Hidden Horizontal Tears of the Posterior Horn of the Medial Meniscus:a Report of 14 Cases / 中国微创外科杂志

ABSTRACT

Objective To investigate the clinical features of hidden horizontal tears of the posterior horn of the medial meniscus and clinical efficacy of arthroscopic partical meniscectomy. Methods A total of 14 cases of hidden horizontal tears of posterior horn of the medial meniscus from May 2011 to May 2013 were enrolled.The knee arthroscopy was carried out through anteromedial and anterolateral approaches.The lesion of tears was exposed after the inner edge of posterior horn of the meniscus was bitten away.The bottom of the posterior horn of meniscus was found instable during the operation, which was then removed to conduct a partial meniscectomy.Afterwards the arthroscopic meniscus plasty of the posterior horn was performed. Results Arthroscopic photographs showed normal appearance in 6 cases and tears underside meniscus in 8 cases, all of which were confirmed to be horizontal medial meniscus posterior horn tear during operation.The mean time of operation was 32 min (range, 26-40 min), and the mean hospitalization time was 6 days ( range, 3-8 d) .There was no complications, such as infections or stiffnesses.All the patients were followed up for 2 -3 years.Subjective symptoms improved significantly after arthroscopic partial meniscectomy.According to the Lysholm knee scoring scale, the scores were (71.1 ±6.6) points preoperatively and (92.0 ±3.4) points postoperatively, with significant difference (t=10.530, P=0.000). Conclusion Diagnosis of hidden horizontal tears of the medial meniscus posterior horn is often difficult, because most patients have osteoarthritic knees.Careful physical examination and MRI are critical for making a correct diagnosis.Arthroscopic partial meniscectomy can help patients obtain better results.