The significance of hemarthrosis of the knee in children

Tibial spine fractures: State of the art

Tibial spine fractures (TSFs) are avulsion fractures at the site where the anterior cruciate ligament inserts onto the tibial eminence. TSFs typically affect children and adolescents aged 8-14 years. The incidence of these fractures has been reported to be approximately 3 per 100,000 per year, but the rising involvement of paediatric patients in sporting activities is increasing the number of these injuries. TSFs are historically classified on plain radiographs according to the Meyers and Mckeever classification system, which was introduced in 1959, but the renewed interest in these fractures and the increasing use of magnetic resonance imaging led to the recent development of a new classification system. A reliable grading protocol for these lesions is paramount to guide orthopedic surgeons in determining the correct treatment for young patients and athletes. TSFs can be addressed conservatively in the case of nondisplaced or reduced fractures or surgically in the case of displaced fractures. Different surgical approaches and, specifically, arthroscopic techniques have been described in recent years to ensure stable fixation while limiting the risk of complications. The most common complications associated with TSF are arthrofibrosis, residual laxity, fracture nonunion or malunion, and tibial physis growth arrest. We speculate that advances in diagnostic imaging and classifications, combined with greater knowledge of treatment options, outcomes, and surgical techniques, will likely reduce the occurrence of these complications in paediatric and adolescent patients and athletes, allowing them a timely return to sports and everyday activities.

Diagnostic values of history taking, physical examination and KT-1000 arthrometer for suspect anterior cruciate ligament injuries in children and adolescents: a prospective diagnostic study

Background

Diagnosing anterior cruciate ligament (ACL) injuries in children and adolescents are more challenging compared to adults. Delayed diagnosis may result in meniscal or chondral injuries. The aim of this study was to determine the diagnostic values of history taking, physical examination and KT-1000 arthrometer for suspect ACL injuries in children and adolescents.

Methods

In this prospective diagnostic study, all children and adolescents (< 18 years) with post-traumatic knee complaints presenting at the out-patient department of the Máxima MC were eligible for inclusion. One experienced knee specialised orthopaedic surgeon was blinded and performed history taking, physical examination and KT-1000 arthrometer measurement. All patients had a magnetic resonance imaging (MRI) for the final diagnosis. Diagnostic values of interest were sensitivity, specificity, positive and negative predictive values (PPV and NPV). The outcomes of the KT-1000 arthrometer were drafted in a relative operating characteristics (ROC) curve to determine the optimal cut-off points.

Results

Sixty-six patients were included, of which 50 had an ACL rupture and 16 had no ACL rupture on MRI. Report of a popping sensation during trauma had a specificity and PPV of 100% for diagnosing ACL injuries. The PPV and NPV of the Lachman test (in case of describing end-feel) were 95 and 82%, of the anterior drawer test 87 and 90% and of the pivot shift test 95 and 81% respectively. The optimal cut-off point of the KT-1000 arthrometer at 133 N force was an absolute translation of ≥7 mm with a PPV and NPV of 97 and 88% respectively.

Conclusions

Report of a popping sensation during trauma has a specificity and PPV of 100% for diagnosing ACL injuries in children and adolescents. Although potentially difficult in children, the Lachman test, anterior drawer test and pivot shift test have a high PPV and NPV when performed by an experienced orthopaedic surgeon. An absolute anterior translation of ≥7 mm of the injured knee in the KT-1000 arthrometer at 133 N has the highest diagnostic values of all tests for diagnosing ACL injuries.

Level of evidence

3

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.

Paediatric injuries around the knee: Bony injuries

The aim of this article is to discuss the diagnosis, management and pitfalls of bony injuries around the skeletally immature knee. Each within their own right is a relatively uncommon injury but associated with potential complications. Distal femoral physeal fractures can result in growth arrest and vascular injury. Tibial spine avulsions can result in an unstable knee. Tibial tubercle fractures can be associated with compartment syndrome and pose a risk to the extensor mechanism of the knee. Fixation can be complicated by growth arrest and subsequent recurvatum deformity. Finally, patella sleeve injuries are often missed and this can also threaten the extensor mechanism. We discuss the approach to clinical and radiological assessment of these injuries, and evidence based recommendations as to how they are best managed to avoid complications.

All-Inside Partial Epiphyseal Anterior Cruciate Ligament Reconstruction Plus an Associated Modified Lemaire Procedure Sutured to the Femoral Button

Anterior cruciate ligament (ACL) tears in skeletally immature patients are on the rise; pediatric athletes are now in constant year-round sports participation. Nonoperative treatment may lead to poor functional outcomes and an increase in associated intra-articular lesions and sometimes can cause drop-out from sports activity. The treatment of these injuries is not at all clear, and appropriate guidelines do not exist. Physeal-sparing and partial physeal-sparing techniques have been described. Concerns about restoring normal knee kinematics with the previously described ACL reconstruction (ACLR) techniques are open to debate. We describe a partial epiphyseal ACLR to be done in skeletally immature patients involved in highly demanding sport activities. This technique is performed with an extraphyseal femoral tunnel drilled retrograde, a transphyseal tibial tunnel, and a retrograde tibial drilling without trespassing the tibial physis. We added a modified Lemaire procedure to improve rotational instability to the previously performed ACLR.

Intercondylar eminence fracture treated by resorbable magnesium screws osteosynthesis: A case series

INTRODUCTION

Tibial spine avulsion fractures are mostly a paediatric injury which appropriate treatment is currently debated in literature. The choice between conservative and surgical treatment is based on the radiographic classification of Meyers-McKeever. The most diffused surgical techniques involve either internal fixation devices (screws) or bone tunnels fixation with resorbable sutures. Today, a third option is represented by resorbable magnesium screws which could combine the best features of the two classical systems. Objective of this study is to investigate the efficacy of these new devices in the surgical treatment of tibial spine avulsions.

MATERIALS AND METHODS

Since 2014 we have seen seven patients with tibial eminence fracture. Patients underwent clinical and radiological examination (MRI, CT scan) before surgery. Only 3 patients that presented with a grade III or IV lesion were treated surgically with internal fixation with magnesium resorbable screws. In post-operative follow-up, functional recovery was evaluated at 1, 2, 4, 6 and 12 months, clinically and by X-ray. Lysholm and IKDC scores were submitted at 1, 2, 6 and 12 months. MRI was repeated at 6 and 12 months.

