Evaluation and treatment of posterior cruciate ligament injuries

Clinical efficacy of arthroscopic high-intensity suture binding combined with button plate suspension fixation in the treatment of posterior cruciate ligament tibial avulsion fractures

PURPOSE

To assess the clinical efficacy of arthroscopic treatment for posterior cruciate ligament (PCL) tibial avulsion fractures using high-intensity suture binding combined with button plate suspension fixation.

METHODS

We retrospectively analyzed clinical data from 32 patients with PCL tibial avulsion fractures treated at our hospital from July 2020 to August 2023. We recorded operation time, intraoperative and postoperative complications, and used imaging to assess fracture reduction and healing. Pain and knee function were evaluated using the Visual Analogue Scale (VAS), range of knee motion, Lysholm score, and International Knee Documentation Committee (IKDC) score.

STUDY DESIGN

Case series; Level of evidence, 4.

RESULTS

All patients were followed for 6 to 18 months, averaging 13.6 months. All incisions healed successfully without postoperative complications. X-rays taken on the first postoperative day showed satisfactory fracture reduction. Three-month post-surgery imaging confirmed healed fractures and no internal fixation failures. At the final follow-up, knee function was well recovered, with only one patient exhibiting a positive posterior drawer test of degree I. Furthermore, the mean VAS score was 0. 5 (range 0.0 to 1.0), active knee extension was 2. 2° (range 0.0 to 5.0), and active knee flexion was 137.7° (range 130.0 to 145.0). The mean Lysholm score was 91.5(range 89.3 to 94.0), and the IKDC score averaged 83.8 ± 3.7, and these outcomes showed statistically significant improvement from preoperative levels (P < 0.001).

CONCLUSIONS

Arthroscopic high-intensity suture binding combined with button plate suspension fixation for PCL tibial avulsion fractures offers several benefits: it is minimally invasive, results in less postoperative pain, enables earlier functional exercise, and provides satisfactory clinical outcomes with fewer complications.

[Treatment of Injuries to the Posterior Cruciate Ligament]

Compared to the anterior cruciate ligament injury, the rupture of the posterior cruciate Ligament (PCL) is the rarer condition. A high healing potential is attributed to the PCL in the literature, which is why conservative therapy is also considered important in addition to surgical treatment 1. Posterior cruciate ligament rupture is often associated with concomitant injuries. Among other things, up to 70% of cases are associated with accompanying injuries to the posterolateral corner 2. The detection of concomitant injuries has a significant influence on the outcome, as isolated surgical PCL stabilization does not lead to satisfactory results in these cases.

Patient-reported Outcomes and Muscle Strength after a Physiotherapy-led Exercise and Support Brace Intervention in Patients with Acute Injury of the Posterior Cruciate Ligament: A Two-year Follow-up Study

Background

While outcomes of posterior cruciate ligament (PCL) injuries treated surgically are well described, prospective studies reporting outcomes of exercise interventions are lacking.

Purpose

The purpose of this study was to investigate changes in patient-reported outcomes of a physiotherapy-led exercise and support brace intervention in patients with acute injury of the PCL over a two-year follow-up period. Furthermore, this study sought to investigate changes in isometric knee muscle strength over an eight-month follow-up period, and finally to report conversion to surgical reconstruction over a two-year follow-up period.

Study design

Case series study, prospective.

Methods

Fifty patients with an acute injury of the PCL were treated with a brace and a physiotherapy-led exercise intervention and followed prospectively. Changes in patient-reported outcomes were measured with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and the Knee injury and Osteoarthritis Outcome Score (KOOS) from baseline (diagnosis) to two-year follow-up. Furthermore, changes in isometric knee flexion and extension strength were measured with a static strength dynamometer from 16 weeks after diagnosis to one-year follow-up. Conversion to surgery was prospectively extracted from medical records. Mean changes were analyzed with a mixed effects model with time as a fixed factor.

Results

The IKDC-SKF score improved 28 (95%CI 24-33) IKDC points from baseline to two-year follow-up. Isometric knee flexion strength of the injured knee increased 0.18 (95%CI 0.11-0.25) Nm/kg from 16 weeks after diagnosis to one-year follow-up, corresponding to an increase of 16%. In contrast, isometric knee extension strength of the injured knee did not change (0.12 (95%CI 0.00-0.24) Nm/kg, p=0.042). Over two years, seven patients converted to PCL surgical reconstruction. One and two-year follow-up were completed by 46 and 31 patients, respectively.

Conclusions

The physiotherapy-led exercise and support brace intervention demonstrated clinically relevant improvements in patient-reported outcomes and knee flexion strength, and the risk of PCL surgical reconstruction was considered low within the first two years.

Level of evidence

3b©The Author(s).

Onlay Technique for Posterior Cruciate Ligament Reconstruction: The Paccola's Technique

The primary function of the posterior cruciate ligament (PCL) is to restrict the posterior translation of the tibia, and its secondary function is to limit the tibial external rotation, mainly at 90° and 120° of knee flexion. The prevalence of PCL rupture ranges between 3% and 37% of patients with knee ligament tears. This ligament injury often is associated with other ligament injuries. Surgical treatment is recommended for acute PCL injuries associated with knee dislocations or when stress radiographs show a tibial posteriorization greater than or equal to 12 mm. The techniques classically described for the surgical treatment are inlay and transtibial, which can be performed in a single- or double-bundle fashion. Biomechanical studies suggest that the double-bundle technique is superior to the single femoral bundle, suggesting less postoperative laxity. However, such superiority has not yet been proven in clinical studies. This paper will describe the step-by-step technique for PCL surgical reconstruction. The tibial fixation of the PCL graft is performed by using a screw and spiked-washer, and the femoral fixation can be done with a single- or double-bundle technique. We will explain the surgical steps in detail, with tips to perform them simply and safely.

Posterior cruciate ligament repair seems safe with low failure rates but more high level evidence is needed: a systematic review

PURPOSE

To discuss recent literature on posterior cruciate ligament (PCL) repair and report on the clinical and radiological outcomes.

METHODS

A systematic review was conducted according to the PRISMA guidelines. In August 2022, three databases (PubMed, Scopus, and Cochrane Library) were searched for studies on PCL repair by two independent reviewers. Articles published between January 2000 and August 2022 focussing on the clinical and/or radiological outcomes, following PCL repair, were included. Patient demographic data, clinical evaluations, patient‑reported outcome measures, post-operative complications and radiological outcomes were extracted.

RESULTS

Nine studies met the inclusion criteria, covering 226 patients with a mean age ranging from 22.4 to 38.8 years and mean follow-up periods ranging from 14 to 78.6 months. Seven studies (77.8%) were level IV and two studies (22.2%) were level III. Arthroscopic PCL repair was performed in four studies (44.4%) while the remaining five studies (55.6%) described open PCL repair. In four studies (44.4%) additional suture augmentation was applied. Arthrofibrosis affected a combined total of 24 patients (11.7%; range 0-21.0%) making it the most common complication and the overall failure rate was 5.6%, ranging from 0 to 15.8%. Two studies (22.2%) performed post-operative MRI and confirmed PCL healing.

CONCLUSION

This systematic review indicates that PCL repair can be a safe procedure with an overall failure rate of 5.6%, ranging from 0% to 15.8%. However, more high quality research is necessary before widespread clinical implementation is warranted.

LEVEL OF EVIDENCE

IV.

Stability of the knee after posterior cruciate ligament reconstruction using peroneus longus tendon graft with three femoral insertion sites. A cadaveric study

Introduction

Many kinds of grafts were used for single-bundle reconstruction of the posterior cruciate ligament (PCL). Recently, the peroneus longus tendon (PLT) was used in some clinical reports. This study aimed to test the best position of the femoral insertion in the case of using PLT for PCL reconstruction.

Methods

Seventeen fresh frozen cadaveric knees were randomized into three groups. Group AL (6 knees): the femoral insertion in PCL reconstruction was at the footprint center of the anterolateral bundle (ALB). Group PM (5 knees): at the footprint center of the posteromedial bundle (PMB). And group MC (6 knees) was at the midpoint of the center of the anterolateral bundle and posteromedial bundle. The PCL of all knees was cut and a PCL reconstruction procedure was performed with autologous peroneus longus tendon (PLT). The stability of each knee was tested in three conditions: PCL was intact, PCL was resected, and PCL was reconstructed. The KT-1000 machine was used to measure the maximum posterior displacement of the tibia under force with the knees at 0, 30, 60, 90, and 120 degrees of flexion.

