Is Mobile-Bearing Medial Unicompartmental Knee Arthroplasty Appropriate for Asian Patients With the Risk of Bearing Dislocation?

BACKGROUND: Mobile-bearing unicompartmental knee arthroplasty (UKA) is an attractive operation for medial unicompartmental knee arthritis, but unexpected bearing dislocation is a drawback. Bearing dislocation occurs more frequently in Asians, whose lifestyle involves deeper knee flexion than Westerners. This study investigated whether mobile-bearing medial UKA is appropriate for Asians by analyzing (1) the rate of bearing dislocation and (2) the results of patients with bearing dislocation. METHODS: We retrospectively reviewed 531 consecutive mobile-bearing medial UKA in the previous 15 years, including 22 patients with bearing dislocation who had at least 2 years of follow-up. The entire patient cohort was divided into 2 groups: the symmetrical bearing (187 knees) and the anatomic bearing (344 knees) groups. In the anatomic bearing group, patients who underwent surgery using the conventional phase III (283 knees) vs the Microplasty (61 knees) instrumentation systems were compared. RESULTS: The overall incidence of bearing dislocation was 4.1% (22/531). Patients with the symmetrical bearing displayed a relatively high dislocation rate of 9.6% (18/187), which significantly decreased to 1.1% (4/344) after changing to the anatomic bearing (P < .001). In the anatomic bearing group, the dislocation rate with the conventional phase III system was 1.4% (4/283). There were no bearing dislocations in the Microplasty system group (0%, 0/61) after at least 2 years of follow-up. CONCLUSION: Although mobile-bearing medial UKA was reported to have a high incidence of bearing dislocation in Asians, this frequency of dislocation is drastically decreased by bearing design and implantation system improvements. We consider mobile-bearing medial UKA appropriate for Asians.

Early detected femoral neck insufficiency fracture in a patient treated with long-term bisphosphonate therapy for osteoporosis: A need for MRI.

INTRODUCTION: Atypical femoral fracture is an uncommon complication of prolonged use of bisphosphonates, mainly occurring in the femoral shaft. We report a case of an atraumatic insufficiency fracture of femoral neck after four years of treatment with a bisphosphonate. PRESENTATION OF CASE: A 71-year-old female presented with history of pain on Lt. hip and difficulty in walking. Although there was no fracture on the radiographs, diagnosis could be made early using magnetic resonance imaging (MRI) scans. She was treated by internal fixation using cannulated screws. DISCUSSION: Because bisphosphonate prevents bone healing and remodeling, it is difficult to accomplish the bony union despite of proper treatment in patients who have fractured after long-term use of bisphosphonate. CONCLUSION: A high suspicion index and early diagnosis through the use of MRI are essential for the successful treatment of these fractures.

An inexpensive and rapid method for removal of multiple stripped locking screws following locking plating: A case report.

INTRODUCTION: Removal of stripped or jammed locking screws involves several difficulties. Especially when two or more screws are involved, their removal is a more challenging and time-consuming process because the various reported techniques have certain limitations. CASE PRESENTATION: Herein, we report a case in which five stripped screws were removed using a novel technique. DISCUSSION: Many techniques to remove damaged locking head screw were introduced, however in case with multiple screws were involved, they are limited to use. In the case, screw extractor, although it is not a medical device, is helpful in terms of time and cost. CONCLUSION: In case with the failure of removal of multiple locking screws, our technique using non-medical screw extractor can be a good option.

The proximally-based sural artery flap for coverage of soft tissue defects around the knee and on the proximal third and middle third of the lower leg: 10 patients followed for 1-2.5 years.

BACKGROUND AND PURPOSE: There have been few reports regarding the proximally based sural artery flap, which is useful for reconstruction of soft tissue defects around the knee and on the proximal third and middle third of the lower leg. Here we report our experience with 10 patients. PATIENTS: The defects in our 10 cases were around the knee (4), on the proximal third of the lower leg (4), and on the middle third (2). 8 patients had fasciocutaneous flaps and 2 had adipofascial flaps. The flap size ranged from 4 to 10 cm in length, and from 5 to 8 cm in width. The pedicle length ranged from 12 to 20 cm. RESULTS: All 10 flaps survived. Congestion and tip necrosis occurred in 1 case with a fasciocutaneous flap, which healed without complications. A superficial infection occurred in 1 case with a fasciocutaneous flap, which healed with antibiotic treatment. Necrosis of grafted skin occurred in 2 cases of adipofascial flap; only one of them, however, required additional surgery. No morbidity of the donor site and no functional deficits were detected in any of the 10 cases. INTERPRETATION: The proximally based sural artery flap is useful for reconstruction of soft tissue defects around the knee joint and on the proximal third and middle third of the lower leg. It is a relatively easy and reliable procedure.