RESULTS

All three surgical patients showed progressive clinical and functional improvement during the follow-up period. The first case showed a quicker overall recovery rate, which might be due to the lower grade of the lesion. Radiographs and MRI evaluation showed regular healing of the injury. The devices appeared completely resorbed at the 6 months follow-up and replaced by newly formed bone at the 12 months follow-up.

CONCLUSIONS

The treatment of tibial spine avulsion fractures with arthroscopic reduction and internal fixation (ARIF) technique by magnesium resorbable screws seems to result in an excellent functional recovery without complications related to fixation devices, which were completely resorbed after 6 months and replaced by newly formed bone after 12 months. This new method could be considered as an alternative option to classic techniques by non resorbable fixation devices or bone tunnel fixation. Further studies are needed in order to evaluate the efficacy of these new devices in a wider group of patients.

What is the best treatment for a child with an acute tear of the anterior cruciate ligament?

With the heightened popularity of childhood sporting activity, the number of paediatric anterior cruciate ligament (ACL) ruptures has increased. Management of these injuries presents a particular challenge due to the open femoral and tibial growth plates. Physeal damage has the potential to cause angular deformity or length discrepancy. This review was conducted to determine the best way to treat this injury. A primary search of Ovid MEDLINE (1 October 2017) used the terms: (ACL or anterior cruciate ligament) and (young or child or children or pediatric or immature or pre-pubescent). Titles/Abstracts of 369 articles were screened for relevance. A total of 217 were excluded, leaving 152 articles for full-paper retrieval. Of these, 9 articles remained with one further article identified during cross-referencing; 10 papers (1 level 2 and 9 level 3) were included for analysis. Comparative studies investigating surgical (140 knees) versus conservative (110 knees) treatment provide evidence in favour of the former, in reducing instability and meniscal tears and improving return to previous activity. Of the papers analysed (163 reconstructions), there was only one case of growth arrest (0.6%) and no cases of length discrepancy. In those studies investigating early (218 patients) versus delayed (140 patients) reconstruction, medial meniscal tears and chondral injuries occurred more frequently in the delayed group. To conclude, for children, there is level 2/3 evidence that early operative ACL reconstruction offers the best chance of a return to pre-injury sporting activity and minimises the risks of further structural damage. Iatrogenic growth disturbance remains a rare but worrying complication.

Arthroscopic Single-Tunnel Pullout Suture Fixation for Tibial Eminence Avulsion Fracture

Various arthroscopic techniques have been devised for fixation of tibial eminence avulsions, namely percutaneous K-wires, arthroscopy-guided screw fixation, staples, TightRope (Arthrex)-suture button fixation, and transosseous suture fixation. Such techniques provide well-pronounced advantages including less postoperative pain, a reduced hospital stay, and minimal scar with resultant earlier and more compliant rehabilitation. As for transosseous suture fixation, the standard technique comprises the creation of 2 tibial tunnels exiting on both sides of the footprint of the avulsion fracture using an anterior cruciate ligament tibial guide with the angle set at 45°. Our technique entails the creation of a single tibial tunnel directed from the proximal anteromedial tibia to the center of the tibial eminence. The technique uses Ethibond suture (No. 5) and/or FiberWire suture (Arthrex) to fix the tibial eminence by pulling the anterior cruciate ligament fibers and tightening the pullout suture at the tibial exit of the tunnel with a 4-hole button. This modified single-tunnel pullout suture technique is an appealing option that has proved to be effective and economical with a shorter operative time. Moreover, it provides a less invasive option for skeletally immature patients.

Management and outcomes of isolated paediatric tibial spine fractures

Paediatric fractures of the tibial spine are relatively rare and controversy remains around how these injuries are best managed (Gans et al., 2014; Hargrove et al., 2004). Consequently most non-specialised paediatric units have limited experience of managing these injuries. This study aims to review the management and outcomes of isolated paediatric tibial spine fractures in a tertiary paediatric orthopaedic centre between 2008 and 2016. Data were collected on patient demographics, mechanism of injury, imaging, Meyers and McKeever grade of injury (Meyers and McKeever), management and outcomes, including Cincinnati and Lysholm-Tegner knee scores at a mean of 36 months post-operatively. 40 patients were included, 21 were male and the mean age was 11.8 years. 3 cases were Meyers and McKeever type I, 13 were type II and 24 were type III. 30 underwent operative management comprising of open reduction and single screw fixation, with or without a washer. 9 patients underwent subsequent metalwork removal at a mean of 10 months post-operatively. 10 underwent non-operative management, consisting of cast immobilisation and bracing. 33 patients (83%) were available for follow up. No statistically significant differences were seen in either outcome score between those treated operatively or non-operatively, or between different grades of injury, or if metalwork were removed or not. Our study shows good functional outcomes following paediatric tibial spine fracture. We advocate the use of CT to assess fracture displacement to help guide management. We have shown type I and reducible type II injuries can successfully be managed conservatively and non-reducible type II and type III injuries can be successfully treated with open reduction and single screw fixation. In our experience post-operative knee stiffness can persist for up to 6 months but generally improves. Metalwork removal was only indicated if the patient had on going stiffness after this time or if they had on going pain.

Occult Intra-articular Knee Injuries in Children With Hemarthrosis

BACKGROUND

Hemarthrosis after acute knee trauma is a sign of a potentially serious knee injury. Few studies have described the epidemiology and detailed injury spectrum of acute knee injuries in a general pediatric population.

PURPOSE

To document the current injury spectrum of acute knee injuries with hemarthrosis in children aged 9 to 14 years and to describe the distribution of sex, age at injury, type of activity, and activity frequency in this population.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All patients in the Stockholm County area aged 9 to 14 years who suffered acute knee trauma with hemarthrosis were referred to Astrid Lindgren Children's Hospital, Karolinska University Hospital, from September 2011 to April 2012. The patients underwent clinical examination, radiography, and magnetic resonance imaging (MRI). The type of activity when injured, regular sports activity/frequency, and patient sex and age were registered. The diagnoses were classified into minor and serious injuries.

RESULTS

The study included 117 patients (47 girls and 70 boys; mean age, 13.2 years). Seventy percent had a serious knee injury. Lateral patellar dislocations, anterior cruciate ligament ruptures, and anterior tibial spine fractures were the most common injuries, with an incidence of 0.6, 0.2, and 0.1 per 1000 children, respectively. The sex distribution was equal up to age 13 years; twice as many boys were seen at the age of 14 years. The majority of injuries occurred during sports. Forty-six patients (39%) had radiographs without a bony injury but with a serious injury confirmed on MRI.