Results

Average posterior displacement of the tibia under force for intact PCL of group AL was 1.6 mm, group MC was 1.2 mm, and group PM was 1.3 mm. After PCL was resected, the knee laxity was increased remarkably: posterior displacement of the tibia of group AL was 8.9 mm, group MC was 9.4 mm, and group PM was 13.6 mm. After PCL was reconstructed, group AL was 1.5 mm, group MC was 2.0 mm, and group PM was 5.6 mm. The results showed that after PCL reconstruction the group AL and group MC give better stability to the knee (p < 0.05, except knee at 120 degrees of flexion). Group AL got more stability than group MC, but the difference was not significant (p ≥ 0.164).

Conclusion

In a single-bundle reconstruction of the PCL with the graft PLT, the femoral insertion at the footprint center of the ALB and the midpoint of the center of the ALB and PMB showed better stability than that at PMB.

PCL insufficient patients with increased translational and rotational passive knee joint laxity have no increased range of anterior-posterior and rotational tibiofemoral motion during level walking

Passive translational tibiofemoral laxity has been extensively examined in posterior cruciate ligament (PCL) insufficient patients and belongs to the standard clinical assessment. However, objective measurements of passive rotational knee laxity, as well as range of tibiofemoral motion during active movements, are both not well understood. None of these are currently quantified in clinical evaluations of patients with PCL insufficiency. The objective of this study was to quantify passive translational and rotational knee laxity as well as range of anterior–posterior and rotational tibiofemoral motion during level walking in a PCL insufficient patient cohort as a basis for any later clinical evaluation and therapy. The laxity of 9 patient knees with isolated PCL insufficiency or additionally posterolateral corner (PLC) insufficiency (8 males, 1 female, age 36.78 ± 7.46 years) were analysed and compared to the contralateral (CL) knees. A rotometer device with a C-arm fluoroscope was used to assess the passive tibiofemoral rotational laxity while stress radiography was used to evaluate passive translational tibiofemoral laxity. Functional gait analysis was used to examine the range of anterior–posterior and rotational tibiofemoral motion during level walking. Passive translational laxity was significantly increased in PCL insufficient knees in comparison to the CL sides (15.5 ± 5.9 mm vs. 3.7 ± 1.9 mm, p < 0.01). Also, passive rotational laxity was significantly higher compared to the CL knees (26.1 ± 8.2° vs. 20.6 ± 5.6° at 90° knee flexion, p < 0.01; 19.0 ± 6.9° vs. 15.5 ± 5.9° at 60° knee flexion, p = 0.04). No significant differences were observed for the rotational (16.3 ± 3.7° vs. 15.2 ± 3.6°, p = 0.43) and translational (17.0 ± 5.4 mm vs. 16.1 ± 2.8 mm, p = 0.55) range of anterior–posterior and rotational tibiofemoral motion during level walking conditions for PCL insufficient knees compared to CL knees respectively. The present study illustrates that patients with PCL insufficiency show a substantial increased passive tibiofemoral laxity, not only in tibiofemoral translation but also in tibiofemoral rotation. Our data indicate that this increased passive multiplanar knee joint laxity can be widely compensated during level walking. Further studies should investigate progressive changes in knee joint laxity and kinematics post PCL injury and reconstruction to judge the individual need for therapy and effects of physiotherapy such as quadriceps force training on gait patterns in PCL insufficient patients.

Protruding anterior medial meniscus and posterior tibial translation as secondary signs of complete and partial posterior cruciate ligament tear

OBJECTIVE

To evaluate whether measurement of protruding anterior meniscus in the medial compartment (PAMM) and posterior tibial translation (PTT) can be used as a secondary sign of posterior cruciate ligament (PCL) tear for differential diagnosis of partial or complete tear.

METHODS

21 cases with complete PCL tear, 35 cases with partial PCL tear, and 55 normal cases were reviewed in this retrospective study. PTT and PAMM were measured from the MR images associated with each case. Non-parametric data were evaluated using the Kruskal-Wallis test and the Mann-Whitney U-test with Bonferroni correction to compare differences among the three groups: complete tear, partial tear, and controls.

RESULTS

There were significant differences in the median values of PAMM among the three groups, and with PAMM increasing as the grade of PCL injury increased. However, there were no significant differences in median PTT among the three groups. Median PAMM in the partial and complete tear groups was significantly higher than in subjects without PCL rupture (adjusted p-value <0.05). Although median PAMM in subjects in the complete tear group tended to be higher than in those with a partial tear, this difference was not statistically significant (adjusted p-values ≥0.418).

CONCLUSION

PAMM is more useful finding than PTT and can predict PCL tear with or without posterior instability. However, PAMM cannot differentiate partial tear and complete tear of the PCL.

ADVANCES IN KNOWLEDGE

PAMM is more useful finding than PTT and can predict PCL tear with or without posterior instability. However, PAMM cannot differentiate partial tear and complete tear of the PCL.

Clinical and functional outcomes of isolated posterior cruciate ligament reconstruction in patients over the age of 40 years

Background

To assess clinical and functional outcomes of patients aged 40 years or older receiving PCL reconstruction surgery.

Methods

All patients older than 40 years with isolated PCL rupture who underwent PCL reconstruction surgery were enrolled into the retrospective study. Associated meniscal injuries, osteochondral lesions, postoperative complications, and the rate of return to the preinjury level of activity were extracted. Outcomes included International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity score. The minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were used to evaluate the clinically relevant value of PCL reconstruction in this population.

Results

In total, 41 patients with a mean age of 51.7 years were included. The mean follow-up time was 32.8 months. Associated lesions included meniscal injuries (48.8%) and osteochondral lesions (97.6%). Improvement in the IKDC score (from 46.5 preoperatively to 79.0 postoperatively, p < 0.0001), Lysholm score (from 65.5 to 88.3, p < 0.0001), and Tegner activity score (from 2.3 to 4.0, p < 0.0001) was recorded. The clinically relevant value based on the MCID showed that 34 of 41 patients (82.9%) had a ΔIKDC score exceeding 16.8; all patients (100%) showed a ΔLysholm score exceeding 8.9; and 35 of 41 patients (85.4%) showed a ΔTegner activity score exceeding 0.5. Regarding the PASS, none of the patients had an IKDC score exceeding 75.9 preoperatively, whereas 27 of 41 patients (65.9%) had a score of more than 75.9 postoperatively. All patient had ≥ grade II knee instability preoperatively. Postoperatively, 36 patients (87.8%) had no significant joint translation, and 5 patients (12.2%) had grade I instability. Twenty-one patients (51.2%) returned to their preinjury level of activity. Five patients (12.2%) developed Ahlbäck grade I radiographic osteoarthritis. No rerupture or other major perioperative complications were reported.

Conclusions

PCL reconstruction is a reliable surgery for middle-aged patients suffering from persistent instability even after failed conservative treatment, with significant improvement in patient-reported outcomes that exceeded MCID in the majority of patients, restoration of subjective instability, and approximately half of the patients returned to preinjury activity levels.

Level of evidence

Level IV, therapeutic case series.

