[Comparative study on effectiveness of posterior-posterior triangulation technique and anteroposterior approach for arthroscopic posterior cruciate ligament reconstruction]

Objective

To investigate the effectiveness of the posterior-posterior triangulation technique for arthroscopic posterior cruciate ligament (PCL) reconstruction by comparing with the anteroposterior approach.

Methods

Retrospective analysis was performed on 40 patients who underwent arthroscopic PCL reconstruction between February 2016 and February 2020. The PCLs were reconstructed via anteroposterior approach in 20 patients (anteroposterior approach group) and posterior-posterior triangulation technique in 20 patients (posterior-posterior triangulation technique group). There was no significant difference in gender, age, cause of injury, injury side, disease duration, preoperative International Knee Documentary Committee (IKDC) score, and Lysholm score between the two groups ( P>0.05). The operation time, surgical complications, and postoperative posterior drawer test, Lysholm score, and IKDC score were recorded and compared between the two groups.

Results

The operation time was (65.25±10.05) minutes in the anteroposterior approach group and (56.15±8.15) minutes in the posterior-posterior triangulation technique group, and the difference was significant ( t=3.145, P=0.003). All incisions healed by first intention, and there was no complication such as vascular and nerve injuries or infection. Patients were followed up (27.05±11.95) months in the anteroposterior approach group and (21.40±7.82) months in the posterior-posterior triangulation technique group, with no significant difference ( t=1.770, P=0.085). At last follow-up, the posterior drawer tests were positive in 4 cases (3 cases of stageⅠand 1 case of stage Ⅱ) of the anteroposterior approach group and in 1 case (stageⅠ) of the posterior-posterior triangulation technique group, showing no significant difference between the two groups ( P=0.342). At last follow-up, Lysholm score and IKDC score in both groups were significantly higher than those before operation ( P<0.05). The above functional scores in the posterior-posterior triangulation technique group were significantly higher than those in the anteroposterior approach group ( P<0.05). Imaging reexamination showed that the position, shape, and tension of the grafts were well in both groups, and the grafts were covered with the synovium in the posterior-posterior triangulation technique group, the meniscofemoral ligaments were well preserved. There was no re-rupture of the reconstructed ligament during follow-up.

Conclusion

Compared to the anteroposterior approach, the posterior-posterior triangulation technique provides a clearer view under arthroscopy, no blind spot, sufficient operating space, and relative safety. Moreover, it is easier to retain the remnant and the meniscofemoral ligaments, and can obtain good short-term effectiveness.

Gait Adaptations at 8 Years After Reconstruction of Unilateral Isolated and Combined Posterior Cruciate Ligament Injuries

BACKGROUND

It remains unclear how posterior cruciate ligament (PCL) reconstruction influences long-term lower extremity joint biomechanics.

PURPOSE

To determine whether patients who underwent PCL reconstruction exhibited long-term alterations in lower limb gait mechanics.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 26 patients underwent gait analyses at 8.2 ± 2.6 years after primary unilateral PCL reconstruction. Sex- and age-matched healthy controls were analyzed for comparison. Gait data were collected using motion capture and force plates. Hip, knee, and ankle angles and moments were compared during initial contact, early stance, and late stance for the reconstructed and uninjured contralateral limbs of patients who underwent PCL reconstruction (PCL group) as well as the limbs of healthy control participants (CON group).

RESULTS

No side-to-side kinematic differences were noted between the reconstructed and contralateral limbs of the PCL group; some trivial differences were noted in knee and hip moments. However, major differences between the PCL and CON groups occurred at the knee. Reconstructed and contralateral limbs of the PCL group exhibited larger knee flexion angles during initial contact (Δ = 7.0° [P < .001] and Δ = 6.9° [P < .001], respectively), early stance (Δ = 5.8° [P = .003] and Δ = 6.7° [P < .001], respectively), and late stance (Δ = 7.9° [P < .001] and Δ = 8.0° [P < .001], respectively) compared with the CON group. During early stance, contralateral limbs of the PCL group displayed larger knee flexion moments (Δ = 0.20 N·m/kg; P = .014) compared with the CON group, and both reconstructed (Δ = 0.05 N·m/kg; P = .027) and contralateral (Δ = 0.07 N·m/kg; P = .001) limbs of the PCL group exhibited larger knee external rotation moments compared with the CON group. During late stance, reconstructed and contralateral limbs of the PCL group exhibited smaller knee extension moments (Δ = 0.24 N·m/kg [P < .001] and Δ = 0.26 N·m/kg [P < .001], respectively) and knee internal rotation moments (Δ = 0.06 N·m/kg [P < .001] and Δ = 0.06 N·m/kg [P < .001], respectively) compared with the CON group. No discrepancies were observed at the hip; minimal differences were noted in sagittal-plane ankle mechanics.

CONCLUSION

Patients who underwent PCL reconstruction generally exhibited bilateral gait symmetry at 8 years after surgery. However, they exhibited important biomechanical deviations in both knees compared with healthy controls. These modifications likely reflect adaptive gait strategies to protect the PCL after reconstruction.

CLINICAL RELEVANCE

Long-term follow-up analyses of patients who underwent PCL reconstruction should not use the uninjured contralateral limb as a "healthy" reference, as it also exhibits mechanical differences compared with controls. Results could inform the development of neuromuscular and strength training programs targeting the restoration of knee biomechanics similar to healthy controls to prevent early-onset degeneration that is frequently associated with altered biomechanics.

