Posterior cruciate ligament injuries of the knee joint

Stepping into the Unknown: Unveiling the Rarity of PCL Fracture-Avulsions

Tears of the posterior cruciate ligament (PCL) are rare, and avulsion fracture of the tibial attachment of the posterior cruciate ligament is even rarer. These injuries usually occur in accidents such as car crashes, causing acute pain, swelling as well as total functional impotence of the knee. Studies on the incidence of these injuries show variable results, but there appears to be an upward trend. The surgical management of PCL avulsion fracture is not clearly established, although arthroscopic techniques are becoming more popular due to their potential benefits. However, some medical centers may have limited access to these methods, thus preferring open surgery options. A case of LCP avulsion fracture in a 36-year-old female patient was reported, and surgery was successfully performed, leading to full recovery after six months with full knee mobility and posterior stability.

Displaced Posterior Cruciate Avulsion Fracture Fixation With Medial Collateral Ligament and Lateral Meniscus Injury Using Combined Open and Arthroscopic Methods

Tibial-sided posterior cruciate ligament avulsion fractures are challenging injuries that often occur concomitantly in the setting of multiligament knee and other soft-tissue injuries. There is no consensus on the optimal surgical approach or timing of treatment for these injuries. This Technical Note describes the fixation of a displaced posterior cruciate ligament avulsion fracture with concomitant grade 3 medial collateral ligament injuries and bucket-handle lateral meniscus tears using open and arthroscopic techniques. This method allows the surgeon to address multiple pathologies in a single stage, although it requires strategic planning and rehabilitation considerations.

Posterior cruciate ligament rupture and all-epiphyseal repair with suture tape augmentation in a 5-year-old girl: a case report and review of the literature

INTRODUCTION

Only a few case reports regarding pediatric posterior cruciate ligament (PCL) ruptures without bone avulsion exist in the literature. The present study aims to share our experience in the diagnosis, treatment, and prognosis of a child with a proximal PCL tear.

MATERIALS AND METHODS

This article reports a 5-year-old female diagnosed with a proximal PCL tear. The ruptured PCL was repaired with an all-epiphyseal suture tape augmentation (STA) without evidence of growth plate violation.

RESULTS

The suture tape was removed under arthroscopy and revealed the PCL was re-attached at 12 months after the first surgery. And at the time of this report, 36 months after surgery, she was doing well without any problems and with negative posterior drawer test.

CONCLUSIONS

Pediatric PCL tear without bone avulsion is rare. However, the torn PCL was noticed healed based on an arthroscopic second-look.

THE OUTCOMES OF POSTERIOR CRUCIATE LIGAMENT TIBIAL AVULSION FIXATION WITH A SCREW USING A DUAL POSTEROMEDIAL PORTAL TECHNIQUE

Objectives

Our purpose was to evaluate the clinical results of PCL tibial avulsion fracture fixation performed with 4 mm cancellous screws using a dual posteromedial (PM) portal technique.

Methods

In a prospective study, we followed 12 patients submitted to PCL tibial insertion avulsion arthroscopic fixation using dual PM portals with cancellous screws from March 2014 to Jan 2020. The proximal higher PM portal served as an instrument portal and provided an optimal trajectory for arthroscopic screw fixation of larger PCL avulsion fractures. The lower PM portal was used as a viewing portal.

Results

Significant improvements were found between the preoperative and postoperative mean Lysholm scores at six months. The preoperative IKDC score mean of 10.13 increased to 89.3 at the end of six months. Minor adverse results with this technique were: grade I on posterior sag in five knees (41.6%), temporary stiffness in two cases (16.7 %), delayed union in one patient (8.3 %), and difficulty squatting at the end of six months in one patient (8.3%). Temporary extension lag was present in two individuals (16.7%), and fixed subtle flexion deficit of 3-5 degrees occurred in one individual (8.3 %).

Conclusion

The outcomes obtained with the proposed technique were similar to those obtained with open techniques, although mild flexion deficits and discreet posterior sag may be present in a significant number of cases. Level of Evidence II; Prospective Cohort Study .

Open reduction and internal fixation of the tibial avulsion fracture of the posterior cruciate ligament: which is better, a hollow lag screw combined with a gasket or a homemade hook plate?

OBJECTIVE

To compare the clinical results of homemade hook plates and hollow lag screws combined with spacers in the treatment of posterior cruciate tibial ligament avulsion fractures.

MATERIALS AND METHODS

This was a retrospective clinical cohort study that included 64 patients with PCL tibial avulsion fractures. Thirty-two of them were fixed with a homemade hook plate (hook plate group), and 32 were fixed with a hollow lag screen combined with a gasket (hollow lag screen group). By reviewing the medical record data and follow-up results, the operation time, postoperative drainage, fracture healing time, surgical complications, knee mobility, recovery of joint function, and whether postoperative gastrocnemius muscle strength changed in the two groups were compared.

RESULTS

All patients had successful wound and fracture healing. No adverse events, such as bone nonunion, infection, wound haematoma, or joint stiffness, occurred in either group. There were no patients with decreased gastrocnemius muscle strength in either group. Internal fixation failure occurred in 2 cases in the hollow lag screen group but not in the hook plate group. There were no significant differences between the two groups in terms of operative time, postoperative drainage, fracture healing time, knee mobility at the last follow-up, or Lysholm score.

CONCLUSION

It is safe and effective to use a homemade hook plate to fix PCL tibial avulsion fractures through an inverted L-shaped posterior medial approach. A homemade hook plate may have potential advantages over a hollow lag screen combined with gasket fixation.

Postoperative Rehabilitation and Return to Sport Following Multiligament Knee Reconstruction

Multiligament knee injuries (MLKIs) are debilitating injuries that increasingly occur in young athletes. Return to sport (RTS) has historically been considered unlikely due to the severity of these injuries. Reporting in the literature regarding objective outcomes following MLKI, including RTS, is lacking, as are clear protocols for both rehabilitation progressions and RTS testing. RTS following MLKI is a complex process that requires an extended recovery duration compared to other surgery types. Progressions through postoperative rehabilitation and RTS should be thoughtful, gradual, and criterion based. After effective anatomic reconstruction to restore joint stability, objective measures of recovery including range of motion, strength, movement quality, power, and overall conditioning guide decision-making throughout the recovery process. It is important to frame the recovery process of the athlete in the context of the severity of their injury, as it is typically slower and less linear. Improved reporting on objective outcomes will enhance our understanding of recovery expectations within this population by highlighting persistent deficits that may interfere with a full recovery, including RTS.

