Clinical Observation Of Rotating-platform Prosthesis For Valgus Knee Deformity

OBJECTIVE: To investigate the efficacy of rotary platform prosthesis in total knee arthroplasty in patients with valgus knee deformity.METHODS: A retrospective analysis was made on the clinical date and follow up of 25 cases(28 knees) of valgus deformity undergoing primary total knee arthroplasty(TKA) by using Gemini MK II(Link, Germany) rotary platform prosthesis in the department of orthopaedics in First Affiliated Hospital of Soochow University. There were 6 males(7 knees) and 19 females(21 knees), at the age from 47 to 82 years, with an average age of 65.4±8.6 years. There were 22 unilateral cases and 3 bilateral cases.Etiology:20 cases(22 knees) of osteoarthritis,4 cases(5 knees) of rheumatoid arthritis,1 case(1 knee) of traumatic arthritis.The disease course was 2~22 years,10.4 years on average.We conducted moderate soft tissue release and precise measuring osteotomy to recover lower limb alignment and balance the gap of flexion and extention,after that,placed the prosthesis accurately. Clinical evaluation of Arthroplasty has been made by referring to the Feller patella scoring systems and knee joints of American hospital for special surgery(HSS).The differences in HSS, femoral tibial angle, maximun flexion and extension angle、range of motion and Feller score were compared and analyzed before and after replacement.RESULTS:The 25 patients(28 knees) were followed up from 12 to 60 months,25.4 months on average. All incisions were well-healed by first intension. No complications such as infection, cutaneous necrosis and pulmonary embolism. NO patellar and prosthetic loosening or infection was observed according to X-ray. 1 medial instability cured after 6 months follow-up by using articular branches and isometric contraction of quadriceps.2 palsies of nervus peroneus communis recovering after 3 months by using neurotrophic medicine and functional rehabilitation exercise.Compared with preoperation,the HSS(hospital for special surgery knee score), femoral tibial angle, maximun flexion and extension angle、range of motion and Feller score, all changes were significantly different(P < 0.01) during final follow-up.CONCLUSION: These results indicated that the rotating-platform prosthesis for valgus deformity were satisfactory,but the operation is complicated,the recoverment of lower limb alignment and the balancement of flexion and extension gap is the key to the surgery,.