Incidental Anterior Cruciate Ligament Calcification: Case Report

The calcification of knee ligaments is a finding noted only in a handful of case reports. The finding of an anterior cruciate ligament calcification has been reported once in the literature. Comparable studies involving the posterior cruciate ligament, medial collateral ligament and an ossicle within the anterior cruciate ligament are likewise discussed in reports of symptomatic patients. We report a case of incidentally discovered anterior cruciate ligament calcification. We discuss the likely etiology and clinical implications of this finding.

The mechanism of "killer turn" causing residual laxity after transtibial posterior cruciate ligament reconstruction

Background

The residual laxity after transtibial posterior cruciate ligament (PCL) reconstruction has been reported by several authors. The sharp angle where the graft exits the tibial tunnel, which is known as "killer turn", is believed to be the main reason. The purpose of this study was to reveal the mechanism of "killer turn" and its effect on both graft and tunnel inlet.

Methods

A total of 60 New Zealand white rabbits were included. All transtibial PCL reconstructions were performed in vitro using Achilles tendon autograft. The cyclic loading tests were conducted when reconstructed knees were subjected to 1500 cycles of tensile force of 50 N with the angle of pull at 45° to the tibial plateau. The tunnel inlet enlargement, graft elongation, stiffness, graft displacement, load to failure, and failure site were all recorded and analysed.

Results

Fifty-eight New Zealand white rabbits were available for biomechanical evaluation. The subjects had significant graft elongation and tunnel enlargement. The graft displacement increased by a mean of 0.92 ± 0.36 mm (16.70%). At the 1500^th cycle, the grafts were significantly elongated by 5.59 ± 4.98%, and the tunnel inlet diameter was also significantly enlarged by 12.08 ± 4.31%. There was a linear correlation between total graft displacement and the two variables (R2 = 0.402, F = 18.515, p < 0.001). The coefficient for tunnel inlet enlargement was 0.419 (p = 0.006), and for graft elongation was 0.583 (p = 0.002). At the load-to-failure test, the failure load was 81.19 ± 20.13 N. Of the 58 grafts, 31 (53.45%) failed at the "killer turn", 13 (22.41%) for the para-tunnel fracture, seven (12.07%) for the graft pull-out, and the remaining seven (12.07%) for the rupture at the mounting site.

Conclusion

The mechanism of "killer turn" compromising posterior stability was that the repetitive friction between graft and tunnel inlet not only attenuated the graft, but also enlarged the tunnel inlet, leading to the displacement of the graft.

All-arthroscopic treatment of tibial avulsion fractures of the posterior cruciate ligament

Background: The posterior cruciate ligament (PCL) avulsion fracture from its tibial insertion is a rare condition. Despite the further technical advent in refixation of avulsion fractures, the reported failure rate of current approaches remains high and the optimal surgical technique has not been elucidated yet.

The purpose of the current study is to present an all-inside arthroscopic reconstruction technique for bony tibial avulsion fractures of the PCL and initial clinical outcomes.

Methods: Patients underwent a thorough clinical and radiological examination of both knees at 3, 6, 12, 18, and if possible also at 24 months.

Clinical evaluation included subjective and objective IKDC 2000, Lysholm score, and KOOS score. Radiographic imaging studies included CT scans for assessment of osseous integration and anatomic reduction of the bony avulsion. In addition to that posterior stress radiographs of both knees using the Telos device (Arthrex, Naples, USA) were conducted to measure posterior tibial translation.

Results: A total of four patients (1 female, 3 male; ø 38 (± 18) years), who underwent arthroscopic refixation of a PCL avulsion fracture using the Tight Rope device were enrolled in this study. Mean follow up was 22 [18–24] months.

The mean subjective IKDC was 72.6% (± 9.9%). Regarding the objective IKDC three patients accounted for grade A, one patient for grade C. The Lysholm score yielded 82 (± 6.9) points. The KOOS score reached 75% (± 13%; symptoms 76%, pain 81%, function 76%, sports 66%, QoL 64%).

All patients showed complete osseous integration and anatomic reduction of the bony avulsion. The mean posterior tibial translation at final follow up was 2.8 [0–7] mm.

Conclusions: All-arthroscopic treatment of tibial avulsion fractures of the posterior cruciate ligament provides satisfactory clinical results in a preliminary patient cohort. It is a reproducible technique, which minimizes soft tissue damage and obviates a second surgery for hardware removal. Further clinical studies with larger patient cohorts and a control group are needed to further confirm these preliminary results.

Clinical value of fat-suppressed 3D volume isotropic spin-echo (VISTA) sequence compared to 2D sequence in evaluating internal structures of the knee

BACKGROUND

Although many three-dimensional (3D) magnetic resonance imaging (MRI) sequences have been used in the clinical field, there are no studies on fat-suppressed (FS) 3D sequences for the diagnosis of knee abnormalities.

