The porous-coated anatomic total hip prosthesis, inserted without cement. A prospective study with a minimum of ten years of follow-up.

One hundred consecutive primary total hip arthroplasties performed with use of a porous-coated anatomic total hip prosthesis, fixed without cement, in ninety-one patients were followed prospectively for a minimum of ten years. At the time of the most recent follow-up, twenty patients (twenty-three hips) had died and seventy-one patients (seventy-seven hips) were living. The average age of the living patients was sixty-six years (range, thirty-two to ninety-two years), and their average Harris hip score was 84 points (range, 33 to 100 points). Twelve percent (nine) of the seventy-seven hips were found to be associated with pain in the thigh when the patients were specifically questioned by the examiner. Eleven hips were revised during the follow-up period. Only the acetabular component was revised in six hips, only the femoral component was revised in one hip, and both the femoral and the acetabular components were revised in four hips. Of the ten acetabular revisions, one was performed because of acute dissociation of the component and eight, because of a combination of polyethylene wear, osteolysis, and loosening; the tenth acetabular revision consisted of exchange of the liner and curettage and bone-grafting of the osteolytic area. Of the five femoral revisions, two were performed because of loosening and three, because of extensive osteolysis of the proximal aspect of the femur. Including the revised components, twelve acetabular components and five femoral components had radiographic evidence of aseptic loosening. Acetabular osteolysis occurred in seventeen hips. Femoral osteolysis occurred in thirty-nine hips: in the proximal aspect of thirty-one hips, in the distal aspect of four, and in both the proximal and the distal aspect of four. The durability of the femoral fixation documented in this study is especially encouraging in view of the fact that this was our initial experience with devices fixed without cement and that a so-called first-generation femoral component was used. However, the study also demonstrated that not all acetabular components fixed without cement function well over the long term and that specific design considerations (adequate initial fixation, congruency between the liner and the shell, an optimum shell-liner capturing mechanism, and a smaller femoral head) are warranted.

Effect of intraoperative blood loss on the serum level of cefazolin in patients managed with total hip arthroplasty. A prospective, controlled study.

The effect of intraoperative blood loss on serum levels of cefazolin in patients being managed with total hip arthroplasty was studied. Eighteen patients, thirteen men and five women, with a mean age of sixty-five years (range, forty to eighty-five years) were enrolled in the study. Fifteen had a primary total hip arthroplasty and three, a revision. Each patient served as his or her own control. Baseline clearance of cefazolin was determined at a minimum of forty-eight hours before the operation. Each patient received one gram of cefazolin intravenously. Serial serum concentrations were determined from specimens drawn at zero, five, ten, twenty, thirty, sixty, 120, 240, and 300 minutes after administration. Fifteen minutes before the skin incision was made, each patient again received one gram of cefazolin intravenously. Serum samples were collected at the same time-intervals, and the serum levels of cefazolin were determined with use of capillary electrophoresis. Data regarding intraoperative blood loss as well as replacement of fluid and blood were recorded. The administration of the antibiotic, retrieval of the serum samples, and estimation of the blood loss were performed by the same person in the same manner for all patients. The preoperative and intraoperative creatinine clearances (mean and standard deviation), estimated with use of the formula of Cockcroft and Gault, were 62.06 +/- 21.28 and 74.02 +/- 24.75 milliliters per minute, respectively. The amount of intraoperative blood loss averaged 1137 +/- 436 milliliters (range, 675 to 2437 milliliters). The preoperative and intraoperative cefazolin clearances averaged 0.49 +/- 0.21 and 0.52 +/- 0.30 milliliter per minute per kilogram, respectively. During joint replacement, the commonly accepted interval between doses of cefazolin is four hours. In the present study, the serum level of cefazolin at four hours was forty-five micrograms per milliliter. This corresponds to an osseous concentration that well exceeds the minimum inhibitory concentration for Staphylococcus aureus, which is 0.5 microgram per milliliter. This study suggests that, with blood losses of less [corrected] than 2000 milliliters, it is not necessary to administer cefazolin at intraoperative intervals of less than four hours in order to maintain a concentration of antibiotics that is higher than the minimum inhibitory concentration for the most common infecting organisms.

Osteolysis around an uncemented cobalt chrome total hip arthroplasty.

