Thomas P. Sculco

The Central Role of Wear Debris in Periprosthetic Osteolysis

Periprosthetic osteolysis remains the leading complication of total hip arthroplasty, often resulting in aseptic loosening of the implant, and a requirement for revision surgery. Wear-generated particular debris is the main cause of initiating this destructive process. The purpose of this article is to review recent advances in our understanding of how wear debris causes osteolysis, and emergent strategies for the avoidance and treatment of this disease. The most important cellular target for wear debris is the macrophage, which responds to particle challenge in two distinct ways, both of which contribute to increased bone resorption. First, it is well known that wear debris activates proinflammatory signaling, which leads to increased osteoclast recruitment and activation. More recently, it has been established that wear also inhibits the protective actions of antiosteoclastogenic cytokines such as interferon gamma, thus promoting differentiation of macrophages to bone-resorbing osteoclasts. Osteoblasts, fibroblasts, and possibly lymphocytes may also be involved in responses to wear. At a molecular level, wear particles activate MAP kinase cascades, NFκB and other transcription factors, and induce expression of suppressors of cytokine signaling. Strategies to reduce osteolysis by choosing bearing surface materials with reduced wear properties (such as metal-on-metal) should be balanced by awareness that reducing particle size may increase biological activity. Finally, although therapeutic agents against proinflammatory mediators [such as tumor necrosis factor (TNF)] and osteoclasts (bisphosphonates and molecules blocking RANKL signaling) have shown promise in animal models, no approved treatments are yet available to osteolysis patients. Considerable efforts are underway to develop such therapies, and to identify novel targets for therapeutic intervention.

Prophylaxis against Deep Venous Thrombosis after Total Knee Arthroplasty. Pneumatic Plantar Compression and Aspirin Compared with Aspirin Alone

A prospective, randomized study was conducted to assess the efficacy of pulsatile pneumatic plantar compression for prophylaxis against deep venous thrombosis after total knee arthroplasty performed with use of regional anesthesia. One hundred and twenty-two patients (164 knees) who were scheduled to have a unilateral or a one-stage bilateral total knee arthroplasty were separately randomized to be managed with either aspirin alone or the pulsatile pneumatic plantar-compression device and aspirin. The prevalence of deep venous thrombosis was 27 per cent (twenty-two of eighty-one knees) in the group treated with pneumatic plantar compression compared with 59 per cent (forty-nine of eighty-three knees) in the patients managed with aspirin alone (the control group) (p < 0.001). A significant difference was also noted in the group that had had a unilateral arthroplasty (a prevalence of 27 per cent [eleven of forty-one knees] in the group treated with pneumatic plantar compression, compared with 67 per cent [twenty-six of thirty-nine knees] in that treated with aspirin alone; p < 0.006) and in the group that had had a one-stage bilateral procedure (a prevalence of 28 per cent [eleven of forty knees] in the group treated with pneumatic plantar compression, compared with 52 per cent [twenty-three of forty-four knees] in that treated with aspirin alone; p < 0.03). No proximal thrombi were noted in any patient who used the pulsatile pneumatic plantar-compression device, while the prevalence of proximal thrombosis in the popliteal or femoral veins was 14 per cent (twelve of eighty-three knees) in the group treated with aspirin alone (p < 0.0003). In the group treated with a unilateral procedure and aspirin alone the prevalence of proximal thrombosis was 13 per cent (five of thirty-nine knees; p < 0.02), while in the group treated with a bilateral procedure and aspirin alone it was 16 per cent (seven of forty-four knees; p < 0.01). Only in the patients who had had a unilateral procedure was use of the compression device associated with significantly less edema postoperatively than was use of aspirin alone. The change between the preoperative and postoperative circumferences of the thigh and leg was significantly less (9 ± 4.1 millimeters [mean and standard deviation] less for the thigh [p < 0.01] and 6 ± 3.9 millimeters less for the leg [p < 0.049]) with the compression device than with aspirin alone. In addition, there was significantly less mean drainage (98 ± 61.1 milliliters) in the group treated with a unilateral procedure and pneumatic compression, compared with that treated with a unilateral procedure and aspirin alone (p < 0.041). An internal timer of the compression device was used to assess the compliance of the patient with use of the device, and a relationship between deep venous thrombosis and the total duration of treatment with the device was found. The patients in whom deep venous thrombosis did not develop used the device for a mean of 96 ± 23.4 hours (range, sixty to 164 hours) postoperatively, or 19.2 ± 5.1 hours a day, while those in whom thrombosis developed used it for a mean of 67 ± 21.1 hours (range, twenty-six to 101 hours), or 13.4 ± 4.3 hours a day (p < 0.001). No untoward effects were noted in any patient who used the device. This study confirms the safety and efficacy of pulsatile pneumatic plantar compression and aspirin compared with aspirin alone and supports the use of mechanical compression for prophylaxis against deep venous thrombosis and for reduction of edema in patients who have had a total knee arthroplasty. In addition, we found a direct relationship between compliance with the use of this device and its efficacy in reducing deep venous thrombosis.

