Cemented Total Hip Arthroplasty In Dogs

Total hip arthroplasty (THA) is an excellent salvage procedure for debilitating conditions that included osteoarthritis, hip luxation, femoral head and neck fracture and revision of femoral head ostectomy providing excellent hip joint function. Six dogs with clinical condition of hip dysplasia with luxation (three), severe osteoarthritis (two) and hip luxation (one) weighing 30 kg b.wt were subjected for THA. The animals were premedicated with glycopyrrolate @ 0.002 mg/kg body weight and 20 minutes later xylazine hydrochloride @ 1 mg/kg body weight i/m and anesthesia was induced with propofol @ 5 mg / kg b.wt i/v and maintained under isoflurane anaesthesia. The animals were preoxygenated 20 minutes prior to surgery with particular considering bone cement implantation syndrome. THA was performed through craniolateral approach of thigh. Indigenously designed stainless steel 316 L modular hip prosthesis to suit the canine femur of four different sizes viz. size5 -9, with the head sizes of +0 or +3 and the acetabular cup made of UHMWPE in the size ranged from 20 to 25 mm outer diameter with radio opaque wire for defining the lateral angle of the cup was used. The implants were selected based on the preoperative template measurement with the ventro-dorsal hip radiographs. PMMA bone cement was used for fixation of implants. Postoperative orthopaedic clinical and radiological assessment was made by numerical scoring system modeled on WOMAC scoring index. Radiographic assessment scores was performed as per Iwata et al.(2008) by standard hip extended radiograph, that included the mean score of canal fill was 1.17 ± 0.48, cement mental fill was 1.00±0.37, presence of radiolucent line in and around the acetabular component was 0.83 ± 0.48, cement porosity was 0.83 ± 0.54 and position of cup was 1.17 ± 0.31. On clinical assessment scores, the mean score of pain on palpation were 2.33 ± 0.56, early complication was 1.83±0.75 and late complication was 1.83± 0.70. The mean score of radiological and clinical assessment was 13.50± 4.67 out of 40 points. The out come of procedure was assessed excellent in three cases, good in one case and poor in two cases. The dogs exhibited signs of pain free limb movement, full range of motion of the limb with increase in thigh muscle mass with no limb shortening except in two cases where implant luxation was noticed for which the implant was removed and made to form pseudoarthrosis.