Extra-articular Tenodesis Using Autogenous Iliotibial Band for Symptomatic Congenital Absence of Anterior Cruciate Ligament: A Report of 2 Cases.

CASE: We report 2 cases of congenital absence of anterior cruciate ligament with symptomatic knee instability in young children. This report describes the surgical technique and outcomes of extra-articular tenodesis using autogenous iliotibial band (ITB) without drilling across the open physis. Excellent results were observed at a short-term follow-up. CONCLUSION: Severe symptoms of knee instability even in young children may warrant surgical approach. Extra-articular tenodesis using autogenous ITB in young children is a good option with positive improvements in knee stability and symptomatic relief.

Bilateral Comparisons of Quadriceps Thickness after Anterior Cruciate Ligament Reconstruction.

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48-72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb; RCL = Pre-operated (PRE): 19.89 ± 6.91 mm, Post-operated(POST): 16.04 ± 6.13 mm, Healthy limb; HL = PRE: 22.88 ± 6.07, POST: 20.90 ± 5.78 mm, F = 9.325, p = 0.009, η2p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR.

Home-based rehabilitation using smart wearable knee exercise device with electrical stimulation after anterior cruciate ligament reconstruction: A study protocol for a randomized controlled trial.

INTRODUCTION: Rehabilitation after anterior cruciate ligament (ACL) reconstruction is critical to patient outcome. Despite its importance; however, hospital-based rehabilitation is limited, with barriers, including distance and cost. With recent technological advancements, wearable devices have actively been used to address these barriers. In this study, we propose a randomized controlled trial protocol investigating the efficacy and feasibility of home-based rehabilitation after ACL reconstruction using a smart wearable device providing electrical stimulation that allows knee exercise. METHODS AND ANALYSIS: This is a protocol proposal for a prospective, single-center, randomized, controlled study. We plan to recruit adults discharged after ACL reconstruction; the recruited subjects will be randomly allocated to 1 of 2 groups, using a computer-generated randomization method: the intervention (n = 20) or control group (n = 20). The intervention group will receive a 6-week home-based rehabilitation program using smart wearable device. The control group will undergo a 6-week self-exercise program as normal. The following outcomes will be assessed at baseline, 2 weeks, and 6 weeks post the 6-week intervention program: quadriceps strength of the affect side as measured by a dynamometer (primary outcome); range of motion; root mean square of quadriceps muscle using surface electromyography; knee function using questionnaire; quality of life; subject's satisfaction score using questionnaire; frequency and duration of exercise; and knee pain. An intention-to-treat analysis will be conducted for the primary outcome. DISCUSSION: This study is a prospective, single-center, randomized, controlled study. This study aims to research the feasibility and efficacy of a 6-week, structured home-based rehabilitation program for patients after ACL reconstruction using a smart wearable device. The findings of this study will help to establish a home-based rehabilitation program to better recovery in patients with ACL reconstruction. TRIAL REGISTRATION NUMBER: This protocol was registered in ClinicalTrials.gov, under the number NCT04079205.

Implementing the Lever Sign in the Emergency Department: Does it Assist in Acute Anterior Cruciate Ligament Rupture Diagnosis? A Pilot Study.

BACKGROUND: Within the emergency department (ED) setting, anterior cruciate ligament (ACL) rupture is commonly misdiagnosed, leading to improper treatment and potential meniscal injury and total joint replacement. Utilizing traditional clinical tests to diagnosis ACL rupture leads to the correct diagnosis in about 30% of cases. The lever sign is a new and effective clinical test used to diagnose ACL rupture with 100% sensitivity. OBJECTIVE: We aim to study if the lever sign used in the ED setting is more sensitive to diagnose ACL rupture than traditional tests. METHODS: Patients between 12 and 55 years of age were examined utilizing either traditional methods or the lever sign. Diagnostic findings in the ED were compared with those of a sports medicine specialist using magnetic resonance imaging as the diagnostic standard. A survey was given to ED providers to collect data on diagnosis and physician confidence in diagnosis. RESULTS: The sensitivity of the lever sign was 100% (94.7% accuracy, 93.75% specificity), whereas the sensitivity of the anterior drawer/Lachman test was 40% (87.5% accuracy, 100% specificity). Physician confidence in diagnosis was higher utilizing the lever sign vs. the anterior drawer/Lachman test at 8.45 (±1.82) compared with 7.72 (±1.82) out of 10, respectively. There was no statistically significant association between diagnostic accuracy with either test and level of training of the ED provider. CONCLUSION: Implementation of the lever sign in the ED setting resulted in a higher sensitivity, higher physician confidence in screening test diagnosis, and a decrease in the number of undiagnosed ACL ruptures.