CONCLUSION

Seventy percent of the patients aged 9 to 14 years with traumatic knee hemarthrosis had a serious intra-articular injury that needed specific medical attention. Fifty-six percent of these patients had no visible injury on plain radiographs. Physicians who treat this group of patients should consider MRI to establish the diagnosis when there is no or minimal radiographic findings. The most common serious knee injury was a lateral patellar dislocation. This should be taken into consideration to improve prevention strategies and treatment algorithms in pediatric knee injuries.

Treatment and Management Outcomes of Tibial Eminence Fractures in Pediatric Patients: A Systematic Review

BACKGROUND

Tibial eminence fractures are rare but occur more frequently in children and adolescents. There are a variety of methods to surgically treat these fractures, but surgeons disagree about the optimal method of reduction and fixation.

HYPOTHESES

Regarding clinical results and complications after treatment in children and adolescent patients with tibial eminence fractures, the authors hypothesize that (1) there is no difference between reduction and fixation with screws versus sutures, (2) there is no difference in arthroscopic versus open reduction and fixation, and (3) outcomes are better in patients with minimally displaced (types I and II) versus completely displaced (types III and IV) fractures.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of the literature was performed studying the treatment of tibial eminence fractures in children and adolescents to determine clinical results, functional outcomes, and complications. A meta-analytic technique on observational studies was used to compare outcomes when sufficient data were available.

RESULTS

The review identified 26 articles with extractable clinical results and data on complications: 1 level 3 article and 25 level 4 articles. Ten of 580 tibial eminence fractures identified in the literature had nonunion, with 60% of nonunions occurring in type III fractures treated by nonoperative modalities. Appreciable healing was noted for both open and arthroscopic fixation techniques as well as patients treated by screw or suture fixation. Laxity (P < .001) and loss of range of motion (P = .009) occurred significantly less after the treatment of minimally displaced fractures (types I and II).

CONCLUSION

The level of evidence supporting various treatments of tibial eminence fractures in children and adolescents is low. There is insufficient evidence to conclude the superiority of open versus arthroscopic fixation or screw versus suture fixation techniques. Nonoperative treatment of completely displaced tibial eminence fractures results in higher rates of nonunion. Type III and IV fractures heal with greater laxity and greater loss of range of motion after treatment. Higher level studies are necessary to determine the optimal method of fixation for tibial eminence fractures.

Biomechanical evaluation of physeal-sparing fixation methods in tibial eminence fractures

BACKGROUND

Tibial eminence fractures occur most commonly in skeletally immature children. Several techniques using physeal-sparing fracture fixation have been described, but their structural properties have not been evaluated.

PURPOSE

To determine the strength and resistance to displacement of physeal-sparing techniques used to fix tibial eminence fractures.

STUDY DESIGN

Controlled laboratory study.

METHODS

Skeletally immature porcine knees were randomized into 4 treatment groups: (1) ultra-high molecular weight polyethylene suture-suture button (UHMWPE/SB), (2) suture anchor, (3) polydioxanone suture-suture button (PDS/SB), and (4) screw fixation. A prospective analysis of bone mineral density using dual-energy x-ray absorptiometry was performed on all specimens. Fracture fragments were created in a standardized manner and measured for size comparison. After fracture fixation, biomechanical testing was performed with cyclical and load-to-failure protocols by loading the tibia with an anterior shear force.

RESULTS

In load-to-failure testing, screw fixation had a significantly lower median peak failure load (186.4 N; lower quartile [LQ], 158.4 N; upper quartile [UQ], 232.6 N) than did UHMWPE/SB (465.8 N; LQ, 397.8 N; UQ, 527.8 N), suture anchors (440.5 N; LQ, 323.0 N; UQ, 562.3 N), and PDS/SB (404.3 N; LQ, 385.9 N; UQ, 415.6 N). UHMWPE/SB demonstrated a significantly higher median yield load (465.8 N; LQ, 397.8 N; UQ, 527.8 N) than did PDS/SB (306.7 N; LQ, 271.4, N; UQ, 405.7 N) and screw fixation (179.0 N; LQ, 120.2 N; UQ, 232.5 N). During cyclical testing, screw fixation demonstrated significantly lower percentage survival of specimens (0%) compared with the other groups (UHMWPE/SB, 100%; suture anchor, 78%; PDS/SB, 78%). After 1000 cycles of loading, PDS/SB fixation had significantly more median creep (6.76 mm; LQ, 6.34 mm; UQ, 8.28 mm) than did UHMWPE/SB (4.43 mm; LQ, 3.80 mm; UQ, 4.73 mm) and suture anchor fixation (3.06 mm; LQ, 2.59 mm; UQ, 4.28 mm). The lowest median stiffness was observed in the PDS/SB group (48.6 N/mm; LQ, 45.3 N/mm; UQ, 54.2 N/mm). UHMWPE/SB fixation demonstrated a significantly higher median peak failure load after cyclic testing (469.0 N; LQ, 380.6 N; UQ, 507.2 N) than did PDS/SB (237.7 N; LQ, 197.3 N; UQ, 298.3 N) and screw fixation (132.4 N; LQ, 123.7 N; UQ, 180.9 N). Suture anchor fixation had significantly more variance, as demonstrated by width of interquartile range, in peak failure load, yield load, and creep than did other techniques.

CONCLUSION

Physeal-sparing fixation of tibial eminence fractures with UHMWPE suture-suture button is biomechanically superior to both PDS suture-suture button and a single screw at the time of surgery and provides more consistent fixation than do suture anchors.

CLINICAL RELEVANCE

Suture anchors provide inconsistent fixation for tibial eminence fractures.

Contact stress and kinematic analysis of all-epiphyseal and over-the-top pediatric reconstruction techniques for the anterior cruciate ligament

BACKGROUND

Adult anterior cruciate ligament (ACL) reconstruction techniques may be inappropriate to treat skeletally immature patients because of the risk of physeal complications. "Physeal-sparing" reconstruction techniques exist, but their ability to restore knee stability and contact mechanics is not well understood.

PURPOSE

(1) To assess the ability of the all-epiphyseal (AE) and over-the-top (OT) reconstruction techniques to restore knee kinematics, (2) to assess whether these reconstruction techniques decrease the high posterior contact stresses seen with ACL deficiency, and (3) to determine whether the AE or OT technique produces abnormal tibiofemoral contact stresses.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten fresh-frozen human cadaveric knees were tested using a robotic manipulator. Tibiofemoral motions were recorded with the ACL intact, after sectioning the ACL, and after both reconstructions in each of the 10 specimens. The AE technique consisted of tunnels exclusively within the epiphysis and was fixed with suspensory cortical fixation devices. The OT procedure consisted of a central and vertical tibial tunnel with an over-the-top femoral position and was fixed with staples and posts on both ends. Anterior stability was assessed with 134-N anterior force at 0°, 15°, 30°, 60°, and 90° of knee flexion. Rotational stability was assessed with combined 8 N·m and 4 N·m of abduction and internal rotation, respectively, at 5°, 15°, and 30° of knee flexion.

