Slif D. Ulrich

Effect of changing indications and techniques on total hip resurfacing.

Recently, improved metal-on-metal bearing technology has led to the reemergence of resurfacing as a reasonable option for total hip arthroplasty. During the course of a prospective multicenter FDA-IDE evaluation of metal-on-metal total hip resurfacings, we modified our indications and emphasized surgical technique where the femoral surface area was small due to femoral cysts and small component size. We assessed the influence of these changes on complication rates in the first cohort of 292 patients and the second of 724, and then compared these outcomes in the second cohort with historical reports of resurfacing. We had a minimum followup of 24 months (mean, 33 months; range, 24-60 months). After changes were made in the indications and technique, the overall complication rate decreased from 13.4% to 2.1% with the femoral neck fracture rate reduced from 7.2% to 0.8%. The outcomes of the second cohort compare with modern-day resurfacing devices and appear superior to historical results. The data suggest patients should be carefully selected and technique optimized to reduce complications. Long-term followup is required to see if these promising results will be maintained.Level of Evidence: Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Treatment of early stage osteonecrosis of the femoral head.

Osteonecrosis is a devastating disease that primarily affects weight-bearing joints. The hip is the most commonly affected joint. Although hip osteonecrosis can affect patients of any age group, it typically presents in young patients between the ages of twenty and forty years1. The factors that affect the progression of this disease are still not fully understood, but radiographic lesion size, femoral head collapse (if present), and, occasionally, clinical presentation at the time of diagnosis have been shown to be predictive of the eventual clinical outcome2,3. After collapse, most patients will require a standard total hip arthroplasty4,5. However, because of the young age of many of these patients, a hip replacement cannot be expected to last the patients lifetime and therefore, when feasible, attempts should be made to save the femoral head prior to collapse with use of less invasive treatment modalities. The efficacy of these procedures has been variable, with reported success rates ranging between 60% and 80% at the time of short-term and midterm follow-up6-8. Current treatments range from pharmacotherapies to surgical interventions that include core decompression, vascularized or nonvascularized bone-grafting, and osteotomy. Recently there have been attempts to enhance these surgical techniques with use of various growth and differentiation factors. The primary purpose of this report is threefold: (1) to discuss the importance of early diagnosis and the standards for identifying and staging osteonecrosis; (2) to assess the efficacy of various treatment modalities and techniques by conducting an extensive literature review and comparing reported outcomes with those of patients treated at our institution; and (3) to provide a recommended treatment algorithm based on the assessment of these treatment options. All patients who were treated at our institution for early stage osteonecrosis of the hip …

Imaging of Musculoskeletal Bacterial Infections by [124I]FIAU-PET/CT

Background Traditional imaging techniques for the localization and monitoring of bacterial infections, although reasonably sensitive, suffer from a lack of specificity. This is particularly true for musculoskeletal infections. Bacteria possess a thymidine kinase (TK) whose substrate specificity is distinct from that of the major human TK. The substrate specificity difference has been exploited to develop a new imaging technique that can detect the presence of viable bacteria. Methodology/Principal Findings Eight subjects with suspected musculoskeletal infections and one healthy control were studied by a combination of [124I]FIAU-positron emission tomography and CT ([124I]FIAU-PET/CT). All patients with proven musculoskeletal infections demonstrated positive [124I]FIAU-PET/CT signals in the sites of concern at two hours after radiopharmaceutical administration. No adverse reactions with FIAU were observed. Conclusions/Significance [124I]FIAU-PET/CT is a promising new method for imaging bacterial infections.