Case report of concomitant avulsion fractures of the medial meniscus and posterior cruciate ligament

RATIONALE

Posterior cruciate ligament (PCL) is the strongest ligament of the knee, and avulsion fractures of PCL are a very rare type of injury. These injuries occur as a result of high-energy traumas, and different accompanying pathologies may be seen. However, tibial avulsion fracture of the PCL associated with a medial meniscus (MM) avulsion fracture has never been reported before. We want to present this unique type of posteromedial knee injury as a case report.

PATIENT CONCERN

A 42-year-old man presented with severe pain and swelling due to a ski injury.

DIAGNOSIS

Concomitant avulsion fractures of PCL and MM were detected after imaging.

INTERVENTIONS

Both avulsion fractures were treated with open reduction and fixation with lag screws using the posterior approach.

OUTCOMES

No complications were encountered, and the painless full range of motion and weight-bearing was achieved at the third month after the operation.

LESSONS

Anatomical reduction and stable fixation of these intra-articular fractures are essential for the stability of the knee. The posterior approach should be kept in mind to access these types of fractures safely. Care should be taken in terms of other injuries that may accompany the PCL avulsion fractures caused by high-energy traumas.

Epidemiology of Posterior Cruciate Ligament Reconstructions in Italy: A 15-Year Study

Background: The posterior cruciate ligament (PCL) is an essential element in knee stability. PCL reconstructions represent an under-investigated topic in the literature due to the rarity of this type of knee injury. This study aims to investigate the incidence of PCL reconstructive surgeries in Italy, following their trend during a 15-year period. Methods: The National Hospital Discharge records (SDO) collected by the Italian Ministry of Health between January 2001 and October 2015 were analyzed. The database reports anonymous data comprising patients’ ages, genders, International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for diagnosis and intervention, census regions, regions of hospitalization, lengths of hospitalization and types of reimbursement. Results: The overall incidence of PCL reconstructions in the Italian population during the study period was 0.46 surgeries per 100,000 inhabitants/year, ranging from 0.32 to 0.54. The median patient’s age was 30 years old, and the male:female ratio was 5.3. PCL lesions were isolated in 39.7% of patients, while anterior cruciate ligament injuries were the most frequently associated lesions (31.1%). Conclusions: The incidence of PCL reconstruction in Italy was low and stable during the study period. Young men are the category at the highest risk for these procedures. Given the paucity of epidemiological data on PCL reconstructions, this data may represent a reference for the current and foreseeable needs in PCL surgeries for countries sharing similar cultural context.

Surgical treatment of posterior cruciate ligament tibial avulsion fractures using a locking compression hook plate: A case series

OBJECTIVE

This study aimed to evaluate the results of surgical treatment of tibial avulsion injuries of the posterior cruciate ligament (PCL) with a 3.5-mm locking compression hook plate (LCHP).

METHODS

From June 2012 to June 2015, 16 consecutive patients (10 males and 6 females, mean age: 38 (range: 19-57) years) presented with isolated tibial avulsion injuries of the PCL. We used a 3.5-mm LCHP and lag screws for open reduction and internal fixation (ORIF) through the posterior medial approach. The operation time, quantity of bleeding, visual analog scale (VAS) scores, stability of posterior drawer test (PDT) results, and fracture healing time were studied to assess clinical efficacy. At the 12-month follow-up, a functional evaluation using knee range of motion (ROM) and the Lysholm knee scoring system (LKSS) was performed.

RESULTS

The data from a mean follow-up of 24.1 (range: 14-33) months from 16 patients were recorded. No neurovascular complications, incision infections, or delayed union or nonunion were observed. The mean operation time was 61.4 (range: 45-80) min. The mean quantity of bleeding was 41.6 (range: 25-66) mL. The mean bone healing time was 11.8 (range: 45-80) weeks. The mean VAS score was 1.63 (range: 0-3) after surgery. The average LKSS and ROM of the knee were 51.75±7.67 and 50.94°±10.19° before surgery and 92.75±5.46 and 127.75°±6.13° at 1 year, respectively. The outcomes were judged to be excellent for 11 patients, good for 4, and fair for 1 (excellent and good rates: 93.8% for 15/16). At the final follow-up (≥1 year), the PDT scores returned to normal.

CONCLUSION

The results showed that 3.5-mm LCHP provided reliable fixation following ORIF of isolated PCL tibial avulsion fractures and was a safe, simple, and effective procedure. This procedure may reduce complications and improve functional recovery relative to those of other procedures.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-1900022920. Registered on 3 May 2019.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Longitudinal changes in location-specific cartilage thickness and T2 relaxation-times after posterior cruciate ligament reconstruction for isolated and multiligament injury

BACKGROUND

Knee cartilage undergoes pathological changes after anterior cruciate ligament rupture. However, little is known about the development and progression of structural pathology after posterior cruciate ligament (PCL) injury. This study aimed to determine the location-specific longitudinal changes in knee cartilage morphology (thickness) and composition (T2 relaxation-times) after PCL rupture and reconstruction (PCLR) and compare these to uninjured controls.

METHODS

Fifteen adults (mean age 39 years (standard deviation 10), 12 men) with PCLR for isolated and multiligment injury had MRIs acquired at a minimum 5 years post-PCLR and 1 year later. Location-specific changes in knee cartilage thickness and T2 relaxation-times were determined quantitatively after segmentation, and compared with annualised cartilage changes in 13 active controls (mean age 45 years (standard deviation 4), 6 men).

FINDINGS

Following PCLR, the annual loss of cartilage thickness was greatest in the medial femoral condyle (mean -4.0%, 95% confidence interval [95% CI] -6.7, -1.4), medial tibia (mean -3.7%, 95% CI -6.1, -1.3), and patella (mean -3.2%, 95% CI -4.7, -1.6). In the medial femoral condyle and trochlea, the PCLR group lost significantly more cartilage thickness than uninjured controls (mean difference -3.7%, 95% CI -0.9, -6.5; and -1.8%, 95% CI -0.1, -3.6, respectively). Deep and superficial zone T2 relaxation-times were relatively constant over time, without longitudinal differences between PCLR and control knees.

INTERPRETATION

PCL reconstructed knees displayed substantially greater rates of cartilage loss in the medial tibiofemoral and patellofemoral compartments compared to uninjured controls, highlighting that the process of degeneration remains active many years after injury.

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.

Arthroscopic Treatment of Femoral Avulsion Fracture of the Posterior Cruciate Ligament in Association with Meniscus Tear

BACKGROUND

Femoral avulsion fracture of the posterior cruciate ligament (PCL) in association with meniscus tear is extremely rare in children, and similar cases are not available in the existing literature.

