Evidence: Level IV, therapeutic case series.

Physical examination of patients with a suspected posterolateral corner injury must be comprehensive. Mechanical alignment, gait, and any hyperextension or varus thrust should all be evaluated. The status of all ligaments of the knee also must be thoroughly assessed. Detecting the presence or absence of a PCL can be difficult but is essential (Table). The dial test is easy to perform and is the most standard and accepted test to assess and follow posterolateral rotatory instability of the knee.

The objective of this study was to determine if consistent posterior femoral rollback of an asymmetrical posterior cruciate retaining (PCR) total knee arthroplasty was mostly influenced by the implant design, surgical technique, or presence of a well-functioning posterior cruciate ligament ( ...

Traumatic dislocation of the knee, confirmed by clinical and radiological evidence of tibiofemoral disarticulation is a rare injury although this definition of dislocation may underestimate the true incidence.1 An injury to two or more of the main ligament structures - anterior cruciate ...

Background Long-term results of Genesis I modular total knee system are not well known. Methods We analyzed data from 345 patients with 393 primary total knee arthroplasties (TKA) using the Genesis I prosthesis. In all cases, the posterior cruciate ligament (PCL) was retained, and the patella was not resurfaced. The minimum follow-up was 10 (range 10-16) years. Results Preoperative range of motion improved from 89°p reoperatively to 105°at the time of the most recent follow-up (p \ 0.001). Mean preoperative Knee Society pain and function scores increased from 29 and 25 points to 91 and 85 points, respectively (p \ 0.001). Tibiofemoral angle shifted from 2.40°of varus before to 4.8°of valgus after the operation (p \ 0.001). Early postoperative complications occurred in 34 knees (8.6%). Manipulation under general anesthesia was done in six knees (1.5%). Nonprogressive radiolucent lines were seen around the femoral component in 16 knees (4%) and at the tibial bone-cement interface in 101 knees (25%). However, in only five cases (1.3%) was there significant progression leading to implant loosening and revision surgery. Eight more revisions were performed due to infection (three knees), stiffness (three knees), excessive wear and fracture of polyethylene liner (one knee), and instability (one knee). The overall survivorship of knee replacement reached 96.7%. Conclusions In the long term (up to 16 years), PCLretaining Genesis I total knee prosthesis is associated with good functional outcomes and low failure rates.

Objectives: To describe a semi-quantitative scoring method for multi-feature, whole-organ evaluation of the knee in osteoarthritis (OA) based on magnetic resonance imaging (MRI) findings. To determine the inter-observer agreement of this scoring method. To examine associations among the features included in the scoring method. Methods: Nineteen knees of 19 patients with knee OA were imaged with MRI using conventional pulse sequences and a clinical 1.5 T MRI system. Images were independently analyzed by two musculoskeletal radiologists using a whole-organ MRI scoring method (WORMS) that incorporated 14 features: articular cartilage integrity, subarticular bone marrow abnormality, subarticular cysts, subarticular bone attrition, marginal osteophytes, medial and lateral meniscal integrity, anterior and posterior cruciate ligament integrity, medial and lateral collateral ligament integrity, synovitis/effusion, intraarticular loose bodies, and periarticular cysts/bursitis. Intraclass correlation coefficients (ICC) were determined for each feature as a measure of inter-observer agreement. Associations among the scores for different features were expressed as Spearman Rho. Results: All knees showed structural abnormalities with MRI. Cartilage loss and osteophytes were the most prevalent features (98% and 92%, respectively). One of the least common features was ligament abnormality (8%). Inter-observer agreement for WORMS scores was high (most ICC values were >0.80). The individual features showed strong inter-associations. Conclusion: The WORMS method described in this report provides multi-feature, whole-organ assessment of the knee in OA using conventional MR images, and shows high inter-observer agreement among trained readers. This method may be useful in epidemiological studies and clinical trials of OA.

The aim of this study was to investigate anteroposterior instability in the CKS and the PFC total knee arthroplasty (TKA) designs. Physical examinations, including VAS, IKS and WOMAC were performed in combination with a detailed fluoroscopic measurement technique for three-dimensional kinematic assessment of TKA design function. Anteroposterior instability rated with the IKS was not significantly different (p = 0.34), but patients with a CKS design showed more limitations according to the WOMAC joint stiffness total score, and for items regarding higher flexion activities in the WOMAC score for knee disability. Kinematic analyses showed that the CKS design tended to have more anterior sliding of the femur on the tibia during mid-and deep flexion activities. The sliding distance was larger at the medial than at the lateral side. This phenomenon has also been described for posterior cruciate ligament deficient knees. Furthermore, the CKS design showed a significantly lower range of tibial rotation (p < 0.05) from maximum extension to maximum flexion during deep knee bend activities. Kinematic differences can be ascribed to posterior cruciate ligament deficiency/laxity or differences in TKA designs.