Total Hip Resurfacing in Patients Who Are Sixty Years of Age or Older

BACKGROUND Metal-on-metal total hip resurfacing arthroplasty has been associated with excellent early results in patients who are younger than sixty years of age, but it remains controversial whether this procedure is appropriate in older patients. The purpose of the present study was to compare the clinical and radiographic outcomes after hip resurfacing in two cohorts of patients: those who were sixty years of age or older, and those who were younger than sixty years of age. METHODS Between November 2002 and August 2005, thirty-five patients (forty hips) who were sixty years of age or older were managed with metal-on-metal total hip resurfacing arthroplasty. The outcomes of these patients were compared with those of 130 patients (153 hips) who were younger than sixty years of age but otherwise had similar preoperative parameters and who had resurfacing arthroplasty performed during the same time interval and by the same surgeon. We evaluated Harris hip scores, Short Form-12 scores, and complications as well as radiographic alignment and radiolucencies. RESULTS At a mean follow-up time of thirty-six months, the mean Harris hip scores improved from 52 points to 94 points in the older patient cohort and from 53 points to 92 points in the younger patient cohort. The final Short Form-12 scores of the two groups were also similar. Two patients who were sixty years or older and five of the younger patients required conversion to a conventional total hip arthroplasty. Femoral neck fracture was the reason for one conversion in each group. There were no impending radiographic failures in either cohort. CONCLUSIONS Although national registries indicate that the risk of femoral neck fracture is higher in older patients, the present study found that these patients had excellent clinical outcomes that were similar to those of patients who were younger. We await longer follow-up results to determine further outcomes in these patients.

Reductions in blood loss with a bipolar sealer in total hip arthroplasty.

Altogether, 50 primary total hip arthroplasties were performed in a prospective, blinded, randomized study comparing a bipolar sealer device to standard electrocautery for hemostasis. Cohorts were evaluated for intra- and postoperative blood loss, transfusion rate, hemoglobin levels and modified Harris hip scores. Variables such as age, gender and body mass index were correlated to transfusion requirements. Total blood loss in the bipolar sealer group was decreased by 40% and transfusions were reduced by 73%. There was a significant reduction in the intra- and postoperative blood loss, p = 0.002 and p = 0.001, respectively. There was no difference in clinical hip scores between groups. The bipolar sealer was an effective coagulation alternative for total hip arthroplasties, reducing blood loss and transfusion requirements without affecting outcome. It appears to reduce tissue damage and smoke production in comparison with standard electrocautery. These results were found even in patients with demographic characteristics associated with a higher risk of blood-related complications.

A Comparison of Subvastus and Midvastus Approaches in Minimally Invasive Total Knee Arthroplasty

BACKGROUND The mini-subvastus and the mini-midvastus approaches are among the most common alternatives to the medial parapatellar approach for total knee arthroplasty. The purpose of this study was to compare the early clinical outcomes of these two approaches. METHODS In this prospective, randomized study of fifty-one patients who underwent bilateral total knee arthroplasty, the mini-subvastus approach was used in one knee and the mini-midvastus approach, in the contralateral knee. There were forty-two women and nine men who had a mean age of seventy years at the time of the index arthroplasties, and they were followed for two years postoperatively. Clinical outcome was assessed and compared with use of the Knee Society pain and function scores, the straight-leg-raising test, range of motion, and isokinetic strength testing. Operating time and blood loss for each approach were also compared. In addition, patients were surveyed concerning which knee they preferred. RESULTS Comparisons of postoperative Knee Society scores between both approaches at the time of the two-year follow-up did not yield a significant difference in outcome. Isokinetic strength testing at twelve weeks postoperatively revealed no significant differences in muscle strength, with a mean extensor peak torque-to-body weight ratio of 0.14 Nm/kg for both groups. No significant difference was found with respect to total blood loss, straight-leg-raising test, range of motion, or patient preference. There was no clinically relevant difference in operative times between the two approaches. CONCLUSIONS The minimally invasive subvastus and midvastus approaches for total knee arthroplasty were both associated with excellent short-term clinical results. Some surgeons believe that the subvastus approach completely avoids damage to the quadriceps mechanism and therefore would be associated with improved muscle function. This prospective series did not identify a substantive difference between the two approaches. We believe that the decision between these surgical approaches should be based on surgeon preference and experience.