CASE PRESENTATION

In this paper, we present a case of a 9-year-old boy treated by an arthroscopic repair technique using two transfemoral tunnels sparing the epiphyseal plate for 8-shaped suture fixation of femoral avulsion fracture of the PCL and using the Fastfix repair system for a meniscus tear. At 3-month postoperative, the boy showed satisfactory recovery with a full range of motion of the right knee and normal muscular strength, and no complications were observed after operation. The patient had been followed up for 24 months and his final assessment demonstrated stable painless knee with excellent functional outcome. In view of this, we suggest that the "figure-of-eight" suture technique using two transfemoral tunnels sparing the epiphyseal plate can be considered a new choice for the treatment of the PCL femoral attachment avulsion, especially in skeletally immature patients. In addition, six similar cases were found in a comprehensive literature review targeting femoral avulsion fracture of the PCL. According to the relevant findings and cases studies, we proposed a new classification named "Xiangya" which might facilitate future clinical decision making.

The morphology and histology study on rabbit degenerated medial meniscus after posterior cruciate ligament rupture

The morphology and histology changes in the medial meniscus after posterior cruciate ligament (PCL) rupture are poorly understood. Forty-eight rabbits were divided into matched mode pairs; each rabbit had an experimental side, in which the PCL was transacted, and a control side. At the 4, 8, 16 and 24 weeks after the PCL transection, each of the 12 rabbits was killed. Histology was performed to detect the expression of the tissue inhibitors of metalloproteinases-1 (TIMP-1), matrix metalloproteinase (MMP)-1 and MMP-13 in the medial meniscus. We found that medial meniscus displayed significant degenerative characteristics in morphology. The histological evaluation of the degeneration found that the expression levels of TIMP-1, MMP-1 and MMP-13 in the medial meniscus were higher in the experiment side than those in the control side (P<0.05). The expression of both TIMP-1 and MMP-13 was initially elevated and then decreased. The MMP-1 expression reached its peak swiftly and then maintained a relatively high level. There were clear time-dependent degenerative changes in the histology of the medial meniscus after PCL rupture. The high expression of TIMP-1, MMP-1 and MMP-13 in the cartilage may be responsible for the degeneration, and PCL rupture may trigger meniscus degradation and ultimately osteoarthritis.

Treatment of acute avulsion of posterior cruciate ligament of left knee with bony fragment by Siddha Varmam therapy and traditional bone setting method

A 42-year-old man with the complaints of left knee swelling, severe pain, difficult to stand was reported to Siddha Varmam division after a road accident. He was diagnosed as acute avulsion of Posterior cruciate ligament (PCL). It was diagnosed based on the history of trauma, knee pain and swelling after trauma, positive posterior drawer test and avulsion fracture shown by radiograph. He was treated with Siddha Varmam therapy and traditional bone setting. After a month of treatment, the PCL avulsion fracture got healed without any surgical interventions and patient able to walk normally. This case report summarises the novel Siddha Varmam therapy and traditional bone setting treatments for acute avulsion of PCL with bony fragment.

Open Posterior Approach versus Arthroscopic Suture Fixation for Displaced Posterior Cruciate Ligament Avulsion Fractures: Systematic Review

Purpose

To compare the clinical outcomes between the open posterior approach and arthroscopic suture fixation for displaced posterior cruciate ligament (PCL) avulsion fractures.

Methods

A literature search was performed on MEDLINE, EMBASE, and the Cochrane Library databases. The inclusion criteria were as follows: papers written in English on displaced PCL avulsion fractures, clinical trial(s) with clear description of surgical technique, adult subjects, a follow-up longer than 12 months and modified Coleman methodology score (CMS) more than 60 points.

Results

Twelve studies were included with a mean CMS value of 72.4 (standard deviation, 7.6). Overall, 134 patients underwent the open posterior approach with a minimum 12-month follow-up, and 174 patients underwent arthroscopic suture fixation. At final follow-up, the range of Lysholm score was 85-100 for the open approach and 80-100 for the arthroscopic approach. Patients who were rated as normal or nearly normal in the International Knee Documentation Committee subjective knee assessment were 92%-100% for the open approach and 90%-100% for the arthroscopic approach. The range of side-to-side difference was 0-5 mm for both approaches.

Conclusions

Both arthroscopic and open methods for the treatment of PCL tibial-side avulsion injuries resulted in comparably good clinical outcomes, radiological healing, and stable knees.

Posterior Cruciate Ligament Avulsion Fractures

PURPOSE OF REVIEW

The purposes of this review are to (1) discuss the epidemiology and workup of the rare posterior cruciate ligament (PCL) avulsion fracture, (2) review the indications for nonoperative and operative management of patients with PCL avulsion fractures, (3) examine surgical outcomes in this patient population, and (4) discuss the authors' preferred management algorithm and surgical approach.

RECENT FINDINGS

In accordance with the rarity of these injuries, the literature is sparse regarding surgical outcomes. Many of these injuries are in the setting of a multi-ligamentous injury. Most authors suggest that displaced PCL avulsion fractures should undergo operative fixation and current data suggests excellent outcomes when treating these patients with either open or arthroscopic fixation, with a low complication rate. PCL avulsion fractures, although rare, should undergo fixation when displacement is present. Current studies report successful outcomes and a low complication rate.

Knee Stability and Movement Coordination Impairments: Knee Ligament Sprain Revision 2017

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to knee ligament sprain. J Orthop Sports Phys Ther. 2017;47(11):A1-A47. doi:10.2519/jospt.2017.0303.

Open Reduction and Internal Fixation of Isolated Posterior Cruciate Ligament Avulsion Fractures: Clinical and Functional Outcome

Purpose

The posterior cruciate ligament (PCL) presents commonly with avulsion fractures of its tibial attachment. An avulsion fracture of the PCL, if not surgically fixed, may lead to secondary changes in the knee joint. Various fixation techniques have been explored with use of lag screws, steel wires, absorbable screws, suture anchors and straddle nails. The purpose of this study was to evaluate the clinical and functional outcome of open reduction and internal fixation of tibial avulsion injuries of the PCL using cannulated cancellous screws.

Materials and Methods

We performed open reduction and internal fixation using cannulated cancellous screws in 14 patients (mean age, 33.9 years) with isolated PCL avulsion injuries. Patients with a duration of injury more than 12 weeks were excluded. The minimum follow-up period was 12 months. Results were assessed radiologically and clinically. Final functional outcome was assessed using the Lysholm knee scoring system.

Results

The average follow-up period was 13.5 months. At the final follow-up, all 14 patients achieved fracture union. The average flexion was 121.7°±9.2° with full extension achieved in all patients. Mild instability (1+) was noted in 4 patients. The Lysholm functional score was excellent in 11 patients, good in 2 patients and fair in 1 patient with an average score of 97±7.6.

