Jeffrey J. Cherian

Nontraumatic Osteonecrosis of the Femoral Head: Where Do We Stand Today? A Ten-Year Update.

➤ Although multiple theories have been proposed, no one pathophysiologic mechanism has been identified as the etiology for the development of osteonecrosis of the femoral head. However, the basic mechanism involves impaired circulation to a specific area that ultimately becomes necrotic.➤ A variety of nonoperative treatment regimens have been evaluated for the treatment of precollapse disease, with varying success. Prospective, multicenter, randomized trials are needed to evaluate the efficacy of these regimens in altering the natural history of the disease.➤ Joint-preserving procedures are indicated in the treatment of precollapse disease, with several studies showing successful outcomes at mid-term and long-term follow-up.➤ Studies of total joint arthroplasty, once femoral head collapse is present, have described excellent outcomes at greater than ten years of follow-up, which is a major advance and has led to a paradigm shift in treating these patients.➤ The results of hemiresurfacing and total resurfacing arthroplasty have been suboptimal, and these procedures have restricted indications in patients with osteonecrosis of the femoral head.

Mechanical, Anatomical, and Kinematic Axis in TKA: Concepts and Practical Applications

Successful total knee arthroplasty (TKA) has often been based on the restoration of the knee to neutral alignment postoperatively. Numerous reports have linked malaligned TKA components to increased wear, poor functional outcomes, and failure. There have been many different alignment philosophies and surgical techniques that have been established to attain the goal of proper alignment, which includes such techniques as computerized navigation, and custom cutting guides. In addition, these methods could potentially have the added benefit of leading to improved functional outcomes following total knee arthroplasty. In this report, we have reviewed and analyzed recent reports concerning mechanical, anatomic, and kinematic axis/alignment schemes used in total knee arthroplasty.

Gross Trunnion Failure After Primary Total Hip Arthroplasty

Unfavorable outcomes from trunnion fretting and corrosion damage have been reported in the literature, gross failures of tapers in primary total hip arthroplasties have been less frequently reported. We report on 5 patients, who presented with gross trunnion failures of modular metal-on-polyethylene or ceramic-on-polyethylene bearings from 5 implant manufacturers, all necessitating revision surgery. None of these patients had an antecedent history of trauma, and the majority presented with pain or instability. No common factor was identified that may be predictive of these type of failures. Since there were 5 different stem designs, this suggests that it may be a rare generic phenomenon occurring with multiple designs. Currently, further investigations are necessary, including retrieval analysis, to identify risk factors that may predispose to such failures.

Dual mobility cups: an effective prosthesis in revision total hip arthroplasties for preventing dislocations

Purpose Postoperative dislocation is one of the most common complications following total hip arthroplasty (THA), and dual mobility articulations have been designed to provide greater hip stability. However, there are few studies that have assessed outcomes of these designs in revision THAs. Our purpose was to evaluate differences in dislocation rates, aseptic survivorship, and patient outcomes between dual mobility articulations and conventional arthroplasties in the revision setting. Methods Patients who underwent revision THA with dual mobility articulations (n = 60) were matched (1:2) to patients who had conventional single articulation prostheses (n = 120). They were matched for body mass index, age, gender, and Paprosky acetabular defect classification, and were followed up for a mean of 30 months (range, 18 to 52 months). The outcomes were evaluated preoperatively and at final follow-up using Harris Hip Scores, the University of California Los Angeles activity scale, and the Short Form-36 questionnaires. Results The dual mobility group had lower dislocation (1.7% (1 out of 60) versus 5.8% (7 out of 120)) and aseptic loosening rates (1.7% (1 out of 60) versus 4.2% (5 out of 120)) compared to the control group. There were no significant differences in functional outcomes, activity level, or overall physical and mental health status between the 2 cohorts. Conclusions When used in the revision setting, dual mobility bearings had fewer dislocations. We believe that these designs may lead to clinically significant improvements in complications while also improving patient reported and functional outcomes, but larger cohort studies are necessary for evaluation.