RESULTS

Both reconstruction techniques off-loaded the posterior aspect of the tibial plateau compared with the ACL-deficient knee in response to both anterior loads and combined moments as demonstrated by reduced contact stresses in this region at all flexion angles. Compared with the ACL-intact condition, both the AE and OT procedures had increased posteromedial contact stresses in response to anterior load at some flexion angles, and the OT technique had increased peripheral posterolateral contact stresses at 15° in response to combined moments. Neither reconstruction technique completely restored the midjoint contact stresses. Both techniques restored anterior stability at flexion angles ≤30°; however, neither restored anterior stability at 60° and 90° of flexion. Both reconstruction techniques restored coupled anterior translation under combined moments. Additionally, the AE procedure overconstrained internal rotation in response to combined moments by 12% at 15° of flexion.

CONCLUSION

Both reconstruction techniques provide anterior and rotational stability and decrease posterior joint contact stresses compared with the ACL-deficient knee. However, neither restored the contact mechanics and kinematics of the ACL-intact knee.

CLINICAL RELEVANCE

Because the AE reconstruction technique has clinical advantages over the OT procedure, the results support this technique as a potential candidate for use in the skeletally immature athlete.

Anterior cruciate ligament prevention strategies: are they effective in young athletes - current concepts and review of literature

PURPOSE OF REVIEW

Participation in sports is on the rise, with young athletes training year round and specializing at earlier ages, predisposing them to sports-related injuries. Once thought to be rare, injuries of the anterior cruciate ligament (ACL) are being seen with a greater frequency in the paediatric population. Numerous preventive training programmes have been developed. The purpose of this review is to discuss risk factors and the effectiveness of preventive programmes in the young athlete.

RECENT FINDINGS

Most ACL prevention programmes take a multifaceted approach, targeting dynamic neuromuscular and proprioceptive deficits. Focus often lies on noncontact mechanisms of injury, jump and landing techniques, and improving movement patterns during pivoting, cutting and change in direction. However, the effectiveness of these programmes in skeletally immature athletes needs to be evaluated.

SUMMARY

Early specialization and increased demand for peak performance at a time of major physiological change, lack of physical fitness and neuromuscular deficits have contributed to an increase in ACL injuries in young athletes. Various preventive training programmes have been developed, but their effectiveness is debatable. We encourage young athletes to partake in preseason training programmes focused on strengthening, neuromuscular and proprioceptive training units under the appropriate supervision of qualified personnel.

MRI findings in adolescent patients with acute traumatic knee hemarthrosis

BACKGROUND

Physical examination may be inconclusive in adolescents presenting with an acute traumatic knee effusion because of pain and guarding. The purpose of this study was to describe the magnetic resonance imaging (MRI) findings in adolescents with traumatic knee effusions and to compare injuries based on age, sex, and physeal maturity.

METHODS

All MRIs using a knee trauma protocol performed at our institution over a 2-year period were evaluated. One hundred thirty-one patients between the ages of 10 to 18 years of age with a clinical history of acute knee trauma and an effusion confirmed on MRI met our study inclusion criteria. They were divided into 2 age groups: 10 to 14 and 15 to 18 years old. Pathology was confirmed using clinical history, MRI, and any available surgical reports.

RESULTS

Of the 131 patients with an acute knee effusion, there were 59 patients in the younger group (10 to 14 y old) and 72 patients in the older group (15 to 18 y old). In the younger group, patellar dislocations (36%), anterior cruciate ligament (ACL) tears (22%), and isolated meniscus tears (15%) were the most common injuries. In the older group, ACL tears (40%), patellar dislocations (28%), and isolated meniscus tears (13%) were the most common injuries. ACL injuries represented 28% of injuries in males and 38% of injuries in females, whereas patellar dislocations represented 28% of injuries in males and 37% of injuries in females. There was a trend toward adolescents with active growth plates sustaining more patellar dislocations and adolescents with closed growth plates sustaining more ACL injuries. Forty-one percent of patients in this study underwent surgery.

CONCLUSIONS

Patellar dislocation is a common injury in children who present with a traumatic knee effusion, especially in young adolescents and females. Adolescents presenting with a traumatic knee effusion should undergo MRI because of the high rate of positive findings missed by physical examination and plain radiographs that may warrant surgical repair or reconstruction.

LEVEL OF EVIDENCE

Level III.

All-epiphyseal, all-inside anterior cruciate ligament reconstruction technique for skeletally immature patients

Anterior cruciate ligament (ACL) injuries are an increasingly recognized problem in the juvenile population. Unfortunately, outcomes with conservative treatment are extremely poor. Adult reconstruction techniques are inappropriate to treat skeletally immature patients because of the risk of physeal complications, including limb-length discrepancy and angular deformities. "Physeal-sparing" reconstruction techniques exist, but their ability to restore knee stability is not well understood. We describe an all-epiphyseal ACL reconstruction for use in skeletally immature patients. This is an all-inside technique with the femoral tunnel drilled retrograde and the tibial tunnel drilled retrograde; both tunnels are entirely within the epiphysis. Fixation of the hamstring autograft is achieved with soft-tissue buttons on both the femur and tibia. We present case examples for 2 patients who underwent the all-inside, all-epiphyseal reconstruction and our postoperative rehabilitation protocol. We present a novel surgical technique for an all-inside, all-epiphyseal ACL reconstruction in skeletally immature patients.

Acute traumatic and sports-related osteochondral injury of the pediatric knee

Adolescents are predisposed to osteochondral (OC) injuries in the knee. The medial facet of the patella, the femoral trochlea, and the lateral femoral condyle are the most common sites of injury. Most of these injuries are classically traumatic but noncontact injuries. Surgery is warranted in most cases of OC fracture. Depending on size, condition, and location of the lesion, options include OC fragment reduction and internal fixation or excision and cartilage resurfacing. Understanding of how to diagnose and treat OC fractures will help optimize outcomes.

Anatomic landmarks utilized for physeal-sparing, anatomic anterior cruciate ligament reconstruction: an MRI-based study

BACKGROUND

Anterior cruciate ligament (ACL) injury and reconstruction in the skeletally immature patient are becoming more common. The purpose of this study was to develop a reproducible anatomic ACL reconstruction technique, based on intra-articular and extra-articular landmarks, that reliably produces a femoral tunnel of adequate length and diameter while avoiding the distal femoral physis.