Evaluation of Deep Vein Thrombosis Risk Factors After Arthroscopic Posterior Cruciate Ligament Reconstruction: A Retrospective Observational Study

We evaluated the risk factors of deep venous thrombosis (DVT) after knee arthroscopic posterior cruciate ligament (PCL) reconstruction in patients with only PCL injury. From August 2014 to December 2020, a total of 172 patients who had accepted knee arthroscopic PCL reconstruction underwent the color Doppler ultrasound of bilateral lower-extremities deep veins on 3 days postoperatively. Based on the inspection results, patients were divided into DVT group (18 males and 8 females, mean age 43.62 years) and non-DVT group (108 males and 38 females, mean age 33.96 years). The potential associations of DVT risk and age, gender, body mass index (BMI), diabetes, hypertension, smoking and other factors were analyzed. An old age (OR = 1.090; 95% CI = 1.025-1.158; P = 0.006), a high BMI (OR = 1.509; 95% CI = 1.181-1.929; P = 0.001) and an increased post-surgery D-dimer (OR = 5.034; 95% CI = 2.091-12,117; P ≤ 0.001) value were significantly associated with an elevated DVT risk after knee arthroscopic PCL reconstruction. Increased age, BMI, and postoperative D-dimer were risk factors of DVT following knee arthroscopic PCL reconstruction in patients with only PCL injury.

Three genes associated with anterior and posterior cruciate ligament injury : a genome-wide association analysis

AIMS

The aim of this study was to screen the entire genome for genetic markers associated with risk for anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injury.

METHODS

Genome-wide association (GWA) analyses were performed using data from the Kaiser Permanente Research Board (KPRB) and the UK Biobank. ACL and PCL injury cases were identified based on electronic health records from KPRB and the UK Biobank. GWA analyses from both cohorts were tested for ACL and PCL injury using a logistic regression model adjusting for sex, height, weight, age at enrolment, and race/ethnicity using allele counts for single nucleotide polymorphisms (SNPs). The data from the two GWA studies were combined in a meta-analysis. Candidate genes previously reported to show an association with ACL injury in athletes were also tested for association from the meta-analysis data from the KPRB and the UK Biobank GWA studies.

RESULTS

There was a total of 2,214 cases of ACL and PCL injury and 519,869 controls within the two cohorts, with three loci demonstrating a genome-wide significant association in the meta-analysis: INHBA, AEBP2, and LOC101927869. Of the eight candidate genes previously studied in the literature, six were present in the current dataset, and only COL3A1 (rs1800255) showed a significant association (p = 0.006).

CONCLUSION

Genetic markers in three novel loci in this study and one previously-studied candidate gene were identified as potential risk factors for ACL and PCL injury and deserve further validation and investigation of molecular mechanisms. Cite this article: Bone Jt Open 2021;2(6):414-421.

Surface metrology of bone surface attachments of knee ligaments

OBJECTIVES

Textural differences between entheses reflect biomechanical activities of the musculoskeletal system. Methods used to measure these surfaces have limitations. Here, the surface metrology of roughness of articular and entheseal surfaces of the knee are investigated with an optical profiler.

METHODS

Osteological specimens of six femora and seven tibiae were prepared from cadavers. Measurements were obtained to surrogate body mass. Specimens were molded with polyvinylsiloxane and casts prepared with resin, which were scanned using a white light optical profiler. Scans were processed by a computer program. Each scan produced 32 variables, categorized into 6 groups for each location.

RESULTS

The distribution of data was mostly normal. Analysis of variance (ANOVA) identified Ssk significant (p-value .002); post hoc Tukey testing indicated significance between femoral PCL and tibial ACL entheses groups (p-value .007), and between tibial ACL and tibial entheses groups (p-value .002) suggesting the ability to differentiate anterior and posterior cruciate ligament entheses. Sku was found significant with a t test between articular and entheseal surfaces. Correlation coefficients were significant between surface metrology parameters and measurements related to body mass.

CONCLUSIONS

This study distinguished differences between entheses of the anterior and posterior cruciate ligaments, with the Ssk parameter most useful. Differences in articular and entheseal surfaces were found with the Sku parameter most useful. Correlations indicated a relationship between body mass and surface metrology parameters. Finally, these findings suggest this method can be used for further investigation of spondyloarthropathies.

[Short-term effectiveness of arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon for posterior cruciate ligament injuries]

Objective

To investigate the short-term effectiveness of arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon for posterior cruciate ligament (PCL) injuries.

Methods

A clinical data of 30 patients with PCL injury, who were admitted between December 2015 and September 2018 and met the selection criteria, was retrospectively analyzed. All patients were treated with arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon and TightRope technique. Among them, 19 were male and 11 were female, aged 17-48 years (mean, 28.2 years). The PCL injury was caused by traffic accident in 8 cases, sport in 14 cases, falling and bruising by a heavy objective in 5 cases, and other injuries in 3 cases. The interval between injury and operation was 10-90 days (mean, 39.3 days). The PCL injury was rated as grade Ⅱ in 6 cases and grade Ⅲ in 24 cases. The posterior drawer test was positive in 26 cases and the inverse Lachman test was positive in 24 cases. The International Knee Documentation Committee (IKDC) score was 61.37±8.49, and the objective IKDC ligament grading was near normal in 2 cases, abnormal in 8 cases, and significantly abnormal in 20 cases. The modified Lysholm knee score was 62.20±5.67. The knee range of motion (ROM) was (101.83±8.15) °.

Results

The operative time ranged from 70 to 110 minutes (mean, 79.7 minutes). All incisions healed by first intetion. All patients were followed up 12-24 months (mean, 19.0 months). There were 3 cases of deep vein thrombosis in the lower extremity after operation, and 1 case of approximately 10° limitation of knee extension. At last follow-up, the posterior drawer test was positive in 2 cases and the inverse Lachman test was positive in 1 case, with significant differences compared with the preoperative period ( χ ²=38.571, P=0.000; χ ²=36.274, P=0.000). The IKDC score was 84.67±3.67, and the objective IKDC ligament grading was normal in 16 cases, nearly normal in 10 cases, abnormal in 3 cases, and significantly abnormal in 1 case; the modified Lysholm knee score was 90.37±4.49; all of the above indexes were significantly better than preoperative ones, and the differences were significant ( t=-12.387, P=0.000; Z=-2.810, P=0.005; t=-22.865, P=0.000). Knee ROM was (88.33±9.86)° at 1 month after operation and reached (113.33±13.48)° at last follow-up, showing significant differences between pre- and post-operation ( P<0.05). MRI re-examination showed that the form and position of reconstructed PCL were satisfactory.

