To observe the follow-up results of standard cemented bipolar hemiarthroplasty with double loop and tension band wiring technique for treatment of unstable intertrochanteric hip fractures in elderly patients with osteoporosis. From May 2000 to May 2006, 86 cemented bipolar hemiarthroplasties were performed in elderly patients who had unstable intertrochanteric fractures. The mean age at the time of surgery was 82 years old. The average follow-up period were 5.3 years. We evaluated post-operative results after operation by clinical and radiographic methods.Purpose
Materials and Methods
To perform comparative analysis between the results of internal fixation using proximal femoral nail system and bipolar hemiarthroplasty in pantrochanteric hip fracture in elderly patients. From January 2006 to February 2012, we reviewed 43 patients, who were treated surgically for pantrochanterichip fractures, with a minimum of 2 years follow up. The patient's age was older than 70 year old. The patients were divided into three groups and evaluated, retrospectively. The fracture reduction were regarded as satisfactory in S-OR-IF group(17 cases) and unsatisfactory in US-OR-IF group(9 cases) and the other group was treated with bipolar hemiarthroplasty (BHA group, 17 cases.)Purpose
Materials and Methods
Dual mobility components in total hip arthroplasty have been successfully in use in Europe for greater than 25 years. However, these implants have only recently obtained FDA approval and acceptance among North American arthroplasty surgeons. Both decreased dislocation rate and decreased wear rates have been proposed benefits of dual mobility components. These components have been used for primary total hip arthroplasty in patients at high risk for dislocation, total hip arthroplasty in the setting of femoral neck fracture, revision for hip instability, and revision for large metal-on-metal (MoM) hip articulation. The literature for the North American experience is lacking. We report indications, short term outcomes, and complications of a series of subjects who received dual mobility outcomes at one institution.Background:
Purpose:
There is strong current interest to provide reliable treatments for one- and two-compartment arthritis in the cruciate-ligament intact knee. An alternative to total knee arthroplasty is to resurface only the diseased compartments with discrete compartmental components. Placing multiple small implants into the knee presents a greater surgical challenge than total knee arthroplasty, and it is not certain natural knee mechanics can be maintained. The goal of this study was to compare functional kinematics in cruciate-intact knees with either medial unicondylar (mUKA), mUKA plus patellofemoral (mUKA+PF), or bi-unicondylar (biUNI) arthroplasty using discrete compartmental implants with preparation and placement assisted by haptic robotic technology. Nineteen patients with 21 knee arthroplasties consented to participate in an I.R.B. approved study of knee kinematics with a cruciate-retaining multicompartmental knee arthroplasty system. All subjects presented with knee OA, intact cruciate ligaments, and coronal deformity ranging from 7° varus to 4° valgus. All subjects received multicompartmental knee arthroplasty using haptic robotic-assisted bone preparation an average of 13 months (6–29 months) before the study. Eleven subjects received mUKA, five subjects received mUKA+PF, and five subjects received biUKA. Subjects averaged 62 years of age and had an average body mass index of 31. Combined Knee Society Pain/Function scores averaged 102 ± 28 preoperatively and 169 ± 26 at the time of study. Knee range of motion averaged −3° to 120° preoperatively and −1° to 129° at the time of the study. Knee motions were recorded using video-fluoroscopy while subjects performed step-up/down, kneeling and lunging activities. The three-dimensional position and orientation of the implant components were determined using model-image registration techniques (Fig. 1). The AP locations of the medial and lateral condyles were determined by computing a distance map between the femoral condyles and the tibial articular surfaces.INTRODUCTION
METHODS
Revision surgery for failed metal-on-metal (MOM) total hip arthroplasty (THA) or hip resurfacing (HR) has been a challenge. Previous studies have reported high failure and complication rates, including dislocation, infection, aseptic loosening and lower patient satisfaction. Options for revision depend on the integrity and stability of the femoral and acetabular components. When both components fail, full revision is required; however, when the acetabular component remains well fixed and oriented, only the isolated femoral component revision can be performed. Dual mobility components can be utilized to match the size to the inner diameter of the metal cup. With the dual mobility implant, the morbidity and complications associated with cup revision are avoided while maintaining a natural femoral head size and potentially increasing range of motion and stability postoperatively compared to standard THA. The aim of this study was to evaluate short- to mid-term results of revision THA after failed metal-on-metal THA or HR using the dual mobility device.Background
Purpose