Twelve Weeks of a Staged Balance and Strength Training Program Improves Muscle Strength, Proprioception, and Clinical Function in Patients with Isolated Posterior Cruciate Ligament Injuries

Ligament reconstruction is indicated in patients with an isolated posterior cruciate ligament (PCL) injury who fail conservative treatment. To eliminate the need for PCL reconstruction, an ideal rehabilitation program is important for patients with an isolated PCL injury. The purpose of this study was to investigate the improvement in functional outcome, proprioception, and muscle strength after a Both Sides Up (BOSU) ball was used in a balance combined with strength training program in patients with an isolated PCL injury. Ten patients with isolated PCL injuries were recruited to receive a 12 week training program as a study group. In the control group (post-PCL reconstruction group), ten subjects who had undergone isolated PCL reconstruction for more than 2 years were enrolled without current rehabilitation. The Lysholm score, IKDC score, proprioception (active and passive), and isokinetic muscle strength tests at 60°/s, 120°/s, and 240°/s, were used before and after training on the injured and normal knees in the study group, and in the post-PCL reconstruction group. The results were analyzed with a paired t-test to compare the change between pre-training, post-training, and the normal leg in the study group, and with an independent t-test for comparisons between the study and post-PCL reconstruction groups. Both the Lysholm and IKDC scores were significantly improved (p < 0.01) after training, and no difference was observed compared to the post-PCL reconstruction group. The active and passive proprioception was improved post-training compared to pre-training, with no difference to that in the post-PCL reconstruction group. Isokinetic knee quadriceps muscle strength was significantly greater post-training than pre-training in PCL injured knees at 60°/s, 120°/s, and 240°/s, and in hamstring muscle strength at 60°/s and 120°/s. Muscle strength in the post-training injured knee group showed no significant difference compared to that in the post-training normal leg and the post-PCL reconstruction group. The post-training improvement of muscle strength was higher in the PCL injured leg compared to the normal leg and there was no difference between the dominant and non-dominant injured leg in the study group. After 12 weeks of BOSU balance with strength training in patients with an isolated PCL injury, the functional outcome, proprioception, and isokinetic muscle strength were significantly improved, and comparable to the contralateral normal leg and the post-PCL reconstruction group. We suggest that programs combining BOSU balance and strength training should be introduced in patients with a PCL injury to promote positive clinical results.

Posterior cruciate ligament reconstruction using a septum-preserving technique

OBJECTIVE

Description of a reproducible surgical technique for single-bundle anterolateral reconstruction of the posterior cruciate ligament (PCL) based on a septum-sparing approach. This technique is less traumatic than the trans-septum approach. The article illustrates surgical steps to simplify the technical aspects of the procedure.

INDICATIONS

A complete grade III symptomatic tear of the PCL associated with instability and often discomfort (deceleration, stairs) or subsequent gonalgia arising from the medial compartment or patellofemoral joint. Injury of the peripheral joint stabilizers alongside the PCL including the posterolateral corner or a complete medial knee injury. The procedure is indicated in chronic cases, but also in acute cases of posterior instability > 10 mm, if it is an intraligamentous tear with dislocated PCL stumps.

CONTRAINDICATIONS

Bony avulsions of the PCL suitable for refixation, soft tissue compromise, infection, advanced osteoarthritic disease.

SURGICAL TECHNIQUE

After diagnostic arthroscopy of the knee, the ipsilateral semitendinosus and gracilis tendons are harvested and prepared as a 6-strand graft for PCL reconstruction. One high anterolateral viewing portal, one low anterolateral portal, one anteromedial portal, and a posteromedial portal are used for single-bundle reconstruction via one femoral and one tibial bone tunnel and hybrid graft fixation.

POSTOPERATIVE MANAGEMENT

Weight bearing is restricted to 20 kg for 6 weeks. PCL brace with tibial support for a period of 12 weeks. Flexion is limited to 30° in the first 2 postoperative weeks, then 60° for 2 weeks, and 90° for 2 further weeks. Passive flexion in prone position is performed. Active focused muscle strengthening exercise is begun after 6 weeks postoperatively and participation in competitive sports is not recommended before full muscle strength and coordination is re-established, at the earliest 9-12 months postoperatively.

RESULTS

Two isolated and 19 combined PCL injuries were treated. Mean patient age was 27.4 years, and the minimal follow-up was 12 months. On average, we found good clinical outcome with slight degree of posterior laxity (4.1 mm) after PCL reconstruction in comparison with the contralateral knee. No patient showed signs of effusion at follow-up. Range of motion was fully restored in 19 of 21 patients. One patient suffered failure due to persistent posterior instability and persistence of symptoms.

Imaging Review of the Posterior Cruciate Ligament

Posterior cruciate ligament (PCL) injuries can often be missed on physical examination, especially in multiligament knee injuries. Therefore, a comprehensive approach to imaging the PCL should be implemented whenever history and examination findings indicate relative risk. Radiography, including a posterior-stress view, and magnetic resonance imaging, when available, provide consistently accurate diagnosis of PCL pathology and common knee comorbidities. Computed tomography and ultrasonography can be useful modalities with potential advantages with respect to availability and access, specific comorbidities, and/or cost-effectiveness.

Evolving evidence in the treatment of primary and recurrent posterior cruciate ligament injuries, part 1: anatomy, biomechanics and diagnostics

The posterior cruciate ligament (PCL) represents an intra-articular structure composed of two distinct bundles. Considering the anterior and posterior meniscofemoral ligaments, a total of four ligamentous fibre bundles of the posterior knee complex act synergistically to restrain posterior and rotatory tibial loads. Injury mechanisms associated with high-energy trauma and accompanying injury patterns may complicate the diagnostic evaluation and accuracy. Therefore, a thorough and systematic diagnostic workup is necessary to assess the severity of the PCL injury and to initiate an appropriate treatment approach. Since structural damage to the PCL occurs in more than one third of trauma patients experiencing acute knee injury with hemarthrosis, background knowledge for management of PCL injuries is important. In Part 1 of the evidence-based update on management of primary and recurrent PCL injuries, the anatomical, biomechanical, and diagnostic principles are presented. This paper aims to convey the anatomical and biomechanical knowledge needed for accurate diagnosis to facilitate subsequent decision-making in the treatment of PCL injuries.Level of evidence V.

Combined ACL-PCL-Medial and Lateral Side Injuries (Global Laxity)

The multiple ligament injured knee is a complex problem in orthopedic surgery. These injuries may or may not present as acute knee dislocations, and careful assessment of the extremity vascular and neurological status is essential because of the possibility of arterial and/or venous compromise, and nerve injury. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and formulate a treatment plan. Knee stability is improved postoperatively when evaluated with knee ligament rating scales, arthrometer testing, and stress radiographic analysis. Surgical timing depends upon the injured ligaments, vascular status of the extremity, reduction stability, and the overall health of the patient. The use of allograft tissue is preferred because of the strength of these large grafts, and the absence of donor site morbidity.

Arthroscopic Posterior Cruciate Ligament Primary Repair

Injury to the posterior cruciate ligament (PCL) is most commonly seen in the setting of a multiligamentous injured knee, and isolated PCL tears are rare. PCL injuries are generally treated either conservatively or by PCL reconstruction using a graft. If a proximal or distal tear is present, the injured ligament can also be treated by primary repair, in which the ligament is reattached to the tibial or femoral insertion. This has the (theoretical) advantages of preserving the native tissue, maintaining proprioception, and can be performed in a less invasive way when compared with reconstruction surgery. In this review, the appropriate patient selection, surgical indications, surgical techniques, and outcomes of primary repair of proximal and distal PCL tears will be discussed. Primary repair may be an alternative treatment for PCL reconstruction if appropriate patient selection is applied.

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.

[Early effectiveness of minimally invasive open reduction and internal fixation versus arthroscopic double-tunnel suture fixation for tibial avulsion fracture of posterior cruciate ligament]

OBJECTIVE

To compare the early effectiveness of minimally invasive open reduction and internal fixation via posterior median approach versus arthroscopic double-tunnel suture fixation in treatment of tibial avulsion fracture of the posterior cruciate ligament (PCL).

METHODS

A clinical data of 31 patients with the tibial avulsion fracture of the PCL and met the criteria between January 2015 and January 2019 was retrospectively analyzed. Nineteen patients (group A) were treated with open reduction and internal fixation with cannulated screw via posterior median approach. The other 12 patients (group B) were treated with arthroscopic double-tunnel suture fixation technique. There was no significant difference between the two groups ( P>0.05) in the gender, age, side of effected limb, the injury cause, the time from injury to operation, the combined meniscus injury, Meyers & McKeever classification and preoperative Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) score, and the difference of tibial posterior displacement between bilateral knees. The operation time, postoperative complications, fracture healing, and the difference of tibial posterior displacement between bilateral knees, Lysholm score, Tegner score, and IKDC score were recorded.

RESULTS

Group B spent significantly longer operation time than group A ( t=7.347, P=0.000). No postoperative complication occurred in group B, and 1 patient in group A had a screw breakage. All patients were followed up 6-36 months (mean, 22 months). X-ray films showed that all fractures healed at 3 months after operation. At last follow-up, there was no significant difference in the patients with normal knee range of motion between the two groups ( P=0.510). At last follow-up, the difference of tibial posterior displacement between bilateral knees, Lysholm score, Tegner score, and IKDC score in the two groups were superior to those before operation ( P<0.05); while there was no significant difference between the two groups ( P>0.05).