METHODS

Magnetic resonance images (MRIs) of one hundred and eighty-eight children (age range, six to seventeen years) were evaluated. Two extra-articular landmarks, the femoral insertion of the popliteus tendon and the lateral femoral epicondyle, and one intra-articular landmark, the central portion of the femoral footprint of the ACL, were identified. Computer software was used to plot these landmarks in all three planes and to draw lines representing two potential femoral tunnels. The first line connected the center of the ACL femoral footprint with the insertion of the popliteus tendon, and the second connected the center of the ACL femoral footprint with the lateral femoral epicondyle. The length of each tunnel, the shortest distance from the center of each tunnel to the distal femoral physis, and the height of the lateral femoral condyle from the physis to the chondral surface and to the base of the cartilage cap were calculated. A three-dimensional MRI reconstruction was used to confirm that placement of a femoral tunnel with use of the chosen landmarks would avoid the distal femoral physis.

RESULTS

The mean distance from the center of the preferred ACL tunnel, which connected the center of the ACL femoral footprint with the insertion of the popliteus tendon, to the distal femoral physis was 12 mm, independent of sex (p = 0.94) or age, and the shortest distance was 8 mm. The length of this proposed tunnel averaged 30.1 mm in the boys and 27.4 mm in the girls (p &lt; 0.001), and it averaged 25.4 mm at an age of six years and 29.7 mm at an age of seventeen years. The mean distance from the center of the alternative tunnel, which connected the center of the ACL femoral footprint with the lateral epicondyle, to the distal femoral physis was 8.8 mm in the boys and 8.9 mm in the girls (p = 0.55). The mean length of this alternative tunnel was 34.3 mm in the boys and 31.6 mm in the girls (p &lt; 0.001).

CONCLUSIONS

Drilling from the center of the ACL femoral footprint to the insertion of the popliteus tendon would have resulted in a mean tunnel length of 27 to 30 mm, and it would have allowed the safe placement of a femoral tunnel at least 7 mm in diameter in a patient six to seventeen years old. The center of the ACL femoral footprint and the popliteus insertion are easily identifiable landmarks and will allow safe, reproducible, anatomic ACL reconstruction in the skeletally immature patient.

Current Concepts of Diagnosis and Management of ACL Injuries in Skeletally Immature Athletes

Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are encountered with increasing frequency. The management of such injuries is controversial. Nonsurgical management often results in functional instability and a higher risk of meniscal and chondral injury to the knee. Conventional methods of ACL reconstruction carry the risk of growth disturbance because of iatrogenic damage to the physes around the knee. Multiple cases of growth disturbance have been reported. This article discusses the relevant anatomy, natural history, risk factors, treatment, and prevention of ACL injuries in skeletally immature patients. Surgical treatment is based on physiologic age. For prepubescent patients, we recommend physeal-sparing combined intra-articular/extra-articular reconstruction with autogenous iliotibial band. In adolescent patients with significant growth remaining, we recommend transphyseal ACL reconstruction with hamstrings autograft and fixation away from the physes. In older adolescent patients, we recommend conventional adult ACL reconstruction with autogenous hamstrings or patellar tendon.

Mimicry of lyme arthritis by synovial hemangioma

To report on the differential diagnosis of lyme arthritis and synovial hemangioma due to similar clinical and radiological signs and symptoms. A 15-year-old boy presented at the age of 9 with recurrent rather painless swelling of the right knee. Altogether four episodes lasting for 1-2 weeks each occurred over a period of 18 months before medical advice was sought. Physical examination revealed only a slightly limited range of motion. Living in an endemic area of borreliosis, he reported a tick bite 6 months prior to onset of his symptoms with erythema migrans and was treated for 10 days with amoxicillin. Serology revealed two positive unspecific bands in IgG immunoblot (p41 and 66) with slight positivity for ELISA. Ultrasound revealed synovial thickening and increased fluid. Despite the weak positive serology a diagnosis of lyme arthritis could not be excluded and intravenous antibiotic treatment with ceftriaxone was started. After two further relapses antiinflammatory therapy including intraarticular steroids were introduced with no long lasting effect. A chronical disease developed with alternate periods of swelling and almost complete remission. Ultrasound as well as MRI demonstrated ongoing signs of synovitis, therefore after further progression, a diagnostic arthroscopy was performed showing an inconspicuous knee joint. A second MRI showed focal suprapatellar enhancement and was followed by open arthrotomy revealing a histopathological proven synovial cavernous juxtaarticular hemangioma. To our knowledge, the differential diagnosis of lyme arthritis and synovial hemangioma has not yet been reported despite obvious clinical similarities. In conclusion, in children and adolescents synovial hemangioma has to be considered in differential diagnosis of recurrent knee swelling. Early diagnosis is important to prevent prolonged suffering from chronic joint swelling with probable joint damages, unnecessary treatment procedures and as well school and sports absenteeism.

Approach to knee effusions

The presence of an intra-articular knee effusion requires an extensive differential diagnosis and a systematic diagnostic approach. Pediatric knee effusions occur most commonly as acute hemarthroses after traumatic injury. However, the knee joint is susceptible to effusions secondary to a wide variety of atraumatic causes. Special attention is required in the atraumatic effusion to distinguish features of infectious, postinfectious, rheumatologic, hematologic, vasculitic, and malignant disease. This review discusses the various etiologies of both traumatic and atraumatic pediatric knee effusions highlighting the historical, physical examination, and laboratory characteristics to aid the emergency provider in diagnosis and initial management.

The International Knee Documentation Committee Subjective Evaluation Form in a preadolescent population: pilot normative data

BACKGROUND

The International Knee Documentation Committee Subjective Knee Evaluation Form is a knee-specific instrument composed of 18 questions. It is commonly used in adult and pediatric studies as a surgical outcome measure. Normative data exist for an adult population, but there have been no published normative results for younger subjects.

PURPOSE

To compile and report pilot normative International Knee Documentation Committee Subjective Knee Evaluation Form scores in a preadolescent population.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The International Knee Documentation Committee Subjective Knee Evaluation Form was administered to 146 seventh-grade students (aged 12-14 years) at 2 local schools. The form was administered in its original format. Demographic and descriptive results were compiled.