Conclusion

It can obtain good short-term effectiveness for PCL injuries by arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon, which has the advantages of reliable surgical approach, safe operation, and precise effectiveness.

Comparing the Efficacy of Kneeling Stress Radiographs and Weighted Gravity Stress Radiographs to Assess Posterior Cruciate Ligament Insufficiency

BACKGROUND

Kneeling posterior cruciate ligament (PCL) stress radiographs are commonly used to evaluate PCL laxity. Patients, however, report significant pain, and the method's reproducibility may be challenged due to its dependence on patient body weight distribution to produce posterior tibial displacement. Weighted gravity stress radiography may offer better reproducibility and comfort than the kneeling technique, but its efficacy has not been studied.

HYPOTHESIS

Weighted gravity PCL stress radiographs will be more comfortable and produce similar measurements of side-to-side difference in posterior tibial displacement when compared with the kneeling technique.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A total of 40 patients with nonoperatively or >6 months postoperatively treated PCL injuries (isolated or multiligamentous) underwent bilateral stress radiographs. Weighted gravity and kneeling stress radiographs were acquired, in random order, for each patient, as well as side-to-side difference in posterior tibial displacement between each knee, patient-reported visual analog scale knee pain (100 mm), time to acquire the images, and patient preference for technique. Paired t tests were used to compare the side-to-side difference, pain score, and time to complete the radiographs.

RESULTS

There was no difference between the 2 radiographic methods in the mean side-to-side difference (gravity: 6.45 ± 4.61 mm, kneeling: 6.82 ± 4.60 mm; P = .72), time required to acquire radiographs (kneeling: 307.3 ± 140.5 seconds, gravity: 318.7 ± 151.1 seconds; P = .073), or number of radiographs taken to obtain acceptable images (kneeling: 3.6 ± 1.6, gravity: 3.7 ± 1.7; P = .73). Patients reported significantly less knee pain during the weighted gravity views (kneeling: 31.8 ± 26.6, gravity: 4.0 ± 12.0; P < .0001). Of the patients, 88% preferred the weighted gravity method.

CONCLUSION

Weighted gravity stress radiographs produce similar side-to-side differences in posterior tibial translation compared with the kneeling stress technique, but do not rely on patient weightbearing and provide significantly better patient comfort. Clinicians should therefore consider the use of weighted gravity stress radiographs in clinical practice to minimize the pain associated with stress radiography while allowing for accurate decision making.

Posterior Cruciate Ligament Resection Does Not Consistently Increase the Flexion Space in Contemporary Total Knee Arthroplasty

INTRODUCTION

It is accepted dogma in total knee arthroplasty (TKA) that resecting the posterior cruciate ligament (PCL) increases the flexion-space by approximately 4mm. Unfortunately, this doctrine is based on historical studies of limited size with variable technique. The aim of this study was to determine the effect of PCL-resection on in vivo tibiofemoral joint space dimensions in a cohort of modern TKAs.

METHODS

Tibiofemoral joint space measurements were made during 129 standardized TKAs by two arthroplasty surgeons. A medial parapatellar approach, computer navigation and provisional bone cuts were performed in all cases with particular attention to preserving PCL integrity. The tibiofemoral gap was measured with a calibrated tension device at extension, 45-degrees, and 90-degrees before and after complete PCL-resection.

RESULTS

51% of patients were female (66/129) with mean age and BMI of 69.5 years and 34.2 kg/m², respectively. After PCL-resection, mean change in center joint space dimension increased 0.33mm at extension, 0.95mm at 45-degrees, and 1.71mm at 90-degrees (P < .001). The 90-degree flexion-space opened ≥4mm in only 10% of patients. Dividing the flexion-space change by femoral implant dimension to account for patient size, the flexion-space at 90-degrees significantly increased more in females compared to males (P = .020).

CONCLUSION

The tibiofemoral joint space increased progressively from extension to mid-flexion through deep-flexion after PCL-resection, yet was substantially less than reported in historical studies. However, large variation in flexion-space opening was observed with some patients failing to increase the flexion-space whatsoever with PCL-resection. This runs counter to conventional TKA understanding and should be considered in modern surgical education.

LEVEL OF EVIDENCE

Therapeutic Level III.

[Study on reconstruction of posterior cruciate ligament with autologous peroneus longus tendon under arthroscopy]

Objective

To discuss the effectiveness of posterior cruciate ligament (PCL) reconstruction with autologous peroneus longus tendon under arthroscopy.

Methods

Between January 2016 and December 2018, 46 patients with PCL injuries were enrolled. There were 34 males and 12 females, with an average age of 40.7 years (range, 20-58 years). There were 43 cases of acute injury and 3 cases of old injury. The anterior drawer test and the posterior tibia sign were positive in 4 cases, the posterior drawer tests and the posterior tibia sign were positive in 46 cases, the varus stress tests were positive in 10 cases, and the valgus stress tests were positive in 6 cases. The difference of dial-test at 30° knee flexion between affected and healthy sides was (5.20±3.91)°. The tibia posterior displacement under posterior stress position was (12.03±2.38) mm. The Lysholm score of the knee joint was 36.68±7.89, the International Knee Documentation Committee (IKDC) score was 33.58±5.97, and the American Orthopaedic Foot and Ankle Association (AOFAS) score of the ankle joint was 97.60±1.85. PCL was reconstructed with autologous peroneus longus tendon under arthroscopy, and the combined meniscus injury, posterolateral complex injury, and anterior cruciate ligament injury were all treated according to the degree of injury.