PURPOSE

To evaluate the usefulness of FS 3D volume isotropic turbo spin echo acquisition (VISTA) imaging for diagnosis of internal structures of knee.

MATERIAL AND METHODS

In 137 patients with 138 knee MRI examinations who had undergone both FS 3D VISTA MRI and two-dimensional (2D) MRI of the knee at 3.0 T, arthroscopic surgery was subsequently performed. Multiplanar reformations (MPR) of FS 3D VISTA images and their MPR sequences were compared with 2D MR images of axial T1-weighted (T1W) images, axial FS T2-weighted (T2W) images, coronal FS T2W images, and sagittal T2W images. Two musculoskeletal radiologists reviewed the images independently.

RESULTS

Arthroscopy revealed 33 anterior cruciate ligament tears, three posterior cruciate ligament tears, 42 lateral meniscus tears, and 68 medial meniscus tears. Five medial collateral ligament tears were clinically confirmed. Image acquisition time was shorter for FS 3D VISTA imaging than 2D imaging. There were no significant differences in diagnostic values between FS 3D VISTA and 2D imaging (P > 0.05). There were excellent inter-observer agreements for both FS 3D VISTA and 2D imaging (κ > 0.84).

CONCLUSION

FS 3D VISTA imaging could replace 2D imaging because of equal diagnostic ability and shorter scan time.

Emerging Updates on the Posterior Cruciate Ligament: A Review of the Current Literature

The posterior cruciate ligament (PCL) is recognized as an essential stabilizer of the knee. However, the complexity of the ligament has generated controversy about its definitive role and the recommended treatment after injury. A proper understanding of the functional role of the PCL is necessary to minimize residual instability, osteoarthritic progression, and failure of additional concomitant ligament graft reconstructions or meniscal repairs after treatment. Recent anatomic and biomechanical studies have elucidated the surgically relevant quantitative anatomy and confirmed the codominant role of the anterolateral and posteromedial bundles of the PCL. Although nonoperative treatment has historically been the initial treatment of choice for isolated PCL injury, possibly biased by the historically poorer objective outcomes postoperatively compared with anterior cruciate ligament reconstructions, surgical intervention has been increasingly used for isolated and combined PCL injuries. Recent studies have more clearly elucidated the biomechanical and clinical effects after PCL tears and resultant treatments. This article presents a thorough review of updates on the clinically relevant anatomy, epidemiology, biomechanical function, diagnosis, and current treatments for the PCL, with an emphasis on the emerging clinical and biomechanical evidence regarding each of the treatment choices for PCL reconstruction surgery. It is recommended that future outcomes studies use PCL stress radiographs to determine objective outcomes and that evidence level 1 and 2 studies be performed to assess outcomes between transtibial and tibial inlay reconstructions and also between single- and double-bundle PCL reconstructions.

The Incidence and Short Term Functional Effect of Partial PCL Release in Fixed and Mobile Bearing PCL Retaining TKA

Posterior cruciate ligament (PCL) release may be required to balance the flexion gap in PCL retaining TKA. This study examines the incidence and functional consequences of PCL release in both fixed and mobile bearing TKA. A consecutive series of 1388 TKAs with 1014 fixed bearing, and 374 mobile bearing implants were reviewed for prevalence of partial PCL release, restoration of potential flexion and objective knee stability at minimum one-year follow-up. Patients receiving mobile bearing inserts were more likely to need partial PCL release (42% versus 17.5%). The occurrence of partial PCL release did not have a significant impact on knee range of motion and subjective knee stability. The need for a partial PCL release appears to be greater in mobile than in fixed bearing. Knees that required a release in both groups demonstrated no difference in restoration of flexion compared with unreleased knees and no adverse effects on flexion stability.

The Supine Internal Rotation Test: A Pilot Study Evaluating Tibial Internal Rotation in Grade III Posterior Cruciate Ligament Tears

Background:

Biomechanical studies have reported that the posterior cruciate ligament (PCL) functions as a restraint against excessive tibial internal rotation at higher degrees of knee flexion.

