Sang Eun Park

Complications of Medial Unicompartmental Knee Arthroplasty

Background We report intra- and postoperative complications of unicompartmental knee arthroplasty (UKA). Methods This study was conducted on 246 cases of UKA which were performed for degenerative osteoarthritis confined to the medial compartment, from May 2002 to May 2010, for which follow-up periods longer than one year were available. Complications were divided into intra- and postoperative complications. Pre- and postoperative clinical scores, the range of motion, and radiologic findings were analyzed. Results Complications developed in a total of 24 cases (9.8%, 24/246). Among them, 6 cases had intraoperative complications while 18 had postoperative complications. Among the 6 intraoperative complications, one fracture of the medial tibial condyle, two fractures of the intercondylar eminence, one rupture of the medial collateral ligament, one widening of the peg hole leading to femoral component malposition and late failure, and one total knee arthroplasty (TKA) conversion of a large bony defect of tibial avascular necrosis were observed. Among the 18 postoperative complications, four cases of aseptic loosening of the femoral component, one soft tissue impingement due to malalignment, nine cases of polyethylene bearing dislocation, one case of suprapatellar bursitis, one periprosthetic fracture, one TKA conversion due to medial component overhanging, and one TKA conversion due to pain of unexplained cause were observed. Conclusions The mid-term clinical outcomes of UKA were excellent in our study. However, the incidence of complications was very high (9.8%). To prevent intra- and postoperative complications, proper selection of the patients and accurate surgical techniques are required.

Extra-Articular Ganglion Cysts around the Knee Joint

Purpose The purpose of this study was to report clinical results of open excision of extra-articular ganglion cysts around the knee joint combined with arthroscopic management of intra-articular pathologies if present. Materials and Methods Of the total 107 cases of cystic lesions around the knee, 23 cases of extra-articular ganglion cysts were reviewed between January 2006 and July 2011. There were 13 males and 10 females with a mean age of 48 years (range, 30 to 73 years). The mean follow-up duration was 40 months (range, 30 to 60 months). Preoperative magnetic resonance imaging (MRI) scan was done in all cases. Open surgical excision of the cyst was performed after arthroscopic management of intra-articular pathologies in all but 1 case. At the last follow-up, Lysholm and International Knee Documentation Committee (IKDC) scores were evaluated and MRI was conducted to detect recurrence. Results The mean Lysholm and IKDC scores showed significant improvement (p=0.005 and 0.013, respectively).The location of the cysts was anterior in 9, lateral in 7, medial in 6, and posterosuperior in 1. Intra-articular pathologies were found in 16/23 cases (69.6%). In 10/23 cases (43%), the cyst was connected to the knee joint. Three months postoperative MRI did not show any recurrence of ganglion cysts except for 1 case. Conclusions In the treatment of extra-articular ganglion cysts, MRI can be useful for detecting intra-articular lesions and connecting orifices, and arthroscopic management of intra-articular pathologies with open excision of the cyst should be considered as a viable treatment option.

Locked floating first metatarsal: open reduction and no fixation - case report.

Level of Evidence: V, Expert Opinion

Atypical Pelvic Crescent Fracture Caused by Vertical Shear Force

The crescent fracture consists of a posterior iliac wing fracture with extension into the sacroiliac joint and a dislocation of the sacroiliac joint. This fracture represents a subset of lateral compression injury. The strong posterior ligaments of sacroiliac joint remain intact and a fracture fragment (crescent shape) involving the posterior superior iliac spines remains firmly attached to the sacrum. We report a patient with atypical pelvic crescent fracture that is mainly influenced by vertical shear injury and is characterized by posterior fracture-dislocations of the sacroiliac joint. In this case report, we review the literature on classification and treatment of atypical type of crescent fracture.