The purposes of this study were (1) to predict the tibial insertion of the posterior cruciate ligament (PCL) and posterior cortex that aligned with the tibial tunnel (PCTT) by use of 2-dimensional plain radiographs by evaluating the relation between plain radiograph and computed tomography (CT) images and (2) to determine the safe angle of the tibial guide for preventing breakage of the posterior cortex. Methods: In 10 fresh cadaveric tibias, the soft tissues were dissected and the tibial footprint of the PCL was identified. The insertion of the PCL, the longest distance from the PCTT to the posterior cortex that aligned with the tibial plateau (PCTP), and the possible maximum angle of the tibial guide to the most posteriorly positioned cortical line were measured from simple anteroposterior (AP) and lateral radiographs, as well as CT. Results: The mean tibial insertion of the PCL from the joint line was located between 5.9 Ϯ 1.1 and 17.4 Ϯ 2.4 mm on the simple AP radiographs and between 2.2 Ϯ 1.2 and 12.3 Ϯ 1.5 mm on the simple lateral radiographs (P ϭ .005). The PCL insertion was from the posterior 48% of the area of the posterior intercondylar fossa to the posterior cortex. The longest distance from the PCTT to the PCTP was 10.8 Ϯ 2.2 mm. The maximum angle of the tibial guide to the PCTT possible on CT and the PCTP on lateral radiographs was 52°Ϯ 5°and 62°Ϯ 4.5°, respectively (P ϭ .005). Conclusions: The mean tibial insertion of the PCL from the joint line was located higher on the lateral radiographs than on the AP radiographs, and the PCL insertion was in the posterior 48% of the area of the PCL fovea to the posterior cortex. The maximum possible angle of the tibial guide to the PCTT based on CT was 52°. Therefore the angle of the tibial guide pin must be limited for tibial footprint reconstruction to prevent posterior wall breakage. Clinical Relevance: Increasing the tibial guide angle may have some advantages, but there is a limit because of posterior wall breakage.

The purpose of this study was to visualize arthroscopically and to describe the micro-and macroscopic anatomy of the poorly known ligament of the anterior capsule of the glenohumeral joint: the so-called ligamentum glenohumerale spirale (spiral GHL). Methods: Twenty-two fresh shoulder joints were dissected, and the anatomy of the anterior capsular structures (the spiral GHL, the middle glenohumeral ligament [MGHL], and the anterior band as well as the axillary part of the inferior glenohumeral ligament [AIGHL and AxIGHL, respectively]) was investigated. For arthroscopic visualization, 30 prospective arthroscopic clinical cases and 19 retrospective video clips of the patients who had an arthroscopic shoulder procedure with a normal subscapularis tendon, labrum, and anterior joint capsule were evaluated. Results: The spiral GHL and the AxIGHL were present in all 22 shoulder specimens. The AIGHL was not recognizable on the extra-articular side of the joint capsule. The MGHL was absent in 3 shoulder specimens (13.6%). Arthroscopically, the spiral GHL was found in 22 (44.9%), the MGHL in 43 (87.8%), and the AIGHL in 46 (93.9%) of the cases. The spiral GHL arose from the infraglenoid tubercle and the triceps tendon and inserted together with subscapularis tendon onto the lesser tubercle of the humerus. Conclusions: Our results suggest that extra-articular structure of the spiral GHL is consistently recognizable, the upper part of which can be arthroscopically identified. Clinical Relevance: Advanced anatomic knowledge of the spiral GHL helps the clinician better understand the normal anatomy of the shoulder joint and also helps to differiantiate it from pathologic findings of the patient. The biomechanical importance of the spiral GHL and its connection with shoulder pathology remains to be determined in futher studies.