One hundred consecutive uncemented Porous Coated Anatomic total hip arthroplasties performed in 91 patients who obtained prospective serial clinical and radiographic evaluation during a minimum 7-year followup period were studied for the occurrence, extent, and progression of localized periprosthetic bone loss (osteolysis). Periprosthetic bone loss occurred around the femoral component in 11 hips, the acetabular component in 2 hips, and both components in 2 hips during the followup interval. The bone loss was progressive in 6 hips (2 of 11 femoral cases, 2 of 2 acetabular cases, and 2 of 2 both component cases). It frequently occurred around components that showed no evidence of acetabular migration or femoral subsidence (11 of 15 cases). The average age at surgery of patients in the bone loss group was 10 years younger than the nonbone loss group (in the 100 hip cohort). Clinically, most patients with bone loss were asymptomatic, with the average Harris hip rating of 92.4 points (range, 85-99 points). With this particular device at this interval of followup (7 years), the acetabular and the proximal femoral osteolytic lesions are of greatest concern. Wear of the acetabular component was greater for cases with osteolysis than for those without osteolysis, but the difference was not significant.

The tibiofibular syndesmosis. Evaluation of the ligamentous structures, methods of fixation, and radiographic assessment.

Twenty-five fresh-frozen cadaveric specimens were used to evaluate the role of the syndesmotic ligaments when the ankle is loaded with external rotation torque. An apparatus was constructed that allowed pure external-rotation torque to be applied through the ankle with the foot in neutral flexion. The apparatus provided solid fixation of the tibia while allowing free movement of the fibula in all planes. The syndesmotic ligaments were incrementally sectioned, and direct measurements of anatomical diastasis were made. Mortise and lateral radiographs were made at each increment under both loaded (5.0 newton-meters) and unloaded conditions. After all structures of the syndesmosis had been divided, the syndesmosis was reduced and was repaired with one or two screws. The strength of the repair was measured with incremental increases in torque of 1.0 newton-meter. The radiographs were measured by three independent observers in a blind fashion. In order to evaluate intraobserver error, each observer was randomly given forty radiographs to reinterpret. Diastasis and rotation were found to be related to the amount of injury of the ligament (p < 0.0001). After the entire syndesmosis had been divided, application of a 5.0-newton-meter torque resulted in a mean diastasis of 7.3 millimeters. The subsequent repair of the anterior tibiofibular ligament with suture failed at a mean of 2.0 newton-meters (range, 1.0 to 6.0 newton-meters) of torque. Repair with two screws was found to be stronger than repair with one, with the first construct failing at a mean of 11.0 newton-meters (range, 5.0 to 15.0 newton-meters) and the second, at a mean of 6.2 newton-meters (range, 2.0 to 10.0 newton-meters) (p = 0.0005). Failure of the screw fixation was not associated with the maximum previous diastasis (p = 0.13). Measurements of anatomical diastasis were compared with measurements made on the mortise and lateral radiographs. Measurements on the stress mortise radiographs had a weak correlation with diastasis (r = 0.41, p < 0.0001). However, measurements on the stress lateral radiographs had a higher correlation (r = 0.81, p < 0.0001). Additionally, interobserver correlation was significantly higher for the measurements on the lateral radiographs (r = 0.87, p < 0.0001) than for those on the mortise radiographs (r = 0.56, p < 0.0001). Intraobserver correlation for the three observers was poor with regard to the measurements on the mortise radiographs (r = 0.12, 0.42, and 0.25). The respective correlations for the measurements on the lateral radiographs were r = 0.81, 0.90, and 0.89.(ABSTRACT TRUNCATED AT 400 WORDS)

The porous-coated anatomic total hip prosthesis, inserted without cement. Results after five to seven years in a prospective study.

The results of 100 primary arthroplasties with a porous-coated anatomic total hip prosthesis that were performed consecutively in ninety-one patients were followed prospectively for five to seven years after the operation or until death. Clinical Harris hip ratings and anteroposterior and lateral radiographs were made preoperatively, several times in the first postoperative year, and at annual intervals thereafter. Average sequential hip ratings were maintained between 92 and 93 points during the follow-up interval. Pain in the thigh, which did not limit function, was recorded at the yearly examinations from the first to the fifth year. After one year, 18 per cent of the thighs were painful, and in succeeding years, 19 per cent, 23 per cent, 26 per cent, and 15 per cent were painful. Radiographs demonstrated that the fixation of the femoral component was by ingrowth of bone in 94 per cent of the hips, by stable fibrous fixation in 1 per cent, and by unstable fibrous fixation in 5 per cent, according to the criteria of Engh et al. By five years, 6 per cent of the acetabular components had migrated, and 5 per cent of the femoral components had subsided. Two acetabular components had been revised, and one revision of a femoral component was pending. The evaluated device was an early-generation prosthesis that was designed for insertion without the use of cement. Further study is necessary to determine the long-term durability of the prosthesis-bone interface.