Purpose:

To investigate the use of a supine internal rotation (IR) test for the diagnosis of grade III PCL injuries. The hypothesis was that internal rotation would be greater in patients with grade III PCL injuries compared with other knee injuries and that the supine IR test would demonstrate excellent diagnostic accuracy.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

A consecutive series of 309 patients underwent arthroscopic and/or open knee ligament reconstruction surgery. Seven patients were excluded based on the inability to perform a side-to-side comparison of internal rotation. Tibial internal rotation was assessed bilaterally on 302 patients during examination under anesthesia by a single orthopaedic surgeon measuring tibial tubercle excursion (mm) while applying internal rotation torque. Internal rotation was graded from 0 to 4 at 60°, 75°, 90°, 105°, and 120° of knee flexion. Data were collected and stored prospectively. The optimal threshold for the supine IR test was chosen based on maximization of the Youden index. Diagnostic accuracy parameters were calculated. Multiple logistic regression models were constructed to assess the influence of other knee pathologies on diagnostic accuracy.

Results:

Examination of the 22 PCL-deficient knees demonstrated an increase in tibial internal rotation at 60°, 75°, 90°, 105°, and 120° of knee flexion. The supine IR test had a sensitivity of 95.5%, a specificity of 97.1%, a positive predictive value of 72.4%, and a negative predictive value of 99.6% for the diagnosis of grade III PCL injuries. Posterolateral corner injury had a significant interaction with the supine IR test, increasing its sensitivity and decreasing its specificity.

Conclusion:

PCL-deficient knees demonstrated an increase in the side-to-side difference in tibial internal rotation compared with other knee pathologies. The supine IR test offers high sensitivity and specificity for grade III PCL injuries and may represent a useful adjunct for diagnosing PCL injuries.

Effect of six degrees of freedom knee kinematics on ligament length and moment arm in an intact knee model

BACKGROUND

Biomechanics studies can help improve athletic performance. However, the biomechanics of knee joint ligament length changes and moment arms over six degrees of freedom (DOF) have yet to be established.

OBJECTIVE

To construct a knee model to investigate the length and moment arm changes of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL).

METHOD

Six DOF joint modeling and analysis were performed using specialized modeling software.

RESULTS

The length of all ligaments varied with tibiofemoral flexion angle, contributed to joint motion, and restrained the joint in different positions. The ACL, MCL, and LCL lengths decreased, the PCL increased, the posterior tibial translation increased, the MCL moment arm increased, and the LCL moment arm decreased between 0° and 90°. The primary ligament restraints were the PCL (0° to 30°), MCL (30° to 60°), and PCL (60° to 90°).

CONCLUSION

The restraining function of each ligament during motion can be modeled based on changes in ligament lengths during tibial translations and rotations during flexion. Understanding the correlations between ligament lengths and moment arm changes over a wide range of motion will help improve our understanding of joint kinematics and may be useful for the diagnosis and treatment of sports injury.

Posterior Cruciate Ligament Tibial Avulsion treated with Open Reduction and Internal Fixation through the Burks and Schaffer Approach

Objective: To report functional outcome in Posterior Cruciate Ligament (PCL) tibial avulsion fractures treated with open reduction and internal fixation through Burks and Schaffer approach. The patient specific functional outcome measures like IKDC grading together with objective grading with stress radiographs have rarely been used -to assess PCL tibial avulsion fractures.

Material and Methods: Twenty seven patients (21 males and 6 females) were included in the study. The mean follow up duration was 22.30±6.82 months. They were assessed using international knee documentation committee (IKDC) grades, Lysholm scoring and stress radiography. The injury severity scores (ISS) of the patients were also recorded.

Results: The mean Lysholm scores at the time of last follow up was 90.85±5.58. The IKDC grades achieved were normal in 20 patients, near normal in five and abnormal in two. The PCL laxity determined on active hamstring contraction stress radiography was grade I in 20 cases and grade II in seven cases. All patients had achieved bony union of tibial avulsion fractures at the time of last follow up. Statistically significant association was found between higher ISS and lower Lysholm scores. (t=3.455, p=0.0019). Good IKDC grades were associated with higher Lysholm scores (analysis of variance, F=32.51, p<.0001). There was no correlation between PCL laxity and functional outcome (t=.857, p = 0.399).

Conclusion: PCL tibial avulsion fractures treated through Burk and Schaffer approach with open reduction and internal fixation produces good results. The early rehabilitation without cast immobilisation prevents arthrofibrosis.

Tenosynovial giant cell tumor arising from the posterior cruciate ligament: a case report and literature review

The localized form of tenosynovial giant cell tumor or pigmented villonodular synovitis is rarely intraarticular in the knee. We reported a 40-year-old woman with a tenosynovial giant cell tumor arising from posterior cruciate ligament (PCL). She suffered sudden knee pain and locking without any reason for two days. A mass with a size of 1.7 × 0.8 × 0.7 cm in the fossa intercondyloidea was detected on the MRI. After one time hyperextension physical examination the patients felt sudden pain relief. During the arthroscopy examination, a loose soft tissue mass was found under the lateral meniscus. Only the synovium tissue lesion on the proximal PCL was detected. The mass had a conceivable thin pedicel and the shape matched well with the tumor bed on the PCL. The histopathology of the mass demonstrated a tenosynovial giant cell tumor. At six weeks follow-up, no clinical evidence of recurrence was noted. A Literature Review of tenosynovial giant cell tumor or pigmented villonodular synovitis arising from the PCL is present.