A new method for diagnosing biochemical abnormalities of anterior cruciate ligament (ACL) in human knees: A Raman spectroscopic study.

Anterior cruciate ligament (ACL) plays an essential role in knee joint stability and kinematics. The microstructural irregularities such as cellular changes and disorganization of the extracellular matrix (ECM) alter the mechanical properties of the ligament, leading to a significant knee functional instability and progression of osteoarthritis (OA). So far, the identification of the local abnormality in ACL has routinely relied on invasive analytical techniques such as histology or biochemical assays. The non-invasive diagnosis using magnetic resonance imaging (MRI) is still limited to identifying the presence/absence of partial/complete ruptures and mucoid degeneration. In this study, laser micro-Raman spectroscopy with near-infrared excitation (785 nm) was applied to human ACL in order to establish optical algorithms for non-destructively diagnosing a degeneration state at molecular level. Raman spectra were obtained from 44 ex-vivo ACL specimens, and these were subsequently classified as an early (subclinical) and advanced (clinical) level of tissue degradation based on the histopathological scoring system. The significant differences in Raman peak intensities were found between the different degeneration groups, which were assigned to the vibrational modes of nucleic acids in cells, collagens, and phospholipids. Linear discriminant analysis (LDA) was performed to identify cut-off values for the distributions of Raman intensity and intensity ratios, which enable to best discriminate between the early and advanced degenerated tissues. Raman intensity algorithms derived from I1101/I1749, [I1002/I1516vs. I1101/I1749], and [I1002/I1749vs. I1101/I1749], yielded a maximum diagnostic sensitivity of 100%, specificity of 80%, and accuracy of 91% for discriminating the degeneration severity. STATEMENT OF SIGNIFICANCE: In this study, laser micro-Raman spectroscopy was applied to human anterior cruciate ligament (ACL) to establish optical algorithms for non-destructively diagnosing the tissue degeneration at molecular level. To our knowledge, this is the first report on Raman diagnosis for human ACL. Linear discriminant analysis (LDA) was performed to identify cut-off values for Raman intensity and intensity ratios, which enable to best discriminate between an early (subclinical) and advanced (clinical) level of ACL degeneration. The intensity ratios of I1101/I1749, [I1002/I1516vs. I1101/I1749], and [I1002/I1749vs. I1101/I1749] yielded a maximum diagnostic sensitivity of 100%, specificity of 80%, and accuracy of 91% for discriminating the ACL degeneration. The present findings might contribute to expanding clinical diagnostic possibilities for non-invasively identifying tissue degeneration.

Single-tunnel anatomic double-bundle anterior cruciate ligament reconstruction has the same effectiveness as double femoral, double tibial tunnel: A prospective randomized study.