CONCLUSION

For the tibial avulsion fracture of PCL, the minimally invasive open reduction and internal fixation and arthroscopic double-tunnel suture fixation can obtain similar early effectiveness. However, arthroscopic surgery has the advantages of being able to simultaneously deal with intra-articular combined injuries, avoiding internal fixator complications, and eliminating the need for secondary operation.

Thick Graft Versus Double-Bundle Technique on Posterior Cruciate Ligament Reconstruction: Experimental Biomechanical Study with Cadavers

Objective  To evaluate the biomechanical effect of graft thickness compared with the double-bundle technique on posterior cruciate ligament (PCL) reconstruction in human cadaveric knees. Methods  A total of 9 human cadaveric knees were tested in 5 conditions: intact knee (INT); single-bundle reconstruction with a 10-mm quadriceps tendon (SB); double-bundle reconstruction with a 10 mm-quadriceps tendon for the anterolateral bundle and a 7-mm doubled semitendinosus tendon for the posteromedial bundle (DB); single-bundle reconstruction with a 10-mm quadriceps tendon plus a 7-mm doubled semitendinosus tendon (SBT); and PCL-deficient (NoPCL). The posterior tibial translation (PTT) was measured in response to a 134-N posterior tibial load at 0 ^∘ , 30 ^∘ , 60 ^∘ e 90 ^∘ of knee flexion. Results  The PTT values of the DB and SBT techniques were always significantly lower (better stability) than those of the SB technique. The PTT values of the SBT technique were significantly lower than those of the DB technique at 60 ^∘ ( p  = 0.005) and 90 ^∘ ( p  = 0.001). Conclusions  Graft enlargement improves knee stability in isolated PCL reconstructions, whereas the graft division in the two-bundle technique worsens this stability at 60 ^∘ and 90 ^∘ of knee flexion. The findings of the present study suggest that knee stability in PCL reconstructions may be improved with the use of thicker grafts in the SB technique rather than performing the DB technique.

The use of allograft tissue in posterior cruciate, collateral and multi-ligament knee reconstruction

PURPOSE

Currently both autograft and allograft tissues are available for reconstruction of posterior cruciate, collateral and multi-ligament knee injuries. Decision-making is based on a complex interplay between anatomical structures, functional bundles and varying biomechanical requirements. Despite theoretically better biological healing and reduced risk of disease transmission autografts are associated with donor site morbidity as well as being limited by size and quantity. The use of allografts eliminates donor-site morbidity but raises cost and issues of clinical effectiveness. The purpose of this paper is to review current concepts and evidence for the use of allografts in primary posterior cruciate, collateral and multi-ligament reconstructions.

METHODS

A narrative review of the relevant literature was conducted for PCL, collateral ligament and multi-ligament knee reconstruction. Studies were identified using a targeted and systematic search with focus on recent comparative studies and all clinical systematic reviews and meta-analyses. The rationale and principles of management underpinning the role of allograft tissue were identified and the clinical and functional outcomes were analysed. Finally, the position of postoperative physiotherapy and rehabilitation was identified.

RESULTS

The review demonstrated paucity in high quality and up-to-date results addressing the issue especially on collaterals and multi-ligament reconstructions. There was no significant evidence of superiority of a graft type over another for PCL reconstruction. Contemporary principles in the management of posterolateral corner, MCL and multi-ligament injuries support the use of allograft tissue.

CONCLUSION

The present review demonstrates equivalent clinical results with the use of autografts or allografts. It remains, however, difficult to generate a conclusive evidence-based approach due to the paucity of high-level research. When confronted by the need for combined reconstructions with multiple grafts, preservation of synergistic muscles, and adapted postoperative rehabilitation; the current evidence does offer support for the use of allograft tissue.

LEVEL OF EVIDENCE

IV.

The usefulness of the oblique coronal plane of three-dimensional isotropic T2-weighted fast spin-echo (VISTA) knee MRI in the evaluation of posterior cruciate ligament reconstruction with allograft: Comparison with the oblique coronal plane of two-dimensional fast spin-echo T2-weighted sequences

PURPOSE

We compared two imaging techniques to assess whether 3D VISTA imaging could replace 2D FSE in diagnosing PCL reconstruction complications.

MATERIALS AND METHODS

This retrospective study included 40 patients who underwent surgery of PCL reconstruction and follow-up knee MRI (3D VISTA and 2D FSE) for evaluation of PCL graft integrity. Each image was interpreted independently by two radiologists without knowledge of radiologic reports or clinical history. The diagnostic performance of the 2D FSE PCL view, 3D VISTA PCL view, orthogonal 2D FSE image, and combined sequences were evaluated in terms of sensitivity, specificity, and accuracy for diagnosing complications of PCL graft. The reference diagnoses were made arthroscopically or clinically.

RESULTS

The sensitivities of the 3D VISTA PCL view were similar to those of the 2D PCL view. The sensitivities of the combination of the orthogonal view and the 3D VISTA PCL view were also similar to those of the combination of the orthogonal view and the 2D PCL view. The specificities and accuracies of each image exhibited similar results. There was no statistically significant difference in diagnostic performance between the 3D VISTA PCL view and the 2D PCL view (solitary or combined with the orthogonal view).

CONCLUSIONS

The diagnostic performance of the PCL views on 3D VISTA images is comparable to that of 2D FSE images in the diagnosis of PCL graft complications.

Posterior laxity increases over time after PCL reconstruction

PURPOSE

Restoration of posterior tibial translation (PTT) after reconstruction of the posterior cruciate ligament (PCL) is deemed necessary to restore physiological knee kinematics. However, current surgical techniques have failed to show a complete reduction of posterior laxity. It was hypothesized that early postoperative PTT increases over time.

METHODS

The study comprised of 46 patients (10 female, 36 male; 30 ± 9 years), who underwent PCL reconstruction in a single-surgeon series. Patients were evaluated by bilateral stress radiographs in a prospective manner preoperatively; at 3, 6, 12 and 24 months; and at a final follow-up (FFU) of at least 5 years. Covariants included age, gender, BMI, tibial slope (TS) and the number of operated ligaments. Two blinded observers reviewed all radiographs, evaluating the TS and the posterior tibial translation.

RESULTS

All patients were evaluated at a mean final follow-up of 102 (range 65-187) months. Mean side-to-side difference of the PTT significantly improved from preoperative to 3-month postoperative values (10.9 ± 3.1 vs. 3.6 ± 3.8 mm; P < 0.0001). The PTT increased to 4.6 ± 3.7 mm at 6 months, to 4.8 ± 3.3 mm at 12 months, to 4.8 ± 3.2 mm at 24 months, to 5.4 ± 3.4 mm at FFU. Consequently, there was a significant increase of PTT between 3-month and final follow-up (3.6 ± 3.8 vs. 5.4 ± 3.4 mm; P = 0.02). Flattening of the TS resulted in a significantly higher PTT compared to subjects with a high TS at 24 months and FFU. There was no significant influence by BMI, age, gender and the number of operated ligaments.

CONCLUSIONS

Early results after PCL reconstruction seem promising as posterior tibial translation is significantly improved. However, there is a significant increase in PTT from early postoperative values to the final follow-up of at least 5 years. This is particularly notable in patients with flattening of the TS. As a consequence, surgeons and patients need to be aware that initial posterior stability should not be equated with the final outcome.

LEVEL OF EVIDENCE

Cohort study, Level III.

The role of isolated posterior cruciate ligament reconstruction in knees with combined posterior cruciate ligament and posterolateral complex injury

PURPOSE

This is a meta-analysis comparing biomechanical outcomes to determine whether an isolated posterior cruciate ligament (PCL) reconstruction can restore normal knee kinematics in a combined PCL/posterolateral complex (PLC) injury and whether double-bundle (DB) PCL reconstruction is superior in controlling posterior and rotational laxity compared with single-bundle (SB) PCL reconstruction in a PCL/PLC-deficient knee.

METHODS

A number of electronic databases were searched for relevant articles published through August 2016 that compared biomechanical outcomes of PCL reconstruction in patients who underwent reconstruction for combined PCL/PLC deficiencies. Data were searched, extracted, analysed, and assessed for quality according to Cochrane Collaboration guidelines, and biomechanical outcomes were evaluated using various outcome values. The results are presented as relative ratios for binary outcomes and standard mean differences for continuous outcomes with 95% confidence intervals.

