Osteochondritis dissecans of the medial femoral condyle associated with congenital hypoplasia of the lateral meniscus and anterior cruciate ligament

The Novel Use of the Lateral Scanogram to Detect Cruciate Deficiency in Children With Congenital Femoral Deficiency

Congenital femoral deficiency (CFD) is often associated with cruciate ligament deficiency. The lateral scanogram may be a potential solution to some limitations for detecting instability associated with cruciate ligament deficiency. This qualitative case study identified two children with congenital femoral deficiency who were assessed with a lateral scanogram and had their results correlated to the clinical examination and MRI. Both cases identified a child with congenital femoral deficiency, one with a total leg length discrepancy (LLD) of 12 cm and the next with 6.5 cm. The weight-bearing lateral scanogram revealed anterior tibial translation, indicating knee instability. Both patients will undergo anterior cruciate ligament (ACL) reconstruction prior to limb lengthening. The lateral scanogram is a useful imaging modality that is capable of detecting anterior tibial translation, and thereby knee instability, in children with congenital femoral deficiency. Larger studies utilizing and evaluating the benefits of lateral scanograms are warranted.

Osteochondritis Dissecans of the Knee: Etiology and Pathogenetic Mechanisms. A Systematic Review

OBJECTIVE

The purpose of this manuscript is to analyze the evidence regarding etiopathogenesis of knee osteochondritis dissecans (OCD) lesions through a systematic review, so to summate the current understanding of the origin and progression of this pathologic articular processes.

DESIGN

A systematic review of the literature was performed on the PubMed and Cochrane databases on October 2017 by 2 independent authors and included all levels of evidence. This included all English language literature, pertaining specifically to etiopathology of knee OCD with exclusions for review articles and expert opinion. Of 965 identified records, 154 full-text articles were assessed for eligibility and 86 studies met the inclusion criteria.

RESULTS

According to these studies, the etiology of OCD can be of a biological or mechanical origin: 40 articles proposed a biological hypothesis, including genetic causes (27), ossification center deficit (12), and endocrine disorders (9); conversely, 52 articles supported a mechanical hypothesis, including injury/overuse (18), tibial spine impingement (5), discoid meniscus (16), and biomechanical alterations (20) as the cause of the onset of OCD. The pathogenic processes were investigated by 36 of these articles, with a focus on subchondral bone fracture and ischemia as the ultimate events leading to OCD.

CONCLUSIONS

Biological and mechanical factors are found to result in subchondral bone remodeling alterations, acting independently or more likely synergically in the progression of knee OCD. The former includes genetic causes, deficit of ossification centers and endocrine disorders; the latter, tibial spine impingement, discoid meniscus, and biomechanical alterations, together with injuries and overuse. The resultant subchondral bone ischemia and/or fracturing appears to determine the onset and progression of OCD.

LEVEL OF EVIDENCE

Systematic review of level II-IV studies, level IV.

Reconstruction of Symptomatic Congenital Anterior Cruciate Ligament Insufficiency

BACKGROUND

Hypoplasia or congenital absence of the anterior cruciate ligament (ACL) is a rare disorder occurring in ∼1 in every 6000 births. Although some patients with hypoplasia or agenesis of the ACL may not complain of instability, others desire to participate in more demanding activities that require the stability of a competent ACL. There are limited reports of surgical treatment of this patient population. The purpose of this study was to report ACL reconstruction in a case series of patients with symptomatic congenital ACL deficiency.

METHODS

A retrospective medical record review of the surgical treatment of 14 knees (13 patients) with congenital absence of the ACL at a tertiary care institution from 1995 to 2012 was performed. Patients with a minimum of 1 year of clinical follow-up were eligible for inclusion.

RESULTS

The mean age at time of surgery was 12.6 (range, 3 to 22), including 6 patients <12 years of age. Mean follow-up was 2.9 years (range, 1 to 6.6). Nine of 13 patients (69%) had underlying congenital abnormalities/associated syndromes. Preoperative Lachman and pivot shift examination was International Knee Documentation Committee grade C or D in all but 1 knee. ACL reconstruction was performed with combined intra-articular/extra-articular physeal sparing reconstruction with iliotibial band (n=5), autograft hamstring (n=2) or bone-patellar tendon-bone (n=3), or allograft (n=4). Multiligament reconstruction of associated ligamentous deficiency was performed in 7 knees (50%). Postoperative Lachman and pivot shift testing was International Knee Documentation Committee (IKDC) grade A or B in all but 1 knee. One patient with congenital absence of multiple knee ligaments required revision ACL reconstruction surgery, with concurrent first-time posterior cruciate ligament reconstruction, due to persistent instability. None required revision surgery due to graft tear at a minimum of 1-year follow-up.