Mobile-bearing posterior-stabilised knee replacements have been developed as an alternative to the standard fixed-and mobile-bearing designs. However, little is known about the in vivo kinematics of this new group of implants. We investigated 31 patients who had undergone a total knee replacement with a similar prosthetic design but with three different options: fixed-bearing posterior cruciate ligament-retaining, fixed-bearing posterior-stabilised and mobile-bearing posterior-stabilised. To do this we used a threedimensional to two-dimensional model registration technique. Both the fixed-and mobilebearing posterior-stabilised configurations used the same femoral component. We found that fixed-bearing posterior stabilised and mobile-bearing posterior-stabilised knee replacements demonstrated similar kinematic patterns, with consistent femoral roll-back during flexion. Mobile-bearing posterior-stabilised knee replacements demonstrated greater and more natural internal rotation of the tibia during flexion than fixed-bearing posterior-stabilised designs. Such rotation occurred at the interface between the insert and tibial tray for mobile-bearing posterior-stabilised designs. However, for fixed-bearing posterior-stabilised designs, rotation occurred at the proximal surface of the bearing. Posterior cruciate ligament-retaining knee replacements demonstrated paradoxical sliding forward of the femur.

Anatomy is the foundation of orthopaedic surgery, and the advancing knowledge of the anterior cruciate ligament (ACL) anatomy has led to the development of improved modern reconstruction techniques that approach the anatomy of the native ACL. Current literature on the anatomy of the ACL and its reconstruction techniques, as well as our surgical experience, was used to develop a flowchart that can aid the surgeon in performing anatomic ACL reconstruction. We define anatomic ACL reconstruction as the functional restoration of the ACL to its native dimensions, collagen orientation, and insertion sites. A guideline was written to accompany this flowchart with more detailed information on anatomic ACL reconstruction and its pitfalls, all accompanied by relevant literature and helpful figures. Although there is still much to learn about anatomic ACL reconstruction methods, we believe this is a helpful document for surgeons. We continue to modify the flowchart as more information about the anatomy of the ACL, and how to more closely reproduce it, becomes available.

Purpose The hypothesis of our study is that a routine tibial cut during cruciate retaining TKA may result in a partial or a total removal of the PCL footprint. Therefore providing a reliable landmark is essential to estimate the probability of PCL damage with a tibial cut and to enable the surgeon to decide pre-operatively whether a cruciate retaining implant design is suitable. Methods In a case series of 175 cruciate retaining TKA, the routinely made standing postoperative AP-view radiographs were evaluated to determine the distance between fibula head and tibial cutting plane. In a second case series knee MRI of 223 subjects were consecutively used to measure the vertical distance between tibial attachment of PCL and fibula head. The probability of partial or total PCL damage was calculated for different vertical distances between tibial cut and fibula head. Results The vertical distance between the tibial cut and the most proximal point of the fibula head averaged 6.1 mm ±4.8 mm. The mean vertical distance from fibula head to proximal and to distal PCL footprint revealed to be 11.4 mm ±3.7 mm and 5.4 mm ±2.9 mm, respectively. The location of the insertion was not significantly different between subgroups such as age (<50 or >50 years), gender and side. Based on our results 11 (7 %) knees were considered at high risk of an entire PCL removal after implantation of a cruciate retaining TKA design. Conclusions Currently available routine tibial preparation techniques result in partial or total posterior cruciate ligament detachment. Fibula head as a landmark aids to predict the PCL location and to estimate its disruption pre-and postoperatively on AP-view radiographs.

After total knee arthroplasty, changes in articular surface geometry, soft tissue treatment, and component alignment can alter normal lower limb function. The guided motion bi-cruciate substituting prosthesis was designed specifically to restore physiological knee joint motion. We determined whether this design could in vivo normal kinematics and kinetics, not only at the replaced knee, but also throughout both lower limbs. Sixteen patients (4 male, 12 female, mean age of 68.2 years with a range from 58 to 79 years) with primary knee osteoarthritis were implanted with the bi-cruciate substituting prosthesis. At 6-month follow-up, knee joint kinematics was assessed by video-fluoroscopy during stair-climbing, chair-rising/sitting, and step-up/down. Lower limb overall function was also assessed on the same day by standard gait analysis with simultaneous electromyography during level walking. By video-fluoroscopy, mean anteroposterior translations between femoral and tibial components during the three motor tasks were 9.7 +/- 3.0, 10 +/- 2.6, and 6.9 +/- 3.5 mm on the medial compartment, and 14.3 +/- 3.5, 18.5 +/- 3.0, and 13.9 +/- 3.8 mm on the lateral compartment, respectively. Axial rotation ranged from 5.6 degrees to 26.2 degrees. Gait analysis revealed restoration of nearly normal walking patterns in most patients. This rare combination of measurements, i.e., accurate rotation-translation at the replaced knee and complete locomotion patterns at both lower limb joints, suggested that bi-cruciate substituting arthroplasty can restore physiological knee motion and normal overall function.