RESULTS

Five biomechanical studies were included in this meta-analysis. There were significant differences in laxities such as posterior tibial translation (PTT), external rotation, varus rotation, and PTT coupled with external rotation in the isolated PCL reconstruction group compared with the native PCL group. Furthermore, there were no significant differences in laxities such as PTT, external rotation, or varus rotation between the SB and DB PCL reconstruction groups.

CONCLUSION

Isolated PCL reconstruction, whether SB or DB, could not restore normal knee kinematics in the PCL/PLC-deficient knee. In such cases, residual laxity after isolated PCL reconstruction can be controlled successfully with PLC reconstruction. Therefore, simultaneous PCL and PLC reconstruction is recommended for patients with combined PCL/PLC injury.

Nonoperative Treatment of PCL Injuries: Goals of Rehabilitation and the Natural History of Conservative Care

PURPOSE OF REVIEW

To review the current practices of nonoperative management of posterior cruciate ligament (PCL) injuries, the natural history of conservative care, and the latest PCL rehabilitation strategies.

RECENT FINDINGS

PCL injuries often occur as part of a multiligamentous knee injury and occasionally occur in isolation. Although patients may be able to tolerate or compensate for a PCL-deficient knee, long-term outcomes after conservative care demonstrate a high rate of arthrosis in the medial and patellofemoral compartments resulting from altered knee kinematics and loads. Good subjective outcomes and a high rate of return to sport have been reported after nonoperative treatment of isolated PCL injuries. However, PCL laxity grade on objective exam does not typically correlate with subjective outcomes, nor does it correlate with the risk of developing osteoarthritis. Although more research is needed on the optimal PCL rehabilitation strategies, general principles include avoiding posterior tibial translation in the initial period to optimize ligament healing, followed by progressive range of motion and strengthening of the quadriceps and core musculature. At 12 weeks, patients may begin an interval running program, followed by agility work and progressive sports-specific training to allow for return to sports. Nonoperative treatment of isolated PCL injuries results in good subjective outcomes and high rate of return to sport.

Current Concepts of Posterolateral Corner Injuries of the Knee

The number of posterolateral corner (PLC) injury patients has risen owing to the increased motor vehicle accidents and sports activities. Careful examination is required because this injury is easy to overlook and may lead to chronic instability. The purpose of this article is to review the anatomy, biomechanics, diagnosis, classification and, treatment of PLC injuries and summarize the recent literatures regarding the treatment outcomes.

Flexion Gap in the Isolated Posterior Cruciate Ligament-Injured Knee Affects Symptom Relief After Conservative Treatment: A Case-Control Study

Background:

The posterior cruciate ligament (PCL) is a primary stabilizer of the knee in the posterior direction. However, PCL deficiency presents a clinical paradox because the outcome of PCL deficiency ranges from total disability to uninterrupted participation in competitive athletics.

Purpose:

To investigate whether posterior laxity (PL) and the flexion gap (FG) influence the results of the conservative treatment of isolated PCL injuries.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 27 patients (23 men, 4 women; mean age, 33 ± 14 years) with isolated PCL injuries between 2007 and 2013 were included in this study. All patients had been treated conservatively for more than 6 months. Nineteen patients achieved excellent relief of their symptoms (conservative treatment [C] group). Eight patients underwent PCL reconstruction owing to their symptoms (surgical treatment [S] group). Side-to-side differences of the FG and the PL were retrospectively measured on axial radiographs and on lateral radiographs with gravity sag views, respectively, and the degree of PCL injury was graded as I (PL, <5 mm) in 7 patients and II (PL, 5 to <10 mm) in 20 patients.

Results:

The mean PL and FG were 6.9 ± 2.5 mm and 2.0 ± 1.8 mm, respectively. A mild positive correlation between the PL and the FG was observed (r = 0.47, P = .02). The mean PL and FG were 6.5 ± 2.9 mm and 1.2 ± 1.0 mm in the C group and 7.7 ± 1.3 mm and 3.8 ± 2.0 mm in the S group, respectively. The FG in the C group was significantly smaller than that in the S group (P < .05), although there was no significant difference between the groups for PL. All patients with grade I injury belonged to the C group, for which the FG was less than 2 mm in all cases. Eight of the patients with grade II injury were in the S group, and their FG was more than 2 mm, except in 1 patient. The FG performed better with an area under the receiver operating characteristic curve of 0.924 (95% CI, 0.000-1.000) compared with 0.599 (95% CI, 0.388-0.809) for the PL. Discrimination between the C and S groups with a cutoff set at 2.30 mm for the FG and 7.45 mm for the PL showed a sensitivity of 75.0% and 75.0% and a specificity of 89.5% and 52.6%, respectively.

Conclusion:

Considering that the FG affects the outcome of conservative treatment, it could be a factor in the indication for the surgical treatment of isolated PCL injuries.

Recurrent posterior knee laxity: diagnosis, technical aspects and treatment algorithm

PURPOSE

Aim of this study was to determine the characteristics, clinical and radiological diagnostic methods of PCL isolated and combined knee injuries.

METHODS

One hundred and twelve patients with a recurrent posterior knee laxity were surgically treated. Clinical examination, MRI, Telos™ stress dynamic X-rays, KT-1000 measurements and the IKDC questionnaire were used to diagnose and evaluate these injuries.

RESULTS

Median follow-up was 4.5 years (2-11 years). Thirty-two patients (28.6 %) had an isolated posterior laxity, 53 (47.3 %) a posterior posterolateral laxity, 21 (18.7 %) a posterior posteromedial laxity and six (5.4 %) patients had a complex posterior and mediolateral laxity. Road traffic accidents and sports injuries were the main causes of trauma. The mean preoperative value of posterior tibial translation was 13.5 mm (SD 1.4) and the mean postoperative value was 4.4 mm (SD 1.7) as measured with the Telos device. In the cases with a concomitant ACL rupture, the mean preoperative value of anterior tibial translation was 6.5 mm (SD 1.3) and the mean postoperative value was 1.7 mm (SD 0.8). The mean pre- and postoperative IKDC scores were 74.5 (SD 4.2) and 87.9 (SD 3.1), respectively. Meniscal and/or cartilage injuries were found in 80 patients (71.4 %).

CONCLUSIONS

Recurrent posterior knee laxity can be restored with the one-stage PCL reconstruction using a quadriceps graft and reconstruction of the posteromedial-posterolateral lesions using the LaPrade techniques. The benefits of this study include enabling surgeons to accurately manage these injuries from a clinical perspective, and treating them with a specific surgical algorithm.

LEVEL OF EVIDENCE

III.

Combined reconstruction of the posterior cruciate ligament and medial collateral ligament using a single femoral tunnel

PURPOSE

Lesions of the medial collateral ligament (MCL) are the most common knee ligament injuries, and lesions associated with the anterior cruciate ligament or the posterior cruciate ligament (PCL) in knee dislocations should be reconstructed to prevent failure of the central pivot reconstruction. The purpose of this study was to evaluate the outcomes of combined PCL/MCL reconstruction using a single femoral tunnel with a minimum 2-year follow-up.

METHOD

A retrospective study of thirteen patients with combined PCL/MCL injuries was conducted. The patients underwent PCL and MCL reconstruction using an Achilles tendon allograft with a single tunnel in the medial femoral condyle, thereby avoiding tunnel conversion.

RESULTS

All patients achieved a range of motion of at least 100°. The mean loss of extension and flexion values compared to the contralateral side was 1° ± 2° and 9° ± 10°, respectively. Our results included 26 reconstructions with three (11.5 %) failures, two in the PCL (15.3 %) and one in the MCL (7.6 %), in three different patients. In the final evaluation, the mean IKDC subjective score was 71.63 ± 16.23, the mean Lysholm score was 80.08 ± 13.87, and the median Tegner score was 6 (range = 2-7).

CONCLUSION

The PCL/MCL reconstruction technique using a single femoral tunnel and an Achilles tendon allograft is safe, avoids the convergence of tunnels in the medial femoral condyle, has excellent results, and is reproducible.

LEVEL OF EVIDENCE

IV.