Conclusions

Stable early fixation for PCL avulsion injuries with early controlled mobilization provided excellent to good results. However, fixation should not be discouraged for late-presenting patients because good to fair results can be achieved in such cases.

Comparison of Joint Loading in Badminton Lunging between Professional and Amateur Badminton Players

The knee and ankle are the two most injured joints associated with the sport of badminton. This study evaluates biomechanical factors between professional and amateur badminton players using an injury mechanism model. The aim of this study was to investigate the kinematic motion and kinetic loading differences of the right knee and ankle while performing a maximal right lunge. Amateur players exhibited greater ankle range of motion (p < 0.05, r = 0.89) and inversion joint moment (p < 0.05, r = 0.54) in the frontal plane as well as greater internal joint rotation moment (p < 0.05, r = 0.28) in the horizontal plane. In contrast, professional badminton players presented a greater knee joint moment in the sagittal (p < 0.05, r = 0.59) and frontal (p < 0.05, r = 0.37) planes, which may be associated with increased knee ligamentous injury risk. To avoid injury, the players need to forcefully extend the knee with internal rotation, strengthen the muscles around the ankle ligament, and maximise joint coordination during training. The injuries recorded and the forces responsible for the injuries seem to have developed during training activity. Training programmes and injury prevention strategies for badminton players should account for these findings to reduce potential injury to the ankle and knee.

Treatment of posterior cruciate ligament avulsion fractures of the tibia using a toothed plate and hollow lag screw

INTRODUCTION

To investigate the feasibility and clinical efficacy of using a toothed plate and hollow lag screw in the surgical treatment of posterior cruciate ligament (PCL) avulsion fractures of the tibia.

METHODS

A total of 21 patients were treated with open reduction and internal fixation using a toothed plate and hollow lag screw, through a posteromedial approach using an inverted L-shaped incision. The patients were allowed appropriate functional exercises, including knee flexion and extension, after removal of the plaster at postoperative weeks 3-6. The follow-up period was between six months and two years.

RESULTS

This was a retrospective study of patients with PCL avulsion fractures of the tibia caused by road traffic accidents (n = 9), sports-related injuries (n = 6), falls (n = 5) and machinery-related injuries (n = 1). 20 patients presented with fresh fractures and one with an old fracture. The patients (13 men, eight women) had a mean age of 41.5 (range 19-72) years. Anatomical reduction of the fracture and satisfactory fixation were achieved in all 21 patients. Bony union was achieved in all patients at 8-12 weeks after surgery. Six months after surgery, knee flexion was 121.9° ± 10.4° and extension was 0°. According to the Lysholm Knee Scoring Scale, 19 patients were rated as 'excellent' and two as 'good'.

CONCLUSION

The use of a toothed plate and hollow lag screw could be a simple and reliable approach for PCL avulsion fractures of the tibia. Patients achieved good knee function after surgery.

Effect of Posterior Cruciate Ligament Rupture on Biomechanical and Histological Features of Lateral Femoral Condyle

Background

The aim of this study was to investigate bone mineral density (BMD) and the biomechanical and histological effects of posterior cruciate ligament (PCL) rupture on the lateral femoral condyle.

Material/Methods

Strain on different parts of the lateral femoral condyle from specimens of normal adult knee joints, including 12 intact PCLs, 6 ruptures of the anterolateral bundle, 6 ruptures of the postmedial bundle, and 12 complete ruptures, was tested when loaded with different loads on the knee at various flexion angles. Lateral femoral condyles were also collected randomly from both the experimental side in which the PCLs were transected and the control side from 4 sets of 12 matched-mode pairs of rabbits at 4, 8, 16, and 24 weeks after surgery, and their BMD and morphological and histological changes were observed.

Results

Partial and complete rupture of the PCL may cause an abnormal load on all parts of the lateral femoral condyle with any axial loading at all positions. Noticeable time-dependent degenerative histological changes of the lateral femoral condyle were observed in the rabbit model of PCL rupture. All of the PCL rupture groups had a higher expression of matrix metalloproteinase-7 (MMP-7) and collagen type II than the control group at all time points (P<0.05), but no significant difference in BMD (P>0.05).

Conclusions

Rupture of the PCL may trigger a coordinated response of lateral femoral condyle degeneration in a time-dependent manner, to which the high level of expression of MMP-7 and collagen type II could contribute.

GAIT PATTERNS AFTER POSTERIOR CRUCIATE LIGAMENT INJURY: A COMPARISON OF SYMPTOMATIC AND ASYMPTOMATIC PATIENTS

This study examined chronic, isolated posterior cruciate ligament (PCL) rupture patients, dividing them into symptomatic and asymptomatic groups according to whether they displayed obvious symptoms in daily activities. Each group comprised 10 patients while 10 healthy, young individuals were adopted as the control group. Using a three-dimensional motion analysis system and force plates, the gait patterns of the PCL-deficient patients were analyzed from both kinematics and kinetics perspectives to identify whether they differed from the control group and to compare symmetry between the injured and uninjured sides. The results showed that the symptomatic PCL-deficient group was closer to "normal", and the asymptomatic PCL-deficient group showed less knee extension moment and lower power absorption in the terminal stance than the control group. Additionally, the symptomatic PCL-deficient group appeared to have a relatively symmetric gait while the asymptomatic PCL-deficient group primarily showed an asymmetric gait also occurring in the terminal stance, including less joint moment and lower power absorption of the hip and knee, and lower vertical ground reaction force (GRF). Regarding the gait adaptations of the asymptomatic PCL-deficient group these compensation mechanisms are most likely to have been produced in order to assist in joint stabilization and reduce symptoms in joints.

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

BACKGROUND

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

HYPOTHESIS

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

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

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

RESULTS

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

CONCLUSION

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

Anatomical dissection and CT imaging of the posterior cruciate and lateral collateral ligaments in skeletally immature cadaver knees

BACKGROUND

Understanding the relationship of the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) to the femoral and tibial physes is important to reducing the risk of physeal injury during surgical reconstruction. The purpose of this study was to identify the location of the attachments of the PCL and LCL in skeletally immature cadaveric knee specimens and to determine their position relative to the physes.

METHODS

Seven skeletally immature cadaveric knee specimens were examined through gross dissection. These specimens were divided into two groups: infants (an age at death of one month for one specimen and eleven months for two specimens) and children (an age at death of eight years for one specimen, ten years for one specimen, and eleven years for two specimens). Metallic markers were placed at the femoral origins of the PCL and LCL and at the tibial insertion of the PCL. Computed tomography (CT) scans were made for each specimen and analyzed with the use of OsiriX imaging software. The width of the PCL tibial insertion footprint and the height of the PCL femoral origin footprint, the distance from the midpoints of the PCL and LCL femoral origin to the distal femoral physis, and the distance from the PCL insertion footprint midpoint to the proximal tibial physis were measured.

