Ohannes A. Nercessian

Osteolysis after Charnley primary low-friction arthroplasty

We reviewed 249 consecutive Charnley primary low-friction arthroplasties in 191 patients performed by one surgeon using a transtrochanteric approach at a minimum follow-up of ten years. Of these, 37 hips in 32 patients showed osteolysis and were compared with 41 hips in 37 matched patients with no osteolysis. We assessed in each case the wear rate, stability of the prosthesis, acetabular angle, socket angle, thickness of the acetabular and femoral cement mantle, canal flare index, femoral score, stem alignment, implant:canal ratio and stem:canal ratio. We found that a high rate of wear, component instability and osteolysis were associated. Osteolysis was three times more common in men than in women. Factors which reduced osteolysis were cement mantles of 6 mm at the acetabulum and of 3 mm in all zones of the femur, a stem:canal ratio of 60% to 70% and an implant:canal ratio of over 99%. The overall incidence of osteolysis was 14.9% but when these technical criteria were met, the incidence was 5.2%. This suggests that careful technique can dramatically reduce the risk of this complication.

Postoperative Sciatic and Femoral Nerve Palsy With Reference to Leg Lengthening and Medializatiod Lateralization of the Hip Joint Following Total Hip Arthroplasty

The radiographs and prospective records of 1284 (1152 primary and 135 revisions) Charnley low friction arthroplasties performed by one surgeon were studied in reference to postoperative elongation of the limb and lateralization or medialization of the center of rotation of the hip joint and their effect on postoperative nerve palsy. Displacement of the center of the hip joint in relation to fixed points on the pelvis was measured. In primary low friction arthroplasties, leg lengthening ranged from 0.4 to 4 cm; in the revision group, they ranged from 0.04 to 5.8 cm. Sixty-six hips were lengthened more than 2 cm. The center of rotation of the hip was lateralized in 18.1% of cases and medialized in 61.9%. A single case of postoperative sciatic nerve palsy (the result of laceration of the sciatic nerve at surgery) was identified. These study results indicate that nerve injuries after total hip arthroplasty may be caused by local insult, and may not be related to elongation of the limb or postoperative alteration of the center of rotation of the hip.

Intrapelvic migration of total hip prostheses. Operative treatment.

We describe a safe operative approach for removal of a prosthesis that has migrated into the pelvis, and we recommend that a two-stage reconstruction be done when revising the total hip-replacement arthroplasty. The first stage consists of the removal of the femoral component and cement through a lateral transtrochanteric approach, followed by removal of the acetabular component through an abdominal-retroperitoneal approach to permit exposure of the major intrapelvic structures and to ascertain their relationship to the acetabular component and cement. After the acetabular component has been removed, bone grafts are applied to the pelvis. Postoperatively, the patient is placed in traction for a time and then is allowed to walk with non-weight-bearing. The second stage of reconstruction, consisting of hip replacement, is performed nine to twelve months after the first stage. A satisfactory result was obtained in the four patients for whom we followed this operative regimen. In one patient, the first-stage procedure yielded a satisfactory result and the second stage was not done.

Trochanteric osteotomy and wire fixation: a comparison of 2 techniques.

Between 1986 and 1989,190 patients (214 hips) with the diagnosis of osteoarthritis or posttraumatic arthritis underwent cemented Charnley total hip replacement surgeries via the biplane or single plane transtrochanteric approach. The technique of surgery was identical in every aspect except for the technique of the trochanteric osteotomy and reattachment. The results indicate that there was no significant difference in union rates between the 2 groups. Six (6.4%) patients in the biplane group and 7 (6.2%) patients in the single plane group had obvious evidence of nonunion at the 1-year evaluation. This study suggests no significant difference in union rate between a group of patients with biplane osteotomy and a closely paired group of patients with single plane osteotomy. Other equally important factors also may influence the rate of union of the trochanter in total hip arthroplasty.

Intraoperative pacemaker dysfunction caused by the use of electrocautery during a total hip arthroplasty

Pacemaker dysfunction encountered during orthopedic procedures is a rare but potentially life-threatening complication. With an increasing number of orthopedic procedures performed on the aging population, it is not uncommon to encounter patients with pacemakers requiring major orthopedic intervention. Most, if not all, major orthopedic procedures performed today require the use of electrocautery for hemostasis. In this article we review the literature for pacemaker complications and report a case of pacemaker failure after a single use of the unipolar electrocautery on a patient undergoing a total hip replacement.

Bilateral osteonecrosis of the femoral head associated with pregnancy: four new cases and a review of the literature.