Results

All incisions healed by first intention. Forty patients were followed up 12-26 months, with an average of 16.0 months. At last follow-up, the Lysholm score of the knee joint was 84.85±7.03, and the IKDC score was 87.13±6.27, which were significant different from preoperative ones ( t=-13.45, P=0.00; t= -39.12, P=0.00); the AOFAS score of ankle joint was 93.98±2.14, which was not significant different from preoperative one ( t=8.09, P=0.90). The tibia posterior displacement under posterior stress position was (2.75±1.76) mm and the difference of dial-test at 30° knee flexion between affected and healthy sides was (1.75±2.09)°, which were significant different from preoperative ones ( t=29.00, P=0.00; t=4.96, P=0.00). The posterior drawer test and the posterior tibia sign were positive in 1 case and negative in 39 cases; the anterior drawer test and the varus and valgus stress tests were all negative.

Conclusion

Reconstruction of PCL with autologous peroneus longus tendon under arthroscopy can significantly improve the stability and function of the knee joint, with satisfactory clinical results.

Comparable Clinical and Radiologic Outcomes Between an Anatomic Tunnel and a Low Tibial Tunnel in Remnant-Preserving Posterior Cruciate Ligament Reconstruction

Background:

There is currently no consensus on the optimal placement of the tibial tunnel for remnant-preserving posterior cruciate ligament (PCL) reconstruction.

Purpose/Hypothesis:

The purpose of this study was to compare the clinical and radiologic outcomes of remnant-preserving PCL reconstruction using anatomic versus low tibial tunnels. We hypothesized that the outcomes of low tibial tunnel placement would be superior to those of anatomic tibial tunnel placement at the 2-year follow-up after remnant-preserving PCL reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively reviewed the data for patients who underwent remnant-preserving PCL reconstruction between March 2011 and January 2018 with a minimum follow-up of 2 years (N = 63). On the basis of the tibial tunnel position on postoperative computed tomography, the patients were divided into those with anatomic placement (group A; n = 31) and those with low tunnel placement (group L; n = 32). Clinical scores (International Knee Documentation Committee subjective score, Lysholm score, and Tegner activity level), range of motion, complications, and stability test outcomes at follow-up were compared between the 2 groups. Graft signal on 1-year follow-up magnetic resonance imaging scans was compared between 22 patients in group A and 17 patients in group L.

Results:

There were no significant differences between groups regarding clinical scores or incidence of complications, no between-group differences in posterior drawer test results, and no side-to-side difference on Telos stress radiographs (5.2 ± 2.9 mm in group A vs 5.1 ± 2.8 mm in group L; P = .900). Postoperative 1-year follow-up magnetic resonance imaging scans showed excellent graft healing in both groups, with no significant difference between them.

Conclusion:

The clinical and radiologic outcomes and complication rate were comparable between anatomic tunnel placement and low tibial tunnel placement at 2-year follow-up after remnant-preserving PCL reconstruction. The findings of this study suggest that both tibial tunnel positions are clinically feasible for remnant-preserving PCL reconstruction.

Quadriceps tendon autograft is an effective alternative graft for posterior cruciate ligament reconstruction in isolated or multiligament injuries: a systematic review

IMPORTANCE

High-grade posterior cruciate ligament (PCL) tears can be a significant cause of patient morbidity and knee instability. The graft of choice for operative repair remains controversial, although recently there has been increased interest in quadriceps tendon (QT) as an autologous graft option.

OBJECTIVE

The purpose of this study was to perform a systematic review to assess reported clinical outcomes of PCL reconstructions using QT autografts.

EVIDENCE REVIEW

A comprehensive review of clinical studies was performed evaluating PCL reconstruction with QT autograft including a systematic search of PubMed, Scopus, Cochrane and Google Scholar databases, and reference lists of relevant papers. Clinical results, stability results, functional outcomes, range-of-motion outcomes, complications and morbidity, and the conclusions of each study were evaluated.

FINDINGS

Seven studies were included in the review of clinical results, including 145 subjects undergoing PCL reconstructions with QT autograft. All studies evaluated quadriceps tendon bone (QT-B) grafts. Among these seven studies, two included isolated PCL reconstruction while five included multiligamentous knee injury reconstruction. These studies suggest that QT-B autograft offers a viable graft option for primary PCL reconstruction with generally favourable patient-reported outcomes, knee stability and range of motion reported along with relatively low complication rates.

CONCLUSIONS AND RELEVANCE

Use of the QT-B autograft may be a reasonable graft option for PCL reconstruction. However, high-quality prospective studies are required to evaluate the long-term safety, efficacy and functional outcomes.

LEVEL OF EVIDENCE

Level IV (Systematic review of Level IV studies).

Evaluating Posterior Cruciate Ligament Integrity in Inflammatory Arthritis Patients Prescribed Biologic Agents: A Radiological Case-Control Study

Introduction

Patients with inflammatory arthropathies present a significant challenge to the arthroplasty surgeon when they present with symptomatic degenerative changes of their knee joint. Debate is ongoing regarding the selection of implants for this cohort of patients. There is conflicting evidence for the use of posterior-stabilising (PS) over cruciate-retaining (CR) designs in this cohort. Biologics are licensed for use in moderate-to-severe disease that has not responded to conventional treatment. To our knowledge, there are no studies that have assessed the integrity of the posterior cruciate ligament (PCL) on magnetic resonance imaging (MRI) in these patients with more advanced disease prescribed biologic agents.

Aim

The aim of this study is to assess the integrity of the PCL on MRI in patients with inflammatory arthritis who are prescribed biologic agents.

