Current pelvic plane software is not accurate and do not address normal acetabular center axis that has minimum impingement and maximum stability relation with femur in navigated THA A retrospective study of 137 consecutive THA, comparing ACA and APP registration data with postoperative pelvic CT, independently measuring acetabular and cup inclination and version. APP registration points were anterior superior iliac spines and symphysis pubis. Computer identifies preoperative ACA as ‘zero’ after averaging superior, anterior and posterior rim points of registration of acetabulum. Reaming and cup orientation is kept within 4 mm of ACA or within 5 degrees of inclination and anteversion of APP software to avoid impingement.Introduction:
Methods:
Purpose of mini-invasive hip arthroplasty, is least damage to skin and muscles. Unlike Roettinger modification to Watson-Jones, our approach requires no special table or instruments. Besides, direction of skin incision is perpendicular to interval between glutei and tensor muscles, thus called a Crisscross Approach. Incision is at direction of retractors causing less skin damage; and parallel to femur allowing expansion. No tendon or muscles are severed achieving a true inter-muscular non invasive approach. Unlike anterior approach, femoral circumflex vessels and lateral femoral cutaneous nerve are spared. 240 prospective patients underwent mini-invasive crisscross technique since December 2006. A standard non-cemented hip was implanted. Previously disrupted hip muscles patients were excluded. In the operating room, patients were secured in a lateral decubitus position with the pelvis flexed at 20°–30° to allow operated leg to extend beyond the table to be placed in a standard plastic bag. The anterior superior iliac spine (ASIS), the greater trochanter (GT) and its tubercle are identified and marked. A line is drawn between ASIS and GT tubercle representing the interval between the glutei and the tensor fascia lata muscles. Another line representing the skin incision is drawn perpendicular. It may be curved a little toward the femur starting two inches inferior and posterior to ipsilateral ASIS extending distally for 3 inches or more for obese or muscular patients. The Crisscross Approach starts with a skin incision being made as above and through the subcutaneous fat identifying the inter-muscular interval between the glutei and the tensor fascia lata. Sharp dissection is made in the connecting fascia only and blunt dissection is needed to separate the two muscles. A branch of the superior gluteal nerve proximally crossing from the glutei to the tensor fascia lata may be encountered but it should not be disturbed as long as blunt dissection is maintained. Curved retractors are placed one above and the other below the femoral neck exposing the anterior capsule. Incision is made in the capsule and the retractors are re-placed to better expose the femoral neck. The appropriate level of neck is osteotomized and the head is extracted as routine. Acetabulum is further exposed by placing the curved retractors at about mid anterior and mid posterior. The final appropriate cup size and orientation is implanted routinely. Before exposing the femoral canal the deep fascia at the junction of the glutei and the vastus lateralis should be incised (about 2–3 inches). This will tremendously help femoral canal exposure. Then the surgeon is positioned anterior, the patient is made fully paralyzed and the table is tilted 20°–30° posteriorly (away from the surgeon). Hip extended 20°–30°, externally rotated to 80°–90° and adducted with a retractor underneath femoral neck and a curved one on greater trochanter to protect the glutei. Leg is allowed to drop in a bag (posteriorly). Canal finder is helpful to avoid going through the cortex Broaching or reaming and final implant insertion as routine. Posterior capsule need not be disturbed; however, the superior and inferior capsule should be detached from the neck to allow better exposure of the femoral canal. Closure starts with one or two stitches in the remainder of the capsule. Then suture deep fascia at the junction of glutei and vastus lateralis with absorbable suture. Finally, subcutaneous fat and skin are closed as routine.Introduction:
Material and Methods:
The prevalence of reversing of extension coronal deformity during flexion and how that may change the routine algorithm of soft tissue balancing in total knee arthroplasty (TKA) has not been published. We name this phenomenon, the reversing coronal deformity (RCD). We observed 12% (45 patients) of coronal deformities consistently reverse in flexion in the osteoarthritic knees before surgery. We conclude that RCD phenomena need to be addressed in every TKA and collateral ligament release need to be modified or avoided; otherwise postoperative flexion instability may be inevitable. Femoral rotation adjustment with posterior capsule release has to be attempted first in RCD patients. We define RCD as the reversing of a coronal extension deformity of more than 2° while the knee reaches 90°of flexion. That is to say a 2° or more varus knee in extension becomes a 2° or more valgus at 90° of flexion or vice versa. We retrospectively analyzed, in a multicenter study the alignment patterns of 387 (US = 270, UK = 117) consecutive computer navigated TKA subjects (June 2004–May 2008). 364/387 (US = 252, UK = 112) subjects were eligible for analysis (23 subjects had incomplete data: US = 18, UK = 5). The coronal deformity kinematics was observed during the range of motion and the range of medial /lateral deflections were analyzed.Introduction
Method
As much as there is interest in mini-invasive surgery (MIS) total hip arthroplasty (THA), there is controversy ranging from a more advantageous to a potentially dangerous alternative to classic THA. The purpose of this study is to compare the results of 130 cementless, standard stem navigated primary THA with data collected retrospectively from 2005 to 2010 (64 classic Hardinge approach (HAL) and 66 MIS intermuscular anterolateral approach by the senior surgeon). Data include: operative time, perioperative bleeding, length of surgery, hospital stay, patient's satisfaction and pain perception. The alignment values at six months to a maximum of 60 months provided necessary statistical information for clinical and radiological comparison of the two groups. Significant differences were found between the two groups with MIS being superior with respect to less surgical time (p = 0.029) and achieving quicker rehab goals with shorter hospital stay (p <0.001). Pain perception was less in MIS group with a higher satisfaction score (p <0.001). Although both groups have the potential of nerve injury to tensor fascia muscle, it's only the classic HAL that jeopardises the glutei nerve supply. MIS approach to navigated THA seems to be an acceptable alternative with some advantages to Classic HAL.