RESULTS

The mean distance from the midpoint of the femoral origin footprint of the PCL to the femoral physis was 11.1 mm (range, 10.6 to 11.7 mm) and 18.8 mm (range, 18.2 to 19.2 mm) distal to the physis for infants and children, respectively. The mean distance from the midpoint of the tibial insertion footprint of the PCL to the tibial physis was 3.1 mm (range, 0.0 to 5.7 mm) and 5.8 mm (range, 2.5 to 8.9 mm) proximal to the physis for infants and children, respectively. The mean width of the tibial insertion of the PCL was 5.5 mm (range, 1.1 to 8.3 mm) for infants and 10.2 mm (range, 8.4 to 11.9 mm) for children. The mean distance from the midpoint of the femoral origin of the LCL to the femoral physis was 6.3 mm (range, 3.9 to 7.7 mm) and 5.9 mm (range, 0.0 to 10.0 mm) distal to the physis for infants and children, respectively.

CONCLUSIONS

The relationship of the PCL and LCL attachments to physeal structures has not been well described. We found the midpoints of the PCL and LCL femoral origins at or distal to, and the midpoint of the PCL tibial insertion at or proximal to, the respective physis in all specimens. This study with CT-scan correlation provides unique information on the location of ligament attachments in relation to the physes.

CLINICAL RELEVANCE

A better understanding of the spatial relationship between the PCL and LCL attachments and their respective physes may help guide drill-hole placement during ligament reconstructions and reduce the risk for iatrogenic physeal injury in skeletally immature patients.

Testosterone reduces knee passive range of motion and expression of relaxin receptor isoforms via 5α-dihydrotestosterone and androgen receptor binding

Ovarian steroids such as estrogen and progesterone have been reported to influence knee laxity. The effect of testosterone, however, remains unknown. This study investigated the effect of testosterone on the knee range of motion (ROM) and the molecular mechanisms that might involve changes in the expression of relaxin receptor isoforms, Rxfp1 and Rxfp2 in the patella tendon and lateral collateral ligament of the female rat knee. Ovariectomized adult female Wistar rats received three days treatment with peanut oil (control), testosterone (125 and 250 μg/kg) and testosterone (125 and 250 μg/kg) plus flutamide, an androgen receptor blocker or finasteride, a 5α-reductase inhibitor. Duplicate groups received similar treatment however in the presence of relaxin (25 ng/kg). A day after the last drug injection, knee passive ROM was measured by using a digital miniature goniometer. Both tendon and ligament were harvested and then analysed for protein and mRNA expression for Rxfp1 and Rxfp2 respectively. Knee passive ROM, Rxfp1 and Rxfp2 expression were significantly reduced following treatment with testosterone. Flutamide or finasteride administration antagonized the testosterone effect. Concomitant administration of testosterone and relaxin did not result in a significant change in knee ROM as compared to testosterone only treatment; however this was significantly increased following flutamide or finasteride addition. Testosterone effect on knee passive ROM is likely mediated via dihydro-testosterone (DHT), and involves downregulation of Rxfp1 and Rxfp2 expression, which may provide the mechanism underlying testosterone-induced decrease in female knee laxity.

Proprioception and clinical results of anterolateral single-bundle posterior cruciate ligament reconstruction with remnant preservation

Purpose

To evaluate the clinical and radiological results and proprioception following anterolateral single-bundle posterior cruciate ligament (PCL) reconstruction with remnant preservation for PCL injury.

Materials and Methods

Twenty patients with an isolated PCL injury (16 males and 4 females) were included in this study. The mean follow-up period was 61 months (≥24 months) and the mean age of the patients was 36 years. Knee joint instability was evaluated using posterior drawer stress radiography. Knee function, level of activities, and individual satisfaction were assessed using the Lysholm knee score, Tegner activity score, and 2000 International Knee Documentation Committee (IKDC) score. Knee proprioception was assessed using an isokinetic machine.

Results

The mean ligament laxity assessed using the posterior drawer stress radiography was improved from 10.8-3.2 mm. The mean Lysholm knee score was improved from 70.0-88.9 points, and the mean Tegner activity score was improved from 2.7-6.2 points. Individual satisfaction assessed using the IKDC score was improved from 62.7-85.4 points (p<0.05). Knee proprioception was not significantly different between the treated and the uninjured knees.

Conclusions

Single-bundle PCL reconstruction with remnant preservation for PCL injury exhibited satisfactory outcomes regarding functional outcome, joint stability, and proprioception.

Posterior cruciate ligament avulsion fracture in children: a case report with long-term follow-up and comprehensive literature review

Isolated posterior cruciate ligament (PCL) avulsion fracture from the tibial attachment in children is extremely rare. The initial diagnosis is often missed in clinical practice. The present report describes the outcome in a long-term follow-up case of an 11-year-old boy involved in a motorcycle accident. The lesion was fixed through an open posterior approach with anatomic reduction. The patient has been followed for 4 years, and his final assessment revealed stable painless knee with an excellent functional outcome. The procedure is described and a surgical video outlines the pre-operative clinical examination. The particularity of this case is the long-term follow-up and the excellent outcome. We reviewed similarly reported cases in the literature and the different methods used in current practice.

A review of the anatomical, biomechanical and kinematic findings of posterior cruciate ligament injury with respect to non-operative management

An understanding of the kinematics of posterior cruciate ligament (PCL) deficiency is important for the diagnosis and management of patients with isolated PCL injury. The kinematics of PCL injury has been analysed through cadaveric and in vivo imaging studies. Cadaveric studies have detailed the anatomy of the PCL. It consists of two functional bundles, anterolateral and posteromedial, which exhibit different tensioning patterns through the arc of knee flexion. Isolated sectioning of the PCL and its related structures in cadaveric specimens has defined its primary and secondary restraining functions. The PCL is the primary restraint to posterior tibia translation above 30° and is a secondary restraint below 30° of knee flexion. Furthermore, sectioning of the PCL produces increased chondral deformation forces in the medial compartment as the knee flexes. However, the drawback of cadaveric studies is that they can not replicate the contribution of surrounding neuromuscular structures to joint stability that occurs in the clinical setting. To address this, there have been in vivo studies that have examined the kinematics of the PCL deficient knee using imaging modalities whilst subjects perform dynamic manoeuvres. These studies demonstrate significant posterior subluxation of the medial tibia as the knee flexes. The results of these experimental studies are in line with clinical consequences of PCL deficiency. In particular, arthroscopic evaluation of subjects with isolated PCL injuries demonstrate an increased incidence of chondral lesions in the medial compartment. Yet despite the altered kinematics with PCL injury only a minority of patients require surgery for persistent instability and the majority of athletes are able to return to sport following a period of non-operative rehabilitation. Specifically, non-operative management centres on a programme of quadriceps strengthening and hamstring inhibition to minimise posterior tibial load. The mechanism behind the neuromuscular adaptation that allows the majority of athletes to return to sport has been investigated but not clearly elucidated. The purpose of this review paper is to draw together the findings of experimental studies on the anatomical and kinematic effects of PCL injury and summarise their relevance with respect to non-operative management and functional outcome in patients with isolated PCL deficiency.

