RESUMO
Objective To discuss the relationship between the injury patterns of medial patellofemoral ligament(MPFL) and injury degrees of vastus medialis obliquus(VMO) after acute patellar dislocation(PD). Methods Knee joint MRI was performed in 79 patients with acute PD. Images were acquired and evaluated using standardised protocols. Injury patterns of MPFL were grouped by severity (partial tear and complete tear)and location (isolated patellar-side tear (PAT), isolated femoral-side tear (FEM) and combined tear (COM) ) for analysis of the prevalence of VMO injury. The VMO elevation was calculated on sagittal and coronal planes. Results The prevalence rates of MPFL tear and VMO lesion were 96.2%(76/79)and 54.4%(43/79)after acute PD.The prevalence rate of VMO lesion was 40.6%(13/32)and 68.2%(30/44)in the partial and complete MPFL tear subgroups,respectively.Complete MPFL tear subgroup showed higher prevalence rate of VMO lesion when compared with partial tear subgroup(χ2=5.727, P=0.017). The prevalence rates of VMO lesion in the PAT, FEM and COM subgroups were 31.8% (7/22), 67.7% (21/31) and 70% (14/20), respectively. There were statistically significant differences among them(χ2=8.549,P=0.014).About the mean VMO elevation,there were statistically significant differences between the complete and partial MPFL tear subgroups, the FEM and PAT subgroups, and the COM and PAT subgroups (P=0.00). Conclusions Compared with partial MPFL tear, complete tear predisposes to VMO lesion and has a higher elevation of the torn VMO after acute PD.The femoral-sided and combined MPFL tears predispose to VMO lesion and have higher elevations of the torn VMO.
RESUMO
Em nove equinos atendidos por apresentarem fixação dorsal de patela intermitente, optou-se pela aplicação de 2mL de contrairritante na região subcutânea, ao longo dos ligamentos patelares medial e intermédio. No período de 12 a 48h após a aplicação, os animais apresentaram aumento de volume e de temperatura local, sensibilidade dolorosa à palpação e relutância à locomoção. Após esse período, os sinais clínicos de inflamação e fixação dorsal de patela foram gradativamente diminuindo até o sétimo dia, em sete dos nove animais avaliados. Após a remissão dos sinais de inflamação, dois animais não responderam ao tratamento, sendo necessária a repetição em um dos casos e realização de desmotomia patelar medial no outro. A aplicação de contrairritante foi eficaz na remissão do sinal clínico de fixação dorsal da patela intermitente. Comparativamente às técnicas cirúrgicas para a correção da enfermidade descritas na literatura, o tratamento promoveu melhora precoce dos sinais, curto período de convalescência e praticidade na realização.
Nine horses were admitted showing intermittent lameness due to upward fixation of the patella (UFP) and were injected with 2mL of counter-irritant subcutaneously, through the middle and medial patellar ligaments. From 12 to 48 hours after application, these animals showed increased volume and local temperature, painful response to palpation and reluctance to bear weight. Subsequently, the inflammatory signs were gradually decreasing until the seventh day, along with signs of UFP in seven of the nine animals. After remission of inflammatory signs, two of the nine horses did not respond to the treatment. In these two animals, one horse needed a repeated counter-irritant injection and the other received the medial patellar desmotomy. The use of counter-irritant was effective in the remission of clinical signs of UFP. In comparison with the surgical techniques described in literature used to correct this disease, the proposed treatment promoted early improvement of clinical signs, short term recovery and was easily performed.