PURPOSE: To investigate whether single femoral, single tibial tunnel anatomic double-bundle anterior cruciate ligament (ACL) reconstruction is equal to or superior to double femoral, double tibial tunnel ACL double-bundle anatomic reconstruction in terms of restoring the stability and functions of the knee joint. METHODS: A prospective clinical study was performed to compare 30 cases of single-tunnel ACL double-bundle anatomic reconstruction to 28 cases of double-tunnel ACL double-bundle anatomic reconstruction, with average follow-up of 36 months. All graft tendons were hamstring tendon autografts. Tunnel placements in all the cases were made anatomically. Clinical results were collected after reconstruction. Graft appearance, meniscus status and cartilage state under arthroscopy were compared and analyzed. RESULTS: Tunnel placements were in the anatomic positions in both groups. On the lateral pivot-shift test performed at 36 months postoperatively, there was no significant difference between groups. Clinical results such as International Knee Documentation Committee score, Tegner activity scale, and range of motion showed no significant differences between the groups. The mean thickness of anteromedial graft was reduced by 10.3% and that of the posterolateral graft was reduced by 11.1% from the original graft thickness evaluated by magnetic resonance imaging. No new meniscal tears were found either group; however, cartilage damage occurred in the double-tunnel group at 39.3%, and this rate was significantly higher than that in the single-tunnel group (10.0%). CONCLUSION: Single femoral, single tibial tunnel anatomic double-bundle ACL reconstruction has the same effectiveness as the double femoral, double tibial tunnel in restoring the knee's stability and functions.

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 absence of the cruciate ligaments with meniscal dysplasia: Unexpected diagnosis in a child with juvenile idiopathic arthritis.

Bilateral agenesis of the cruciate ligaments is a rare congenital anomaly. We report a unique case of a young girl who had congenital short femur and diagnosed with polyarticular juvenile idiopathic arthritis (JIA) and later discovered to have congenital absence of both anterior and posterior cruciate ligaments and meniscal dysplasia in both the knees when MRI was performed at 11 years of age. The MRI was performed to evaluate knee laxity and persistent symptoms despite medical management and multiple steroid injections for arthritis treatment. This patient is one of the youngest with congenital absence of both the cruciate ligaments to be treated with ACL reconstruction. We highlight the unique radiographic imaging manifestations of congenital cruciate ligament agenesis and emphasize the role of MRI to confirm and depict additional intraarticular abnormalities.

Estudo comparativo entre métodos manual e digital no cálculo do ângulo do platô tibial em cães / Comparative study of manual and digital method in the calculation of the tibial plateau angle in dogs

São poucos os dados publicados sobre a aplicabilidade ou a confiabilidade dos métodos digitais para mensuração do ângulo do platô tibial (APT) em comparação à mensuração manual. O objetivo deste estudo foi comparar o APT obtido pelo cálculo manual padrão, em filmes radiográficos, com os valores obtidos por cálculos em imagens digitais, por meio do software do computador. Foram analisadas radiografias digitais do membro pélvico, direito e esquerdo, em perfil verdadeiro, de 20 cães saudáveis, com idade superior a um ano. Três observadores com graus de experiência semelhantes em cálculo do APT realizaram as mensurações em cada radiografia. Primeiramente, foram calculados os ângulos dos platôs tibiais manualmente nas películas radiográficas e, posteriormente, os cálculos foram realizados na imagem digital, por meio do software para medicina veterinária do sistema de raios X digital. Os resultados do presente estudo demonstraram diferenças significativas entre os métodos, com valor das médias do cálculo digital 20,48±3.71 e do cálculo manual 23.90±4.02. Valor de P foi < 0,01 na comparação entre médias dos dois grupos. Na avaliação interobservadores, houve diferença significativa no cálculo manual no perfil direito, o que sugere maior variação no cálculo manual quando comparado ao digital. O cálculo realizado pelo software apresentou menor variação nos valores interobservadores. Acredita-se que a menor variação obtida nos resultados aqui apresentados se dê em razão das facilidades proporcionadas pelo software. Conclui-se que houve diferença entre os valores obtidos por meio dos métodos convencional e digital no cálculo do ângulo do platô tibial, sendo os valores digitais menores entre os observadores, e que o método digital no cálculo do ângulo do platô tibial levou à menor variação quando comparado ao método manual.(AU)