Case report: Osteochondral avulsion fracture of the posteromedial bundle of the PCL in knee hyperflexion

BACKGROUND

Injury of the PCL of the knee in adults usually results in rupture rather than avulsion fracture and avulsions usually occur at the tibial insertion.

CASE DESCRIPTION

We report an avulsion of the PCL with a femoral origin in a 22-year-old man who was injured by hyperflexion of the knee and was treated with arthroscopy. There were two parts in the partial osteochondral avulsion fracture of the PCL posteromedial (PM) bundle. One part was fixed with polydioxanone suture through drill holes and the other was removed. The fracture healed after 3 months and the knee was stable. At 11 months postoperatively the patient had returned to full-time work without pain or restrictions. The Lysholm II knee score was 95 points. Physical examination showed a negative posterior drawer sign.

LITERATURE REVIEW

We identified four other reported cases of PCL femoral origin avulsion fractures in adults. The subjects were 20 to 25 years old in four of five reports, including our patient. Three of the five patients had involvement of only the lateral cortex of the medial femoral condyle whereas two other patients including our patient, had an osteochondral fracture. The mechanism of PCL avulsion seems to be similar to that of a PCL rupture.

PURPOSES AND CLINICAL RELEVANCE

The hyperflexion injury may result in injury of the PM bundle of the PCL. Our case and one other in the literature suggest such avulsions need not involve the entire PCL.

Clinical results of arthroscopic single-bundle transtibial posterior cruciate ligament reconstruction: a systematic review

BACKGROUND

Reconstruction of the posterior cruciate ligament has traditionally been performed using an arthroscopically assisted single-bundle transtibial technique. Unfortunately, clinical studies evaluating this procedure are rare. In addition, there are no pooled analyses evaluating the effectiveness of this procedure for isolated posterior cruciate ligament tears.

HYPOTHESIS

Patients who undergo arthroscopically assisted, single-bundle, transtibial posterior cruciate ligament reconstruction will exhibit subjective improvement in knee function despite persistent objective knee laxity.

STUDY DESIGN

Systematic review.

METHODS

A structured literature search was performed to identify those clinical studies assessing the results of an arthroscopically assisted single-bundle transtibial posterior cruciate ligament reconstruction for isolated posterior cruciate ligament tears. The published data meeting the inclusion criteria were systematically reviewed with an emphasis on residual posterior laxity, subjective and objective functional outcome, activity level, patient satisfaction, incidence of osteoarthritis, and postoperative complications.

RESULTS

A total of 10 studies were identified that met the inclusion criteria. Mean postoperative instrumented posterior knee laxity varied from 1.96 mm to 5.90 mm, which was considerably improved from preoperative values (range, 8.38-12.3 mm). The range of mean values of the Lysholm knee scores was 81 to 100 points. The overall International Knee Documentation Committee rating was categorized as "normal" or "nearly normal" in 75% of patients and the mean Tegner activity score varied from 4.7 to 6.3 points. Degenerative osteoarthritis was frequently noted at the time of the most recent follow-up. There were few complications reported.

CONCLUSION

Arthroscopically assisted single-bundle transtibial posterior cruciate ligament reconstruction for isolated posterior cruciate ligament tears can improve posterior knee laxity by 1 grade, although this procedure does not reliably restore normal knee stability. Return to recreational and athletic activity was predictable, with 75% of patients exhibiting a normal or nearly normal objective outcome, although degenerative osteoarthritis was not prevented by this procedure.

Posterior cruciate ligament mediated avulsion fracture of the lateral tibial condyle: a case report

Avulsion fractures of the posterior cruciate ligament (PCL) are uncommon. On the basis of the site of damage of the PCL, hyperflexion, pretibial trauma, and hyperextension are proposed as mechanisms of PCL injuries. On the other hand, avulsion fractures of the tibial condyle are also rare. We report a PCL-mediated avulsion fracture of the lateral tibial condyle along with the tibial insertion of the PCL by extension-distraction force on the knee that has not been previously described in any study. This rare case may imply that application of an extension-distraction force to the PCL cause the avulsion fracture.

Functional outcome following PCL and complex knee ligament reconstruction

The purpose of this study was to evaluate the functional outcome of surgical reconstruction of the posterior cruciate ligament (PCL). In particular we wanted to document the recovery of knee muscle function. Twenty three patients underwent single bundle reconstruction of the PCL. There were four isolated PCL reconstructions. The remainder had PCL reconstructions combined with other ligament reconstructions. Patients were followed up at 2, 6, 12 and 26 weeks post operatively and underwent detailed functional assessment at 12 and 24 months. Outcome measures included the International Knee Documentation Committee (IKDC) score, the Tegner activity rating, and muscle dynamometry evaluating peak torque for knee flexion and extension. At final follow up 19 (83%) patients were rated as normal or nearly normal by the IKDC score. Seventeen (74%) patients returned to moderate or strenuous activity. Ligament stability was rated as normal or nearly normal in 20 (87%) patients. All 23 patients regained normal or nearly normal range of motion of the knee following surgery. Knee flexion peak torque demonstrated an average percentage deficit from the normal side of 24% at 12 months and 14% at 24 months. The deficits for extension were 35% and 9% for the same time points. PCL reconstruction is associated with a satisfactory clinical outcome but muscle function abnormalities may persist for 2 years.

Active non-operative treatment of acute isolated posterior cruciate ligament injury with cylinder cast immobilization

The objective of our study was to investigate the outcome of an active non-operative treatment of the acute isolated posterior cruciate ligament (PCL) injury using cylinder cast immobilization and brace with tibial supporter. This study included 17 acute and isolated PCL injuries with two years or more of follow-up for each patient. We applied a cylinder cast immobilization with tibial supporter with full extension of the knee for 6 weeks, and then another 6 weeks of PCL brace with tibial supporter and posterior elastic rubber band to prevent posterior sagging of the proximal tibia. There was improved anteroposterior stability with some residual laxity and improved clinical results at the last follow-up. The conservative treatment utilizing cylinder cast immobilization and brace may be one of the recommendable treatment methods in an isolated and acute PCL injury.