Salvage and reinfusion of postoperative sanguineous wound drainage. A preliminary report.

Thirty-five patients who were to have posterior spinal arthrodesis, total hip arthroplasty, or total knee arthroplasty were entered into one of two groups: Group A, to receive unwashed, filtered sanguineous drainage from the wound, or Group B, to receive washed, filtered drainage. The purpose of this prospective study was to evaluate the safety, efficacy, and difficulty of reinfusion of washed compared with unwashed drainage that had been salvaged from the wound after an orthopaedic operation. The sixteen patients in Group A received a mean of 475 milliliters of unwashed drainage for each total knee arthroplasty, 427 milliliters for each total hip arthroplasty, and ten milliliters for the one posterior spinal arthrodesis. The complications included immediate hypotension (two patients), hyperthermia (one patient), and hypotension five hours after reinfusion (one patient). The latter patient died, four days after the operation, of a massive myocardial infarction. The nineteen patients in Group B received a mean of 193 milliliters of washed, filtered drainage for each total knee arthroplasty, 203 milliliters for each total hip arthroplasty, and 179 milliliters for each posterior spinal arthrodesis. Salvage and reinfusion of washed drainage from the wound caused no problems in these patients.

Randomized Trial of Hypotensive Epidural Anesthesia in Older Adults

BACKGROUND Data are sparse on the incidence of postoperative cognitive, cardiac, and renal complications after deliberate hypotensive anesthesia in elderly patients. METHODS This randomized, controlled clinical trial included 235 older adults with comorbid medical illnesses undergoing elective primary total hip replacement with epidural anesthesia. The patients were randomly assigned to one of two levels of intraoperative mean arterial blood pressure management: either to a markedly hypotensive mean arterial blood pressure range of 45-55 mmHg or to a less hypotensive range of 55-70 mmHg. Cognitive outcome was assessed by within-patient change on 10 neuropsychologic tests assessing memory, psychomotor, and language skills from before surgery to 1 week and 4 months after surgery. Prospective standardized surveillance was performed for cardiovascular and renal outcomes, delirium, thromboembolism, and blood loss and replacement. RESULTS The two groups were similar at baseline in terms of age (mean, 72 yr), sex (50% women), comorbid conditions, and cognitive function. After operation, no significant differences in the incidence of early or long-term cognitive dysfunction were observed between the two blood pressure management groups. There were no significant differences in the rates of other adverse consequences, including cardiac, renal, and thromboembolic complications. In addition, no differences occurred in the duration of surgery, intraoperative estimated blood loss, or transfusion rates. CONCLUSIONS Elderly patients can safely receive controlled hypotensive epidural anesthesia with this protocol. There was no evidence of greater risks, or early benefits, with the use of the more markedly hypotensive range.

Total condylar knee arthroplasty: a long-term followup.

