Posterior Cruciate and Posterolateral Ligament Reconstruction in an Adolescent with Open Physes

Posterior Cruciate Ligament Femoral Avulsion Fractures in Pediatric Patients: A Report of 2 Interesting Surgical Cases

CASE

This report describes 2 cases of femoral-sided posterior cruciate ligament (PCL) avulsion injuries. A 10-year-old male patient presented with a chronic nonunion of a bony PCL femoral avulsion. In addition, a 4-year-old boy presented with an acute, displaced PCL femoral avulsion off the medial femoral condyle. Both injuries were repaired using arthroscopic techniques.

CONCLUSION

Femoral-sided PCL avulsions are very rare in pediatric patients and have not been reported often. We hope to increase the awareness of PCL femoral avulsion injuries in pediatric patients by describing 2 unique cases.

Misdiagnosed cartilaginous PCL avulsion in young children

Posterior Cruciate Ligaments injuries are rare in children and usually due to bony avulsion fractures or midsubstance tears. This study focused on cartilaginous avulsions initially misdiagnosed despite of MRI assessment. Two 6-year-old boys had cartilaginous avulsion fracture injury at the femoral attachment of the PCL. One had associated medial meniscal lesion and was reinserted. The other conducted to non-union. MRI second lecture reveals an original description with nail-biting sign on cartilage surface of anterior notch, and a close PCL angle without anterior tibial translation. No bone bruise was associated. Similarly, to ACL cartilaginous tibial avulsions, PCL cartilaginous femoral avulsions are underdiagnosed. When knee hemarthrosis occurs under the age of nine, clinician and radiologist should be aware that cartilaginous avulsion of ACL and PCL also could be the main pattern of lesion.

Mechanical and Microstructural Properties of Native Pediatric Posterior Cruciate and Collateral Ligaments

Background:

Although anterior cruciate ligament (ACL) tears have received the most attention, the medial collateral ligament (MCL) is thought to be the most commonly injured knee ligament overall. The lateral collateral ligament (LCL) and posterior collateral ligament (PCL) are less frequently compromised but can be involved in severe multiligament injuries. The paucity of information on the native properties of these ligaments in the pediatric population hinders the overall optimization of treatment for these injuries.

Purpose:

To characterize the mechanical and microstructural properties of pediatric MCLs, LCLs, and PCLs using a rare cadaveric cohort (mean age, 9.2 years).

Study Design:

Descriptive laboratory study.

Methods:

MCLs, LCLs, and PCLs were harvested from 5 fresh-frozen pediatric knee specimens (3 male, 2 female) and were subjected to a tensile loading protocol. A subset of contralateral tissues from a single donor was analyzed using bright-field, polarized light, and transmission electron microscopy to measure collagen fiber morphology.

Results:

The pediatric MCL exhibited values for ultimate stress (11.7 ± 6.7 MPa), ultimate strain (18.2% ± 6.8%), and the Young modulus (93.7 ± 56.5 MPa) that were similar to values for the LCL (11.4 ± 11.5 MPa, 27.7% ± 12.9%, and 64.4 ± 76.6 MPa, respectively). The PCL demonstrated decreased ultimate stress (4.2 ± 1.8 MPa), increased ultimate strain (28.8% ± 11.9%), and a decreased Young modulus (19.8 ± 10.4 MPa) when compared with the MCL and LCL. All 3 ligaments had similar mean crimp wavelengths (MCL, 32.8 ± 3.6 µm; LCL, 27.2 ± 3.5 µm; PCL, 25.8 ± 3.5 µm) and collagen fibril diameters (MCL, 88.0 ± 26.0 nm; LCL, 93.3 ± 34.6 nm; PCL, 90.9 ± 34.0 nm); however, the fibril distribution profiles exhibited different modalities.

Conclusion:

The pediatric MCL and LCL possessed similar mechanical properties, while the pediatric PCL was weaker but capable of withstanding higher amounts of strain. All 3 of these pediatric structures were weaker than what has been reported in studies with adult cohorts.

Clinical Relevance:

Results from this study can be considered preliminary mechanical and microstructural data for healthy pediatric collateral and posterior cruciate ligaments that can be used to guide further laboratory and clinical research.