Posterior cruciate ligament deficiency: biomechanical and biological consequences and the outcomes of conservative treatment. A systematic review

The objective of the study was to evaluate the biomechanical and biological consequences of posterior cruciate ligament deficiency, determine compensatory mechanisms and assess the efficacy of non-operative treatment. Medline, CINAHL, SPORTdiscus, Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews were searched at 30th October 2006 for the terms "PCL" and "posterior cruciate ligament" both independently and including the terms "injury", "deficiency" and "insufficiency". Literature searches identified 598 potentially relevant articles, after exclusions there were 47 articles that fulfilled the inclusion criteria: 30 articles analyzing PCL deficiency and 17 studies on the outcomes for non-operative treatment. The authors reviewed all selected articles and abstracted data into predetermined tables depending upon classification. Studies indicate that posterior cruciate ligament deficiency results in posterior tibial translation with combined injuries displaying greater laxity. Results were inconsistent for rotational stability but deficiency increases joint contact pressure and may result in articular damage. A loss of proprioception occurs but the effect on strength and kinetics is inconclusive. There is a lack of evidence for compensatory muscle activity. Return to activity is possible for the majority of non-operatively treated grade I and II isolated injuries. Comparative analysis was not possible in many instances due to study design or experimental protocols. Further research is required to establish the compensatory mechanisms stabilizing the posterior cruciate ligament deficient knee and to investigate the outcomes for non-operatively treated patients.

Femoral avulsion fracture of the posterior cruciate ligament in association with a rupture of the popliteal artery in a 9-year-old boy: a case report

Ruptures of the posterior cruciate ligament (PCL) and especially proximal bony avulsion fractures in children are very rare. This in combination with a rupture of the popliteal artery is extremely rare. Thus, an exact incidence is not available from the literature. Overall, these injuries are severe and often lead to chronic knee instability. We report a case of a 9-year-old boy who suffered a traumatic displacement of the left knee with a rupture of the popliteal artery. Prior to transfer to our department, he was treated by a saphenous vein bypass graft and by a transfixation of the knee using two oblique percutaneous pins. We performed magnetic resonance imaging (MRI) scan of the knee which revealed a femoral avulsion fracture of the PCL. Other ligaments and menisci were intact. A transosseous femoral fixation using non-absorbable stitches was carried out. A 1-year follow-up after surgery demonstrates intact peripheral perfusion and sensation, straight axes of both legs and a physiological gait. Minimal differences of the length and circumference of both legs could be measured. The posterior laxity (Lachman-test) was about 5/8 mm (right/left knee) and 2/5 mm (right/left knee) in 90 degrees flexion. The range of motion (extension/flexion) was 5/0/140 degrees -/5/100 degrees (right-left knee). Intact cruciate ligaments were confirmed by MRI. Minimal experience exists in treatment of combined injuries to the PCL and the popliteal artery in children.

Tensioning of remnant posterior cruciate ligament and reconstruction of anterolateral bundle in chronic posterior cruciate ligament injury

PURPOSE

Posterior cruciate ligament (PCL) injuries have potential for intrinsic healing and several magnetic resonance imaging studies have reported that the PCL healed with continuity but also with residual laxity. The goal of our study was to introduce a new method and investigate the outcome of tensioning of the remnant PCL and reconstruction of the anterolateral (AL) bundle of the PCL using modified inlay technique.

TYPE OF STUDY

Therapeutic study.

METHODS

Forty-nine patients who underwent tensioning of the remnant PCL and reconstruction of the AL bundle of the PCL were evaluated 45.7 months (range, 24 to 78 months) on average after surgery. Tensioning was performed by distal transfer of the tibial attachment. The AL bundle of the PCL was reconstructed with 4 bundles of hamstring tendon (34 cases), bone-patellar tendon-bone graft (7 cases), or Achilles tendon allograft (8 cases), arthroscopically at the femoral tunnel and by the modified inlay technique through a posteromedial approach in the supine position. In 35 patients who had a combined posterolateral rotatory instability, the posterolateral corner reconstruction was performed. Stability was assessed by stress radiographs with the Telos device and maximal manual testing with KT-1000 arthrometer. The clinical results were assessed by IKDC and OAK scores. Physical examination was performed using the posterior drawer test, varus stress test, posterolateral drawer test, and dial test in 30 degrees and 90 degrees flexion.

RESULTS

The average side-to-side difference of posterior tibial translation on posterior stress radiographs decreased from 10.4 +/- 2.1 mm to 2.2 +/- 1.0 mm. The average side-to-side difference in maximal manual test with the KT-1000 arthrometer also decreased from 8.2 +/- 1.5 mm to 1.9 +/- 1.0 mm. The final IKDC score was A in 10 (20.4%), B in 33 (67.3%), and C in 6 (12.2%) patients. The average OAK score improved from 63.3 +/- 8.3 to 91 +/- 7.3.

CONCLUSIONS

Good clinical results and very good posterior stability were achieved with tensioning of the remnant PCL and reconstruction of the AL bundle using the modified inlay technique in chronic PCL injuries. With this technique, the surgeon can operate without changing the patient's position during surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Follow-up of Posttraumatic Ligamentous and Meniscal Knee Lesions Detected at MR Imaging: Systematic Review

PURPOSE

To perform a systematic review of the literature regarding the natural course of ligamentous and meniscal knee lesions detected at magnetic resonance (MR) imaging.

MATERIALS AND METHODS

The MEDLINE database was searched from January 1966 to February 2003. Studies were included if all of the following criteria were met: patients had collateral ligament, cruciate ligament, or meniscal lesions; MR imaging was performed in all patients; study included a group and/or subgroup of patients who underwent conservative treatment during follow-up; patients returned to the clinic for follow-up and clinical data or MR imaging outcomes were noted; and article was written in English, Dutch, German, French, Spanish, Italian, Swedish, Danish, or Norwegian. The quality of each study was assessed by using a standardized criteria set, and kappa statistics were used to grade the level of agreement between the two reviewers. Studies with quality scores of 8 or more were designated as high quality. Results were compared with regard to study design and quality scores.

RESULTS

The literature search identified 649 articles, and 11 studies (five on posterior cruciate ligament [PCL] injuries, five on anterior cruciate ligament [ACL] injuries, and one on meniscal injuries) met the inclusion criteria. No studies on the follow-up of collateral ligament injuries were identified. Four studies were of high quality, and the kappa value for quality items was 0.80. Between 77% and 93% of the partial or complete PCL ruptures regained continuity. In cases of partial or total ACL rupture, repair of continuity was also possible. A possible association between MR imaging continuity and clinical stability was identified.