CONCLUSIONS

Surgical stabilization of symptomatic congenital ACL insufficiency, with associated ligamentous reconstruction as required on a case-by-case basis, results in improved stability at early clinical follow-up, with low complication rates.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Bilateral Hypoplasia of Both Medial and Lateral Menisci Partially Fused With the Cartilage Surface of the Tibial Plateau

Hypoplastic meniscus is an extremely rare abnormality. The authors present the first case of meniscal hypoplasia with a partial fusion of meniscus and tibial cartilage. A 22-year-old man underwent surgery for a chronic patellar dislocation. Preoperative magnetic resonance imaging and arthroscopy incidentally revealed hypoplasia of both medial and lateral menisci. Moreover, the posterior horn of the medial meniscus and middle body of the lateral meniscus were fused with the cartilage surface of the tibia. Magnetic resonance imaging of the contralateral knee showed similar meniscal anomalies. This case presents an interesting and extremely rare abnormality of the meniscus. [Orthopedics. 2018; 41(6):e884-e887.].

Bilateral Hypoplasia of the Medial and Lateral Menisci

Hypoplasia of the meniscus is a very rare congenital abnormality, with only a few cases reported to date. A 9-year-old girl visited our hospital due to lateral knee pain following a hyperextension injury to the left knee. Magnetic resonance imaging showed hypoplasia of the medial and lateral menisci, as well as a posterior horn tear of the lateral meniscus, in both knee joints. To our knowledge, this is the first report of a patient with hypoplasia of the medial and lateral menisci in both knee joints.

Congenital Medial Meniscus Hypoplasia

An 18-year-old man with no prior surgical history presented with left knee pain after sustaining a basketball injury and was diagnosed with transient patellar dislocation. Magnetic resonance imaging was ordered to further assess the extent of injury.

Functional and radiographic outcomes of unstable juvenile osteochondritis dissecans of the knee treated with lesion fixation using bioabsorbable pins

BACKGROUND

The purpose of this study was to evaluate the functional and radiographic outcome of fixation of unstable juvenile osteochondritis dissecans lesions of the knee after a minimum of 2 years of follow-up.

METHODS

A total of 33 unstable juvenile osteochondritis dissecans lesions in 30 patients underwent fixation using bioabsorbable pins through arthrotomy or under arthroscopy. The patients consisted of 23 males and 7 females, and the average age at the time of operation was 14.4 years (range, 11 to 17 y). The functional outcomes were evaluated using the Lysholm score and Hughston's criteria at a mean follow-up of 3.3 years (range, 2.1 to 6.3 y). Healing of the osteochondritis dissecans lesions were confirmed by plain radiographs and magnetic resonance imaging.

RESULTS

The Lysholm score improved significantly at 3 months after the surgery, and was maintained until the final follow-up. Radiographically, 32 of 33 lesions healed after fixation of the lesion (healing rate was 97.0%). Healing was achieved at an average of 2.4 months on plain radiographs and 4.2 months on magnetic resonance imaging. According to Hughston's criteria, 25 patients were graded as excellent, 4 as good, and 1 as poor at the final follow-up.

CONCLUSIONS

The fixation of the unstable juvenile osteochondritis dissecans lesions with bioabsorbable pins demonstrated improved clinical outcomes and radiographic high healing rates at a mean of 3.3 years of follow-up. We advocate this procedure for patients with unstable juvenile osteochondritis dissecans lesions of sufficient quality to enable fixation which will preserve the normal contour of the distal femur.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Surgical treatment of a rare isolated bilateral agenesis of anterior and posterior cruciate ligaments

The isolated bilateral agenesis of both cruciate ligaments is a rare congenital disorder. A 17-year-old male came to our attention due to an alteration in gait pattern, pain, and tendency to walk on the forefoot with his knee flexed. The patient did not recall previous injuries. Upon physical examination anterior and posterior chronic instability were observed. Radiographic examination of both knees showed hypoplasia of the tibial eminence, a hypoplastic lateral femoral condyle, and a narrow intercondylar notch. MRI brought to light a bilateral agenesis of both posterior cruciate ligaments. Arthroscopic evaluation confirmed bilateral isolated agenesis of both cruciate ligaments. We recommended a rehabilitation program to prepare the patient for the arthroscopic construction of both cruciate ligaments.

Osteochondritis dissecans of the lateral tibial condyle associated with agenesis of both cruciate ligaments

Osteochondritis dissecans is a rare cause of painful knees in children. Only 10 cases of lateral tibial condyle involvement have been reported in the literature. Congenital agenesis of both cruciate ligaments has been described even less, and its prevalence is unknown. The authors report an atypical association of osteochondritis dissecans of the tibia with congenital absence of both cruciate ligaments. A 12-year-old male soccer player presented with a painful right knee. Magnetic resonance imaging revealed the diagnosis. The child was treated conservatively. At 18-month follow-up, radiographs showed osseointegration of the osteochondritis dissecans, and the patient had resumed normal athletic activity without pain. To the authors' knowledge, this is the only report describing such an association. The authors discuss the possible etiology of osteochondritis dissecans associated with agenesis of the cruciate ligaments and highlight the possibility of this association when osteochondritis dissecans of the tibia is diagnosed in a child with a painful knee. In this patient, the strain due to anteroposterior instability may have been the cause of osteochondritis. Conservative treatment should be considered in this setting.

