Objective

This paper aims to analyze the kinetics of the over-ground wheel-type body weight supporting system (BWS); tendency changes of low extremity joint moment (hip, knee, ankle), 3 axis accelerations of a trunk, cadence and gait velocity as weight bearing level changes.

The purpose of this study was to evaluate the Mid-term results (minimum 5 year) of the use of 36 mm metallic femoral head coupled with 1st generation HXLPE in patients with the age of less than or equal to 50 years-old. This retrospective study included 31 cases sustained hip pain needed Total Hip Replace Arthroplasty. We used cementless stem(FMT, Zimmer, Warsaw, Indiana) at 28 cases and cement stem(Versys, Zimmer, Warsaw, Indiana) at 3 cases. We used Trilogy (Zimmer, Warsaw, Indiana) in all cases as an acetabular cup and Longevity (Zimmer, Warsaw, Indiana) in all cases as a HXLPE. Mean acetabular cup size was 52.88mm. Mean HXLPE liner thickness at 45o was 6.18mm [Fig.1]. Mean Harris hip score was 91(86–96) and all cases obtained more than 15 scores in Merle d'Aubigne and postel method at recent follow ups. All femoral stem showed stable fixation status. Mean acetabular cup Inclination was 50.6o and Anteversion was 23.1o. During follow ups, there was no complication including dislocation, osteolysis, infection and plastic fracture. Bedding-in wear rate was 0.079±0.034mm/yr. And Steady- state was 0.043±0.016mm/yr. In vitro study, 1stgeneration HXLPE showed negative mechanical property changes due to high dose radiation and remelting. So, concerns remained in using HXLPE to active patients. But we checked a good results in terms of functional scores and wear rates. And, there was no major complication during minimal 5 years check ups. So, the authors thought THRA with 36mm- metallic heads on 1st-Generation Highly Cross-linked Polyethylene as a bearing surface could be a good option in less than or equal to 50 years patients.

The purpose of this study was to review the total ankle arthroplasties performed in consecutive series of 78 ankles and to determine the short-term results in cases with over 12 months follow-up. Preoperative diagnoses were post-traumatic osteoarthritis in 40 ankles (51.3%), primary osteoarthritis in 32 ankles (41.0%), and systemic arthritis in six ankles (7.7%). HINTEGRA^® (Newdeal SA, Lyon, France) total ankle system was used in all cases

Fifty-five total ankle arthroplasties including four revision cases, followed up for over 12 months (range, 13~49 months) were included in this study. Ankles were divided into three groups according to the coronal plane deformity in preoperative standing ankle AP radiograph; Varus (≥10°; 20 ankles (39.2%)), neutral (< 10° varus or valgus; 25 ankles (49%)), and valgus (≥10° valgus; 6 ankles (11.8%)). Various additional surgeries were performed simultaneously with the arthroplasty to correct the deformities; deltoid ligament release (25 cases), posterior tibialis tendon lengthening (2 cases), peroneus longus tendon transfer to brevis (5 cases), lateral ankle reconstruction with modified Broström procedure (4 cases), lateral closed-wedge calcaneal osteotomy (3 cases), percutaneous heel cord lengthening (19 cases), and gastrocnemius recession (1 case). In one patient with severe valgus deformity, staged total ankle arthroplasty was conducted after primary triple arthrodesis.

Preoperative and postoperative visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, range of motion (ROM), as well as patient’s satisfaction and willingness to receive the operation again were evaluated The results were compared among the three groups. Serial radiographs were reviewed for any radiological changes.

AOFAS score has improved from 54.3 ± 11.4 pre-operatively to 79.2 ± 11.4 at last follow-up. VAS has decreased from 6.8 ± 1.6 to 3.2 ± 1.6. Mean improvement in ROM was 15.6 ± 16.2 degrees. Forty-eight cases (873%) were satisfied with excellent or good results and 49 cases (89.1 %) were willing to receive the operation again. No significant differences in the postoperative VAS (p=0.14), AOFAS score (p=0.79), and ROM (p=0.06) were found among the three groups. Hetero-topic ossifications were observed in 12 cases (23.5%) and periosteal reactions proximal to medial malleolus occurred in four cases (7.8%).

Perioperative complications include one intraoperative medial malleolus fracture which was successfully managed with two cannulated-screws, and one medial malleolar stress fracture at six weeks after surgery which has healed spontaneously. One case with osteolysis around tibial screws was managed with bone graft. One case with deep fungal infection was converted to arthrodesis after infection control. Four ankles had to be revised including three cases of polyethylene bearing change due to dislocation, and one case of tibial component and bearing change due to loosening. The patient with revised tibial component was converted to arthrodesis due to recurred loosening. The Kaplan-Meier cumulative survival rate was 90.9% at 12 months and 87.8% at 49 months postoperatively.

The short term clinical results of HINTEGRA ankles showed favorable results. No significant differences were observed among different groups of coronal plane deformities when adequate additional surgeries were performed simultaneously. Long term follow-up study is required.