Continuous sagittal radiological evaluation of stair-climbing in cruciate-retaining and posterior-stabilized total knee arthroplasties using image-matching techniques

In this study, we evaluated the in vivo kinematics of stair-climbing after posterior stabilized (PS) and cruciate retaining (CR) total knee arthroplasty (TKA) using radiographic-based image-matching techniques. Mid-flexion anteroposterior stability was demonstrated in all knees after CR TKA. However, paradoxical femoral translation at low flexion angles was seen in both designs. The post-cam mechanism did not function after PS TKA. Larger posterior tibial slope in PS TKA was linked to forward sliding of the femur at mid-flexion and unintended anterior tibial post impingement at knee extension. CR TKA is more sagittally stable in mid-flexion during stair climbing and attention must be given to minimize posterior tibial slope when using late cam-post engaging PS TKA designs.

Condylar-stabilizing tibial inserts do not restore anteroposterior stability after total knee arthroplasty

The Triathlon condylar-stabilizing (CS) lipped insert is designed to provide anteroposterior (AP) stability of the posterior-stabilized (PS) insert, without a post. The purpose of this study was to compare the AP stability of the knee in patients with Triathlon CS and PS total knee arthroplasty (TKA) with midterm follow-up. Thirty-one patients received a Triathlon PS TKA in one knee and a Triathlon CS TKA in the contralateral knee, and 28 patients were followed up with a minimum duration of 5years. Although there was no difference in functional outcomes, the posterior displacement was significantly greater in the CS TKA group than in the PS TKA group (P<0.001). The Triathlon CS lipped insert could not restore posterior stability with PCL sacrifice.

Immunohistochemical analysis of the neural structures of the posterior cruciate ligament in osteoarthritis patients submitted to total knee arthroplasty: an analysis of thirty-four cases

OBJECTIVES

Many authors recommend posterior cruciate ligament-retaining arthroplasty with the intention to maintain the proprioception properties of this ligament. Preservation of the neuroreceptors and nervous fibers may be essential for retaining the proprioception function of the posterior cruciate ligament. The present study was thus developed to evaluate the presence of neural structures in the posterior cruciate ligament resected during posterior stabilized arthroplasty in osteoarthritis patients. In particular, clinical, radiographic and histological parameters were correlated with the presence or absence of neural structures in the posterior cruciate ligament.

METHODS

In total, 34 posterior cruciate ligament specimens were stained with hematoxylin-eosin and Gomori trichrome. An immunohistochemical analysis using antibodies against the S100 protein and neurofilaments was also performed. The presence of neural structures was correlated with parameters such as tibiofemoral angulation, histological degeneration of the posterior cruciate ligament, Ahlbäck radiological classification, age, gender and the histologic pattern of the synovial neurovascular bundle around the posterior cruciate ligament.

RESULTS

In total, 67.5% of the cases presented neural structures in the posterior cruciate ligament. In 65% of the cases, the neurovascular bundle was degenerated. Nervous structures were more commonly detected in varus knees than in valgus knees (77% versus 50%). Additionally, severe histologic degeneration of the posterior cruciate ligament was related to neurovascular bundle degeneration.

CONCLUSIONS

Severe posterior cruciate ligament degeneration was related to neurovascular bundle compromise. Neural structures were more commonly detected in varus knees. Intrinsic neural structures were detected in the majority of the posterior cruciate ligaments of patients submitted to knee arthroplasty for osteoarthritis.

Consequences of tibial tunnel reaming on the meniscal roots during cruciate ligament reconstruction in a cadaveric model, Part 2: The posterior cruciate ligament

BACKGROUND

Recent emphasis has turned to reconstructing the posterior cruciate ligament (PCL) after injury. However, single-bundle PCL reconstruction of the anterolateral bundle may potentially injure the posterior meniscal roots.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine if posterior meniscal root injuries occurred because of tunnel reaming for single-bundle PCL reconstruction. It was hypothesized that tibial tunnel reaming within the anterolateral bundle footprint during PCL reconstruction would result in clinically significant decreases in posteromedial (PM) root attachment areas and in ultimate failure strength for the PM root.

STUDY DESIGN

Controlled laboratory study.

