The 2019 Revised Version of Association Research Circulation Osseous Staging System of Osteonecrosis of the Femoral Head.

BACKGROUND: The Association Research Circulation Osseous (ARCO) presents the 2019 revised staging system of osteonecrosis of the femoral head (ONFH) based on the 1994 ARCO classification. METHODS: In October 2018, ARCO established a task force to revise the staging system of ONFH. The task force involved 29 experts who used a web-based survey for international collaboration. Content validity ratios for each answer were calculated to identify the levels of agreement. For the rating queries, a consensus was defined when more than 70% of the panel members scored a 4 or 5 rating on a 5-point scale. RESULTS: Response rates were 93.1%-100%, and through the 4-round Delphi study, the 1994 ARCO classification for ONFH was successfully revised. The final consensus resulted in the following 4-staged system: stage I-X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II-X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III-fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV-X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. This revised staging system does not incorporate the previous subclassification or quantitation parameters, but the panels agreed on the future development of a separate grading system for predicting disease progression. CONCLUSION: A staging system has been developed to revise the 1994 ARCO classification for ONFH by an expert panel-based Delphi survey. ARCO approved and recommends this revised system as a universal staging of ONFH.

Outcome of minimally invasive hip replacement in obese, overweight, and nonobese patients.

The goal of this study was to determine whether obesity affects implant positioning or early functional outcome after minimally invasive total hip replacement. The authors evaluated 119 patients who had undergone minimally invasive total hip replacement via a direct anterior approach. The patients were segregated according to World Health Organization body mass index categories: nonobese, overweight, or obese. Perioperative variables, resulting cup position, and early outcome (Harris Hip Score) were assessed. The only significant difference among the groups was mean operative time (obese > overweight > nonobese). Although the obese group's 2-year Harris Hip Score was the lowest, all patients had good to excellent results. In conclusion, minimally invasive hip replacement in obese patients provides early outcomes comparable to those in nonobese patients.

Total joint arthroplasty in patients with rheumatoid arthritis: a United States experience from 1992 through 2005.

To determine whether total joint arthroplasty (TJA) for patients with rheumatoid arthritis (RA) is decreasing, we collected Nationwide Inpatient Sample database information (1992 through 2005) on (1) the number of primary TJAs for all patient diagnoses, (2) the number of primary TJAs for patients with RA, and (3) distribution of age and sex in both groups. To account for population growth, a given year's arthroplasty estimate was normalized against its population. The trends over time were analyzed using a multivariable Poisson regression model (significance, P < .05). We found that the number of primary TJA procedures increased in the general and RA populations but that, after adjusting for population growth, age, and sex, the rate was significantly lower in patients with RA.

Learning curve for the anterior approach total hip arthroplasty.

The anterior approach to total hip arthroplasty has the advantages of using intermuscular and internervous planes, but it is technically demanding. We evaluated the learning curve for this approach with regard to operative parameters and immediate outcomes. From November 2005 through May 2007, 73 patients underwent 81 consecutive primary anterior-approach total hip arthroplasties. We grouped the hips into three consecutive groups of 20 and one of 21, and surgical and fluoroscopy times, estimated blood loss, intraoperative and postoperative complications, patient comorbidities, component position, and leg-length discrepancy were compared (statistical significance, p < 0.05). Comparing Groups 1 and 4, there were only two significant differences: operative time, 124 to 98 minutes, respectively, and estimated blood loss, 596 to 347 mL, respectively. Proficiency improved after Group 2 (40 cases) and was more marked after Group 3 (60 cases), with no major complications. Surgeons considering this approach should expect a substantial learning period.

Trochanteric bursitis after total hip arthroplasty: incidence and evaluation of response to treatment.

We examined the efficacy of corticosteroid injection as treatment for postarthroplasty trochanteric bursitis and the risk factors for failure of nonoperative treatment. There were 32 (4.6%) cases of postsurgical trochanteric bursitis in 689 primary total hip arthroplasties. Of the 25 hips with follow-up, 11 (45%) required multiple injections. Symptoms resolved in 20 (80%) but persisted in 5. We found no statistically significant differences between patients who did and did not develop trochanteric bursitis, or between those who did and did not respond to treatment. There was a trend toward younger age and greater limb-length discrepancy in nonresponders. In conclusion, (1) corticosteroid injection(s) for postoperative trochanteric bursitis is effective; and (2) nonoperative management may be more likely to fail in young patients and those with leg-length discrepancy.

Sagittal plane balancing in the total knee arthroplasty.