Osteonecrosis is thought to result from the temporary or permanent loss of blood supply to the bones. Without proper nutrition, the bone tissue dies, is resorbed, and collapses. If the process involves the bones in a joint, it often leads to collapse of the joint surface. Four new cases of bilateral osteonecrosis of the femoral head occurring during pregnancy are described, with pathologic examination of core tissue biopsy substantiating the diagnoses. Operative and nonoperative management included anti-inflammatory medication, pulsating electromagnetic fields, core decompression, and total hip replacement. A review of the literature is undertaken to document the reported cases of osteonecrosis of the femoral head associated with pregnancy. Idiopathic osteoporosis of the femoral head is a condition that mimics osteonecrosis of the femoral head and can be a challenge in diagnosis during the latter stages of pregnancy. Bilateral osteonecrosis of the femoral head during pregnancy is rare. Patients may have other predisposing factors leading to femoral head necrosis. Transient osteoporosis of the femoral head during pregnancy can present with a clinical picture similar to osteonecrosis. Avascular necrosis of the femoral head should be considered in the differential diagnosis of pain about the hip developing during pregnancy or in the immediate postpartum period.

Comparison of complications after transtrochanteric and posterolateral approaches for primary total hip arthroplasty

For this study, 100 total hip arthroplasties (THAs) in a transtrochanteric approach group and 100 THAs in a posterolateral approach group were performed at one university hospital by a single, experienced surgeon. These THAs were then followed up for a minimum of 2 years to determine the incidence of postoperative complications. In our study, patients undergoing primary THA by the posterolateral approach were 18.4 times more likely to be complication free than patients in whom the transtrochanteric approach was used. This benefit, combined with a shortened surgical time, decreased blood loss, and technical ease, shows the advantages of the posterolateral approach for THA.

Neurologic Injury in the Upper Extremity After Total Hip Arthroplasty

The results of 7150 consecutive primary and revision total hip arthroplasties performed between 1976 and 1990 were reviewed retrospectively. Sixteen upper extremity neurologic palsies were identified in 16 patients. The incidence of upper extremity nerve palsies after total hip arthroplasty was 0.22%. There were five men and 11 women (average age, 59.5 years; range, 27–81 years). The neurologic injuries consisted of 10 ulnar nerve palsies, four brachial plexopathies, one axillary nerve palsy, and one median nerve palsy. Patients were evaluated with respect to age, gender, preoperative diagnosis, type of procedure (primary versus revision), and surgical approach. Preoperative diagnoses included: inflammatory arthritis (11), osteoarthritis (two), avascular necrosis (one), developmental dysplasia of the hip (one), and posttraumatic arthritis (one). Fourteen of 16 patients (88%) had complete recovery. Two patients (12%) had persistent symptoms despite operative intervention. The only significant predisposing factor to developing an upper extremity neurologic injury after total hip arthroplasty was the preoperative diagnosis of an inflammatory arthropathy. Upper extremity neurologic injuries after total hip arthroplasty are rare. Patients with the preoperative diagnosis of an inflammatory arthropathy are at greater risk for experiencing upper extremity neurologic injury. The prognosis is favorable, with 88% of patients having complete recovery. Cautious induction of anesthesia and careful attention to patient positioning in the perioperative, intraoperative, and postoperative period are essential to help minimize the incidence of neurologic injuries in the upper extremity after total hip arthroplasty.

Influence of demographic and technical variables on the incidence of osteolysis in Charnley primary low-friction hip arthroplasty.

The influence of demographic and technical variables on the incidence of osteolysis in Charnley primary low-friction arthroplasty was investigated. Demographic variables included age, gender, diagnosis, and Charnley joint class. Technical variables included the design of acetabular and femoral components, subchondral plate retention versus removal, and cementing techniques. We analyzed 633 hips (in 494 patients) implanted by a single surgeon between 1970 and 1984 using Kaplan-Meier survival graphs. Radiographically determined osteolysis was defined as the end point. The incidence of osteolysis at 5 years was 2% (confidence interval [CI] +/- 0.5%); at 10 years, 8% (CI +/- 1.6%); at 15 years, 15% (CI +/- 2.2%); and at 20 years, 17% (CI +/- 3.5%). Younger patients (age < 65 years) and men were both found to have a significantly increased incidence of osteolysis (P<.05). No significant association with osteolysis was found for the other demographic and technical variables investigated. Osteolysis predates loosening and failure of hip arthroplasty. Regular assessment with the goal of earlier identification, especially in higher risk younger and male patients, is important to avoid excessive bone loss and technical difficulties in revision surgery.