Kinematic strategies for obstacle-crossing in patients with isolated posterior cruciate ligament deficiency

The posterior cruciate ligament (PCL) plays an important role in the structural stability and sensory feedback at the knee. Altered structural and proprioceptive function at the PCL-deficient knee may affect the joint motions and the end-point control during functional activities. The current study identified the effects of unilateral PCL deficiency (PCLD) on the end-point control and joint kinematics of the lower limbs during obstacle-crossing. Eighteen patients with unilateral PCLD and eighteen healthy controls were each asked to walk and cross obstacles of heights of 10%, 20% and 30% of their leg lengths, with the affected and the unaffected limb leading, while their kinematic data were measured. Patients with PCLD were found to cross obstacles with significantly increased toe-clearance (p<0.01), increased trailing toe-obstacle distance (p<0.05) and reduced crossing speed (p<0.01) when compared to the controls. Similar end-point control was observed in the PCLD group whether leading with the affected or unaffected limb, which appears to be as a result of bilateral kinematic accommodation to reduce the risk of tripping. To achieve similar toe-clearances, crossing strategies with the unaffected limb leading involved angular changes at more joints than those with the affected limb leading. The PCLD group appeared to adopt a conservative strategy to reduce the risk of tripping over the obstacle during obstacle-crossing, using different joint kinematic changes depending on whether the affected or unaffected limb was leading. It is suggested that monitoring of the kinematic strategies adopted by patients with PCLD during obstacle-crossing may be needed in future rehabilitation programs with the aim of reducing tripping risks during obstacle-crossing.

Imaging of Athletic Injuries of Knee Ligaments and Menisci: Sports Imaging Series

Acute knee injuries are a common source of morbidity in athletes and if overlooked may result in chronic functional impairment. Magnetic resonance (MR) imaging of the knee has become the most commonly performed musculoskeletal MR examination and is an indispensable tool in the appropriate management of the injured athlete. Meniscal and ligamentous tearing are the most frequent indications for surgical intervention in sports injuries and an understanding of the anatomy, biomechanics, mechanisms of injury, and patterns of injury are all critical to accurate diagnosis and appropriate management. These will be discussed in reference to meniscal tears and injuries of the cruciate ligaments as well as injuries of the posterolateral and posteromedial corners of the knee. (©) RSNA, 2016.

Optimal management of posterior cruciate ligament injuries: current perspectives

Background

The optimal management of posterior cruciate ligament (PCL) injuries is debated by orthopedic surgeons. A natural history study (NHS) of acute, isolated PCL tears in patients with a mean follow-up of 14.3 years was previously published. The purpose of this study was to compare and contrast the results of the NHS study with those of other studies with similar follow-up time after operative and nonoperative management of isolated PCL tears.

Material and methods

With reviewing the literature, six operative management and six nonoperative management studies were found for treating isolated PCL injuries. We analyzed the subjective and objective outcomes of these 12 studies and compared them to the results of the NHS to determine optimal management of PCL injuries.

Results

Final follow-up times ranged from a mean of 6.2 to 15 years in the nonoperative studies and 6.3 to 12 years in the operative studies. Side-to-side differences in laxity following surgical management ranged from 1.1 to 7 mm on KT-1000 arthrometer testing and 2.8 to 4.7 mm on Telos stress testing. Tegner scores at final follow-up ranged from 6.6 to 7.7 in nonoperative studies and 5.7 to 7.4 in operative studies. International Knee Documentation Committee scores were 73.4, 82.7, and 84 in nonoperative studies and 65 and 87 in the operative studies. Lysholm scores were 85.2 in the nonoperative study and ranged from 81 to 92.1 in operative studies. Osteoarthritis was reported with ranges from 17% to 88% in nonoperative studies and 13.3% to 63.6% in operative studies.

Conclusion

We found that the subjective and objective results in the NHS compare favorably to those of outcomes for PCL reconstruction. Unless a technique is found that can completely restore knee stability, it is unlikely that simply reducing posterior laxity will improve outcomes or prevent the development of osteoarthritis.

Magnetic resonance imaging of degenerative changes of the posterior cruciate ligament

Background Mucoid degeneration and ganglia reflect a continuum of degenerative changes within the posterior cruciate ligament (PCL). Purpose To assess the prevalence of and radiologists' familiarity with PCL mucoid degeneration and ganglia. Material and Methods Knee magnetic resonance imaging (MRI) from July 2013 to June 2015, excluding patients who had a preceding trauma or MRI findings indicative of a prior injury, were retrospectively reviewed, with the specific request to assess degenerative changes of the PCL, by the same musculoskeletal radiologists who previously reported these examinations, and one fellow. Results A total of 692 patients entered this study. The radiologists and the fellow together identified mucoid degeneration in 34 patients (4.9%), ganglia in 14 patients (2.0%), and both in four patients (0.6%). Several patterns of PCL mucoid degeneration were identified: diffuse thickening in seven patients, partial thickening in 16 (four associated with a ganglion), longitudinal intraligamentous PCL signal-intensity abnormalities resembling a "tram track" in 15. In all cases there was increased signal intensity on fluid-sensitive sequences. In the previous reports, only three cases of PCL mucoid degeneration out of 38 (7.9%) were described, with intraligamentous PCL signal-intensity abnormalities. In the reports of the patients with degeneration and ganglia, only ganglia were described. In the previous reports, ganglia were correctly diagnosed. Conclusion Mucoid degeneration of the PCL is much more common than previously assumed and is underestimated by radiologists.

[Posterior cruciate ligament injuries]

Posterior cruciate ligament (PCL) injuries are still often overlooked and treatment of a ruptured PCL is inherently different in comparison to anterior cruciate ligaments (ACL). Conservative treatment is the first-line therapy for acute isolated PCL injuries leading to good clinical and biomechanical results. Injuries to the PCL combined with rupture of other stabilizing ligaments, such as the collateral ligaments or the posterolateral corner of the knee joint are treated surgically. The same is true for high grade chronic PCL insufficiency. Meticulous classification of PCL injuries taking all stabilizing factors of the knee joint as well as the time from injury into account are essential for successful treatment of PCL injuries.

Microstructural and Mechanical Properties of the Posterior Cruciate Ligament: A Comparison of the Anterolateral and Posteromedial Bundles

BACKGROUND

The microstructural organization (collagen fiber alignment) of the posterior cruciate ligament (PCL), which likely corresponds with its functional properties, has only been described qualitatively in the literature, to our knowledge. The goal of this study was to quantify the tensile mechanical and microstructural properties of the PCL and compare these qualities between the anterolateral and posteromedial bundles.

METHODS

Twenty-two knee specimens from 13 donors (8 male and 5 female; mean age [and standard deviation] at the time of death, 43.0 ± 4.1 years; mean body mass index, 30.0 ± 6.7 kg/m²) were dissected to isolate the PCL, and each bundle was split into 3 regions. Mechanical testing of each regional sample consisted of preconditioning followed by a ramp-and-hold stress-relaxation test and a quasi-static ramp-to-failure test. Microstructural analysis was performed with use of a high-resolution, division-of-focal-plane polarization camera to evaluate the average direction of collagen orientation and the degree to which the collagen fibers were aligned in that direction. Results were compared between the anterolateral and posteromedial bundles and across the regions of each bundle.

RESULTS

The anterolateral and posteromedial bundles demonstrated largely equivalent mechanical and microstructural properties. Elastic moduli in the toe and linear regions were not different; however, the posteromedial bundle did show significantly more stress relaxation (p = 0.004). There were also few differences in microstructural properties between bundles, which again were seen only in stress relaxation. Comparing regions within each bundle, several mechanical and microstructural parameters showed significant relationships across the posteromedial bundle, following a gradient of decreasing strength and alignment from anterior to posterior.

CONCLUSIONS

The PCL has relatively homogenous microstructural and mechanical properties, with few differences between the anterolateral and posteromedial bundles. This finding suggests that distinct functions of the PCL bundles result primarily from size and anatomical location rather than from differences in these properties.

CLINICAL RELEVANCE

These properties of the PCL can be used to assess the utility of graft choices and operative techniques for PCL reconstruction and may partly explain limited differences in the outcomes of single-bundle compared with double-bundle reconstruction techniques for the PCL.

MRI analysis of tibial PCL attachment in a large population of adult patients: reference data for anatomic PCL reconstruction

Background

Consistent reference data used for anatomic posterior cruciate ligament (PCL) reconstruction is not well defined. Quantitative guidelines defining the location of PCL attachment would aid in performing anatomic PCL reconstruction. The purpose was to characterize anatomic parameters of the PCL tibial attachment based on magnetic resonance imaging (MRI) in a large population of adult knees.