Postoperative stiffness or instability may result from a total knee arthroplasty imbalanced in the sagittal plane. Total knee arthroplasty instrumentation systems differ in the basic strategies used to assure this balance. In an anterior referencing system, changes in femoral size affect flexion gap tightness, and femoral size selection is paramount to assure sagittal plane balance. Conversely, in posterior referencing systems, femoral size changes do not affect the flexion gap but, rather, influence femoral component-patella articulation. Flexion/extension gap systems use calibrated spacer blocks to ensure gap balance but do not guarantee midrange stability; if used incorrectly, they may cause component malposition and joint line elevation. The authors reviewed the strengths and weaknesses of system types and provided system-specific troubleshooting guidelines for clinicians addressing intraoperative sagittal plane imbalance.

Periprosthetic thyroid metastasis after total knee arthroplasty: a report of two cases and review of the literature.

Total knee arthroplasty (TKA) is an attractive option for relief of pain secondary to degenerative joint disease. Overall, knee replacement surgery typically results in excellent outcomes. Nevertheless, failure caused by malalignment, infection, wear, and osteolysis is known to occur. Pain after TKA may be secondary to numerous etiologic factors-most commonly, loosening, fracture, infection, and malposition of components. This case report presents two patients who developed pain after TKA that was caused by periprosthetic thyroid metastasis and who subsequently sustained a fracture below the tibial component. Clinical and radiographic examinations, as well as surgical follow-up, are presented to underscore the need for a focused history and physical examination in the initial evaluation of a patient with a painful TKA.

Survivorship of femoral revision hip arthroplasty in patients with osteonecrosis.

BACKGROUND: Recent studies have indicated that the rate of successful long-term outcome after primary total hip arthroplasty for patients with osteonecrosis may be improved with the use of later-generation porous-coated prostheses (biologic ingrowth fixation) and cement techniques (cement fixation). Less is known about the long-term outcome after revision arthroplasty in the same patient population. The purpose of this study was to characterize the clinical and radiographic outcomes of revision total hip arthroplasty in patients with osteonecrosis. METHODS: We evaluated thirty-four osteonecrotic hips in thirty patients who had undergone revision of a femoral component of a prior total hip arthroplasty. There were nineteen men (twenty-two hips) and eleven women (twelve hips) with a mean age of forty-six years. Thirty one of thirty-four hips were implanted without cement. The cementless prostheses were of different stem lengths, but thirty of thirty-one were proximally porous coated. The mean duration of follow-up was 8.2 years. Prerevision radiographs were used to determine the degree of femoral bone loss according to the classification system of Della Valle and Paprosky. The need for revision was analyzed for correlation to known risk factors for osteonecrosis, age and gender of the patient, and degree of prerevision femoral deficiency. A clinical and radiographic evaluation of outcome was performed. RESULTS: This was the first revision for twenty-seven hips, the second for five hips, and the third for two hips. Preoperatively, the defects included four Type I, nine Type II, fifteen Type IIIA, two Type IIIB, one Type IV, and three unknown. The femoral component was rerevised in twelve of the thirty-four hips. One of the failures was the only fully porous-coated stem that was implanted. One of the three cemented implants failed, as compared with eleven of the thirty-one noncemented implants. Survival rates were 90.9% at five years, 54.8% at ten years, 54.8% at fifteen years, and 27.4% at twenty years. With the small sample size, no relationship could be identified with regard to frequency of re-revision and defects, associated risk factors, patient age, or gender. CONCLUSIONS: There was a high failure rate of revised, uncemented, proximally coated femoral components in patients with osteonecrosis of the femoral head at the time of the intermediate-term follow-up. The cause of failure could not be correlated with patient age, gender, risk factors for osteonecrosis, or femoral bone stock. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Chondroprotective agents: glucosamine and chondroitin.

The near universal finding of the safety of glucosamine and chondroitin combined with some compelling evidence of their efficacy should spur further research into their mechanism of action, optimal dosing, long-term effects on disease modification, and clinical applicability. When recommending a supplement to patients, the clinician should take into account the purity of the ingredients, reputation of the manufacturer, and the molecular weight of chondroitin supplied.

Total hip arthroplasty: differences in outcome measures between men and women.