Background: No biomechanical study has been performed analyzing the merits of reconstructing the popliteofibular ligament (PFL) through a tibial tunnel with an anatomic reconstruction of the posterolateral knee. Hypothesis: There is no difference in an anatomic posterolateral knee reconstruction with or without a PFL reconstruction placed through a tibial tunnel in restoring knee motion to the intact, uninjured state, and the knee is not overconstrained with this reconstruction. Study Design: Controlled laboratory study. Methods: Eight paired knees were tested in the intact state and then sectioned to simulate a grade III posterolateral knee injury. The reconstruction for the first paired knee reconstructed the PFL (through a tibial tunnel), popliteus tendon, and fibular collateral ligament (group 1); the matched knee reconstruction involved only the popliteus tendon and fibular collateral ligament (group 2). Results: Reconstructions for group 1 knees restored knee motion to the int...

To evaluate the feasibility of identifying the anterior and posterior meniscofemoral ligaments (aMFL and pMFL, respectively) at arthroscopy, both visually and using the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;meniscal tug test&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;, which exploits the anatomical attachments of the posterior cruciate ligament (PCL) and MFLs. This is an observational type of study. Arthroscopy using anteromedial and anterolateral portals was performed in 68 knees in 68 patients (36 right, 32 left). The MFLs were identified using several anatomical cues, including their femoral and meniscal attachments, their obliquity relative to the PCL, and the meniscal tug test. Identification was classed as easy or hard by the operating surgeon. From 68 knees, the aMFL was seen and confirmed to be an MFL using the tug test in 60 (88%). Identification of the aMFL was classed as easy in 64 (94%), whilst the pMFL was easy to identify in only 6 (9%) of knees, of which 3 had a ruptured PCL. Thus, with the exception of PCL-deficient knees, it was felt that the meniscal &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;tug test&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; as applied in this study was not suitable for the pMFL. The study shows that identification of the aMFL is possible in most knees at arthroscopy, using the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;tug test&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and other anatomical cues. However, identification of the pMFL may require a posterior portal. A subgroup of PCL injuries in which the MFLs were intact was also observed. The &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;meniscal tug test&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; can be used in arthroscopic examinations of the PCL to distinguish between fibres of the true PCL from the MFLs, thus avoiding the misdiagnosis of partial versus complete PCL rupture. This will also aid studies examining the role of the MFLs in stabilising the PCL-deficient knee.

PURPOSE: The purpose of this study was to evaluate a low-cost and easily reproducible technique for biomechanical studies in cadavers. In this kind of study, the natural effect of loading of the joint and shear forces are not taken into account. The objective is to describe the plastic deformation of the ligaments into 3-dimensional space. METHOD: For 18 intact human cadaver knees, the cruciate ligaments were divided into 3 fiber bundles, the tibial or femoral fixation points were marked, and 2 perpendicular different x-ray exposures were performed, thus obtaining radiographs of spatial projections of the bundle in 3 anatomic planes (frontal, sagittal, and transversal). From the measurements made on the x-ray films, we obtained the average distance between the 2 fixation points of the cruciate ligaments on the tibia and the femur at 4 different flexion angles. RESULTS: The distance between the fixation points of the medial and lateral fiber bundles of the cruciate ligaments did not ...

A rare case of a 28-year-old Asiatic male with the isolated absence of a posterior cruciate ligament is reported. Clinical features, diagnostic steps, therapeutic strategies and follow-up are described. A review of the literature is also presented.

The goal of this study was to determine whether single-tunnel-double-bundleequivalent posterior cruciate ligament (PCL) reconstruction using an aperture femoral fixation device better replicated normal knee kinematics than single-bundle reconstruction. Eight fresh-frozen human cadaver knees underwent arthroscopically assisted PCL reconstruction and were examined with a robotic testing system to assess knee joint kinematics under combinations of applied internal, neutral, and external rotational tibial torque and anteroposterior translational forces at 0°, 30°, 60°, 90°, and 120° flexion. Three conditions were tested: (1) intact PCL; (2) single-tunnel PCL reconstruction with anterolateral and posteromedial bundle fixation at 90°/90° (single bundle); and (3) 90°/0° (double-bundle equivalent), respectively. Posterior tibial translation was the primary outcome measure. Compared with the intact knee, double-bundleequivalent reconstruction under external tibial torque allowed greater posterior translation across the flexion arc as a whole (P=.025) and at 30° flexion (P=.027) when results were stratified by flexion angle. No other kinematic differences were found with single-bundle or double-bundle-equivalent fixation, including mediolateral translation and both coupled and isolated tibial rotation (P>.05). Single-bundle PCL reconstruction closely approximated native knee rotational and translational kinematics, whereas double-bundle-equivalent reconstruction permitted increased posterior translation with applied external tibial torque, particularly at lower flexion angles. Single-bundle PCL reconstruction provides knee stability similar to the intact condition, making it a practical alternative to conventional double-bundle PCL reconstruction. The authors found that double-bundle-equivalent reconstruction provided no advantage to justify its clinical use.