Osteonecrosis of the knee: review

Osteonecrosis is a devastating disease that can lead to end-stage arthritis of various joint including the knee. There are three categories of osteonecrosis that affect the knee: spontaneous osteonecrosis of the knee (SONK), secondary, and post-arthroscopic. Regardless of osteonecrosis categories, the treatment of this disease aims to halt further progression or delay the onset of end-stage arthritis of the knee. However, once substantial joint surface collapse has occurred or there are sign of degenerative arthritis, joint arthroplasty is the most appropriate treatment option. Currently, the non-operative treatment options consist of observation, non-steroidal anti-inflammatory drugs (NSAIDs), protected weight bearing, and analgesia as needed. Operative interventions include joint preserving surgery, unilateral knee arthroplasty (UKA), or total knee arthroplasty (TKA) depending on the extent and type of disease. Joint preserving procedures (i.e., arthroscopy, core decompression, osteochondral autograft, and bone grafting) are usually attempted in pre-collapse and some post-collapse lesions, when the articular cartilage is generally intact with only the underlying subchondral bone being affected. Conversely, after severe subchondral collapse has occurred, procedures that attempt to salvage the joint are rarely successful and joint arthroplasty are necessary to relieve pain. The purpose of this article is to highlight the recent evidence concerning the treatment options across the spectrum of management of osteonecrosis of the knee including lesion observation, medications, joint preserving techniques, and total joint arthroplasties.

Cementless Total Knee Arthroplasty: A Review

There is ongoing debate over the use of cementless fixation in total knee arthroplasty (TKA). Previous generation prostheses resulted in less than optimal outcomes which was somewhat attributed to design issues. As the demand for TKA is continuously increasing and the current U.S. age population is getting younger, cemented fixation may not provide adequate long-term outcomes due to failure of fixation. Thus, there has been a reemergence of the development and use of cementless TKA. Recent short-term trials have demonstrated that modern cementless TKA has comparable survivorship and functional outcomes as cemented prostheses. However, more prospective, randomized trials are needed to clearly delineate any differences between these two fixation options.

Long-Term Survivorship and Clinical Outcomes Following Total Knee Arthroplasty

Total knee arthroplasty (TKA) is one of the most successful commonly performed orthopedic procedures; as such, the purpose was to assess the long-term outcomes and survivorship of primary TKAs with a dual-radius prosthesis. We evaluated 125-patients (145-knees), with a mean age of 63 years (37-90 years) for a mean 11-year follow-up (10-13 years). Outcomes were assessed with KSS, UCLA, SF-36, satisfaction scores, and aseptic survivorship analysis. At 10-year follow-up, the UCLA (6-points), KSS objective (84-points) and functional (73-points), SF-36 physical (41-points) and mental (51-points), and patient satisfaction (14-points) scores were reported to be good to excellent. The 10-year Kaplan-Meier survivorship rate was 99%; one TKA demonstrated radiographic loosening. At a minimum 10-year follow-up, this device demonstrated satisfactory outcomes and outstanding aseptic-survivorship rates.

The Economic Impact of Periprosthetic Infections After Total Hip Arthroplasty at a Specialized Tertiary-Care Center

BACKGROUND Periprosthetic infections after total hip arthroplasty represent an increased risk for patient morbidity and mortality, and an increased economic burden. The purpose of this study was to compare a group of patients who had periprosthetic infections after total hip arthroplasty to a matched group of patients who underwent primary total hip arthroplasty in terms of the associated costs, length of hospitalization, and number of readmissions (within 1 year). METHODS Between 2007 and 2011, 16 consecutive infected patients were matched to 32 noninfected patients (1:2 ratio). RESULTS The mean episode cost, length of hospitalization, and median readmissions was significantly higher in the infected group when compared to the matched cohort:

Bicruciate-retaining total knee arthroplasty: a review.

88,623 vs

New and Common Perioperative Pain Management Techniques in Total Knee Arthroplasty

25,659, 7.6 vs 3.29 days, and 2 vs 0, respectively. CONCLUSION Periprosthetic infections after THA resulted in an increased episode cost by approximately 3-fold, mean hospitalization period 2-fold, and led to a higher median number of readmissions.