INTRODUCTION: Patient-related factors impact the long-term survival of hip arthroplasty. This study evaluated whether there were differences in outcome measures between men and women undergoing total hip arthroplasty. METHODS: A retrospective study of prospectively collected data on 75 primary total hip arthroplasties in 72 patients was conducted. Medical history, physical examination, Harris Hip scores, and Quality of Life forms (SF-36) were obtained for each patient preoperatively and postoperatively. Preoperative radiographs were assessed using the Kellgren and Lawrence scoring system. Only patients with a minimum follow-up of 2 years were included. RESULTS: Preoperatively, women and men had comparable Kellgren and Lawrence scores and Harris Hip scores. Of the 8 subscores for the SF-36, only the Physical Functioning subscore was significantly different preoperatively. Similar results were noted postoperatively; again, only the Physical Functioning subscores were significantly different between men and women. CONCLUSIONS: Physician assessments were not significantly different preoperatively and postoperatively for men or women. The results for the SF-36 were similar except for a significant difference in the Physical Functioning subscore preoperatively and postoperatively. According to the Medical Outcomes Trust, the SF-36 Physical Functioning score has been shown to be the best all-around measure of physical health.

Meralgia paresthetica of the contralateral leg after total hip arthroplasty.

In the United States, total hip arthroplasty (THA) is typically performed with the patient in the lateral decubitus position. Positioning of the morbidly obese patient can be technically challenging and may require special positioning equipment. Although the increased incidence of complications after THA in obese patients has been well documented, neurologic complications in the contralateral limb are rare. This article describes a case of a patient with impairment of the lateral femoral cutaneous nerve in the contralateral leg after THA.A 55-year-old woman with a body mass index of 34.24 kg/m(2) underwent THA in the right lateral decubitus position. Because of her body habitus, a bean-bag positioner was used. Total hip arthroplasty was performed using a direct lateral approach. Intraoperative surgical time was 2.5 hours, and total anesthesia time was 3.5 hours. A few days postoperatively, the patient began to experience "burning and shooting" pain in the contralateral hip, but she did not report this pain until 6 weeks postoperatively. She was treated initially with a single lidocaine injection. When this was ineffective, she was treated with topiramate (100 mg daily) and vitamin B6 (100 mg orally twice daily). The symptoms lessened markedly at 5 months and resolved completely at 9 months postoperatively.Meralgia paresthetica is an uncommon, but known, complication of THA. To our knowledge, it has been reported only in the operative limb. This report reinforces the need for careful positioning to avoid pressure over the anterior superior iliac spine intraoperatively.

Lateral femoral cutaneous nerve impairment after direct anterior approach for total hip arthroplasty.

The anterior supine approach for total hip arthroplasty (THA) offers the advantage of operating through a true intravascular and intranervous plane, but it places the lateral femoral cutaneous nerve at risk. The purpose of this study was to identify the incidence of and impairment relating to injury of the lateral femoral cutaneous nerve. We performed a retrospective chart review of 81 hips undergoing anterior supine THA from November 2005 through May 2007 to determine operative time, estimated blood loss, fluoroscopic time, type of anesthesia used, intraoperative complications, and postoperative systemic and wound complications. Postoperative radiographs were evaluated for leg-length discrepancy, acetabular inclination and anteversion, and femoral stem position. Patients were reassessed at 6 weeks, 3 months, 6 months, 1 year, and 2 years. At each visit, patients were questioned about numbness or paresthesias in the distribution of the lateral femoral cutaneous nerve; if present, the patient outlined the area with a marking pen. This area was photographed, and data were collected. No hip had frank numbness; 12 hips (14.8%) had paresthesias. For those 12, symptoms resolved in 4 by 6 months, in 6 by 1 year, and in 10 (83.3%) by 2 years; 2 remained unresolved. No significant difference was found between patients with and without paresthesias or between patients with resolved or unresolved paresthesias. Impaired sensation did not appear to affect functional outcome or Harris Hip Score. Incision position, dissection plane, retractor placement, tension and soft tissue handling, and surgeon experience may affect incidence of injury to the lateral femoral cutaneous nerve.

Evaluating the function of total joint replacements - biomed 2010.

The primary function of hip and knee joints is to permit movement. The pathology of arthritic diseases leads to loss of articular surface anatomy and deformity which will impede motion. Consequently, one of the primary goals of total joint replacement is to restore mobility. The assessment of implants in the research and development phase includes the use of computer models, joint simulators and clinical trials. Clinical evaluation assesses motion, the ability of a patient to perform certain activities and the potential use of assistive devices. These assessments encompass patient examination and measurement of motion about the joint, instrumented tools (accelerometers, gait analysis), questionnaires (self-report, interview-based), and performance-based evaluations. In order to fully appreciate the functional outcome of a total joint implant, more than one type of assessment is required.

Cementing polyethylene liners into non-modular acetabular components in revision total hip arthroplasty.