RESULTS

One hundred twenty-five completed responses were eligible for analysis. The mean age was 13.2 years (SD, 0.5; range, 12.2-14.2 years); 15% of participants had a history of knee injury or pain. The mean International Knee Documentation Committee score for all respondents was 89.4 (SD, 10.5; 95% confidence interval, 87.6-91.3; range, 52-100).

CONCLUSION

This study provides pilot normative data for mean International Knee Documentation Committee scores in a preadolescent population. The mean score in this younger cohort is consistent with normative data of adults age 35 years or younger. Although the International Knee Documentation Committee Subjective Knee Evaluation Form is often used in adolescent surgical studies, its validity in these populations remains to be established. Further work to establish the psychometric properties of the current form in younger age groups would be of significant benefit to clinicians.

Transphyseal anterior cruciate ligament reconstruction in skeletally immature pubescent adolescents

BACKGROUND

Management of anterior cruciate ligament injuries in skeletally immature patients is controversial. Conventional surgical reconstruction techniques for adults can cause iatrogenic growth disturbance due to physeal damage in children. The purpose of this study was to evaluate the results of a transphyseal reconstruction technique in pubescent but skeletally immature adolescents.

METHODS

Between 1996 and 2004, sixty-one knees in fifty-nine skeletally immature pubescent adolescents (Tanner stage 3) with a mean chronological age of 14.7 years (range, 11.6 to 16.9 years) underwent transphyseal reconstruction of the anterior cruciate ligament with use of an autogenous quadrupled hamstrings-tendon graft and metaphyseal fixation. Thirty-one knees had additional meniscal surgery. The functional outcome, graft survival, radiographic outcome, and any growth disturbance were evaluated at a mean of 3.6 years (range, 2.0 to 10.2 years) after the surgery.

RESULTS

Two patients (3%) underwent revision anterior cruciate ligament reconstruction because of graft failure at fourteen and twenty-one months postoperatively. For the remaining fifty-nine knees, the mean International Knee Documentation Committee subjective knee score (and standard deviation) was 89.5 +/- 10.2 points and the mean Lysholm knee score was 91.2 +/- 10.7 points. The result of the Lachman examination was normal in fifty-one knees and nearly normal in eight; it was not abnormal or severely abnormal in any knee. The result of the pivot-shift examination was normal in fifty-six knees and nearly normal in three knees; it also was not abnormal or severely abnormal in any knee. The mean increase in total height was 8.2 cm (range, 1.2 to 25.4 cm) from the time of surgery to the time of final follow-up. No angular deformities of the lower extremity were measured radiographically, and no lower-extremity length discrepancies were measured clinically. Complications included three cases of arthrofibrosis requiring manipulation with the patient under anesthesia.

CONCLUSIONS

Transphyseal reconstruction of the anterior cruciate ligament with use of an autogenous quadrupled hamstrings-tendon graft with metaphyseal fixation in skeletally immature pubescent adolescents provides an excellent functional outcome with a low revision rate and a minimal risk of growth disturbance.

Physeal sparing reconstruction of the anterior cruciate ligament in skeletally immature prepubescent children and adolescents. Surgical technique

BACKGROUND

The management of anterior cruciate ligament injuries in skeletally immature patients is controversial. Conventional adult reconstruction techniques risk potential iatrogenic growth disturbance due to physeal damage. The purpose of this study was to evaluate the results of a physeal sparing, combined intra-articular and extra-articular reconstruction technique in prepubescent skeletally immature children.

METHODS

Between 1980 and 2002, forty-four skeletally immature prepubescent children and adolescents who were in Tanner stage 1 or 2 (with a mean chronological age of 10.3 years) underwent physeal sparing, combined intra-articular and extra-articular reconstruction of the anterior cruciate ligament with use of an autogenous iliotibial band graft. Twenty-seven patients had additional meniscal surgery. Functional outcome, graft survival, radiographic outcome, and growth disturbance were evaluated at a mean of 5.3 years after surgery.

RESULTS

Two patients underwent a revision reconstruction for graft failure at 4.7 and 8.3 years postoperatively. In the remaining forty-two patients, the mean International Knee Documentation subjective knee score (and standard deviation) was 96.7 +/- 6.0 points, and the mean Lysholm knee score was 95.7 +/- 6.7 points. The results of the Lachman examination for anterior cruciate ligament integrity were normal for twenty-three patients, nearly normal for eighteen patients, and abnormal for one patient. The results of the pivot-shift examination were normal for thirty-one patients and nearly normal for eleven patients. Four of the twenty-three patients who underwent concurrent meniscal repair had a repeat arthroscopic meniscal repair or partial meniscectomy. The mean growth in total height from the time of surgery to the final follow-up evaluation was 21.5 cm. No patient had an angular deformity measured radiographically or a discrepancy in the length of the lower extremities measured clinically.

CONCLUSIONS

Physeal sparing, combined intra-articular and extra-articular reconstruction of the anterior cruciate ligament with use of an autogenous iliotibial band graft in skeletally immature prepubescent children and adolescents provides excellent functional outcome with a low revision rate and a minimal risk of growth disturbance.

Magnetic resonance imaging AIDS in detecting concomitant injuries in patients with tibial spine fractures

Tibial spine fracture is one of the clinical entities of anterior cruciate ligament injury, and sometimes is accompanied by concomitant injuries. The purpose of this study was to review magnetic resonance imaging findings in 25 patients with tibial spine fractures and to assess the use of these findings in determining the presence of concomitant injuries. Of these 25 patients, 10 were children and 15 were considered adults (average age, 24.2 years old). A radiologist retrospectively assessed tibial spine fractures and concomitant injuries, such as meniscus and ligament injuries. Comparing the pediatric and adult groups, all additional ligament injuries were confirmed in the adult group. In the pediatric group, only one patient with a chronic injury had meniscus injuries. There were no meniscus tears in pediatric patients with acute injuries. In the adult group, three medial meniscus tears were found in two patients with chronic injuries and one patient with acute injury, and four lateral meniscus tears were found in one patient with a chronic injury and three patients with acute injuries. Because tibial spine fractures in adults may be accompanied by concomitant injuries requiring surgical treatment, magnetic resonance imaging is recommended.