Evaluation of the learning curve associated with uncemented primary porous-coated anatomic total hip arthroplasty.

The results of the first and second groups of 50 consecutive primary, uncemented porous-coated anatomic arthroplasties were analyzed to evaluate the learning curve associated with the procedure. Femoral fit, acetabular cup angle, femoral fracture rate, minimum two-year clinical hip ratings, and clinical symptoms were compared between the two groups. Significant improvement in achieving better femoral canal filling with the prosthesis and lower acetabular cup angle placements was documented in the second 50 cases. Although a definite learning curve in mastering the technique of uncemented total hip arthroplasty was observed, thigh pain rate and clinical ratings were not improved after two years.

Quadriceps contusions. West Point update.

A 3 year study of 117 quadriceps contusions in West Point cadets was undertaken to document the effectiveness of a three-phased therapy program to return these young athletes to full activity with a normal knee range of motion and without recurrence of injury. The treatment protocol of this study was modeled after the 1973 West Point study of Jackson and Feagin with two major changes: 1) resting the injured leg in flexion (versus extension) and 2) emphasizing early flexion exercises (versus extension). Classification of contusions was based on knee range of motion at 12 to 24 hours after the injury (mild, greater than 90 degrees; moderate, 45 degrees to 90 degrees; severe, less than 45 degrees). The average disability time was 13 days for mild, 19 days for moderate, and 21 days for severe contusions. Myositis ossificans developed in 9% of cadets and was associated with five risk factors (knee motion less than 120 degrees, injury occurring during football, previous quadriceps injury, delay in treatment greater than 3 days, and ipsilateral knee effusion.

Assessing the results of hip replacement. A comparison of five different rating systems.

One hundred hips in patients who had had primary uncemented replacements were followed up for one or two years, and assessed by five different methods. All produced different results. The Hospital for Special Surgery rating produced the most optimistic assessment and the Merle d'Aubigné rating the most pessimistic. The functional class of the patients, as defined by Charnley in 1979, significantly affected the ratings, and these should clearly be included in all rating systems. Moreover, if systems are to be compared, they should all use descriptive words, such as limp or pain, in precisely the same way.

Syndesmosis sprains of the ankle.

A retrospective review of the clinical records and radiographs of 1344 ankle sprains occurring over a 41-month period at the United States Military Academy was performed. The incidence and severity of these sprains did not differ significantly from other studies with the exception of those injuries involving the tibiofibular ligaments. Those patients sustaining incomplete injuries to the ankle syndesmosis had a recovery time of almost twice that of those patients with severe (3rd degree) ankle sprains (55 vs. 28 days). Eight of 13 patients with 10 of 15 incomplete syndesmosis injuries were available for follow-up examination and radiographs at an average time of 20 months postinjury (range of 7-39 months). All patients with this injury had a positive "squeeze test" (compression of the fibula to the tibia at mid-calf) at the time of initial examination. Nine of 10 patients developed ossification of the syndesmosis in follow-up radiographs. None of these patients had developed chronic ankle instability, loss of motion, or arthritic changes of the joint at the time of final followup.

Office management of the acute ankle sprain.

Ankle injuries occur frequently in an athletic population. Understanding the anatomy, biomechanics, pathomechanics, differential diagnosis, and special pediatric considerations allows an accurate diagnosis. Treatment with a nonoperative aggressive goal-oriented therapy program has been successful at the United States Military Academy.

Chondral fractures of the knee. Cause for confusion.

Knee pain in the athlete can pose difficulty in diagnosis. At the United States Military Academy at West Point we have had occasion to see a group of patients presenting with meniscal symptoms of locking, catching, giving way, and joint line tenderness who, on arthroscopic examination, have chondral fractures of the medial or lateral femoral condyle. These individuals have undergone arthroscopy and debridement of the chondral defect. Both retrospectively and prospectively we have been unable to find any defects on radiographs and there appears to be purely cartilaginous involvement. These individuals appear to have a relatively poor prognosis for recovery after arthroscopy. Treatment has been a standard course of range of motion exercises, strengthening, and antiinflammatory medications. However, the mean rehabilitation time has been almost triple the time associated with a routine meniscal injury. We feel that it is important to discuss the chondral fracture so that the orthopaedic surgeon can be aware of this possibility in the differential diagnosis of knee pain in the athlete.