Between July 1977 and December 1983, 80 patients underwent 120 arthroplasties using a total condylar knee prostheses. Forty-one patients (68 knees) died and 13 patients were lost to followup. Twenty-six patients with 34 total condylar replacements were available for clinical followup. During the followup, 10 knees in nine patients (8.3%) from the overall 80 patients (120 knees) underwent revision; three (four knees) for aseptic loosening, one for periprosthetic fracture, three for infection, and two patients underwent revision for pain. Three revisions (three patients) occurred in the group of 26 patients available for followup. The average age of this group of patients at followup was 78 years (range, 53–94 years). There were 10 men and 16 women. Considering the high mean age of the patients in the series and patients’ overall health status, the clinical results were extremely good. Kaplan-Meier analysis showed a survivorship of 91% at 23 years followup, considering revision as an end point. Although there have been several changes in total knee replacement designs, materials, and implantation techniques, the long-term outcome of the original total condylar knee prosthesis is excellent.

Fulfillment of Patients' Expectations for Total Hip Arthroplasty

BACKGROUND Fulfillment of patient expectations is an important outcome of total hip arthroplasty. The objective of the present study was to determine the proportion of expectations that were fulfilled following total hip arthroplasty as well as how the fulfillment of expectations relates to patient and clinical characteristics. METHODS Preoperatively, patients completed the Hospital for Special Surgery Hip Replacement Expectations Survey, measuring physical and psychological expectations, and the American Academy of Orthopaedic Surgeons Lower Limb Core Scale, measuring symptoms and function. Approximately four years after surgery, patients were interviewed by telephone and were asked whether each expectation that they had cited preoperatively had been fulfilled. RESULTS Four hundred and five patients were interviewed. The mean age of the patients was sixty-six years, and 58% of the patients were women. Forty-three percent of the patients reported that all of their expectations had been fulfilled completely. For the entire sample, the mean proportion of expectations that had been fulfilled completely was 87%. Patients who were younger, who were employed, who had a body mass index of <35 kg/m(2), who did not have complications, who did not have a postoperative limp, and who had better preoperative and postoperative Lower Limb Core scores had a greater proportion of expectations fulfilled (p <or= 0.05). CONCLUSIONS A better postoperative Lower Limb Core score was most closely associated with the fulfillment of expectations following total hip arthroplasty. Not having a postoperative limp was independent of the postoperative Lower Limb Core score, indicating that the impact of a limp is greater than its manifestation as a physical disability. Better preoperative status also was an independent predictor, indicating that patient expectations are more likely to be fulfilled if the patient is not the most severely impaired at the time of surgery.

Minimally invasive total hip arthroplasty: the Hospital for Special Surgery experience

The mini-incision technique is not a radically new technique. The surgeon familiar with the posterior approach will immediately appreciate the inherent similarities. The technique can be developed on a graduated basis by individual surgeons. The surgeon should begin by documenting the length of his or her current routine incision, and then the incision can be progressively reduced in length at a rate that is comfortable. At no time is it necessary to compromise the goals of the procedure because of inadequate visualization. The mini-incision is not for every patient. Obese individuals (BMI> 30), patients with very muscular thighs, stiff hips, or severe deformity may not be candidates for an 8-cm incision, but familiarity with this technique allows even these patients to be operated on through a smaller incision than the traditional 20-25 cm. The initial drive for shorter incisions was a result of patient concerns regarding the cosmesis of the scars and the desire for a more rapid recovery. Subsequent development of the technique and clinical analysis over the last 7 years has shown that THA can be performed safely and effectively through a mini-incision in most patients. So far the author shave found no increased risk for intraoperative or postoperative complications and no problems with component malposition. Longer follow-up is required to determine the long-term outcome; however, in the short term, patients have less blood loss, shorter operative times, and a reduced incidence of limp and cane use at 6 weeks.