Methods

The PCL tibial attachment site was examined in 736 adult knees with an intact PCL using 3.0-T proton density–weighted sagittal MRI. The outcomes measured were the anterior-posterior diameter (APD) of the tibial plateau; angle between the tibial plateau and the posterior tibial ‘shelf’ (the slope where the PCL tibial attachment site was) (PTS); length of the PTS; proximal, central, and distal PCL attachment positions as well as the width of the PCL attachment site; and vertical dimension of the PCL attachment site inferior from the tibial plateau.

Results

The average APD of the tibia plateau was 33.6 ± 3.5 mm, yielding significant differences between males (35.5 ± 3.0 mm) and females (31.6 ± 2.7 mm), P <.05, and there was a significantly decreasing trend with increasing age in males (P <.05). Mean angle between the tibial plateau and the PTS was 122.4° ± 8.1°, and subgroup analysis showed that the young group had a differently smaller angle (120.9° ± 7.5°) than the middle-aged (123.7° ± 8.2°) and the old (123.4° ± 7.7°) in males population, while there were no significant differences between sexes (P >.05). The proximal, central positions and width of the PCL attachment site were 13.4 ± 3.0 mm, 17.8 ± 3.0 mm and 9.6 ± 2.4 mm along the PTS, with significant differences between males and females (P <.05), and accounted for 60.0 % ± 9.1 %, 80.0 % ± 4.6 % and 43.3 % ± 9.7 % of the PTS respectively, with no significant differences between sexes and among age groups (all P >.05).

Conclusions

This study provides reference data of the tibial PCL attachment based on MRI in the sagittal orientation. In analysis of retrospective data from a large population of adult patients, the quantitative values can be used as references to define the inserted angle and depth of the drill guide, and the exact position and size of the tibial PCL tunnel for performing arthroscopic anatomic PCL reconstruction.

Presentation, examination, investigation and early treatment of acute knee injuries

Acute knee injuries are common presentations that frequently occur during sporting activities and can result in permanent disability. However, they often result in a single visit, seldom receive surgical intervention and, in the main, are cared for entirely by General Practitioners or Emergency Department physicians. Thorough clinical assessment and appropriate early treatment at the primary presentation is vital in order to offer the best chance of maximal functional recovery and to minimize long-term disability. This requires a sound knowledge of basic knee anatomy, careful assessment of the mechanism of injury, detection and consideration of physical ndings and the results of adjunctive investigations. This article aims to give a comprehensive review of the examination, investigation and early treatment of acute knee injuries at the primary presentation. In addition, comments on important epidemiological and aetiological factors and a brief description of basic knee anatomy are also provided.

Biomechanical Evaluation of Posterior Cruciate Ligament Reconstruction With Quadriceps Versus Achilles Tendon Bone Block Allograft

BACKGROUND

Long-term studies of posterior cruciate ligament (PCL) reconstruction suggest that normal stability is not restored in the majority of patients. The Achilles tendon allograft is frequently utilized, although recently, the quadriceps tendon has been introduced as an alternative option due to its size and high patellar bone density.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the biomechanical strength of PCL reconstructions using a quadriceps versus an Achilles allograft. The hypothesis was that quadriceps bone block allograft has comparable mechanical properties to those of Achilles bone block allograft.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-nine fresh-frozen cadaveric knees were assigned to 1 of 3 groups: (1) intact PCL, (2) PCL reconstruction with Achilles tendon allograft, or (3) PCL reconstruction with quadriceps tendon allograft. After reconstruction, all supporting capsular and ligamentous tissues were removed. Posterior tibial translation was measured at neutral and 20° external rotation. Each specimen underwent a preload, 2 cyclic loading protocols of 500 cycles, then load to failure.

RESULTS

Construct creep deformation was significantly lower in the intact group compared with both Achilles and quadriceps allograft (P = .008). The intact specimens reached the greatest ultimate load compared with both reconstructions (1974 ± 752 N, P = .0001). The difference in ultimate load for quadriceps versus Achilles allograft was significant (P = .048), with the quadriceps group having greater maximum force during failure testing. No significant differences were noted between quadriceps versus Achilles allograft for differences in crosshead excursion during cyclic testing (peak-valley [P-V] extension stretch), creep deformation, or stiffness. Construct stiffness measured during the failure test was greatest in the intact group (117 ± 9 N/mm, P = .0001) compared with the Achilles (43 ± 11 N/mm) and quadriceps (43 ± 7 N/mm) groups.

CONCLUSION

While the quadriceps trended to be a stronger construct with a greater maximum load and stiffness required during load to failure, only maximum force in comparison with the Achilles reached statistical significance. Quadriceps and Achilles tendon allografts had similar other biomechanical characteristics when used for a PCL reconstruction, but both were inferior to the native PCL.

CLINICAL RELEVANCE

The quadriceps tendon is a viable graft option in PCL reconstruction as it exhibits a greater maximum force and is otherwise comparable to the Achilles allograft. These findings expand allograft availability in PCL reconstruction.

Acute augmentation for interstitial insufficiency of the posterior cruciate ligament. A two to five year clinical and radiographic study

BACKGROUND

there is need to ascertain clinical and imaging outcomes after posterior cruciate ligament (PCL) augmentation.

METHODS

we performed a retrospective analysis of clinical, imaging and functional data on 21 physically active males who underwent arthroscopic trans-tibial augmentation of the PCL for symptomatic grade III PCL insufficiency. The average follow-up time was 50 months (24-60 months). The Lysholm knee score was administered to all the patients, ligament laxity was evaluated with the posterior drawer test, the KT-1000 arthrometer, and the anteromedial tibial step-off. Standing antero-posterior, lateral and Merchant's view radiographs were taken preoperatively and at annual follow-up.

RESULTS

post-operatively, ligament laxity and Lysholm knee scores were significantly improved than at baseline. Sixteen patients (73%) returned to pre-injury sport activity level, 3 patients (14%) returned to a lower level, 2 had to stop. We found radiographic degenerative changes in 5 of 22 affected knees (23%), with evidence of a statistically significant association between the occurrence of degenerative changes and the interval time from injury to surgery and duration of the follow up.

CONCLUSIONS

arthroscopic transtibial single bundle autograft hamstring augmentation significantly improves the function of the knee, with an overall satisfactory outcome of 82% at 2-5 years from surgery.

Usefulness of oblique coronal magnetic resonance images of the knee after posterior cruciate ligament reconstruction

OBJECTIVE:

To know the usefulness of the oblique coronal view of the posterior cruciate ligament (PCL) in the evaluation of the graft normal anatomy and the diagnostic accuracy of combining the PCL view with orthogonal views for the evaluation of PCL graft failure or impingement after reconstruction procedures.

METHODS:

This retrospective study included 54 patients who underwent PCL-view MRI after PCL reconstruction surgery. Anatomic identification of graft failure and impingement was scored by two radiologists. The ability to diagnose PCL graft failure with the PCL view, orthogonal view or combined PCL/orthogonal views was evaluated by calculating the sensitivity, specificity and accuracy.

RESULTS:

The entire width discrimination scores and margin sharpness scores for the PCL view were significantly higher than those for the orthogonal view for both readers. The specificities and accuracies for the PCL view and the combined PCL/orthogonal views were higher than those for the orthogonal view alone, but these differences were not statistically significant.

CONCLUSION:

The PCL view provided a better anatomic evaluation than the orthogonal view with regard to the entire width evaluation and margin sharpness evaluation of the PCL graft. The combined view of orthogonal and PCL views was slightly more sensitive and accurate, but not significantly so, in the diagnoses of graft failure and impingement.

ADVANCES IN KNOWLEDGE:

The PCL view provided a better anatomic evaluation than the orthogonal view with regard to the entire width evaluation and margin sharpness evaluation of the PCL graft. The PCL view was slightly more sensitive and accurate, but not significantly so, in the diagnoses of graft failure and impingement.

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.

