Rida A. Kassim

Functional Outcome After Revision Hip Arthroplasty: A Metaanalysis

The current study systematically reviews the literature describing patient outcomes after revision total hip arthroplasties using conventional global hip score ratings. Two thousand one hundred thirty-seven English-language articles published from 1966 through 2000 were identified through a computerized literature search and bibliography review. A three-step filter process was used to identify articles to be included in the metaanalysis. Forty-two articles with 2578 patients had data abstracted for the analysis. Metaanalysis of global hip scores was done using a fixed effects model with the assumption that the variances of each measurement were identical across studies. Thirty-nine articles reporting on 46 cohorts progressed through three filters and went to data extraction and analysis. Revision total hip arthroplasty is a reasonably safe and effective procedure for failed hip replacement Based on this exploratory analysis revision hip procedures seem to have comparable longevity, to primary hip replacement but appear to have slightly lower functional outcome (as measured by global hip scores), and slightly higher morbidity and mortality rates than primary procedures. Inconsistent reporting in the original studies limited exploration of other factors that may have affected outcomes.

Total Knee Arthroplasty After Varus Osteotomy of the Distal Part of the Femur

Background: There is little information in the literature regarding the outcome of total knee arthroplasty following distal femoral varus osteotomy. The purpose of the present study was to evaluate the intermediate-term results of total knee arthroplasty following distal femoral varus osteotomy.Methods: The study group consisted of nine consecutive patients (eleven knees) who had had a total knee arthroplasty following varus osteotomy of the distal part of the femur. The average age of the patients was forty-four years (range, fifteen to seventy years) at the time of the arthroplasty. The results were evaluated with use of the Knee Society score preoperatively and after a mean duration of follow-up of 5.1 years. Radiographs made preoperatively and at the time of follow-up were evaluated for alignment in the coronal plane.Results: The mean Knee Society knee score was 35 points before the arthroplasty and 84 points after the arthroplasty. The mean Knee Society function score was 49 points before the arthroplasty and 68 points after the arthroplasty. The mean interval between the femoral osteotomy and the total knee replacement was fourteen years (range, two to thirty-two years). A constrained prosthesis was required in five of the eleven knees. Two knees had an excellent result, five had a good result, and four had a fair result. The mean arc of motion improved from 81.8° to 105.9°. The mean radiographic alignment was 3.6° of valgus (range, 7° of varus to 18° of valgus) before the arthroplasty and 3.3° of valgus (range, 1° of valgus to 6° of valgus) at the time of the latest follow-up. There were no infections or wound complications.Conclusion: Total knee arthroplasty following distal femoral varus osteotomy decreases pain and improves knee function, but the procedure is technically demanding and is associated with inferior results when compared with those of primary arthroplasty performed in a patient without a prior femoral osteotomy. In the present series, the use of an intramedullary femoral alignment guide increased the tendency to place the femoral component in relative varus angulation (that is, in <5° of valgus). We recommend checking the alignment of the femoral component with an extramedullary guide in knees that have had a previous distal femoral varus osteotomy.Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

The Patella in Revision Total Knee Arthroplasty

The prevalence of patellofemoral complications following resurfacing in total knee arthroplasty has been reported to range from 4% to 41%1,2. Complications related to the patellofemoral articulation are the cause of up to 45% of all total knee arthroplasty revisions3 and 41% of re-revisions. Boyd et al.1 showed an increased reoperation rate in patients in whom the patella was not resurfaced. This article will discuss the diagnosis and treatment of problems that occur at the patellofemoral articulation as well as issues related to the management of the patellofemoral joint and extensor mechanism during revision total knee arthroplasty, including evaluation of component fixation, assessment of compatibility of preexisting well-fixed components with revision implants, and management of patellar bone loss. The extensor mechanism is composed of the quadriceps muscle and tendon, the patella, the patellar tendon, and their insertions into the tibial tuberosity. The patella functions in this mechanism as a pulley, altering the direction of quadriceps force and increasing the lever arm of the quadriceps in its role of extending the knee, thus resulting in a decrease in (tibiofemoral) reactive forces. The patella and the extensor mechanism also function as secondary restraints to anteroposterior translation of the tibiofemoral joint. The trochlea of the femur serves as a constraining articulation that maintains the position of the patella anterior to the femur. Maintenance of this position allows for maximum mechanical advantage of the entire muscle-tendon-bone unit. Failure of this construct at any point along its length leads to either complete inability to extend the knee joint or to substantial weakness. During the past two decades, there have been improvements in the design of patellar and femoral components and a better understanding of the surgical techniques needed to ensure proper function of the patellofemoral articulation and the extensor mechanism. …

Complications after revision total knee arthroplasty.