Methods

A case-control study was performed, with cases identified through chart review to confirm prescription of biologic agents for inflammatory arthropathies, who also had contemporaneous MRI knee scans performed. Knee MRIs for age- and sex-matched controls with osteoarthritis (OA) and meniscal pathology were identified from the National Joint Registry and the Hospital In-Patient Enquiry (HIPE), respectively.

The MRIs were reviewed by two musculoskeletal radiologists who were blinded to the clinical details. They were asked to assess the MRIs to determine PCL integrity, synovial Inflammation, and any associated pathology.

Results

No difference was noted in the rate of synovitis, PCL attenuation, or PCL tears between the OA and inflammatory arthropathy groups (p > 0.05).

Conclusions

The results of this study show no difference in the integrity and continuity of the PCL in those patients for age- and sex-matched controls on MRI. This finding lends support to the use of CR total knee arthroplasty in patients with inflammatory arthropathy on biologic agents.

Tunnel Enlargement Correlates With Postoperative Posterior Laxity After Double-Bundle Posterior Cruciate Ligament Reconstruction

Background:

There exists little information in the relevant literature regarding tunnel enlargement after posterior cruciate ligament (PCL) reconstruction (PCLR).

Purpose:

To sequentially evaluate tunnel enlargement and radiographic posterior laxity through double-bundle PCLR using autologous hamstring tendon grafts.

Study Design:

Case series; Level of evidence, 4.

Methods:

We prospectively analyzed 13 patients who underwent double-bundle PCLR for an isolated PCL injury. Three-dimensional computed tomography images were obtained at 3 weeks, 6 months, and 1 year postoperatively, and the tunnel enlargement was calculated by sequentially comparing the cross-sectional areas of the bone tunnels. We also sequentially measured radiographic posterior laxity. The correlation between the tunnel enlargement ratio and the postoperative increase in posterior laxity was evaluated.

Results:

The cross-sectional area at the aperture in each tunnel significantly increased from 3 weeks to 6 months (P < .003), but it did not continue doing so thereafter. The 6-month tunnel enlargement ratios of the femoral anterolateral tunnel, the femoral posteromedial tunnel, the tibial anterolateral tunnel, and the tibial posteromedial tunnel were 31.6% ± 23.5%, 90.3% ± 54.7%, 30.5% ± 26.8%, and 49.6% ± 37.0%, respectively, while the corresponding ratios at 1 year were 28.1% ± 19.8%, 83.1% ± 56.9%, 26.8% ± 32.8%, and 47.6% ± 39.0%, respectively. The posterior laxity was 9.0 ± 4.0 mm, −1.5 ± 2.3 mm, 3.4 ± 2.0 mm, and 3.9 ± 1.9 mm, preoperatively, immediately after surgery, 6 months and 1 year postoperatively, respectively. From the immediate postoperative period, the posterior laxity significantly increased at 6 months postoperatively (P < .001), but it did not thereafter. The postoperative increase in posterior laxity had a significant positive correlation with the anterolateral tunnel enlargement ratio in both femoral and tibial tunnels at 6 months (ρ = 0.571-0.699; P = .011-.041) and 1 year (ρ = 0.582-0.615; P = .033-.037).

Conclusion:

Tunnel enlargement after PCLR mainly occurred within 6 months, with no progression thereafter. The anterolateral tunnel enlargement positively correlated with postoperative increase in posterior laxity.

[Effectiveness comparison of partial versus intact posterior cruciate ligament-retaining in total knee arthroplasty with cruciate-retaining prosthesis]

Objective

To compare the effectiveness of partial versus intact posterior cruciate ligament (PCL)-retaining in total knee arthroplasty (TKA) with cruciate-retaining (CR) prosthesis.

Methods

A total of 200 patients with osteoarthritis, who met the selection criteria and proposed unilateral TKA with CR prosthesis, were included in the study and randomly assigned into two groups ( n=100). The patients were treated with intact retention of the double bundles of PCL in intact group and with partial resection of the anterior lateral bundle of PCL and the anterior bone island at the time of intraoperative tibial osteotomy in partial group. Patients with lost follow-up and re-fracture were excluded, and 84 cases in partial group and 88 cases in intact group were included in the final study. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, body mass index, course and grade of osteoarthritis, preoperative varus deformity of knee joint, flexion contracture, range of motion, clinical and functional scores of Knee Society Score (KSS). The operation time, wound drainage volume during 24 hours after operation, visual analogue scale (VAS) score at 24 hours after operation, range of motion of knee joint, clinical and functional scores of KSS, and the anteroposterior displacement of knee joint at 30° and 90° flexion positions were compared between the two groups.

Results

There was no significant difference between the two groups in operation time, wound drainage volume during 24 hours after operation, and VAS score at 24 hours after operation ( P>0.05). Patients in both groups were followed up after operation. The follow-up time was 25-40 months (mean, 30.2 months) in intact group and 24-40 months (mean, 31.8 months) in partial group. There was no significant difference in the range of motion and clinical scores of KSS between the two groups at 6, 12, and 24 months after operation ( P>0.05). The functional scores of KSS were significantly higher in intact group than in partial group ( P<0.05). There was no significant difference between the two groups in the anteroposterior displacement of knee joints at 30° flexion position at 6, 12, and 24 months after operation ( P>0.05). When the knee was at 90° flexion position, there was no significant difference between the two groups at 6 and 12 months after operation ( P>0.05), but the intact group was significantly smaller than partial group at 24 months after operation ( P<0.05). Postoperative incision continued exudation in 4 patients (2 cases of partial group and 2 cases of intact group), and incision debridement in 2 patients (1 case of partial group and 1 case of intact group). No prosthesis loosening, excessive wear, or dislocation of gasket was found during follow-up.

Conclusion

The double bundle of PCL plays an equally important role in maintaining the stability of the knee joint, and the integrity of PCL should be kept as much as possible when TKA is performed with CR prosthesis.

