Collateral Ligament Knee Injuries in Pediatric and Adolescent Athletes

The application of a return-to-performance pathway for a professional footballer recovering from a surgical repair of an isolated lateral collateral knee ligament rupture. A case report

OBJECTIVES

Isolated rupture of the lateral collateral ligament (LCL) of the knee is extremely rare in professional football, and there is a paucity of literature describing the rehabilitation for this injury. This case report demonstrates the use of a return-to-performance (RTPerf) pathway that is time-independent, has clear criteria, and progressive phases to help inform decisions made by a multidisciplinary team (MDT).

METHODS

A 25-year-old professional footballer sustained an isolated LCL rupture following a tackle by an opposing player, forcing his knee into excessive varus motion. Five days after the injury, the player underwent surgical repair of the LCL before commencing an RTPerf pathway.

RESULTS

The player returned to team training 12 weeks after surgery before successfully returning to play (RTPlay) at 13.5 weeks. The player completed full RTPerf at 16 weeks and continued to play with no evidence of instability or pain.

CONCLUSION

This case report outlines how an RTPerf pathway can be successfully used to guide the management of isolated LCL ruptures of the knee.

[Ligamentous and meniscal injuries of the pediatric knee joint]

Intraligamentous injuries to the anterior cruciate ligament (ACL) and meniscus injuries are rare in children and adolescents and often occur as a result of sports injuries. Clinically, they usually present as a hemarthrosis. The diagnosis of choice is the MRI examination. Surgical treatment of intraligamentary ACL injuries using the transphyseal technique is now also the gold standard treatment for children and adolescents, leg axis and length checks are necessary after surgery until growth is complete. Meniscus injuries are also addressed surgically. Postoperative follow-up treatment and rehabilitation are particularly important in order to prevent reinjury. The disc meniscus is a special entity and is also treated surgically if it is symptomatic. Isolated collateral ligament and posterior cruciate ligament ruptures are rarities.

Does mechanical loading restore ligament biomechanics after injury? A systematic review of studies using animal models

BACKGROUND

Mechanical loading is purported to restore ligament biomechanics post-injury. But this is difficult to corroborate in clinical research when key ligament tissue properties (e.g. strength, stiffness), cannot be accurately measured. We reviewed experimental animal models, to evaluate if post-injury loading restores tissue biomechanics more favourably than immobilisation or unloading. Our second objective was to explore if outcomes are moderated by loading parameters (e.g. nature, magnitude, duration, frequency of loading).

METHODS

Electronic and supplemental searches were performed in April 2021 and updated in May 2023. We included controlled trials using injured animal ligament models, where at least one group was subjected to a mechanical loading intervention postinjury. There were no restrictions on the dose, time of initiation, intensity, or nature of the load. Animals with concomitant fractures or tendon injuries were excluded. Prespecified primary and secondary outcomes were force/stress at ligament failure, stiffness, laxity/deformation. The Systematic Review Center for Laboratory animal Experimentation tool was used to assess the risk of bias.

RESULTS

There were seven eligible studies; all had a high risk of bias. All studies used surgically induced injury to the medial collateral ligament of the rat or rabbit knee. Three studies recorded large effects in favour of ad libitum loading postinjury (vs. unloading), for force at failure and stiffness at 12-week follow up. However, loaded ligaments had greater laxity at initial recruitment (vs. unloaded) at 6 and 12 weeks postinjury. There were trends from two studies that adding structured exercise intervention (short bouts of daily swimming) to ad libitum activity further enhances ligament behaviour under high loads (force at failure, stiffness). Only one study compared different loading parameters (e.g. type, frequency); reporting that an increase in loading duration (from 5 to 15 min/day) had minimal effect on biomechanical outcomes.

CONCLUSION

There is preliminary evidence that post-injury loading results in stronger, stiffer ligament tissue, but has a negative effect on low load extensibility. Findings are preliminary due to high risk of bias in animal models, and the optimal loading dose for healing ligaments remains unclear.

Isolated femoral avulsion of the popliteus tendon: a systematic review of the literature

The popliteus tendon is an important part of the posterolateral corner of the knee. Isolated injuries to the posterolateral corner are very rare, as most injuries occur in multiligamentous knee trauma. Purely isolated popliteus tendon injuries are even more rare. There is very little evidence for treatment of isolated popliteus tendon avulsion injuries. The aim of this systematic review is to report on all publications regarding isolated popliteus tendon avulsion injuries and hopefully provide some guidance for future treatment algorithms. A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies were included if they documented isolated popliteus tendon avulsion injuries. Exclusion criteria were studies with popliteus injuries in combination with other knee ligamentous injuries and popliteus tendon injuries other than femoral avulsion injuries. Twenty-eight studies were included which mentioned in total 38 patients with isolated popliteus tendon avulsion injuries. 24 patients (63%) were treated operatively. 3 (8%) patients were diagnosed arthroscopically but did not receive any surgical treatment. 9 patients (24%) were treated conservatively. In two publications, there was no mention of treatment. We found no clear recommendations in the literature for treatment of this rare injury.