Despite the large number of revision total knee arthroplasties performed over the last twenty-five years, few data exist regarding overall complication rates after this procedure. As epidemiologic techniques (i.e., meta-analysis) are applied to the existing literature base and as orthopaedic prospective study design improves, a clearer picture of the incidence, prevalence, and risk of complications after revision total knee arthroplasty will be gained. The focus of this paper is to review the current knowledge regarding selected complications of revision total knee arthroplasty: neurovascular injury, vascular injury, and venous thromboembolic disease. Among the complications involving the neurovascular structures about the knee during primary and revision total knee arthroplasty1-6, the most commonly reported injury involves the peroneal nerve. At the knee, this nerve is located 34 to 36 mm posterolateral to the tibial plateau and runs over the posterior border of the lateral biceps femoris tendon in an inferolateral direction over the fibular neck3. While direct injury to the nerve is rare, traction, compression, and ischemia are the most likely mechanisms of injury2. Reported rates of peroneal neurapraxia have ranged from 0.002% to 1.8% in the Swedish Registry7. Mont et al.8 reported a 0.58% prevalence of peroneal nerve palsy after primary total knee arthroplasty. As far as we know, no reports in the recent literature have specifically addressed the prevalence of neurologic injury after revision total knee arthroplasty. The risk factors and mechanisms of injury to the neural structures are similar for primary and revision total knee arthroplasty. These risk factors include valgus deformity of >20°, flexion contracture of >20°2, previous lumbar laminectomy, and epidural analgesia6. Rose et al.2 noted that loss of motor function of the tibialis anterior and extensor hallucis longus is the key …

Pubic ramus insufficiency fractures following total hip arthroplasty. A report of six cases.

Stress fractures are not uncommon in active individuals in their twenties and thirties, particularly athletes, runners, and military recruits 1. They represent fatigue fractures in which abnormal muscular stresses are applied to normal bone in a repetitive fashion, leading to increased forces on the bones. Insufficiency fractures, on the other hand, occur in patients who have underlying bone disease, resulting in fractures during activities of daily life. Acute or subacute pain in the hip within the first few years following total hip arthroplasty is unusual when the replacement components are secure radiographically. The differential diagnosis includes subacute infection and periarticular bursitis or tendinitis. Pubic ramus insufficiency fractures also can be a cause of these symptoms and should be considered as part of the differential diagnosis. Isolated cases of pubic ramus insufficiency fracture have been reported following total hip arthroplasty with cement ( Table I ) 2-7. We present the cases of six patients with a pubic ramus insufficiency fracture following total hip arthroplasty in which a cementless acetabular component had been used. Our patients were notified that data concerning their cases would be submitted for publication. View this table: TABLE I: Cases of Pubic Ramus Stress Fractures Following Total Hip Arthroplasty Case 1. A sixty-one-year-old woman with a medical history of hypertension, hypothyroidism, osteoporosis, and depression presented to our orthopaedic clinic with severe low-back pain that started after she got up from bed. The work-up revealed a sacral stress fracture, which was treated conservatively. One year later, she had another episode of localized low-back pain, and magnetic resonance imaging revealed a fracture of the fourth lumbar vertebra. Four years after the initial evaluation, she sustained a fall that resulted in a femoral neck fracture, which was treated by open reduction and internal fixation. The following year, osteonecrosis of the left femoral …

Varus Distal Femoral Osteotomy

The young patient with knee osteoarthritis (OA) presents a challenging treatment dilemma to the orthopedic surgeon. In the varus knee, delay of OA progression has been successfully performed with proximal tibial osteotomy; in the valgus knee, however, varus distal femoral osteotomy (VDFO) has usually had better results. VDFO is indicated in the physiologically young, active patient in whom conservative therapy for symptomatic lateral compartment arthritis in a stable knee without significant flexion deformity has failed. Meticulous preoperative planning is crucial and entails obtaining long-leg standing radiographs to determine the mechanical and anatomic axes. The medial closing wedge technique is the most common method of performing VDFO, although the lateral opening, dome osteotomy, and hemicallotasis techniques have all had their proponents. Proper pin placement is necessary to correctly make the osteotomy and to obtain the desired correction of deformity. The osteotomy is then stabilized with internal fixation, usually a 90° blade plate. Postoperative weight-bearing is generally delayed for 6–8 weeks. Complications can include nonunion, failure of fixation, infection, loss of correction, and acceleration of medial compartment arthritis. With proper selection and careful attention to detail, VDFO can be successful in delaying the need for total knee arthroplasty (TKA), and it has been associated with 71%–83% good/excellent Hospital for Special Surgery scores at 4–8-year follow-up.

Exposure in revision total knee arthroplasty

Several techniques are available for the often difficult problem of surgical exposure in revision total knee arthroplasty. They include soft tissue and bony methods. This article presents an up-to-date review of these various procedures, with an emphasis on technique and outcomes.