METHODS

Testing was performed on 12 matched pairs of human cadaveric knees. For each pair of knees, one knee was left intact, while the contralateral knee was prepared with a tibial tunnel placed 5 mm anterior to the center of the tibial PCL attachment and within the previously described footprint of the anterolateral bundle of the PCL for single-bundle PCL reconstruction. The attachment areas of the posterior meniscal roots were measured with a coordinate measuring device before and after PCL tunnel reaming. The posterior meniscal roots were then pulled to failure with a dynamic tensile testing machine.

RESULTS

There was a significant mean decrease in the attachment area of the PM root (%Δ, 28%; 95% CI, 16-40) after PCL tunnel reaming compared with the intact state (P=.005). The mean ultimate failure strength of the native PM root (mean, 440 N; 95% CI, 347-534) was also significantly stronger (mean, 40%; 95% CI, 18-61; P=.005) than that of the PM root after PCL tunnel reaming (mean, 243 N; 95% CI, 176-309). No changes were found for the posterolateral (PL) root after PCL tunnel reaming.

CONCLUSION

Tibial tunnel reaming for single-bundle PCL reconstruction in the anterolateral bundle footprint significantly reduced the ultimate failure strength and attachment area of the PM meniscal root. The attachment area and ultimate failure strength of the PL root were unaffected by tunnel reaming.

CLINICAL RELEVANCE

Tibial tunnels reamed in the footprint of the anterolateral bundle during single-bundle PCL reconstruction can cause iatrogenic damage to the PM meniscal root attachment. Thus, tibial tunnels should strive to be reamed in the center of the entire tibial PCL attachment site during PCL reconstruction.

Reconstruction for chronic grade-II posterior cruciate ligament deficiency in Malaysian military personnel

PURPOSE

To evaluate the outcome of reconstruction for chronic grade-II posterior cruciate ligament (PCL) deficiency in Malaysian military personnel.

METHODS

Medical records of 16 male military personnel aged 25 to 41 years who underwent reconstruction for chronic grade-II PCL deficiency using the quadruple hamstrings tendon by a single surgeon were reviewed. The mean time from injury to surgery was 43.6 (range, 3-104) months. 10 patients had grade-I (n=4), grade-III (n=2), and grade-IV (n=4) lesions of the medial femoral condyles. Seven patients had medial (n=6) and lateral (n=1) meniscus tears. At the 2-year follow-up, patients were asked to complete a questionnaire consisting of the Lysholm score, Tegner activity level, and International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form. Posterior drawer test, KT-2000 arthrometer test for posterior translation of the tibia, and military health grade (MHG) were assessed by an independent assessor.

RESULTS

At the 2-year follow-up, the mean Lysholm score was 83; the score was excellent in 2 patients, good in 9, fair in 4, and poor in one. The mean IKDC subjective score was 74. The median Tegner activity level increased from 5.5 to 6. The posterior drawer test of 11 patients improved to grade I and the remaining 5 remained at grade II. The mean posterior translation of the tibia was 2.4 mm postoperatively; the posterior translation was normal in 8 patients, nearly normal in 7, and abnormal (≥ 6 mm) in one. The MHG improved in 14 patients and remained unchanged in 2. The latter 2 patients had no chondral lesion or meniscus injury. The first one was 40 years old with a postoperative IKDC score of 55 and a Tegner activity level of 2. The second one was 34 years old with a postoperative IKDC score of 65 and posterior translation of the tibia of 6 mm.

CONCLUSION

Surgical reconstruction for chronic grade-II PCL injury achieved satisfactory outcome and may be appropriate for military personnel.

Transtibial versus tibial inlay techniques for posterior cruciate ligament reconstruction: long-term follow-up study

BACKGROUND

The most common technique for posterior cruciate ligament (PCL) reconstruction is transtibial or tibial inlay. However, few studies have reported long-term outcome comparisons between the 2 techniques.

HYPOTHESIS

Tibial inlay PCL reconstruction with patellar tendon autograft will exhibit better clinical and radiographic outcomes than transtibial PCL reconstruction with hamstring autograft.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 66 patients (66 knees) treated with PCL reconstruction for chronic injuries constituted the study cohort. Patients were divided into 2 groups: transtibial with hamstring (36 patients) and tibial inlay with patellar tendon (30 patients). The mean time from injury to reconstruction was 12.2 months (range, 2-60 months), and the mean follow-up was 148 months (range, 98-196 months). Outcomes were measured by use of Lysholm knee scores, Tegner activity scores, return to preinjury sports activity, posterior drawer test, laxity test with a Telos device, and development of osteoarthritis.