Validation of a six degree-of-freedom robotic system for hip in vitro biomechanical testing

Currently, there exists a need for a more thorough understanding of native hip joint kinematics to improve the understanding of pathological conditions, injury mechanisms, and surgical interventions. A biomechanical testing system able to accomplish multiple degree-of-freedom (DOF) movements is required to study the complex articulation of the hip joint. Therefore, the purpose of this study was to assess the repeatability and comparative accuracy of a 6 DOF robotic system as a testing platform for range of motion in vitro hip biomechanical analysis. Intact human cadaveric pelvises, complete with full femurs, were prepared, and a coordinate measuring machine collected measurements of pertinent femoral and pelvic bony landmarks used to define the anatomic hip axes. Passive flexion/extension path and simulated clinical exam kinematics were recorded using a 6 DOF robotic system. The results of this study demonstrate that the 6 DOF robotic system was able to identify hip passive paths in a highly repeatable manner (median RMS error of <0.1mm and <0.4°), and the robotically simulated clinical exams were consistent and repeatable (rotational RMS error ≤0.8°) in determining hip ranges of motion. Thus, a 6 DOF robotic system is a valuable and effective tool for range of motion in vitro hip biomechanical analysis.

Posterior tibial displacement in the PCL-deficient knee is reduced compared to the normal knee during gait

PURPOSE

Most individuals with an isolated posterior cruciate ligament (PCL) injury do not complain of disability even if posterior instability is objectively revealed by a static physical examination, such as the posterior drawer test. This suggests it is insufficient to only evaluate posterior instability under static conditions. Therefore, we have investigated the effect of isolated PCL injury on the detailed kinematics of the knee in a dynamic environment such as during gait.

METHODS

Eight unilateral PCL-deficient males and eight healthy control volunteers participated in this study. Isolated PCL injury was diagnosed by clinical examination. Stress X-ray imaging showed an average side-to-side difference of 12.7 ± 3.5 mm. Knee kinematics including anteroposterior tibial displacement were analysed during walking using the point cluster technique.

RESULTS

Posterior tibial displacement from initial contact was significantly smaller during 9-22 % of the gait cycle by an average of 0.4 cm in the PCL group, compared to controls. In the PCL-deficient knee, the external rotational angle increased by an average of 3.3° at the loading response during 3-11 % of the gait cycle and the varus angle from initial contact increased by an average of 2.0° during 28-52 % of the gait cycle, compared to controls.

CONCLUSIONS

Dynamic changes in the rotation and posterior translation patterns were seen after isolated PCL injury, suggesting the kinematics of PCL-deficient knees might be different to normal knees. These factors may contribute to long-term osteoarthritic change. Consequently, when choosing conservative treatment for PCL injury, these changes should be considered to prevent osteoarthritic change.

LEVEL OF EVIDENCE

III.

Intraoperative laxity measurements using a navigation system in anatomical double-bundle posterior cruciate ligament reconstruction

PURPOSE

The objective of this study was to evaluate knee kinematics during double-bundle posterior cruciate ligament reconstruction (DB-PCLR) intraoperatively using a navigation system, and especially assess biomechanical behaviour of the anterolateral bundle (ALB) and posteromedial bundle (PMB) graft in DB-PCLR. Also, clinical results of minimum 2-year follow-up were investigated.

METHODS

Nine patients received DB-PCLR with hamstring graft. Before reconstruction, knee laxities, including posterior tibial translation (PTT) in neutral rotation at 15°, 30°, 45°, 60°, 75° and 90° of knee flexion, were measured using a kinematic-based navigation system. After the PMB or ALB was temporally fixed, the knee laxities were measured in the same manner. Each patient was evaluated pre- and post-operatively with side-to-side difference of tibial position in gravity sag view and Lysholm score.

RESULTS

Both ALB and PMB fixation restrained the PTT compared to  PCL deficiency throughout all knee flexion angles. At 90° of knee flexion, ALB fixation significantly decreased PTT compare to PMB fixation (p = 0.014) and DB-PCLR significantly decreased PTT compare to ALB fixation (p = 0.045). The mean side-to-side difference of tibial position in gravity sag view was 12.0 ± 1.7 mm preoperatively and 2.3 ± 1.8 mm at final follow-up, and the mean Lysholm scores were 68.9 ± 20.9 and 96.3 ± 2.9, respectively.

CONCLUSIONS

There were no significant differences in the PTT between ALB and PMB fixations at 0° to 75° of knee flexion, and both ALB and PMB reconstructions are important for restraining PTT. At 90° of knee flexion, the ALB grafts may be more important to control PTT compared to PMB grafts; however, neither single-bundle reconstruction with ALB nor PMB could function as DB-PCLR did. In addition, PTT after DB-PCLR was strongly correlated side-to-side difference in posterior sag view at the final follow-up. The results from this study indicated that both ALB and PMB are important to stabilize PCL-deficient knees.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

The necessity of clinical application of tibial reduction for detection of underestimated posterolateral rotatory instability in combined posterior cruciate ligament and posterolateral corner deficient knee

PURPOSE

The purpose of this study was to evaluate the usefulness of tibial reduction during dial test for clinical detection of underestimated posterolateral rotatory instability (PLRI) in combined posterior cruciate ligament (PCL)-posterolateral corner (PLC) deficient knee in terms of external rotation laxity and clinical outcomes.

METHODS

Twenty-one patients who classified as grade I PLRI using dial test with subluxated tibia, but classified as grade II with tibial reduction evaluated retrospectively. The mean follow-up was 39.3 months (range 24-61 months). Each patient was evaluated by the following variables: posterior translation and varus laxity on radiograph, KT-1000 arthrometer, dial test (reduced and subluxated position), International Knee Documentation Committee, Orthopädische Arbeitsgruppe Knie scoring system and Tegner activity scale.

RESULTS

There were significant improvements in posterior tibial translation (8.6 ± 2.0 to 2.1 ± 1.0 mm; P < 0.001), varus laxity (3.3 ± 1.3 to 1.4 ± 0.5 mm; P < 0.001) and external rotation (13.2° ± 0.8° to 3.6° ± 1.1° at 30°, 13.3° ± 0.9° to 3.6° ± 0.9° at 90°; P < 0.001). The clinical scores were improved significantly at the last follow-up (P < 0.001). The external tibial rotation during dial test with tibial reduction increased from 6.8° ± 0.9 to 13.2° ± 0.8° at 30° of knee flexion, from 7.0° ± 0.8° to 13.3° ± 0.9° at 90° (P < 0.001).

CONCLUSIONS

The clinical application of reduction of posteriorly subluxated tibia during the dial test was essential for an appropriate treatment of underestimated PLRI in combined PCL-PLC deficient knee.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Arthroscopic fixation of an avulsion fracture of the tibia involving the posterior cruciate ligament

A total of 22 patients with a tibial avulsion fracture involving the insertion of the posterior cruciate ligament (PCL) with grade II or III posterior laxity were reduced and fixed arthroscopically using routine anterior and double posteromedial portals. A double-strand Ethibond suture was inserted into the joint and wrapped around the PCL from anterior to posterior to secure the ligament above the avulsed bony fragment. Two tibial bone tunnels were created using the PCL reconstruction guide, aiming at the medial and lateral borders of the tibial bed. The ends of the suture were pulled out through the bone tunnels and tied over the tibial cortex between the openings of the tunnels to reduce and secure the bony fragment. Satisfactory reduction of the fracture was checked arthroscopically and radiographically.

The patients were followed-up for a mean of 24.5 months (19 to 28). Bone union occurred six weeks post-operatively. At final follow-up, all patients had a negative posterior drawer test and a full range of movement. KT-1000 arthrometer examination showed that the mean post-operative side-to-side difference improved from 10.9 mm (standard deviation (sd) 0.7) pre-operatively to 1.5 mm (sd 0.6) (p = 0.001). The mean Tegner and the International Knee Documentation Committee scores improved significantly (p = 0.001). The mean Lysholm score at final follow-up was 92.0 (85 to 96).

We conclude that this technique is convenient, reliable and minimally invasive and successfully restores the stability and function of the knee.

Cite this article: Bone Joint J 2015;97-B:1220–5.

Complications of posterolateral corner injuries of the knee and how to avoid them

Knee dislocations and in particular posterolateral corner injuries to the knee are severe injuries demanding an organized approach and technically challenging surgery. Complications include unrecognized vascular or neurological injury and failure to reconstruct appropriately. During reconstruction, performing an inappropriate operation (failure to recognize malalignment) or technical error with tunnel or hardware placement can lead to delayed problems. Wound infection and wound breakdown is common as in arthrofibrosis often from overconstraint of the knee. Attention to principles and expertise in technique can minimize these complications.