PURPOSE: To review mid-term results after replacing the polyethylene liner in a well-fixed acetabular shell. METHODS: 22 patients underwent replacement of the polyethylene liner in a well-fixed acetabular shell using cementation. The inner surface of the metal shell was scored with grooves (1 to 2 mm deep) for cement interdigitation. Trial liners were used to assess the appropriate size, with an aim to provide at least 2 mm of an even cement mantle behind the polyethylene liner. None of the liners were constrained or lipped. Clinical and radiographic outcomes were evaluated, and Harris Hip Scores obtained. Radiographic loosening of the acetabular shell was recorded. Implant survival was evaluated using the Kaplan- Meier estimator. RESULTS: After a mean follow-up of 70 (range, 21-189) months, 17 patients had stable hips and their mean Harris Hip Score was 89 (range, 72-93). Four patients underwent re-revision after 28 to 108 months for aseptic loosening of the acetabular shell (n=2) and recurrent dislocation (n=2). One patient showed radiographic evidence of acetabular migration but was stable. The femoral components of all patients were stable. 92% of patients had good-to-excellent results. Implant survival at 60 months was 81% (95% confidence interval [CI], 51-94%); it became 91% (95% CI, 61-99%) if reductions for dislocations were excluded. CONCLUSION: Cementation of an undersized polyethylene liner into a non-modular shell is one option for revision of a well-fixed acetabular shells. Nonetheless, further follow-up is required to determine if it remains a viable option in the long term. If there is any doubt about the stability of the acetabular shell, a complete revision should be performed.

Outcome measures for evaluation of treatments for osteonecrosis.

With the advent of cell-based therapies, biologics, and pharmaceuticals for the potential treatment of osteonecrosis, it is important to conduct evaluations using scientifically accepted outcomes measures. For the treatment of osteonecrosis, most studies have focused on pain relief, surgery, or the need for surgery, disease progression (advancing stage), and change in lesion size. Quantification of imaging techniques continue to gain in sophistication but have not yet been validated for use in clinical trials. Despite recent interest in using biomarkers or genetic markers in the diagnosis and analysis of disease progression, more research is needed to determine the sensitivity and specificity of these techniques with respect to osteonecrosis.

Outcome of uncemented primary femoral stems for treatment of femoral head osteonecrosis.

Cementless total hip replacement has been advocated for patients with osteonecrosis of the femoral head. This study examined the outcome of the femoral stem of four generations of an uncemented, proximally porous-coated, chrome-cobalt total hip prosthesis. There were 158 cases in 141 osteonecrosis patients (74 men, 67 women) who had a mean age of 46 years (range, 17-83 years). The mean follow-up was 103 months (range, 20-235 months). The femoral components of 144 cases were not revised and had a mean Harris hip score of 84 (+/-15) at final follow-up. Of the 14 revisions (8.9%), the primary reasons for revision were loosening or significant osteolysis. There were one infection and one chronic dislocation. Proximally porous-coated, anatomic, press-fit stems provide excellent long-term results in patients with osteonecrosis of the femoral head.

Analysis of retrieved hemiresurfacing implant.

The aim of this study was to examine the bony interface underlying a femoral hemiresurfacing implant. The specimen was subjected to radiographic and histologic analyses. The presence of a cement mantle was not uniform throughout the interface. When cement was evident, trabecular bone was found interdigitated within the mantle. When cement was not present, a fibrous tissue membrane was detected between the metal surface of the implant and the host bone. Disruption of the bone stock surrounding the stem was observed. While the reason for the revision was for relief of severe pain for acetabular chondrolysis, bony support of the implant may have been compromised.

Use of fluoroscopically guided intra-articular hip injection in differentiating the pain source in concomitant hip and lumbar spine arthritis.

UNLABELLED: We retrospectively tested the effectiveness of fluoroscopically guided intra- articular hip injection in differentiating the pain generator in patients with atypical lower extremity pain and concomitant radiographic hip and spine arthritis. After the hip injection, 74 of 83 patients had pain relief (pain score improvement, 7.2 to 2.7) and functional improvement (Harris hip score [HHS] improvement, 54.3 to 80.4). Of those 74 patients, 50 (mean preoperative HHS, 60.3) went on to hip arthroplasty (for 48 of these 50, mean HHS increased to 84.4); the other 24 patients are being treated nonoperatively so far. The 11 patients who did not experience pain relief (9 after initial injection plus 2 after total hip arthroplasty) were found to have spinal pathology and were treated accordingly. STATISTICS: sensitivity, 100%; specificity, 81%; positive predictive value, 97%; negative predictive value, 100%.