An extra-articular cause of locking knee

Knee locking caused by osteochondroma of the proximal tibia adjacent to the pes anserinus: A case report

BACKGROUND

Osteochondroma is one of the most common benign bone tumors, and it may cause bone and joint deformities and limited range of motion of an adjacent joint. The pes anserinus region is one of the most frequent sites of osteochondroma, but knee locking caused by osteochondromas in the pes anserinus region is extremely rare.

CASE SUMMARY

We describe a 13-year-old Japanese girl's extra-articular knee locking that occurred when the semitendinosus tendon got caught in osteochondroma that had developed in the pes anserinus region. The osteochondroma was surgically resected. The postoperative outcome has been excellent, with no recurrence of knee locking or tumor one-year post-surgery.

CONCLUSION

When a young person develops knee locking, the possibility of extra-articular as well as intra-articular locking should be considered. Osteochondroma, one of the causes of extra-articular locking, can be treated with surgery with good postoperative results.

Pes Anserinus Bursitis due to Tibial Spurs in Children

Osteochondromas are the most common bone tumours. Although these tumors are relatively common in the long bones of children, the varied clinical and radiographic presentation of such neoplasms around the knee joint can cause diagnostic delays, especially when not associated with a palpable swelling. Proximal tibial osteochondromas can sometimes unusually present as spurs/ rose thorns leading to pes anserinus bursitis and vague knee pain. We describe the clinico-radiographic features of such proximal tibial metaphyseal osteochondromas giving rise to pes anserinus bursitis in three children, including bilaterally symmetrical osteochondroma in one of the cases, who were treated conservatively with good outcomes.

Extra-osseous osteochondroma-like soft tissue mass of the patello-femoral space

Background

Extraskeletal cartilaginous tumors are uncommon. Osteochondromas usually arise from the metaphyseal region of the growing skeleton.

Case presentation

A 53 year old man presented with a three years history of anterior knee pain and inability to flex his knee more than 90°. Clinical examination and imaging studies revealed a nodular calcific mass in the anterior portion of the knee, displacing the medial portion of the patellar tendon. Following excision, histopathology confirmed the diagnosis of extra-osseous osteochondroma-like soft tissue mass, with no recurrence 24 months after surgery.

Conclusion

An integrated clinical-pathologic diagnosis helps to clarify the nature of extraskeletal cartilaginous tumors that can arise at unusual anatomic site. Complete local surgical excision is the management of choice.

Acute traumatic extension deficit of the knee

The purpose of this study was to evaluate the events leading to acute traumatic extension deficit of the knee and the arthroscopic findings in these patients. A total of 78 consecutive patients treated in the Turku university hospital during the years 1994-1996 were included. The mean annual incidence of acute traumatic extension deficits of the knee in our study was 1.1 per 10 000 inhabitants. The single most common (33%) event causing the extension deficit was non-sports related twisting of the knee. Various sports related activities accounted for 42% of the extension deficits, and soccer was the most common sport in this group. In conclusion, acute traumatic extension deficit of the knee is usually a sign of serious intra-articular damage, and the most likely finding (in 82% of the patients in our study) is either a meniscal rupture, an anterior cruciate ligament (ACL) rupture, a patellar dislocation, or a combination of these. The lesions in these knees require prompt evaluation by an orthopaedic surgeon mainly because of the high number of bucket-handle and menisco-capsular insertion ruptures of the menisci, which are possibly suitable for repair.