Isolated Femoral LCL Avulsion Fracture in the Adult Knee: Two Patient Cases and Literature Review

Avulsion injuries of the LCL most commonly occur at the fibular insertion. Femoral LCL avulsion injuries have only been previously described in pediatric patients or as multiligament knee injury components among adults. This case series with comprehensive literature review describes for the first time 2 cases of isolated LCL femoral avulsion fractures in adults including conservative treatment outcomes. Both patients sustained a strong varus stress mechanism to their right knee, following sport injury or road traffic accident. For both patients, a complete radiographic evaluation including X-rays, MRI, and CT scan confirmed no other associated knee lesions. The femoral LCL avulsion fractures that were observed were minimally displaced and noncomminuted. Furthermore, imagery suggested preserved integrity at the superior lateral genicular artery, adjacent articular capsule, and IT band. Based on clinical and imaging evaluations, the decision was made to follow conservative treatment. By 10 weeks postinjury, both patients were asymptomatic with early radiological fracture healing evidence. Comparative varus stress radiographs at 20° knee flexion revealed no side-to-side differences and clinical exam showed no posterolateral rotatory instability. The second patient case presented with mild femoral LCL attachment calcification on follow-up CT-scan. Following a detailed analysis of anatomic injury characteristics, we suggest that patients with isolated femoral LCL avulsion fractures have low secondary displacement risk provided SLGA, articular capsule, and IT band integrity are present. In contrast to high-grade ligamentous and distal avulsion LCL injuries, we recommend conservative treatment for patients who sustain these lesions.

Treatment of knee sprains in children

The incidence of knee sprains in children is steadily increasing. Skeletal immaturity and anatomical features of the child's ligamentous structures explain the frequency of bone avulsions in young children. Peripheral ligament injuries are the most common and often benign. Nevertheless, associated injuries of the cruciate or patellofemoral ligament(s) are not rare and must not be missed. Age is a determining factor in diagnostic guidance. Anterior intercondylar tibial eminence fractures, otherwise known as tibial spine fractures (TSF), usually occur in young children. Ligamentous distension at the time of the accident would explain the residual laxity that can affect the prognosis of these fractures. The treatment of interstitial ruptures of the ACL follows recommendations that are becoming clearer through multicentric studies. Reparation techniques, historically rejected as ineffective, have again become topical under specific conditions with the aim of preserving the native ACL and its proprioceptive receptors, which are essential in children. ACL reconstruction techniques have made progress in children, especially with techniques adapted from adults. Preservation of growth plates remains pertinent, especially at the femur to avoid growth disorders, thus highlighting the important role paediatric orthopaedic surgeons have in the management of these knee sprains.

Direct On-Lay Repair of Isolated Pediatric Lateral Collateral Ligament Knee Injury with Biceps Femoris Tendon Rotation Graft Augmentation: A Case Report

CASE

A 13-year-old male American football player sustained an isolated grade III lateral collateral ligament (LCL) rupture and underwent direct repair with biceps femoris rotation graft augmentation after failure of nonoperative management. The procedure was performed without any complications or graft site morbidity and achieved complete functional resolution.

CONCLUSION

Isolated LCL injuries in the pediatric population are an extremely rare finding, with no evidence of rotation graft in the literature to date. Most of these cases involve multiligamentous knee injuries in the adult population, and therefore, there is no consensus regarding pediatric repair vs. reconstruction in this presentation.

Imaging of Patellofemoral Instability

Patellar instability is a broad term that encompasses patellar dislocation, patellar subluxation, and patellar instability. Although both functional and anatomic considerations contribute to symptoms of patellar instability, the most important are thought to be patella alta, trochlear dysplasia, and lateralization of the tibial tubercle. In patients with a history suspicious for prior patellar dislocation, careful evaluation of MRI and radiographic studies can reveal characteristic findings. The most common methods to address patellofemoral instability are medial patellofemoral ligament reconstruction and tibial tubercle osteotomy with either anteromedialization or medialization. Less commonly trochleoplasty is indicated as well. Patients may be treated with one of or a combination of these techniques, each of which has specific indications and complications.