RESULTS

The preoperative mean Lysholm knee score was 59.9 (range, 37-70) in the transtibial group and 54.5 (range, 22-76) in the tibial inlay group, improving postoperatively to 89.9 (range, 74-100) and 92.1 (range, 80-100), respectively. The mean Tegner activity scores increased from 2.5 (range, 2-5) to 5.9 (range, 4-7) in the transtibial group and 2.3 (range, 2-4) to 6.0 (range, 3-8) in the tibial inlay group. Twenty-one patients (58.3%) in the transtibial group and 19 patients (63.3%) in the tibial inlay group were able to return to preinjury sports activity. In the posterior drawer test, 6 patients in the transtibial group and 4 patients in the tibial inlay group showed grade II laxity. The mean side-to-side difference was 10.1 mm (range, 7-12 mm) in the transtibial group and 10.4 mm (range, 9-13 mm) in the tibial inlay group, improving postoperatively to 4.1 mm (range, 0-8 mm) and 4.2 mm (range, 1-8 mm), respectively. There was significant improvement between preoperative and final follow-up values. However, there were no significant differences between the 2 groups in final follow-up outcomes. Final follow-up radiographs showed that 6 patients (16.7%) in the transtibial group and 3 patients (10.0%) in the tibial inlay group were rated grade C according to International Knee Documentation Committee guidelines.

CONCLUSION

Clinical and radiographic outcomes between the 2 PCL reconstruction techniques were comparable. Osteoarthritis was observed in patients, with a significant proportion presenting loss of joint space. Examined factors, excluding meniscectomy, were not correlated with the development of osteoarthritis.

Significant effect of the posterior tibial slope on the weight-bearing, midflexion in vivo kinematics after cruciate-retaining total knee arthroplasty

The purpose of the present study was to compare weight bearing (WB) and non-WB conditions, and to evaluate the effect of the posterior tibial slope (PTS) on the in vivo kinematics of 21 knees after posterior cruciate ligament-retaining total knee arthroplasty during midflexion using 2-dimensional/3-dimensional registration. During WB, medial pivot and bicondylar rollback were observed. During non-WB, both the medial and lateral condyles moved significantly more anteriorly as compared to the WB state. These patients were divided into 2 groups according to their PTS. The large PTS group showed a significant posterior displacement of the medial femoral condyle as compared with the small PTS group, but no significant difference was observed at the lateral femoral condyle during both WB and non-WB. The PTS influenced knee kinematics through gravity (124/125).

Effects of knee flexion angle and loading conditions on the end-to-end distance of the posterior cruciate ligament: a comparison of the roles of the anterolateral and posteromedial bundles

BACKGROUND

It is commonly accepted that the anterolateral (AL) bundle of the posterior cruciate ligament (PCL) is tight in flexion and that the posteromedial (PM) bundle is tight in extension. However, a recent in vivo study showed that both bundles were tight in extension.

PURPOSE

To investigate the effects of knee flexion angle, rotational torque, and anterior/posterior translational force on the end-to-end distance between the femoral and tibial insertion sites of each bundle of the PCL.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Cadaveric knees (10 specimens) were mounted on a robotic system, and the relative positional data between the femur and tibia were acquired during passive flexion/extension, with an applied 5-N·m rotational torque and an applied 89-N translational force. The bony surface and PCL insertion data were acquired with a 3-dimensional scanner after gross dissection and were superimposed onto the positional data. The end-to-end distance between the 2 PCL insertion sites of the femur and tibia was measured.

RESULTS

The end-to-end distance increased from full extension to 90° for both the AL (9.2 ± 1.8 mm; from 30.0 to 39.2 mm) and PM bundles (5.8 ± 2.2 mm; from 32.0 to 37.7 mm). With an internal rotational torque, the end-to-end distance of the PM bundle increased significantly (P < .05) at 0°, 30°, and 60° of knee flexion. Under a posterior translational force at 90° of knee flexion, the length of both bundles increased to their longest measurements (AM bundle: 40.6 ± 4.2 mm; PM bundle: 38.4 ± 3.8 mm).

CONCLUSION

The end-to-end distance of the AL and PM bundles of the PCL increased in flexion, and this pattern was maintained during tests with posterior translational force. The PM bundle was more affected by the rotational torque than was the AL bundle.

CLINICAL RELEVANCE

Both bundles of the PCL may serve a greater functional role in flexion than in extension. The PM bundle might be more important for the control of rotation than the AL bundle. Posterior translation at 90° of knee flexion could be the most stressful condition for both bundles of the PCL, which may have implications for an injury mechanism.