Surgical treatment of posterior cruciate ligament lesions does not cause growth disturbances in pediatric patients

PURPOSE

The aim of the present study was to describe epidemiology, management and outcome of pediatric and adolescent patients with posterior cruciate ligament (PCL) injuries.

METHODS

Sixteen patients of less than 18 years of age with 7 PCL avulsion fractures and 9 PCL tears were included over a 10-year period. Trauma mechanism, additional injuries and treatment methods were analyzed. Follow-up examination included range of motion and ability to perform squats. Pedi-IKDC and Lysholm score were obtained and posterior shift was measured in kneeling view radiographs and compared to the contralateral side. Patients were grouped into pediatric patients with open physes at the time surgery and adolescent patients with closing or closed physes. In case of open physes, growth disturbances were assessed.

RESULTS

Six of the treated patients (median age 12.5 years, range 10-13) had open physes at time of surgery. Five of those sustained avulsion fractures and treatment consisted of open reduction and screw fixation in four cases and graft reconstruction in one case. One patient sustained a PCL tear and underwent graft reconstruction. Follow-up at a median of 71.5 months (range 62-100) did not reveal any growth disturbances. Median Pedi-IKDC was 71.9 (range 51.7-92.1), median Lysholm score was 81.5 (range 66-88) and median posterior shift difference was 2.5 mm (range 0-11). The remaining 10 patients (median age 16 years, range 14-17) had closing/closed physis at the time of operation. Two patients presented with avulsion fractures treated with open reduction and screw fixation and 8 patients sustained PCL tears treated with graft reconstruction. At a median follow-up of 69.5 months (range 11-112), median Pedi-IKDC was 86.8 (range 36.8-97.7), median Lysholm score was 84.0 (range 45-95) and median posterior shift difference was 4 mm (range 0-15).

CONCLUSIONS

In our small number of pediatric patients with PCL injuries, open reduction and epiphyseal screw fixation of displaced avulsed fractures and steep tunnel drilling in case of PCL reconstruction did not cause growth disturbances. Nevertheless, long-term functional impairment should be expected and close follow-up has to be recommended.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

Paediatric physeal sparing posterior cruciate ligament (PCL) reconstruction with parental donation allograft: Rationale and operative approach

BACKGROUND

Paediatric PCL injuries are rare but constitute a significant management challenge. We describe a novel approach to the surgical management of an 11-year-old boy who presented with persisting symptomatic instability following 18months of failed conservative therapy.

METHODS

PCL reconstruction was performed using a physeal sparing, all-inside technique under fluoroscopic control. This avoids the potential for iatrogenic growth injury. A parentally donated hamstrings allograft was used to ensure adequate graft size, and reinforced using a non-elastic two millimetre braided suture. Graft reinforcement safeguards against stretching during the early healing phase, but must be removed thereafter to avoid creating a physeal tether.

RESULTS

At three months, clinical examination under anaesthesia showed equivalent PCL laxity in the operated knee compared to the normal contralateral knee. The graft reinforcement tape was incised as planned with no change in laxity assessment. Arthroscopic evaluation demonstrated a quiet joint with a well healed graft and no synovitis. Postoperative long leg radiographs showed no growth deformity against preoperative status.

CONCLUSION

In paediatric patients with persisting symptomatic instability despite appropriate conservative management, surgical reconstruction of the PCL should be considered. Standard treatment has higher complication rates and poorer graft survival than in an adult cohort. Specific problems include iatrogenic growth plate injury causing growth arrest or angular deformity, inadequate graft size if using hamstrings autograft, and the additional technical challenge of small patient size. Early results from extra-physeal, all-inside PCL reconstruction using a parentally donated allograft are promising and may provide an alternative solution to traditional surgical management.

Posterior cruciate ligament reconstruction in skeletal immature children

PURPOSE

Rupture of the posterior cruciate ligament (PCL) is a rare knee injury in children with open growth plates. The follow-up results of six patients with open physes treated with PCL reconstruction are presented. The objective is to evaluate the clinical outcomes of PCL reconstruction for six skeletally immature patients.

METHODS

Between 2006 and 2010, six skeletally immature patients were treated with PCL reconstruction. At the time of surgery, the median age was 9 years (range 6-14). The median follow-up time after surgery was 50 months (range 41-90). Outcomes were evaluated by KOOS and Tegner scores, instrumented knee laxity, and radiologic long-axis leg length measurements.