Magnetic resonance imaging of medial collateral ligament avulsion fractures of the knee in children: a potentially underestimated injury

BACKGROUND

Literature regarding medial collateral ligament (MCL) injuries is focused on adults with superficial MCL disruptions. However, children follow different injury patterns, with avulsion fractures at ligament attachment sites occurring commonly. Such avulsions have not been characterized for pediatric MCL injuries.

OBJECTIVE

To elucidate imaging findings, and review management and outcomes of pediatric MCL avulsion fractures.

MATERIALS AND METHODS

We conducted a 10-year retrospective review of knee magnetic resonance (MR) imaging reports for patients younger than 16 years old diagnosed with acute MCL avulsion fracture. MR imaging was reviewed to confirm and characterize the components of the avulsion (perichondrium without or with cartilage, and/or bone) and to identify additional knee injuries. Radiographs, if available, from the time of injury were reviewed. Clinical management and patient outcomes were recorded.

RESULTS

Eighteen patients (13 boys, 5 girls) incurred an acute MCL avulsion fracture. All avulsions involved the deep MCL attachment: 17 meniscofemoral and 1 meniscotibial component. Two avulsions also included the superficial MCL attachment. Nine boys had non-osseous avulsions, all radiographically occult. All girls had radiographically apparent avulsions. Three girls and three boys sustained associated knee derangements, most commonly anterior cruciate ligament (ACL) injury (n=4). All MCL avulsions were initially treated conservatively; one child required subsequent surgery for ongoing pain.

CONCLUSION

Pediatric MCL avulsion fractures in this study uniformly involve the attachment of the deep MCL and can be entirely non-osseous, particularly in boys who lag in skeletal maturity, making these injuries radiographically occult. MR imaging may be required to recognize these avulsions, which can impact the duration of rest and knee bracing.

Arcuate sign-fibular head avulsion fracture and associated injuries in the pediatric and adolescent population

PURPOSE

To describe the first "arcuate sign" case series in the pediatric population, radiologic features of the associated injuries, management, and how they compare with the adult population.

METHODS

Retrospective study included patients under 18 years of age with a classic "arcuate sign" on radiographs. Data collected included patient demographics, mechanism of injury, and management. Radiographs and advanced imaging (MRI, CT) were reviewed by two musculoskeletal radiologists in a blinded fashion and findings recorded.

RESULTS

Seven patients (4 males, 3 females) with mean age 15 years (range 14-17 years) were included in the study. All 7 injuries were related to sports, 5/7 (71%) being non-contact injuries. Five patients had MRI done-1 LCL injury, MPFL sprain, and MCL sprain were reported; 3 popliteofibular ligament and popliteus sprains were seen; and 3 bone contusions were present on imaging. None of the patients had meniscus or cruciate ligament tears. One patient had an additional fracture of the lateral tibial plateau at the ilio-tibial band attachment and an associated peroneal nerve injury. Five out of seven (71.4%) were treated non-operatively and were able to return back to activity at a mean of 7.2 weeks from injury. Two out of seven (28.6%) needed operative intervention for the fracture but not arthroscopic repair.

CONCLUSION

Pediatric patients with a radiographic arcuate sign tend not to have ACL, PCL, or meniscal injuries, and treatment is predominantly non-operative in contrast to literature reported in adults.

Meniscofibular ligament: how much do we know about this structure of the posterolateral corner of the knee: anatomical study and review of literature

PURPOSE

The present study is a systematic review of a relatively unknown structure of the posterolateral corner of the knee, the meniscofibular ligament (MFL), aiming at summarizing and broadening current scientific knowledge regarding this ligament anatomy, function, imaging and injury.

MATERIALS AND METHODS

A systematic review was performed according to the PRISMA guidelines. Medline (PubMed) and Cochrane Library databases were reviewed for every kind of study reporting on the MFL through December 2019. Due to between-study differences in (anatomy, function, imaging, injury) examining the ligament, the findings were summarized from each study, but the results were not pooled.

RESULTS

The MFL is a ligament extending between the inferolateral portion of lateral meniscus, just anterior to the popliteus tendon, and the fibular head. It provides stability to the posterolateral corner of the knee joint, it can be demonstrated in magnetic resonance imaging and magnetic resonance arthrography and has a potential role in lateral meniscus injuries. Further research is required to clearly understand the prognosis and management of MFL injury.

CONCLUSION

The current systematic review, focusing only on the MFL of the knee, summarizes the existing knowledge on anatomy, gross morphology, histology, function, biomechanics and imaging and contributes to the further understanding of the MFL.

Non-operative management of an isolated lateral collateral ligament injury in an adolescent patient and review of the literature

We present a rare case of isolated traumatic pure ligamentous rupture of the lateral collateral ligament of the knee in an adolescent high-level footballer managed non-operatively with a good functional outcome and return to sport in 4 months.