There are few published data on the applicability and reliability of digital methods for measuring the TPA compared with manual measurement. The objective of this study was to compare the TPA obtained by calculating standard manual on conventional radiographs, with the values obtained by calculations in digital images through a computer program. Bilateral digital radiographs of hind limb were analyzed in true profile for 20 healthy dogs older than two years. Three observers with similar levels of experience in calculating the TPA conducted measurements on each radiograph. First we calculated the angle of the tibial plateaus manually in x-ray film and then the calculations were made through the program offered by the computer program in the digital image. The results of this study showed significant differences between the methods, with average value of 20.48±3.71 digital calculating average and 23.90±2.4 in the manual calculation. P value was < 0.01 when comparing averages. No significant difference in manual calculation in right profile were found between interobserver assessments, suggesting greater variation in manual calculation compared to digital. The calculation performed by the software showed less variation in values. The slight variation obtained in our results is believed to be due to the facilities provided by the software. There was a difference between the values obtained by means of conventional and digital methods for calculating the angle of the tibial plateau, and the smaller digital values between the observers and the digital method in the calculation of the tibial plateau angle led to less variation when compared to the manual method.(AU)

[A soccer player with an unstable knee]. / Een voetballer met een instabiele knie.

A 19-year-old soccer player presented with instability of his left knee after a rotation trauma. Congenital absence of the anterior cruciate ligament was suspected because of leg length discrepancy and specific MRI findings. He regained stability after an anterior cruciate reconstruction.

Multiple Ligament Reconstruction for Absent Cruciate and a Congenital Short Femur Case Report and Review of the Literature.

Congenital short femur syndrome is a rare condition affecting about 0.017 of every 1,000 births. Patients frequently have ligamentous abnormalities, most frequently aplastic or hypoplastic cruciate ligaments. Advances in limb lengthening procedures have increased movement expectations for these patients, thus necessitating surgical treatment for their ligamentous abnormalities. An individual case is presented, including history, physical exam, and imaging demonstrating both the short femur and absent cruciate ligaments. A surgical reconstruction technique of the anterior cruciate ligament, posterior cruciate ligament, and posterolateral corner is described. At 1-year follow-up, the patient had 0° to 135° of ROM. He reported no pain but mild swelling experienced during squatting. His knee continues to be stable in all planes with a grade 1A Lachman exam and a grade 1 posterior drawer with no posterolateral corner laxity.

The use of history to identify anterior cruciate ligament injuries in the acute trauma setting: the 'LIMP index'.

OBJECTIVE: To identify the injury history features reported by patients with anterior cruciate ligament (ACL) injuries and determine whether history may be used to identify patients requiring follow-up appointments from acute trauma services. METHODS: Multisite cross-sectional service evaluation using a survey questionnaire design conducted in the UK. The four injury history features investigated were 'leg giving way at the time of injury', 'inability to continue activity immediately following injury', 'marked effusion' and 'pop (heard or felt) at the time of injury'(LIMP). RESULTS: 194 patients with ACL injury were identified, of which 165 (85.5%) attended an acute trauma service. Data on delay was available for 163 (98.8%) of these patients of which 120 (73.6%) had a follow-up appointment arranged. Patients who had a follow-up appointment arranged waited significantly less time for a correct diagnosis (geometric mean 29 vs 198 days; p<0.001) and to see a specialist consultant (geometric mean 61 vs 328 days; p<0.001). Using a referral threshold of any two of the four LIMP injury history features investigated, 95.8% of patients would have had a follow-up appointment arranged. CONCLUSIONS: Findings support the value of questioning patients on specific injury history features in identifying patients who may have suffered ACL injury. Using a threshold of two or more of the four LIMP history features investigated would have reduced the percentage of patients inappropriately discharged by 22.2%. Evidence presented suggests that this would significantly reduce the time to diagnosis and specialist consultation minimising the chance of secondary complications.

Outcome of Tibial Closing Wedge Osteotomy in 55 Cranial Cruciate Ligament-Deficient Stifles of Small Dogs (<15 kg).