RESULTS

The median KOOS score at follow-up was 88 (range 26-98). The median Tegner score was 6 (range 4-7). The median side-to-side difference in laxity according to KT-1000 was 2 mm (range 1-5) at 25° of flexion and 3 mm (range 3-6) at 70° of flexion. A median side-to-side difference in flexion of 8° was found. All but one patient had returned to playing sports at follow-up. One patient's index leg had a length discrepancy of 16 mm.

CONCLUSIONS

PCL reconstruction resulted in fair to good clinical outcomes for skeletally immature children. Clinically relevant leg length discrepancy was found in one of the six patients examined in this study.

LEVEL OF EVIDENCE

Level IV.

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.

Treatment of posterior cruciate ligament injuries in pediatric and adolescent patients

BACKGROUND

There is sparse literature regarding the outcomes of treatment for posterior cruciate ligament (PCL) injuries in pediatric and adolescent patients. PCL injuries are rare and are often treated conservatively. The purpose of this study was to review 2 separate cohorts of patients with pediatric and adolescent PCL injuries: those treated surgically with direct repair or ligament reconstruction and those managed nonoperatively.

METHODS

Twenty-five patients 18 years or younger underwent treatment of 26 PCL injuries (1 bilateral) at a single institution between 1993 and 2009. Fourteen patients (15 knees) underwent operative treatment, while 11 patients were treated nonoperatively. Demographic and clinical features of each group were reviewed, and validated functional outcome measures [Pediatric International Knee Documentation Committee (Pedi-IKDC), Lysholm, and Tegner scores] were analyzed.

RESULTS

Eleven patients (6 females; mean age, 14.4 y) who sustained PCL injuries were treated nonoperatively, At a mean clinical follow-up of 26.7 months, none of the patients who underwent nonoperative treatment had symptomatic instability, with a 100% return-to-play rate. The mean Pedi-IKDC, Lysholm, and Tegner scores were 87.4, 89.0, and 7.5, respectively. In the 15 knees of 14 patients who underwent surgery (4 female; mean age, 15.1 y) mean clinical follow-up was 27.8 months. All of the patients achieved full or near-full range of motion, and none of the patients showed growth arrest or angular deformity. However, 1 patient showed mild joint-space narrowing, and the mean Pedi-IKDC, Lysholm, and Tegner scores were 81.3, 80.1, and 7.2, respectively. Patients who had sustained knee dislocations had lower Pedi-IKDC scores than those who had not dislocated, 70.2 versus 85 (P=0.047).

CONCLUSIONS

Outcomes for nonoperative treatment of partial PCL tears or nondisplaced avulsion injuries are good in young patients. PCL repair or reconstruction is a safe and viable treatment option in pediatric and adolescent patients with multiligament injuries or those with isolated PCL injury who have failed conservative treatment, with outcomes related to the severity of the initial injury.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

All-epiphyseal semitendinosus PCL reconstruction in a 10-year-old child

BACKGROUND

Tears of the posterior cruciate ligament (PCL) in pediatric patients, especially avulsions from its tibial insertion, are not frequently encountered by physicians. However, with an increasing incidence of ligamentous injuries to the knee in skeletally immature patients, orthopaedic surgeons will more frequently need to decide how best to manage a PCL injury in children with open physes.

METHODS

A 10-year-old boy sustained an avulsion of the PCL from its tibial insertion site after a bicycle motocross racing accident. He required a PCL reconstruction after failed conservative treatment and an unsuccessful attempt at primary repair. This successful physeal sparing reconstruction was accomplished using a modified method of femoral tunnel placement in combination with the tibial inlay technique.

RESULTS

A magnetic resonance imaging was acquired 2 years postoperatively when physical examination demonstrated both legs of equal length, no varus or valgus deformity, and a normal posterior drawer examination. Four years after the reconstruction, he continues to bicycle motocross race while experiencing no further symptoms and complete restoration to his prior quality of life.

CONCLUSIONS

The use of the tibial inlay technique together with the modified femoral tunnel location prevented transphyseal drilling while attaining a favorable anatomic placement of the graft while avoiding the "killer" turn associated with the transtibial approach.

LEVEL OF EVIDENCE

Level IV (Therapeutic Study).