CONCLUSION

The ACL and PCL can regain continuity after partial or complete rupture. On the basis of this review, no conclusions can be drawn about the natural course of meniscal or collateral ligament injury seen at MR imaging.

Cicatrisation sur tuteur synthétique dans les ruptures récentes du ligament croisé postérieur

PURPOSE OF THE STUDY

Treatment of recent laxity of the posterior cruciate ligament is not standardized. The purpose of this work was to analyze results of reconstruction with adjunction of a synthetic ligament for major recent isolated or combined laxity of the posterior cruciate ligament (triades, pentades or dislocations). Our hypothesis was that the synthetic ligament acts like a tutor for healing of the torn ligament.

MATERIAL AND METHODS

This retrospective analysis included 14 patients (1 woman and 13 men), mean age 27 years. All were competition athletes except one who did not practice sports. Three quarters of the patients were traffic accident victims. The series included three isolated posterior ligament tears, six combined laxities, and five knee dislocations. Average posterior laxity was 24 mm preoperatively. The procedure was performed 7 to 53 days after the accident. Arthroscopic reconstruction was performed for six patients and arthrotomy for eight. All associated lesions were repaired during the same procedure except for two cases (one anterior cruciate ligament and one popliteal tendon). Posterior cruciate ligament repair was achieved with the adjunction of a polyester ligament (LARS) using a one or two strand technique. Patients were reviewed at 36 months mean follow-up (10 - 88 months). The IKDC score was determined. A posterior drawer was measured manually with Telos at 70 degrees.

RESULTS

Five stiff knees required either mobilization under anesthesia or arthrolysis. One tear occurred late after the accident during a new trauma. Subjectively, two patients were very satisfied, eight satisfied and three disappointed. Mean knee motion measurements were 6/0/130 degrees . A differential posterior drawer persisted in twelve knees. The Telos measurement of posterior drawer changed from a mean 24 mm to a mean 8 mm. The overall IKDC score was A: 0, B: 7, C: 3, and D: 2. Persistent posterior laxity was the predominant cause of poor scores. Outcome was less satisfactory for all items of posterolateral laxity. There was no difference between the 2- and 4-strand techniques. There were no cases of morbidity (synovitis, spontaneous tear) directly related to the synthetic ligament.

DISCUSSION

The gain in posterior laxity was substantial. Results depended on associated lesions, particularly lateral involvement (stiffness, IKDC score) rather than the repair technique. The synthetic ligament appeared to play the role of a tutor: a single strand measuring 6 mm in diameter is sufficient. This technique spares tendon stock and could be proposed for major posterior cruciate ligament laxity. A longer follow-up will be necessary to confirm the durable stability.

Below Knee Impact Responses using Cadaveric Specimens

Knee injuries represent about 10% of all injuries suffered during car crashes. Efforts to assess the injury risk to the posterior cruciate ligament (PCL) have been based on a study available in the literature (Viano et al., 1978), in which only two of the five knees tested had PCL ruptures. The aims of the current study were to repeat the study with a higher number of samples, study the effects of other soft tissues on knee response, and assess the adequacy of the experimental setup for the identification of a PCL tolerance. A total of 14 knees were tested using a high-speed materials testing machine. Eight were intact knees (with the patella and all the muscular and ligamentous structures), three were PCL-only knees (patella and all the muscular and ligamentous structures other than the PCL removed), and the last three were PCL-only knees with the tibia protected from bending fracture. Of the eight intact knees tested, only one had PCL mid substance rupture, one had a partial articular fracture of the tibia below the plateau, and six had simple transverse fracture of the tibial metaphysis. Of the three PCL-only knees without tibial protection, one had PCL mid substance rupture, one had avulsion at the posterior intercondylar attachment point, and the last one had a simple oblique fracture of the tibial metaphysis. Of the three PCL only knees with tibia protection, two had PCL mid-substance ruptures and the third one had an avulsion at the tibial insertion site with partial articular fracture of the lateral plateau. Overall, the results of the current study were similar to those observed by Viano et al. (1978). The average displacement at failure for all PCL related injuries was 17.2+/-2.8 mm for the current study (n=6) and 16.2+/-3.9 mm for Viano et al. (1978) (n=4). This value is higher than the Injury Assessment Reference Value of 15 mm proposed by Mertz (1984) and used in various regulations. Both studies suggest that the existence of the soft tissues other than the PCL affect the injury outcome and that the intact knee would suffer predominantly tibial metaphyseal fractures possibly due to bending. Consequently, it is concluded that the current experimental setup can produce isolated PCL injuries but the data available are inadequate to characterize PCL tolerance. A Hybrid III knee equipped with a ball bearing knee slider was also tested using a pendulum setup. Apart from the initial higher stiffness, the overall response of this knee lies within the force-deflection corridors defined using the response of the cadaver knees with PCL mid-substance failure.

Epidemiology of posterior cruciate ligament injuries

BACKGROUND

The epidemiology of posterior cruciate ligament (PCL) injuries has not been well clarified. Isolated and combined PCL injuries are a frequently missed diagnosis. A better understanding of typical injury mechanisms may help in more accurate diagnosis of these injuries.

METHODS

In this study the epidemiology of PCL insufficiency in 494 patients was retrospectively analysed. Stress-radiography was used to quantify posterior tibial displacement.

RESULTS

The mean age at the time of injury was 27.5+/-9.9 years. Traffic accidents (45%) and athletic injuries (40%) were the most common injury causes. Motorcycle accidents (28%) and soccer-related injuries (25%) accounted for the main specific injury causes. The most common injury mechanisms were dashboard injuries (35%) and falls on the flexed knee with the foot in plantar flexion (24%). The mean side-to-side difference of posterior tibial displacement on posterior stress-radiographs in 90 degrees of flexion was 13.4+/-4.7 mm. According to the posterior displacement values, 232 (47%) patients had isolated PCL ruptures, while 262 (53%) patients with a posterior displacement of >12 mm were classified as having a combined posterior instability. There were significantly more combined PCL lesions due to vehicular trauma as compared with athletic trauma ( p<0.0001).

CONCLUSIONS

In many PCL lesions, initiation of an adequate treatment regimen is delayed despite typical injury mechanisms and symptoms. In the future, a better understanding of the epidemiology of PCL injuries should enable us to diagnose the injury more reliably through a detailed history and a thorough physical and radiographic examination in the acute setting.

The acute management of soft tissue injuries of the knee

The acute management of soft tissue injuries of the knee requires knowledge of the injury mechanism, physical findings, and results of adjunctive tests. Knee dislocations, fractures, and extensive soft tissue injury requires immediate and thoughtful treatment. All injuries are afforded the benefit of the basic principles of rest, ice, compression, and elevation until definitive treatment is carried out.