Perioperative outcomes after unilateral and bilateral total knee arthroplasty

Background:The safety of bilateral total knee arthroplasties (BTKAs) during the same hospitalization remains controversial. The authors sought to study differences in perioperative outcomes between unilateral and BTKA and to further compare BTKAs performed during the same versus different operations during the same hospitalization. Methods:Nationwide Inpatient Sample data from 1998 to 2006 were analyzed. Entries for unilateral and BTKA procedures performed on the same day (simultaneous) and separate days (staged) during the same hospitalization were identified. Patient and healthcare system–related demographics were determined. The incidences of in-hospital mortality and procedure-related complications were estimated and compared between groups. Multivariate regression was used to identify independent risk factors for morbidity and mortality. Results:Despite younger average age and lower comorbidity burden, procedure-related complications and in-hospital mortality were more frequent after BTKA than after unilateral procedures (9.45% vs. 7.07% and 0.30% vs. 0.14%; P < 0.0001 each). An increased rate of complications was associated with a staged versus simultaneous approach with no difference in mortality (10.30% vs. 9.15%; P < 0.0001 and 0.29% vs. 0.26%; P = 0.2875). Independent predictors for in-hospital mortality included BTKA (simultaneous: odds ratio, 2.23 [95% confidence interval, 1.69–2.95]; P < 0.0001; staged: odds ratio, 2.01 [confidence interval, 1.28–3.41]; P = 0.0031), male sex (odds ratio, 2.02 [confidence interval, 1.75–2.34]; P < 0.0001), age older than 75 yr (odds ratio, 3.96 [confidence interval, 2.77–5.66]; P < 0.0001), and the presence of a number of comorbidities and complications. Conclusion:BTKAs carry increased risk of perioperative morbidity and mortality compared with unilateral procedures. Staging BTKA procedures during the same hospitalization offers no mortality benefit and may even expose patients to increased morbidity.

Diagnostic and Therapeutic Use of Sonography-Guided Iliopsoas Peritendinous Injections

OBJECTIVE Our objective was to review our experience performing sonography-guided iliopsoas bursal/peritendinous injections as a diagnostic and therapeutic tool in the workup and treatment of patients with hip pain. CONCLUSION Sonography-guided iliopsoas bursal/peritendinous injections are useful in determining the cause of hip pain. They can provide relief to most patients with iliopsoas tendinosis/bursitis after hip replacement. The results of injection alone are not as successful in cases of idiopathic iliopsoas tendinosis/bursitis, but the technique can help determine which patients may benefit from a surgical tendon release.

The International Consortium of Orthopaedic Registries: Overview and Summary

FDA Post-Market Efforts and Interest in Orthopaedics The United States Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) monitors both mandatory and voluntary post-market reporting to identify adverse events and problems associated with medical devices. Although the manufacturers of medical devices are required to report deaths, injuries, and malfunctions directly to the FDA, the device users are required to report these events to the manufacturer and are required to report only deaths to the FDA. Voluntary reporting systems such as the MedWatch program, the MAUDE (Manufacturer and User Facility Device Experience) database, and the MedSun (Medical Product Safety Network) enhanced surveillance network provide nationwide medical device surveillance in the U.S. However, these reporting systems have important weaknesses, such as incomplete, inaccurate, or nonvalidated data, reporting biases related to event severity, concerns that reporting may result in adverse publicity or litigation, and general underreporting of events. Most importantly, denominator data are missing, which makes evaluation of the incidence or prevalence of a safety-related event impossible. The FDA’s interest in orthopaedic device safety and in the development of infrastructure for enhanced safety monitoring is natural and timely; the lack of such safety evidence is particularly troubling for the most commonly used implants. Over 700,000 joint replacements involving implantable devices are conducted annually in the U.S. alone, and the annual volume is projected to increase twofold for hip joint replacements and sevenfold for knee joint replacements, to a total of more than 3 million annually, in just the next twenty years. Moreover, these surgical procedures are expected to become more expensive, with costs tripling in just the next five years. Despite remarkable advancements in orthopaedics, including new devices and improved surgical techniques, the value of many therapeutic devices has not been established in clinical trials or in real-world settings. Several factors contribute to this shortcoming: (1) rapidly changing device technology coupled with an enormous number of devices on the market; (2) the need for large numbers of patients and long-term follow-up to adequately evaluate the primary safety end point, which is longterm device failure or need for revision; and (3) the need for prospective data collection, planning, and substantial funding to evaluate short and long-term patient-reported outcomes, which are the primary effectiveness end points. The poor state of research and the resulting inability to learn about a device’s benefits, its potential harms, and the balance between them hinder decision-making by the FDA and other stakeholders such as the Centers for Medicare & Medicaid Services (CMS) and commercial insurers.