This article examines how the relationship between sagittal and coronal anatomy, anterior cruciate ligament (ACL) graft dimensions, and tibial and femoral tunnel placement affects the posterior cruciate ligament (PCL) and roof impingement, and their undesirable clinical consequences of motion loss and instability. Based on these interrelationships, a variety of checkpoints are defined that can be used intraoperatively to determine whether placement of the tibial tunnel guidewire avoids PCL and roof impingement, and whether placement of the femoral tunnel guidewire avoids PCL impingement with either transtibial or transportal techniques. A simple, 3-dimensional tibial drill guide that consistently places the tibial tunnel correctly without PCL and roof impingement so the femoral tunnel, when drilled through the tibial tunnel, restores the normal tension pattern in the ACL graft also is described. Arthroscopic and radiographic checkpoints that assess the final placement of the ACL graft and tibial and femoral tunnels are discussed.

Introduction Injuries of the posterolateral corner (PLC) of the knee are rare. They are difficult to diagnose and can cause severe disability. This study presents the 20-to 70-month clinical and radiological outcomes of the anatomical reconstruction technique of LaPrade et al. Materials and methods Twenty-one patients with chronic PLC injuries underwent anatomical PLC reconstruction. The anatomical locations of the popliteus tendon, fibular collateral ligament, and popliteofibular ligament were reconstructed using a 2-graft technique. The patients were evaluated subjectively with the Tegner, Lysholm, and International Knee Documentation Committee (IKDC) subjective knee scores and objectively with the IKDC objective scores; additionally, varus stress radiographs were taken to evaluate knee stability. Results: Significant (p\0.05) improvements were observed in the postoperative Lysholm, IKDC-s, and Tegner scores compared with preoperatively. The IKDC objective subscores (lateral joint opening at 20 of knee extension, external rotation at 30 and 90 , and the reverse pivot-shift test) had improved significantly at the time of the final 40.9 ± 13.7-month follow-up.Lateralcompartment opening on the varus stress radiographs had decreased significantly in the postoperative period. However, there was still a significant difference compared with the uninjured knee. There was no significant improvement in the IKDC-s, Lysholm, or Tegner scores between the nine patients with isolated PLC injuries and twelve with multiligament injuries. Conclusions: Significant improvement in the objective knee stability scores and clinical outcomes with anatomical reconstruction showed that this technique can be used to treat patients with chronic PLC injured knees. However, longer-term multicentre studies and studies with larger groups comparing multiple techniques are required to determine the best treatment method for PLC injuries.

The objectives of this study were to compare preoperative and postoperative knee kinematics for subjects implanted with flexion-enhanced posterior cruciate-retaining total knee arthroplasty during deep flexion and to examine flexion performance of the prosthesis design. Three-dimensional kinematics was analyzed by fluoroscopic examinations of subjects using a singleplane model-image registration technique. Preoperatively, knee kinematics demonstrated small posterior femoral translation and limited axial rotation. These motions differed significantly from patterns previously reported for normal knees. Postoperatively, flexion performance was maintained, averaging 130°, and kinematic patterns were similar to preoperative patterns. Although total knee arthroplasty can reduce pain and maintain functional performance, it appears that the characteristics of varus arthritic knee mechanics persist after arthroplasty.

We present the case of a paraglider who suffered a valgus external rotation hyperextension injury of the right knee. The incomplete diagnosis of an isolated anterior cruciate ligament (ACL) intrasubstance tear was made and a reconstruction of the ACL with semitendinosus autograft was performed. The associated lesion of the posterior cruciate ligament (PCL) was overlooked and thus the ACL was fixed in a posterior sag position. This led to activity-related pain without any instability. The patient underwent revision surgery with débridement of the ACL and reconstruction of the PCL with quadriceps tendon.

Case ReportArthroscopic Repair of the Posterior Cruciate Ligament:Two TechniquesAlejandro Espejo-Baena, MD, Rafael Lopez-Arevalo, MD, Victor Urbano, MD,Elvira Montanez, MD, and Felipe Martn, MDSummary: Isolated posterior cruciate ligament injuries are rare and their ...