Posterior Cruciate Ligament Repair With Suture Augmentation: A Report of Two Cases With Two-Year Follow-Up

We present two cases of posterior cruciate ligament (PCL) repair with suture augmentation (SA) in the setting of multiligamentous knee injury (MLKI). Excellent clinical outcomes were obtained at two-year follow-up with both patients returning to sport following injury. Both patients demonstrated improvements in Knee Injury and Osteoarthritis Outcome Score (KOOS) that exceeded the minimal clinically important difference (MCID) as reported in the literature for ligamentous knee injuries. One patient developed arthrofibrosis, which was successfully treated with manipulation under anesthesia and arthroscopic lysis of adhesions two months postoperatively. Both patients had full knee range of motion (ROM) by a one-year follow-up. One patient returned to full preinjury level of sport at six months postoperatively while the other patient returned to 50% of preinjury intensity at two-year follow-up. This series of two cases of PCL repair with SA in MLKIs demonstrates that PCL repair with SA is a viable procedure that can result in excellent short-term outcomes and restore knee stability.

[Functional assessment in total knee arthroplasty comparing the posterior cruciate ligament preservation versus postero-stabilization]

INTRODUCTION

The two most commonly used types of prostheses are the total knee prosthesis with posterior cruciate ligament preservation and posterior cruciate ligament replacement.

OBJECTIVE

To assess whether there is a difference in functionality between the two procedures.

MATERIAL AND METHODS

Observational, retrospective and cross-sectional study with 134 patients divided into group A (N = 67) with ligament preservation and group B (N = 67) with posterior substituting. Using the American Association Scale for Knee Prosthetics with Insall modification to assess functionality. Statistical analysis: use of 2 with Yates correction.

RESULTS

In group A the results: excellent (31%); good (24%); regular (22%) bad (22%). In group B the results: excellent (34%); good (31%); regular (16%) and bad (19%); without statistical difference between the two groups.

CONCLUSIONS

No statistically significant difference was observed between age, gender, laterality of injury, or between number of patients with excellent results, good regular and bad according to the scale used. The high percentage of poor results in both groups of this series for the knee prosthesis is striking.

Knee Dislocation with Ipsilateral Tibial Fracture Treated with an Intramedullary Locked Nail and Simultaneous Transtibial Tunnel Knee Ligament Reconstruction: A Case Report of Autografts and Limited Resources

Knee dislocations associated with ipsilateral tibial shaft fracture represent one of the most challenging injuries in trauma surgery. This injury occurs in only 2% of all tibial fractures in several series. With the use of intramedullary nail (IMN) of the tibia, current practice paraments suggest that transtibial tunnels should be avoided and ligamentous knee surgery be delayed until healing of the shaft fracture occurs. We report a novel case which was successfully managed by delayed IMN and multiligamentous transtibial posterior cruciate ligament (PCL) and posterolateral corner (PLC) autograft reconstructions. A 27-year-old male sustained a Gustilo-Anderson grade IIIa tibial shaft fracture and a Schenck IIIL knee dislocation (KD3L) in the ipsilateral knee. At 2 weeks, the patient was then taken back to the operating theater to undergo definitive bone fixation and ipsilateral simultaneous knee ligamentous reconstruction. The knee was stabilized by open reconstruction of the PCL under fluoroscopic control using an ipsilateral quadriceps autograft fixed with metallic interference screws. The PLC was reconstructed with ipsilateral semitendinosus autograft harvested through a separate 1.5-cm standard anteromedial incision using the technique described by Stannard et al. After graft fixation, the 90 degree posterior and posterolateral drawer and 0 and 30 degrees varus stress tests were negative. After 12 months follow-up, the patient had no complaints regarding pain or instability. The tibial fracture had healed and no knee axis deviation could be noted. The patient had returned to recreational low demand activities and motorcycle riding. Treatment of a combined tibial shaft fracture with an ipsilateral knee dislocation may be satisfactorily accomplished with an IMN for the tibia and transtibial tunnel fixation for knee ligament reconstruction allowing for a single rehabilitation course and a shorter recovery without having to use a third stage for knee ligamentous reconstruction.

Arthroscopic Suture Fixation With Autograft Augmentation Reconstruction for Delayed Tibial Avulsion Fractures of the Posterior Cruciate Ligament

Background:

The optimal surgical treatment of delayed avulsion fractures of the posterior cruciate ligament (PCL) is still controversial.

Purpose:

To evaluate the clinical results of arthroscopic suture fixation of tibial avulsion fractures of the PCL with autograft augmentation reconstruction.

Study Design:

Case series; Level of evidence, 4.

Methods:

From January 2013 to February 2017, we treated 15 patients with delayed tibial avulsion fractures of the PCL arthroscopically through posteromedial and posterolateral portals. The PCL and avulsion bone fragment were fixed with No. 2 nonabsorbable FiberWire sutures that were pulled out through a single tibial bone tunnel and fixed on a small Endobutton. Concomitantly, anatomic PCL augmentation reconstruction was performed, and the graft was pulled out through the same tunnel and fixed with an interference screw. Knee stability was assessed using the posterior drawer test, and the side-to-side difference was determined using a KT-1000 arthrometer with 134 N of posterior force at 30° of knee flexion. The International Knee Documentation Committee (IKDC) 2000 subjective form and Lysholm scale were used to evaluate clinical outcomes at follow-up. Overall, 12 patients were enrolled for analysis. The mean follow-up period was 34.4 months (range, 26-49 months).

Results:

At the final follow-up, 2 patients encountered 10° terminal flexion limitations. All patients had negative posterior drawer test results. The KT-1000 arthrometer side-to-side difference was significantly decreased from 8.25 ± 1.96 mm preoperatively to 1.08 ± 0.86 mm at the last follow-up (P < .001). The mean IKDC and Lysholm scores, respectively, increased from 54.67 ± 7.13 and 53.50 ± 7.90 preoperatively to 91.13 ± 3.78 and 94.25 ± 3.32 at the final follow-up (P < .001 for both).