OBJECTIVE: To describe the outcome of cranial closing wedge osteotomy (CWO) of the tibia for treatment of cranial cruciate ligament (CrCL)-deficient stifles in dogs with a body weight of <15 kg. STUDY DESIGN: Retrospective case series. ANIMALS: Forty-five client-owned dogs (n=55 stifles). METHODS: Medical records (2005-2014), radiographs, and owner questionnaire were used to identify the surgical procedure performed, associated complications and outcome in 45 dogs undergoing CWO in 55 stifles. RESULTS: Data for 55 stifles from 45 dogs were included. Bichon Frise was the most frequent dog breed (n=11). Mean pre- and postoperative tibial plateau angle (TPA) were 36.3° (95% CI 35.1-37.5) and 7.5° (95% CI 6.7-8.2), respectively. Pin and tension bands were placed in 38/55 stifles (69%). The most frequent complication at short-term follow-up (2 weeks) was incisional complications in 8 stifles; all resolved with systemic antibiotic administration alone. Data were available for all stifles at 8 week follow-up with an overall complication occurrence in 16/55 stifles (28%); 1 dog required revision surgery. Tibial osteotomy healing was evident on radiographs at 8 weeks postoperative in 53 stifles (96%), considered complete in 27 stifles, and good in 26 stifles. Follow-up owner questionnaire was available for 36 dogs at a mean of 24 months and 34/36 owners (94%) were satisfied with the procedure and considered their dog had a good quality of life with minimal long-term complications. CONCLUSION: Dogs with a body weight <15 kg undergoing CWO for treatment of a CrCL-deficient stifle had a good outcome based on clinical status, radiographic evaluation, and owner questionnaire.

Short-term outcome and complications of TPLO using anatomically contoured locking compression plates in small/medium-breed dogs with "excessive" tibial plateau angle.

OBJECTIVES: To report short-term radiographic and clinical outcome and complications following tibial plateau levelling osteotomy for the treatment of cranial cruciate ligament insufficiency in dogs less than 18·1 kg with tibial plateau angle greater than 35° using anatomically contoured six-hole locking compression plates. METHODS: Retrospective data were collected on: preoperative, postoperative and follow-up tibial plateau angles, plateau segment rotation, tibial tuberosity width and length of the cranial aspect of tibial tuberosity segment from the patellar tendon insertion and rotation of the tibial plateau below the level of the insertion of the patellar ligament. RESULTS: In 26 small dogs (29 stifles in total), mean preoperative, postoperative and follow-up tibial plateau angles were 38·2°, 4·8°, and 4·4°, respectively. Documented postoperative complications were limited to patellar tendinopathy in a single case (3·4%) and tibial tuberosity or fibula fracture were not observed. CLINICAL SIGNIFICANCE: Short-term radiographic and clinical outcome of tibial plateau levelling osteotomy stabilised with anatomically contoured six-hole locking compression plates for the treatment of small dogs with large tibial plateau angle suggests a very low risk of complications. Rotation beyond the "safe point" is necessary to perform full rotation in some cases, but does not appear to incur an increased risk of tibial tuberosity fracture.

Anterolateral ligament abnormalities in patients with acute anterior cruciate ligament rupture are associated with lateral meniscal and osseous injuries.

OBJECTIVE: To determine the frequency of anterolateral ligament (ALL) injury in patients with acute anterior cruciate ligament (ACL) rupture and to analyse its associated injury patterns. METHODS: Ninety patients with acute ACL rupture for which MRI was obtained within 8 weeks after the initial trauma were retrospectively identified. Two radiologists assessed the status of the ALL on MRI by consensus. The presence or absence of an ALL abnormality was compared with the existence of medial and lateral meniscal tears diagnosed during arthroscopy. Associated collateral ligament and osseous injuries were documented with MRI. RESULTS: Forty-one of 90 knees (46 %) demonstrated ALL abnormalities on MRI. Of 49 knees with intact ALL, 15 (31 %) had a torn lateral meniscus as compared to 25 torn lateral menisci in 41 knees (61 %) with abnormal ALL (p = 0.008). Collateral ligament (p ≤ 0.05) and osseous injuries (p = 0.0037) were more frequent and severe in ALL-injured as compared with ALL-intact knees. CONCLUSION: ALL injuries are fairly common in patients with acute ACL rupture and are statistically significantly associated with lateral meniscal, collateral ligament and osseous injuries. KEY POINTS: • ALL injuries are fairly common in patients with acute ACL rupture. • ALL injuries are highly associated with lateral meniscal and osseous injuries. • MRI assessment of ACL-injured knees should include evaluation of the ALL.