Intra-articular traumatic disorders of the knee in children and adolescents

Intra-articular knee injuries in children traditionally have been considered rarer than injuries in adults. Few studies establish the prevalence of knee injuries before skeletal maturity, but arthroscopic studies suggest an increased frequency of anterior cruciate ligament ruptures, meniscal tears, and osteochondral fractures. We report our experience with 15 anterior cruciate ligament injuries and 38 meniscus injuries treated between 1996 and 2001. The treatment of anterior cruciate ligament injuries is determined by Tanner's maturity criteria. In the three cases of Stage II injuries, surgery was delayed for up to 24 months in the 12 older patients, an immediate reconstruction was done using hamstring tendons in the three youngest patients, and patellar tendon treatment was done in the remaining cases. We had only one complication caused by the fracturing of the bone plug. The most frequent meniscus injuries were the traumatic tears (23 cases), 80% of which were peripheral and longitudinal. Whenever possible, the entire meniscus (suture in 4 cases) or the greater part of it (economic resection in 19 cases) should be conserved. Despite the satisfactory results, the average followup of the meniscal series (26.1 months) is too short a period to evaluate thoroughly the deterioration of the joint after a meniscectomy.

Magnetic resonance imaging of the knee in children and adolescents. Its role in clinical decision-making

BACKGROUND

Recent studies have questioned the utility of magnetic resonance imaging in the diagnosis of pediatric knee disorders because of the morphologic changes during growth and the low accuracy of the formal interpretation of the magnetic resonance imaging scan by a radiologist. The purpose of this study was twofold: (1) to report the accuracy of formal interpretations of magnetic resonance imaging scans of the knee in children and adolescent patients by a radiologist, and (2) to determine the benefit, if any, of a personal review of the magnetic resonance imaging scan of the knee by the orthopaedic surgeon, as a routine part of the diagnostic evaluation.

METHODS

A three-year prospective study of all patients who underwent knee arthroscopy performed by a single surgeon, at two children's hospitals, was completed. The analysis focused on the six most common diagnoses: anterior cruciate ligament tear, lateral meniscal tear, medial meniscal tear, osteochondritis dissecans, discoid lateral meniscus, and osteochondral fracture. The preoperative diagnosis of the surgeon was determined by integrating the history and the findings on the clinical examination, plain radiographs, and magnetic resonance imaging scans (including the radiologist's interpretation).

RESULTS

Ninety-six patients with ninety-six abnormal knees were included. The mean age was 14.6 years at the time of surgery. Relative to operative findings, kappa values for the formal interpretations of the magnetic resonance imaging scans by a radiologist were 0.78 for an anterior cruciate ligament tear, 0.76 for a medial meniscal tear, 0.71 for a lateral meniscal tear, 0.70 for osteochondritis dissecans, 0.46 for discoid lateral meniscus, and 0.65 for osteochondral fracture. Relative to operative findings, kappa values for the preoperative diagnoses by the surgeon were 1.00 for an anterior cruciate ligament tear, 0.90 for a medial meniscal tear, 0.92 for a lateral meniscal tear, 0.93 for osteochondritis dissecans, 1.00 for discoid lateral meniscus, and 0.90 for osteochondral fracture. The preoperative diagnosis by the surgeon was better (p < 0.05) than the formal interpretation of the magnetic resonance imaging scans by the radiologist with respect to an anterior cruciate ligament tear, lateral meniscal tear, osteochondritis dissecans, and discoid lateral meniscus.

CONCLUSIONS

Integration of patient information with an orthopaedic surgeon's review of the magnetic resonance imaging scan of the knee in children and adolescent patients improves the identification of pathological disorders in four of the six categories evaluated. This study questions the necessity for and appropriateness of a routine interpretation of a magnetic resonance imaging scan of the knee in children and adolescents by a radiologist.

Fate of the anterior cruciate ligament-injured knee

Most patients with anterior cruciate ligament (ACL) injuries do well with activities of daily living even after follow-up in the range of 5 to 15 years. Most can participate in some sports activity if they are inclined to do so, but most will have some limitations in vigorous sports, and only a few will be entirely asymptomatic. The challenge to the clinician is to understand and predict how ACL deficiency in a given patient will affect that patients's life and activities. In counseling patients about treatment after an ACL injury, the clinician can use knee ligament arthrometry measurements and pre-injury sports activity to estimate the risk of injury over the next 5 to 10 years. Meniscus, chondral, and sub-chondral injuries are not uncommon, but rarely require surgical intervention in the early phase of ACL deficiency. The prevalence of clinically significant meniscal damage increases with time, and is associated with increasing disability, surgery, and arthrosis in high-risk patients. Ligament reconstruction has not been shown to prevent arthrosis, but in prospective studies it appears to reduce the risk of subsequent meniscal injury, improve passive anteroposterior knee motion limits, and facilitate return to high-level sporting activities.

Partial tears of the anterior cruciate ligament in children and adolescents

BACKGROUND

The functional outcome after partial anterior cruciate ligament tears in children and adolescents treated without reconstruction has not been established.

HYPOTHESIS

Nonreconstructive management of partial anterior cruciate ligament tears can be effective in certain pediatric patients.

STUDY DESIGN

Prospective cohort study.

METHODS

We studied 45 skeletally mature and immature patients 17 years of age or less who had an acute hemarthrosis, magnetic resonance imaging signal changes, grade A or B Lachman and pivot shift result, and an arthroscopically documented partial anterior cruciate ligament tears. All patients were treated without reconstruction, underwent a structured rehabilitation program, and were followed up for a minimum of 2 years.

RESULTS

Fourteen patients (31%) underwent subsequent reconstruction. Significant associations with subsequent reconstruction included tears that were greater than 50%, predominantly posterolateral tears, a grade B pivot shift test result, and older chronologic and skeletal age. Among patients who did not require reconstruction, those with tears that were greater than 50% or predominantly posterolateral had significantly lower Lysholm, satisfaction, and Cincinnati Knee Scale scores.

CONCLUSIONS

Nonreconstructive management is recommended for partial anterior cruciate ligament tears in children and adolescents 14 years of skeletal age or younger with normal or near-normal Lachman and pivot shift results. Reconstruction is recommended in older athletes or in those with greater than 50% or predominantly posterolateral tears.