Conclusion:

Arthroscopic suture fixation with autograft augmentation reconstruction for delayed tibial avulsion fractures of the PCL showed good clinical stability and function in this study.

Lower Tibial Tunnel Placement in Isolated Posterior Cruciate Ligament Reconstruction: Clinical Outcomes and Quantitative Radiological Analysis of the Killer Turn

Background

The "killer turn" effect after posterior cruciate ligament (PCL) reconstruction is a problem that can lead to graft laxity or failure. Solutions for this situation are currently lacking.

Purpose

To evaluate the clinical outcomes of a modified procedure for PCL reconstruction and quantify the killer turn using 3-dimensional (3D) computed tomography (CT).

Study design

Case series; Level of evidence, 4.

Methods

A total of 15 patients underwent modified PCL reconstruction with the tibial aperture below the center of the PCL footprint. Next, 2 virtual tibial tunnels with anatomic and proximal tibial apertures were created on 3D CT. All patients were assessed according to the Lysholm score, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Tegner score, side-to-side difference (SSD) in tibial posterior translation using stress radiography, and 3D gait analysis.

Results

The modified tibial tunnel showed 2 significantly gentler turns (superior, 109.87° ± 10.12°; inferior, 151.25° ± 9.07°) compared with those reconstructed with anatomic (91.33° ± 7.28°; P < .001 for both comparisons) and proximal (99° ± 7.92°; P = .023 and P < .001, respectively) tibial apertures. The distance from the footprint to the tibial aperture was 16.49 ± 3.73 mm. All patient-reported outcome scores (mean ± SD) improved from pre- to postoperatively: Lysholm score, from 46.4 ± 18.87 to 83.47 ± 10.54 (P < .001); Tegner score, from 2.47 ± 1.85 to 6.07 ± 1.58 (P < .001); IKDC sports activities score, from 19 ± 9.90 to 33.07 ± 5.35 (P < .001); and IKDC knee symptoms score, from 17.87 ± 6.31 to 25.67 ± 3.66 (P < .001). The mean SSD improved from 9.15 ± 2.27 mm preoperatively to 4.20 ± 2.31 mm postoperatively (P < .001). The reconstructed knee showed significantly more adduction (by 1.642°), less flexion (by 1.285°), and more lateral translation (by 0.279 mm) than that of the intact knee (P < .001 for all).

Conclusion

Lowering the tibial aperture during PCL reconstruction reduced the killer turn, and the clinical outcomes remained satisfactory. However, SSD and clinical outcomes were similar to those of previously described techniques using an anatomic tibial tunnel.

[Effectiveness comparison of LARS artificial ligament and autogenous hamstring tendon in one-stage reconstruction of anterior and posterior cruciate ligaments]

OBJECTIVE

To compare the effectiveness of arthroscopic one-stage reconstruction of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) with LARS artificial ligament and autogenous hamstring tendon, respectively.

METHODS

A retrospective study was performed on 23 patients with ACL and PCL injuries, who were treated with one-stage reconstruction, between June 2013 and June 2017. The ACL and PCL were reconstructed with LARS artificial ligament in 11 patients (artificial ligament group) and autogenous hamstring tendon in 12 patients (autogenous tendon group). There was no significant difference in gender, age, side of injury, cause of injury, time from injury to operation, and preoperative Lysholm score and International Knee Documentation Committee (IKDC) score between the two groups ( P>0.05). The operation time, the time of recovery of daily activities and preoperative exercise level, the occurrence of surgical-related complications, Lysholm score, IKDC score, and the results of knee stability assessment were recorded and compared between the two groups.

RESULTS

The operation time and the time of recovery of daily activities and preoperative exercise level were significantly shorter in artificial ligament group than in autogenous tendon group ( P<0.05). All incisions healed primarily. In autogenous tendon group, the common fibular nerve injury occurred in 1 case and intermuscular vein thrombosis occurred in 1 case. No complication occurred in the remaining patients of the two groups. All the patients were followed up 24-54 months (mean, 36.4 months). At last follow-up, the Lysholm score and IKDC score of the two groups were significantly higher than preoperative scores ( P<0.05). There was no significant difference between the two groups ( P>0.05). The varus and valgus stress tests of the two groups were negative. There was no significant difference in anterior drawer test, posterior drawer test, and Lachman test between the two groups ( P>0.05).

CONCLUSION

The effectiveness of arthroscopic one-stage reconstruction of ACL and PCL with LARS artificial ligament or autogenous hamstring tendon was similar. The knee function and stability recover well. But the patients with LARS artificial ligament reconstruction can resume daily activities and return to exercise earlier.

Elongation Patterns of the Posterior Cruciate Ligament after Total Knee Arthroplasty

This study aimed to understand the ability of fixed-bearing posterior cruciate ligament (PCL)-retaining implants to maintain functionality of the PCL in vivo. To achieve this, elongation of the PCL was examined in six subjects with good clinical and functional outcomes using 3D kinematics reconstructed from video-fluoroscopy, together with multibody modelling of the knee. Here, length-change patterns of the ligament bundles were tracked throughout complete cycles of level walking and stair descent. Throughout both activities, elongation of the anterolateral bundle exhibited a flexion-dependent pattern with more stretching during swing than stance phase (e.g., at 40° flexion, anterolateral bundle experienced 3.9% strain during stance and 9.1% during swing phase of stair descent). The posteromedial bundle remained shorter than its reference length (defined at heel strike of the level gait cycle) during both activities. Compared with loading patterns of the healthy ligament, postoperative elongation patterns indicate a slackening of the ligament at early flexion followed by peak ligament lengths at considerably smaller flexion angles. The reported data provide a novel insight into in vivo PCL function during activities of daily living that has not been captured previously. The findings support previous investigations reporting difficulties in achieving a balanced tension in the retained PCL.