Congenital Absence of the Anterior Cruciate Ligament.

The incidence of congenital absence of the anterior cruciate ligament (ACL) is extremely low. Congenital ACL absence has most often been found in association with conditions such as knee dislocation, knee dysplasia, proximal focal femoral deficiency, and fibular hemimelia. We report on the incidental finding of ACL aplasia in a patient with a medial meniscal tear and history of leg-length discrepancy. As has been found in prior case studies, this patient had hypertrophy of the meniscofemoral ligament of Humphrey, which likely lent her stability. This case highlights the importance of differentiating between a stable and an unstable knee in congenital absence of the ACL.

Ring-shaped lateral meniscus with hypoplasic anterior cruciate ligament.

Knee joint lesions can be solitary or occur concomitantly with other lower limb abnormalities. Ring-shaped lateral meniscus (RSM) and hypoplasic anterior cruciate ligament (ACL) are two rare malformations. The therapeutic management of such abnormalities is not consensual, and highly depends on clinical symptomatology. We report a case of a 25-year-old girl with progressive knee pain whose MRI demonstrated a continuous segment of lateral meniscus situated along the medial aspect of the lateral compartment, continuous with the otherwise normal-appearing lateral meniscus, compatible with an RSM. This anatomic variant can be mistaken by a displaced meniscal fragment, like a bucket-handle tear, a central tear of a discoid meniscus, or incomplete discoid meniscus, as previously reported. Her MRI examination also showed a thinned ACL with anomalous lateral course. This abnormality may be mistaken for an ACL rupture and/or a meniscofemoral ligament with agenesis of ACL. Multiple images in different planes as well as following the course of meniscal and ligaments are critical clues to avoid misdiagnosis. As a result, the diagnosis of an RSM along with hypoplasic ACL with abnormal attachment was assumed based on MRI and confirmed during arthroscopy. The patient was treated conservatively with clinical outcome improvement.

[Congenital aplasia of cruciate ligaments causing knee osteoarthritis]. / Kongenit korsbåndsaplasi som årsag til gonartrose.

We report a case of a 56-year-old women with severe unilateral osteoarthritis and translation due to congenital aplasia of both cruciate ligaments, which was found during knee arthroplasty surgery. Cruciate ligament insufficiency is a known risk factor in osteoarthritis but is very rarely caused by congenital aplasia and is most often due to trauma. While the patient had several common risk factors for the development of osteoarthritis the congenital aplasia may have contributed significantly in this case of osteoarthritis.

Congenital absence of the anterior cruciate ligament in monozygotic twins.

Cases of congenital absence of the cruciate ligaments are seen rarely in the literature. When reported, they are almost exclusively associated with various additional lower extremity deformities. We report the cases of 15-year-old monozygotic twin brothers. Both brothers presented with right knee pain and instability and were found on magnetic resonance imaging (MRI) to have congenital absence of the right anterior cruciate ligament (ACL). Examination of full length leg radiographs and MRI of the knee showed no associated abnormalities. Twin B previously underwent partial medial meniscectomy performed by an outside orthopaedic surgeon at which time the absence of the ACL was noted but not repaired. After diagnosis at our practice, both twins underwent arthroscopically assisted ACL construction with bone-patella-bone-autograft. Following recovery from surgery, both twins returned to high level athletics. These cases are among few reports of isolated congenital absence of the ACL, and to our knowledge there are no other cases of isolated congenital absence of the ACL in monozygotic twins.

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.