Restoring range of motion via stress relaxation and static progressive stretch in posttraumatic elbow contractures.

HYPOTHESIS Loss of range of motion after injury or surgery of the elbow is a common complication. We hypothesized that an orthosis that used progressive stretch and stress relaxation principles would improve elbow range of motion. METHODS This study evaluated the result of a patient-directed, bidirectional orthosis that uses static progressive stretch and stress relaxation principles to improve elbow range of motion in patients who had posttraumatic elbow contractures. Treatment in 37 elbows consisted of a 30-minute stretching protocol performed in 1 to 3 sessions daily for a mean of 10 weeks (range, 2-22 weeks). RESULTS The mean gain in range of motion was 26 degrees (range, 2 degrees -60 degrees ). Gains of motion were noted in 35 of 37 elbows. Patients lowered their analgesic use and were highly satisfied with the device (mean satisfaction score of 8.5 of 10 points possible). DISCUSSION This device compared favorably with reports of other devices. Consistent improvements in restoring range of motion can be achieved with short treatment times by using a device based on the principles of static progressive stretch and stress relaxation in patients with posttraumatic elbow contractures.

Results of Total Knee Replacement for Isolated Patellofemoral Arthritis: When Not to Perform a Patellofemoral Arthroplasty

Many procedures have been used to treat advanced isolated patellofemoral arthritis, with varying results. Patellofemoral arthroplasty (PFA) is a bone-conserving procedure that has shown short-term success but has relatively high revision rates. Total knee arthroplasty (TKA) has been recommended for treatment of this disease in patients who are older than 60 years of age. Recent literature indicates that PFA is most successful in patients who have isolated patellofemoral arthritis secondary to trochlear dysplasia or patellar fracture and in patients who are younger than 60 years; TKA is recommended for older patients who have primary or idiopathic isolated patellofemoral arthritis.

Static progressive stretch for the treatment of knee stiffness

Persistent knee stiffness is common after knee arthroplasties, cruciate ligament repairs, and trauma. Static progressive stretch protocols have shown success in treating contractures of the elbow, ankle, and knee in case reports and small case series. This study evaluated static progressive stretch as a treatment method for patients who had refractory knee stiffness, and compared the outcomes to published results of other therapeutic modalities. Forty-one patients who had knee stiffness and who had not improved with conventional physical therapy modalities were treated with a patient-directed orthosis that utilized the principles of static progressive stretch. After a mean of 9 weeks of use (range, 3 to 27 weeks), the total arc of motion increased by a mean of 33 degrees (range, 0 to 85 degrees ). Forty of 41 patients had increased motion at a mean final follow-up time of 1 year (range, 6 months to 2 years), and 93% were satisfied with the results. The outcomes were comparable to other nonoperative treatments reported in the literature, but the results in the present study occurred in a shorter mean treatment time. An orthosis that utilizes the principles of static progressive stretch may be a successful treatment for improving the range of motion and satisfaction of patients who have knee contractures.

Minimally Invasive Lateral Approach to Total Knee Arthroplasty

Minimally invasive knee surgery can be accomplished through several exposures used in standard total knee arthroplasty. These exposures include the medial parapatellar, subvastus, and midvastus approaches. The authors describe a new minimally invasive direct lateral approach in an attempt to minimize soft tissue damage and preserve quadriceps muscle function in 35 patients (35 knees). There were 23 women and 12 men with a mean age of 65 years. At a mean follow-up of 3.8 years, the mean Knee Society objective and functional scores improved to 94 and 92 points, respectively. The assessment of quadriceps muscle strength, anterior knee pain, and patient satisfaction was promising. However, the downside of this pilot cohort was that using instruments and implants that have not been customized for this approach led to a considerable rate of early complications that may limit the potential of this new approach. Thus, further refinements are needed to increase clinical success and allow this technique for general use.