Diagnostic performance of clinical examination and selective magnetic resonance imaging in the evaluation of intraarticular knee disorders in children and adolescents

To determine the diagnostic performances of clinical examination and selective magnetic resonance imaging in the evaluation of intraarticular knee disorders in children and adolescents we compared them with arthroscopic findings in a consecutive series of pediatric patients (< or = 16 years old). Stratification effects by patient age and magnetic resonance imaging center were examined. There were 139 lesions diagnosed clinically, 128 diagnosed by magnetic resonance imaging, and 135 diagnosed arthroscopically. There was no significant difference between clinical examination and magnetic resonance imaging with respect to agreement with arthroscopic findings (clinical examination, 70.3%; magnetic resonance imaging, 73.7%), overall sensitivity (clinical examination, 71.2%; magnetic resonance imaging, 72.0%), and overall specificity (clinical examination, 91.5%; magnetic resonance imaging, 93.5%). Stratified analysis by diagnosis revealed significant differences only for sensitivity of lateral discoid meniscus (clinical examination, 88.9%; magnetic resonance imaging, 38.9%) and specificity of medial meniscal tears (clinical examination, 80.7%; magnetic resonance imaging, 92.0%). For magnetic resonance imaging, children younger than 12 years old had significantly lower overall sensitivity (61.7% versus 78.2%) and lower specificity (90.2% versus 95.5%) compared with children 12 to 16 years old. There was no significant effect of magnetic resonance imaging center. In conclusion, selective magnetic resonance imaging does not provide enhanced diagnostic utility over clinical examination, particularly in children, and should be used judiciously in cases where the clinical diagnosis is uncertain and magnetic resonance imaging input will alter the treatment plan.

Characteristic pattern and management of intra-articular knee lesions in different pediatric age groups

Posttraumatic hemarthrosis of the knee joint usually leads to arthroscopy. In a retrospective study we defined an age-specific spectrum of injuries and, subsequently, assigned an age-dependent diagnostic management for children up to 16 years. From January 1986 to December 1996, 1,273 patients up to 16 years of age with knee trauma presented to the emergency department. Overall, soft-tissue lesions prevailed (82%). Hemarthrosis occurred in only 18.0%. The patients were classified in three groups: group 1 (528 children younger than 10 years of age) with hemarthrosis in only 5.7% (mainly metaphyseal fractures and patellar dislocations), group 2 (207 preadolescents from 11 to 12 years of age) with hemarthrosis in 17.9% (patellar dislocations and fractures), and group 3 (538 adolescents between the age of 13 and 16 years) with hemarthrosis in 30.3% (main findings were intra-articular fractures and patellar dislocations, additionally, 16 ligamentous and two meniscal lesions). Correspondingly, physical examination, conventional radiography, and magnetic resonance imaging (most appropriate diagnostic tool for patellar dislocation) were sufficient to reveal injuries in children up to 13 years of age. Arthroscopy was predominantly justified in those older than 13 years of age, but only if it leads to therapeutic consequences.

Arthroscopic repair of the posterior cruciate ligament in a 3-year-old child

We report a case of symptomatic acute posterior cruciate ligament (PCL) rupture in a 3-year-old boy. At arthroscopy, the PCL was avulsed from the femoral attachment with intact ligament substance. Arthroscopic repair of the PCL was performed by transosseous sutures, which were placed using a suture-punch and an anterior cruciate ligament drill guide. Two years later there was a perfect objective and functional result.

Pediatric knee. Clinical assessment and common disorders

Knee pain and injury are commonly seen in children and adolescents. A comprehensive evaluation of the knee is built on an appreciation of the anatomy, biomechanics, and pathophysiology of common disorders. This article considers these issues and describes a sequential technique for physical examination of the knee. Relevant imaging options and management strategies also are discussed.

Acute hemarthrosis of the knee in children

The purpose of this study was to determine the cause of acute hemarthrosis of the knee in a prospective pediatric patient population. Between December 1988 and August 1991, 21 consecutive children who were seen with an acute traumatic hemarthrosis of the knee had an arthroscopic evaluation. The average age of the children at the time of injury was 14 years, 3 months (range, 10 to 17 years). The mechanism of injury was a torsional strain to the knee in 12 (71%) of the 17 patients who could accurately remember the injury. The initial evaluation included a history, physical examination, and anteroposterior, lateral, sunrise, and comparison radiographs. The arthroscopic procedure was performed under general anesthesia, and the arthroscopic findings were compared with preoperative findings. During arthroscopic examination, an osteochondral fracture of the lateral femoral condyle or patella was identified in 14 (67%) of the 21 patients. Preoperative radiographs failed to identify the fracture in 5 (36%) of the 14 patients who had an osteochondral fracture. The anterior cruciate ligament was visualized and probed; an injury was found in only two cases (10%). We concluded that in children an acute traumatic hemarthrosis reflects a major injury to the knee. The children in this study had a high frequency of osteochondral fractures; ACL injuries were found in only two patients. Because of the unreliable nature of radiographic evaluation, arthroscopic evaluation is a valuable tool in differential diagnosis and treatment of acute hemarthrosis of the knee.

The importance of arthroscopy in sports injuries in children and adolescents

Within a 3-year period (1985-1988), 60 children and adolescents with knee injuries sustained mainly while skiing or playing football (soccer) underwent clinical examination, X-radiography and arthroscopy. Nearly all the patients still had open epiphyseal plates in the knee region. Arthroscopy revealed more severe intra-articular trauma than had been suspected on the basis of clinical findings. The skiing injuries most commonly involved anterior cruciate ligament tears, whereas injuries of the patellar retinaculum and medial meniscus lesions predominated in soccer injuries. On comparison with arthroscopic diagnosis, clinical diagnosis was erroneous in about 45%. The most common mistaken clinical diagnosis was "medial meniscus tear". Of the 60 knee joints subjected to arthroscopy, 40 were severely enough injured to warrant surgery. Only one had normal intra-articular findings. The study demonstrates that children and adolescents can suffer knee trauma requiring surgery, despite open growth plates. Downhill skiing and soccer are particularly risky sports in this respect. Therefore, sports injuries involving haemarthrosis are clearly an indication for arthroscopy, even in childhood and adolescence. Arthroscopy enables early identification of the type and extent of intra-articular trauma and subsequent early initiation of appropriate therapy.

Synovial haemangioma of the knee joint

Synovial haemangioma of joints are rare, but usually affect the knee joints of children and adolescents. Recurrent swelling, usually due to haemarthrosis, and intermittent pain may be present for a long time before the diagnosis is made. In this case report the common features of the condition are described, with emphasis on the occurrence of atraumatic haemarthrosis in children. The value of arthroscopy in diagnosis is discussed.

Arthroscopy in children

Arthroscopy was performed on the knees of 67 children aged 2-16 years with an overall clinical diagnostic accuracy of 45%. The most common clinical diagnoses were meniscal tear and patello-femoral pain and the accuracy of these diagnoses was 33% and 59% respectively. Diagnostic accuracy seemed unrelated to age. Arthroscopy led to definitive treatment which relieved symptoms in 21 (31%) of cases, revealed a diagnosis only in 43 (64%), and was non-contributory in 3 (4.5%). The procedure did not significantly help patients with patello-femoral pain.