One-stage anatomic double bundle anterior and posterior cruciate ligament reconstruction

INTRODUCTION

Main evidence of the heavy knee dislocations is the rupture of both Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL). There are limited sources for the treatment of both ligaments at a single stage. Materials-method: One-staged anatomic double-bundle ACL and PCL reconstruction technique has been applied to 2 cases aged 20 and 36 with traumatic knee dislocation. Lateral collateral ligament and posteriolateral corner reconstruction added to one case, and medial collateral ligament and posteriomedial corner reconstruction for the other case. Because of additional femur fractures of the both cases, ligament reconstructions have been applied after the main treatment. Anterior tibialis tendon (ATT) allograft has been used for graft for both cases because of other stabilization deficiencies of knees. It has been confirmed that femoral and tibial tunnels constructed with anatomic double-bundle technique are fitting to anatomic locations by the post-operation CT results. Post fixation screw has been used for tibia, and endobutton at femur.

RESULTS

Tracking records of patients at 8th month shows that; Lysholm score of the case aged 20 was 89, and 85 for the case aged 36. While KT-1000 values was 3.7 mm, and 4.1 mm for 15 N power; and 9.1 mm-9.6 mm with the maximum power.

CONCLUSION

Surgical technical details of one-staged double-bundle reconstruction for ACL and PCL injuries which is gaining popularity recently has been stated.

The usefulness of the oblique coronal plane in knee MRI on the evaluation of the posterior cruciate ligament

BACKGROUND

Imaging findings of posterior cruciate ligament (PCL) injury may be equivocal, particularly when the patient has suffered a partial ligament tear. Some PCLs are positioned more horizontally, making it difficult to diagnose injury based on routine imaging planes alone due to partial volume artifact.

PURPOSE

To evaluate the diagnostic accuracy of combining oblique coronal imaging (PCL view) with traditional orthogonal views for PCL evaluation.

MATERIAL AND METHODS

This retrospective study included 20 patients with PCL injury and 43 patients with intact PCL who underwent PCL view imaging. Anatomic identification of PCL pathology on the orthogonal magnetic resonance imaging (MRI) sequences and PCL views was evaluated. Subjective scoring of the PCL was performed by two radiologists who assessed the possibility of a PCL tear based on an entire length view, an entire width view, and margin sharpness according to a 4-point scale. Diagnostic accuracy using these two views was evaluated by calculating the sensitivity, specificity, and accuracy. Arthroscopic and clinical findings were used as the reference standard.

RESULTS

Total scores for the PCL view were higher than those of orthogonal views (P < 0.001). Both readers found that anatomic identification using the full width view and sharp margin to be superior using the PCL view compared with the orthogonal views (P < 0.001). The specificities and accuracies were higher in cases where an additional PCL view was provided, but did not show statistical significance.

CONCLUSION

PCL view provides better anatomic evaluation of the PCL and mild improvement in the specificity and accuracy.

A prospective, randomized comparison of posterior stabilized versus cruciate-substituting total knee arthroplasty: a preliminary report with minimum 2-year results

We compared 56 patients who received a PS post/cam tibial insert and 55 patients who received a more congruent anterior-lipped tibial insert. We hypothesized that clinical outcomes would be equivalent and that tourniquet time and intraoperative blood loss would differ. The mean follow-up is 45 months (30-57 months). Clinical and radiographic outcomes were equivalent for both groups, except that male PS patients received significantly more transfusions than male CS patients (P<.039) and tourniquet time was significantly longer for all patients in the PS group (P<.015). At the minimum 2-year follow-up in this ongoing study, the results demonstrate equivalent functional and radiographic outcomes of the 2 devices, and significant differences in the perioperative findings of transfusion rates and tourniquet times.

Clinical, Functional, and Morphological Evaluations of Posterior Cruciate Ligament Reconstruction With Remnant Preservation: Minimum 2-Year Follow-up

BACKGROUND

Numerous posterior cruciate ligament (PCL) reconstruction techniques have evolved and have revealed satisfactory outcomes; however, the optimal operative method for PCL reconstruction remains controversial.

HYPOTHESIS

Transtibial PCL reconstruction with a remnant preservation technique would result in successful clinical, radiological, functional, and morphological outcomes. In addition, it was hypothesized that the results of combined PCL and posterolateral corner (PLC) reconstruction would be comparable with those of isolated PCL reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 168 patients who underwent arthroscopic PCL reconstruction with or without reconstruction of the PLC between March 2006 and June 2011 were retrospectively reviewed. Ninety-two patients who met the inclusion criteria were enrolled, and 47 of 92 patients who underwent combined PCL and PLC reconstruction were evaluated as a subgroup. The PLC was reconstructed using the single fibular sling method. The patients were assessed by means of the Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score, and Tegner activity score. Stability was evaluated using a KT-2000 arthrometer and Telos device. Proprioception was assessed using the Biodex System. Follow-up magnetic resonance imaging (MRI) was performed in 34 patients, and second-look arthroscopic surgery was conducted in 36 patients.

