
Morel Lavallée Clinic and Treatment
Morel Lavallée Clinic And Treatment. A 36-year-old male patient reported pain in his right knee for 1 year associated with playing basketball, which improved after physiotherapeutic treatment.
However, he had recently worsened, accompanied by a slightly painful bulging in the popliteal fossa, which limited flexion of the same knee. He reported a history of trauma to the posterior region of both knees, when performing exercises on a circus trapeze two months ago, an unusual practice.
At the time, he felt local discomfort for a few days, which improved spontaneously and did not seek medical attention. He had a history of Os Good Schlatter Disease in both knees during adolescence and had been asymptomatic for several years (Figure 1).
In the MRI, carried out a year ago, to investigate the onset of pain, the presence of a popliteal cyst and patellar chondromalacia were detected, defined as the supposed cause of the pain, after sports (Figures 2-5).
He sought medical attention, worried about the posterior bulging of his right knee, which bothered him a lot when he flexed his knee. He took x-rays and no changes were observed (Figures 6 and 7).
Subsequently, a new resonance was performed, in which a soft tissue tumor was detected in the popliteal fossa, and he was advised to see an orthopedic oncologist for a biopsy and probable resection (Figures 8 to 15).
Upon receiving the patient, we detailed the anamnesis, which highlighted the real importance of the trauma that occurred 2 months ago, on a circus trapeze, which limited his activities due to pain, but he did not seek medical attention at the time, as he was on vacation. On physical examination, we noticed a tense bulging, but elastic fiber in the right popliteal fossa, which was painful only on pressure and not on palpation. No neurological changes, no regional lymph node enlargement which, when in flexion, worsened the pain.

When calmly analyzing the images, we observed an image with low signal when T1-weighted and high signal when T2-weighted, which may initially suggest a lesion with liquid content. To differentiate from solid lesions, which are therefore more likely to be malignant, we must interpret the contrast images. In this patient’s case, the contrast accumulated only on the periphery of the lesion, strengthening the hypothesis of only liquid content, that is, without internal vascularization that would allow the contrast to spread within the lesion. We could now postulate the hypotheses of a cyst or an organized hematoma. However, some solid tumors can mimic this pattern of contrast enhancement, such as myxomas and some neural tumors.

Another important fact is that the lesion is superficial. The majority of malignant tumor lesions are found deep within the muscular fascia, further reducing the probability of being a malignant neoplasm, but approximately 1% of superficial tumor lesions are malignant, so this hypothesis cannot be completely ruled out.
The third characteristic that must be highlighted in the images of this case is that in addition to being superficial, this lesion is located exactly between the muscular plane and the subcutaneous fat plane. Very clearly it can be seen that the lesion is dissecting the two planes and assuming a half-moon shape, suggestive of liquid under external pressure that shapes the convexity of the external surface of the muscular plane and the internal surface of the fatty plane. Solid lesions can present different shapes, but they tend to be more rounded and well-defined.
Given the characteristics of the images, clinical history and physical examination, the diagnostic hypothesis of an organized traumatic hematoma, dissecting the tissue planes, Morel-Lavallée injury, was postulated. It was decided to puncture the hematoma in an office environment with asepsis and local anesthesia to relieve symptoms.
The patient remained with a Neoprene tensor around the knee for 4 days after the puncture to prevent the hematoma from re-forming and after 2 weeks he reported complete improvement in the condition.
Authors of the case
Author: Prof. Dr. Pedro Péricles Ribeiro Baptista
Orthopedic Oncosurgery at the Dr. Arnaldo Vieira de Carvalho Cancer Institute
Office : Rua General Jardim, 846 – Cj 41 – Cep: 01223-010 Higienópolis São Paulo – SP
Phone: +55 11 3231-4638 Cell:+55 11 99863-5577 Email: drpprb@gmail.com