Agenesis of the posterolateral bundle of anterior cruciate ligament

The objective of this article is to report an anterior cruciate ligament variation that has not been previously described, in which the posterolateral bundle of anterior cruciate ligament is congenitally not developed. The clinical picture and the magnetic resonance images are presented, and the arthroscopic appearance is described.

Unilateral aplasia of both cruciate ligaments

Aplasia of both cruciate ligaments is a rare congenital disorder. A 28-year-old male presented with pain and the feeling of instability of his right knee after trauma. The provided MRI and previous arthroscopy reports did not indicate any abnormalities except cruciate ligament tears. He was referred to us for reconstruction of both cruciate ligaments. The patient again underwent arthroscopy which revealed a hypoplasia of the medial trochlea and an extremely narrow intercondylar notch. The tibia revealed a missing anterior cruciate ligament (ACL) footprint and a single bump with a complete coverage with articular cartilage. There was no room for an ACL graft. A posterior cruciate ligament could not be identified. The procedure was ended since a ligament reconstruction did not appear reasonable. A significant notch plasty if not a partial resection of the condyles would have been necessary to implant a ligament graft. It is most likely that this would not lead to good knee stability. If the surgeon would have retrieved the contralateral hamstrings at the beginning of the planned ligament reconstruction a significant damage would have occurred to the patient. Even in seemingly clear diagnostic findings the arthroscopic surgeon should take this rare abdnormality into consideration and be familiar with the respective radiological findings. We refer the abnormal finding of only one tibial spine to as the "dromedar-sign" as opposed to the two (medial and a lateral) tibial spines in a normal knee. This may be used as a hint for aplasia of the cruciate ligaments.

Osteochondritis dissecans of the medial femoral condyle associated with malformation of the menisci

Osteochondritis dissecans is a form of osteochondrosis limited to the articular epiphysis and the relationship of osteochondritis dissecans and discoid lateral meniscus has been clearly identified. This article presents a 10-year-old boy with osteochondritis dissecans of the medial femoral condyle associated with hypoplastic medial and partial deficient lateral menisci. The patient presented with activity-related pain and intermittent swellings of his left knee for 2 months without any evidence of significant knee trauma. Magnetic resonance imaging revealed anomalous medial meniscus mimicking displaced bucket-handle tear and partially deficient lateral meniscus with osteochondritis dissecans at the lateral aspect of medial femoral condyle without any significant bone loss with a non-dislocated fragment. Arthroscopy of the knee revealed an incomplete separated osteochondral flap with partial discontinuity that was unstable on probing on the lateral aspect of the medial femoral condyle. The medial meniscus was hypoplastic without a body and only the meniscal rim could be seen. The lateral meniscus had an anomalous vertical insertion of the posterior horn, normal body, but an absent anterior horn. The anterior cruciate ligament was intact, but looked like a peacock's tail. Arthroscopic fixation of the chondral lesion was performed. At 30-months follow-up, the boy had no limitation in his daily and sports activity. The present case is the first description of congenital anomaly of the both menisci and osteochondritis dissecans together. Meniscal or ligamentous anomalies of the knee may be associated with osteochondritis dissecans.

Bilateral hypoplasia of the medial meniscus

Only a few cases of the nearly unknown hypoplastic meniscus abnormality have been described. A case report of an incidental finding in a young female with a bilateral hypoplastic medial menisci is presented and, as far as we know, is the first report of bilateral hypoplasia of the medial meniscus in the literature.

Knee reconstruction in syndromes with congenital absence of the anterior cruciate ligament

The authors review their experience with four patients with congenital deficiency of the anterior cruciate ligament (ACL) who underwent surgical treatment of symptomatic knee instability at a mean age of 15.8 years (range 14-17 years). Associated syndromes included fibular hemimelia, congenital short femur, and an unspecified skeletal dysplasia. All patients had undergone multiple previous realignment and leg lengthening procedures and were skeletally mature at the time of the reconstruction. All four patients underwent ACL reconstruction, and one patient underwent concomitant posterolateral corner reconstruction. One patient required an osteochondral autograft transplant procedure in addition to ACL reconstruction. Hypertrophy of the meniscofemoral ligament of Humphrey was a consistent anatomic finding at surgery. The patients were followed for a mean of 38 months (range 26-58 months) after the reconstruction. The mean preoperative Lysholm II score was 38 (range 28-56); the score had improved to a mean of 81 (range 78-93) at the latest follow-up. The authors conclude that reconstructive surgery is a viable option for restoration of knee stability and function in appropriately selected patients with congenital ACL deficiency.