RESULTS

The minimum follow-up duration was 24 months in all patients. Clinical outcomes and posterior instability improved significantly. The mean Lysholm score improved from 56.7 ± 7.1 to 89.3 ± 7.3, the mean IKDC subjective knee score improved from 53.3 ± 9.6 to 86.2 ± 6.1, and the mean Tegner activity score was 2.5 ± 0.8 preoperatively and 5.1 ± 1.3 postoperatively (all P < .001). The mean side-to-side difference on posterior stress radiography with the Telos device improved significantly, decreasing from 12.1 ± 2.5 mm to 2.7 ± 1.3 mm (P < .001). The mean side-to-side difference on varus stress radiography was reduced from 5.9 ± 0.8 mm preoperatively to 1.3 ± 1.0 mm after combined PCL and PLC reconstruction (P < .001). Postoperative proprioception recovered to a level similar to that of the uninvolved side, and MRI and second-look arthroscopic surgery showed a high rate of complete healing and synovialization in patients who underwent either isolated PCL reconstruction or combined PLC and PCL reconstruction.

CONCLUSION

Transtibial PCL reconstruction with remnant preservation resulted in satisfactory clinical, functional, radiological, and morphological outcomes. The results of combined posterolateral rotatory instability were comparable with those for isolated PCL reconstruction with adequate PLC reconstruction.

Fixation of delayed union or non-union posterior cruciate ligament avulsion fractures

PURPOSE

To report the outcome of fixation for delayed union or non-union posterior cruciate ligament (PCL) avulsion fractures.

METHODS

Seven men and 4 women aged 24 to 35 (mean, 28) years underwent lag screw or suture fixation for non-union or delayed union of avulsion fracture of PCL tibial attachment after a mean delay of 8.6 (range, 4-14) months. Patient satisfaction was assessed using a visual analogue scale (VAS). Functional outcome was evaluated using the Lysholm scale.

RESULTS

The mean follow-up period was 17 (range, 8-36) months. The mean Lysholm score improved from 82 preoperatively to 92 at the final follow-up (p=0.34), the mean range of knee motion improved from 82º to 87º (p=0.008), and the mean VAS score for patient satisfaction improved from 4.3 to 7.4 (p=0.0004). All patients but one achieved bone union after a mean of 7.5 (range, 7-9) weeks. Functional outcome was excellent for 6 patients, good for 4, and fair for one. Posterior drawer test was positive (grade I laxity) in 3 patients whose outcome was good for 2 and fair for one. The latter had non-union after Ethibond suture repair for a communited fracture. There were no instances of wound complications or implant loosening.

CONCLUSION

Fixation with lag screw or suture combined with bone grafting for delayed union or non-union of PCL avulsion fractures achieves acceptable functional outcome.

Occupational consequences after isolated reconstruction of the insufficient posterior cruciate ligament

BACKGROUND

With incorrect or even without treatment, acute injuries of the posterior cruciate ligament (PCL) can lead to chronic instability of the knee joint. After delayed treatment, negative occupational changes and reduced quality of life can occur. These aspects have not yet been investigated. The purpose of this study was to evaluate occupational consequences after isolated reconstruction in cases of chronic PCL insufficiency.

FINDINGS

12 patients treated with PCL reconstruction in a single bundle technique, using hamstring tendon grafts, were evaluated. All patients were operated upon at least 3 months after injury. Mean time of follow-up was 51 ± 18.2 months (14-75). Radiological assessment (Telos stress device) showed a side comparison of total translation of 4.5 ± 2.6 mm. Occupational consequences have been evaluated by the classification system "REFA". Median time incapacity for work was 8 weeks. Nearly all patients achieved the mental status of the normal population (SF-36), but physical status was still restricted. A pre- to postoperative improvement of the clinical scores could be seen: Lysholm-Score: 46.4 ± 17.3 to 84.7 ± 14.1, HSS-Score: 74.3 ± 10.5 to 88.3 ± 10.7. Postoperative evaluated scores were: Tegner score: 4.8 ± 1.2, IKDC score: 80.0 ± 16.2, VPS: 3.4 ± 2.7. Patients with low physical load in their workplace described significantly better clinical results in every clinical score (p < .05) and less pain than patients with high physical load prior to the accident (VPS: REFA < 2: 2.4 ± 2.6, REFA ≥ 2: 5.5 ± 1.7; p < 0.05).

CONCLUSIONS

Operative treated patients with a chronic PCL insufficiency achieve an improvement of the clinical result. Patients with low physical load at their workplace achieve less restrictions.

High-energy bilateral knee dislocations in a young man: a case report

Bilateral knee dislocations are rare. We report one such case in a 22-year-old man. His clinical presentation, radiographical findings, and the operative and non-operative treatments are discussed, with emphasis on the timing of treatment and rehabilitation.