There is great contemporary interest to provide treatments for knees with medial or medial plus patellofemoral arthritis that allow retention of the cruciate ligaments and the natural lateral compartment. Options for bicompartmental arthroplasty include custom implants, discrete compartmental implants and monoblock off-the-shelf implants. Each approach has potential benefits. The monoblock approach has the potential to provide a cost-efficient off-the-shelf solution with relatively simple surgical instrumentation and procedure. The purpose of this study was to determine if monoblock bicompartmental knee arthroplasty shows evidence of retained cruciate ligament function and clinical performance more similar to unicompartmental arthroplasty than total knee arthroplasty. Nine females and one male patient were enrolled in this IRB approved study. Each subject received unilateral bicompartmental knee arthroplasty an average of 2.6 years (2.0 to 3.6 years) prior to this study. Subjects averaged 65 years (58–72 years) and 28 BMI (25–31) at the time of surgery. Mean outcome scores at the time of study were 97/95 for the Knee Society knee/function score, 16.4 Oxford score, 6.5 UCLA Activity score and 137 degrees range of motion. Subjects were observed using dynamic fluoroscopy during lunge, kneeling and step-up/down activities. Subjects also received CT scans of the knee in order to create bone/implant composite shape models. Model-image registration techniques were used to determine 3D knee kinematics (Figure 1). Knee angles were quantified using a flexion-abduction-rotation Cardan sequence and condylar translations were determined from the lowest point on the condyle with respect to the transverse plane of the tibial segment. Maximum knee flexion during lunge and kneeling activities averaged 112°±8° and 125°±7°, respectively. Tibial internal rotation averaged 10°±6° and 12°±10° for the lunge and kneeling activities. For both deeply flexed postures, the medial condyle was 1 mm anterior to the AP center of the tibia while the lateral condyle was 11 mm and 13 mm posterior to the tibial center. For the step-up/down activity, tibial internal rotation increased an average of 2° from 5° to 75° flexion, but was quite variable (Figure 2). Medial condylar translations averaged 4 mm posterior from 5° to 25° flexion, followed by 6 mm anterior translation from 25° to 80° flexion (Figure 3). All knees showed posterior condylar translation from extension to early flexion. An important potential benefit to any bicompartmental arthroplasty treatments is retention of the cruciate ligaments and maintenance of more natural knee function. The knees in this study showed excellent or good clinical outcomes and functional scores, and relatively activity high levels. There was no evidence of so-called paradoxical anterior femoral translation during early flexion, indicating retained integrity of the natural AP stabilizing structures. Weight-bearing deep flexion during lunge and kneeling activities was comparable to previously reported unicompartmental and well-performing total knee arthroplasty subjects. Kinematics were quite variable between subjects. Monoblock bicompartmental arthroplasty appears to permit functional retention of the cruciate ligaments, consistent with functionally stable knees. Further efforts should focus on the specific surgical placement of off-the-shelf bicompartmental implants to optimize knee function and provide consistent knee mechanics.
Unicompartmental knee arthroplasty (UKA) can achieve excellent clinical and functional results for patients suffering from single compartment osteoarthritis. However, UKA is considered to be more technically challenging to perform, and malalignment of the implant components has been shown to significantly contribute to UKA failures. The purpose of this investigation was to determine the clinically realized accuracy of UKA component placement using surgical navigation and dynamically referenced tactile-robotics. Pre-op CT, post-op CT, and surgical plan were available for 22 knees out of the first 45 procedures performed using a new tactile-guided robotic system. 3D component placement accuracy was assessed by comparing the pre-operative plan with the post-operative implant placement (desired versus actual). Bone and implant models were obtained from postoperative CT scans taken immediately following the surgery. A 3D to 3D iterative closest point registration procedure was performed and the measured implant position was directly compared to the preoperative plan. Errors were assessed as single axis root-mean-square (RMS) entities.INTRODUCTION
METHODS
Ten patients, who were unsuitable for limb lengthening over an intramedullary nail, underwent lengthening with a submuscular locking plate. Their mean age at operation was 18.5 years (11 to 40). After fixing a locking plate submuscularly on the proximal segment, an external fixator was applied to lengthen the bone after corticotomy. Lengthening was at 1 mm/day and on reaching the target length, three or four screws were placed in the plate in the distal segment and the external fixator was removed. All patients achieved the pre-operative target length at a mean of 4.0 cm (3.2 to 5.5). The mean duration of external fixation was 61.6 days (45 to 113) and the mean external fixation index was 15.1 days/cm (13.2 to 20.5), which was less than one-third of the mean healing index (48 days/cm (41.3 to 55). There were only minor complications. Lengthening with a submuscular locking plate can successfully permit early removal of the fixator with fewer complications and is a useful alternative in children or when nailing is difficult.