Lower Limb Biomechanics During Level Walking After an Isolated Posterior Cruciate Ligament Rupture

Background:

The posterior cruciate ligament (PCL) is an important structure in knee stabilization. Knee cartilage degeneration after a PCL injury has been reported in several studies. Understanding the changes in movement patterns of patients with PCL ruptures could help clinicians make specific treatment protocols to restore patients’ sporting ability and prevent joint degeneration. However, the kinematics and kinetics of the lower limb in patients with PCL injuries are still not clear.

Purpose:

To investigate the biomechanical characteristics during level walking in patients with isolated PCL deficiency.

Study Design:

Controlled laboratory study.

Methods:

Three-dimensional videographic and force plate data were collected for 27 healthy male participants (control group) and 25 male patients with isolated PCL-deficiency (PCL-d group) walking at a constant self-selected speed. Paired and independent t tests were performed to determine the differences between the involved and uninvolved legs in the PCL-d group and between the PCL-d and control groups, respectively.

Results:

Compared with the control leg, both legs in the PCL-d group had smaller knee moments of flexion and internal rotation; greater hip angles of flexion and adduction; greater hip moments of internal rotation; greater ankle angles of extension and adduction; and smaller ankle moments of flexion, adduction, and internal rotation. Moreover, compared with the uninvolved leg in the PCL-d group, the involved leg in the PCL-d group had significantly smaller knee extension angles and moments during the terminal stance phase, greater hip external rotation angles and extension moments, and smaller ankle adduction angles and flexion moments.

Conclusion:

PCL ruptures altered walking patterns in both the involved and uninvolved legs, which could affect alignment of the lower limb and loading on the knee, hip, and ankle joints. Patients with PCL injuries adapted their hip and ankle to maintain knee stability.

Clinical Relevance:

The kinematic and kinetic adaptations in the knee, hip, and ankle after a PCL rupture during level walking are likely to be a compensatory strategy for knee instability. The results of this study suggest that these adaptations should be considered in the treatment of patients with PCL ruptures.

[Clinical study on reconstruction of posterior cruciate ligament with platelet rich plasma combined with 3-strand peroneus longus tendons]

OBJECTIVE

To investigate the effectiveness of the reconstruction of posterior cruciate ligament (PCL) with platelet rich plasma (PRP) and 3-strand peroneal longus tendons under arthroscope.

METHODS

Between June 2014 and December 2017, 58 patients with PCL rupture were randomly divided into two groups: the trial group (PRP assisted reconstruction of 3-strand peroneal longus tendons) and the control group (4-strand hamstring tendon reconstruction alone), 29 cases in each group. There was no significant difference in gender, age, injury side, Kellgren-Lawrence grade, time from injury to operation, and preoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, International Knee Documentation Committee (IKDC) score, Lysholm score between the two groups ( P>0.05). Before operation, at 3 months and 12 months after operation, the IKDC score and Lysholm score of the two groups were recorded to evaluate the knee joint function, AOFAS ankle-hindfoot score was used to evaluate ankle function; KT-2000 examination (knee flexion of 90°, 30 lbs) was used to evaluate the difference of bilateral knee joint posterior relaxation at 12 months after operation, and MRI was used to evaluate ligament reconstruction; CT was used to evaluate the bone tunnel expansion of femur and tibia at 3 months and 12 months after operation.

RESULTS

The operation was completed successfully in both groups, there was no complication in the donor tendon area. All the incisions healed by first intention. All the patients were followed up for more than 1 year. The follow-up time of the trial group was 13-17 months, with an average of 15.0 months; that of the control group was 15-20 months, with an average of 15.4 months. At 3 and 12 months after operation, there was no significant difference in AOFAS ankle-hindfoot score when compared with preoperative score and between the two groups ( P>0.05). At 3 and 12 months after operation, the IKDC score and Lysholm score of the two groups were significantly improved, and further improvement was found at 12 months when compared with at 3 months ( P<0.05); the scores in the trial group were significantly better than those of the control group ( P<0.05). At 12 months after operation, the difference of the posterior relaxation of the bilateral knees in the trial group was less than 5 mm in 27 cases, 6-10 mm in 2 cases; in the control group was less than 5 mm in 20 cases, 6-10 mm in 6 cases, and >10 mm in 3 cases; the difference between the two groups was not significant ( Z=0.606, P=0.544). At 12 months after operation, MRI of knee joint showed that all patients had good PCL graft. The MRI score of the trial group was better than that of the control group ( t=2.425, P=0.019). CT examination at 3 and 12 months after operation showed that the bone tunnel expansion of femur and tibia in the trial group were significantly better than those in the control group ( P<0.05).

CONCLUSION

PRP combined with 3-stand peroneal longus tendons can significantly improve the function and stability of knee joint, effectively promote graft remodeling, and promote tendon bone healing, reduce the expansion of bone tunnel. The effectiveness is satisfactory.

[The killer turn in the posterior cruciate ligament reconstruction: mechanism and improvement]

OBJECTIVE

To summarize the research progress of killer turn in posterior cruciate ligament (PCL) reconstruction.

METHODS

The literature related to the killer turn in PCL reconstruction in recent years was searched and summarized.

RESULTS

The recent studies show that the killer turn is considered to be the most critical cause of graft relaxation after PCL reconstruction. In clinic, this effect can be reduced by changing the fixation mode of bone tunnel, changing the orientation of bone tunnel, squeezing screw fixation, retaining the remnant, and grinding the bone at the exit of bone tunnel. But there is still a lack of long-term follow-up.

CONCLUSION

There are still a lot of controversies on the improved strategies of the killer turn. More detailed basic researches focusing on biomechanics to further explore the mechanism of the reconstructed graft abrasion are needed.