Measured distance from posterior tibia to popliteal artery increases with flexion and subluxation of the knee.

Purpose: Popliteal artery laceration is a devastating complication in total knee arthroplasty (TKA). Its anatomic position relative to the tibia has been studied using ultrasound or magnetic resonance imaging. This is the first study performed in a laboratory using radiographic measurements to determine if increased flexion and subluxation of the knee increase the distance between the tibia and popliteal artery. Methods: The femoral artery was infused with radiopaque dye in six cadavers. The knee was placed in two different degrees of flexion and three of subluxation. The radiographic distance between standardized markers in the posterior tibia and popliteal artery was measured. Results: The average distance from the tibial peg to the popliteal artery at 90° of flexion increased from 0% to 50% to 100% subluxation. The increase was statistically significant (Friedman test p = 0.016). The contrast between neutral and 100% subluxation was statistically significant (Sign test p = 0.031). At 115° flexion, average distance from the peg to popliteal artery significantly increased as subluxation increased (Friedman test p = 0.05). In three specimens, at 115° of flexion and 100% subluxation, a line perpendicular to the axis of the tibia, failed to intersect the popliteal artery. The measured distance increased from 90° to 115° of flexion at a given degree of subluxation, but this difference did not reach statistical significance. Conclusions: Increasing flexion and subluxation of the tibia results in increasing distance between the cut plane of the tibial plateau and popliteal artery and decreases risk of laceration. Level of Evidence: Not applicable.

Late Atraumatic Ceramic Head Fracture in Total Hip Arthroplasty: A Case Report.

Introduction: Atraumatic ceramic femoral head fracture is an uncommon but overwhelming complication of total hip arthroplasty (THA). The complication rate is low, with few reports in the literature. It is critical to continue researching late fracture risk to mitigate these instances. Case Report: A 68-year-old Caucasian female presented with an atraumatic ceramic femoral head fracture in the setting of a ceramic-on-ceramic THA 17 years after primary surgery. The patient was successfully revised to a dual-mobility construct with a ceramic femoral head and a highly cross-linked polyethylene liner. The patient returned to normal function without pain. Conclusion: The complication rate for fracture of the ceramic femoral head is as low as 0.001% for fourth-generation aluminum matrix composite designs, while the complication rate of late atraumatic ceramic fracture is largely unknown. We present this case to add to the current literature.

Liposomal Bupivacaine vs Ropivacaine for Adductor Canal Blocks in Total Knee Arthroplasty: A Prospective Randomized Trial.

BACKGROUND: The purpose of this study is to determine the benefit of the analgesic liposomal bupivacaine compared to ropivacaine, by assessing pain and joint stiffness, and total oral opioid consumption by milligram morphine equivalent (MME) after total knee arthroplasty. METHODS: Patients were randomized to receive either the study drug (liposomal bupivacaine admixed with bupivacaine) or the control drug (ropivacaine) in an adductor canal block. Only the anesthesiologist performing the block was aware of which arm of the study the patient was randomized to. MME, pain, Knee injury and Osteoarthritis Outcome Score Joint Replacement, and overall benefit of analgesia scores were recorded 24, 48, and 72 hours post-surgery either face-to-face or via telephone depending on patient discharge status. RESULTS: One hundred patients were enrolled into the study and analyzed: 54 in the control group and 46 in the experimental group. Primary outcomes measured were pain as a numerical rating scale, MME, and length of stay in hours. Secondary outcomes were joint pain and stiffness recorded as Knee injury and Osteoarthritis Outcome Score Joint Replacement outcome and overall benefit of analgesia score. No statistically significant between-group differences were observed for any measured outcome. CONCLUSION: We did not find any supporting evidence that liposomal bupivacaine yields increased pain relief following total knee arthroplasty compared to the control drug, ropivacaine.

No Increase in Instability with Obturator Externus Release in Direct Anterior Approach.

Use of the direct anterior approach in total hip arthroplasty is becoming increasingly common. Complications associated with this approach pertain to proximal femoral exposure. Selective capsular and tendinous releases improve exposure intraoperatively. Release of obturator externus has been avoided to prevent postoperative instability. A retrospective case-control review of consecutive patients who underwent direct anterior approach was performed. Demographic information, sequence of releases performed, dislocations that occurred postoperatively, and revision total hip arthroplasties (THAs) were recorded. Overall dislocation rate was 0.6% (2/340). Obturator externus release was performed in 169 cases (49.7%). Both groups with and without release experienced a single dislocation event (p = 1.0). Overall revision rate was also 0.6% (2/340). One dislocation underwent revision for instability. Selective release of obturator externus after other releases have failed to improve proximal femoral exposure does not result in an increased rate of postoperative hip instability in direct anterior approach THA. (Journal of Surgical Orthopaedic Advances 30(2):082-084, 2021).

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.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 1: Glucocorticoid-Associated Osteonecrosis.

BACKGROUND: Glucocorticoid usage, a leading cause of osteonecrosis of the femoral head (ONFH), and its prevalence was reported in 25%-50% of non-traumatic ONFH patients. Nevertheless, there have been no unified criteria to classify glucocorticoid-associated ONFH (GA-ONFH). In 2015, the Association Research Circulation Osseous addressed the issue of developing a classification scheme. METHODS: In June 2017, a task force was set up to conduct a Delphi survey concerning ONFH. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey consists of questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, the panel reached a consensus on the classification criteria. The response rates were 100% (Round 1), 96% (Round 2), and 100% (Round 3), respectively. RESULTS: The consensus on the classification criteria of GA-ONFH included the following: (1) patients should have a history of glucocorticoid use >2 g of prednisolone or its equivalent within a 3-month period; (2) osteonecrosis should be diagnosed within 2 years after glucocorticoid usage, and (3) patients should not have other risk factor(s) besides glucocorticoids. CONCLUSION: Association Research Circulation Osseous established classification criteria to standardize clinical studies concerning GA-ONFH.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 2: Alcohol-Associated Osteonecrosis.

BACKGROUND: Although alcohol is a leading risk factor for osteonecrosis of the femoral head (ONFH) and its prevalence reportedly ranges from 20% to 45%, there are no unified classification criteria for this subpopulation. In 2015, Association Research Circulation Osseous decided to develop classification criteria for alcohol-associated ONFH. METHODS: In June of 2017, Association Research Circulation Osseous formed a task force to conduct a Delphi survey. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey included questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, consensus was reached on the classification criteria. The response rates for the 3 Delphi rounds were 100% (round 1), 96% (round 2), and 100% (round 3). RESULTS: The consensus on the classification criteria of alcohol-associated ONFH included the following: (1) patients should have a history of alcohol intake >400 mL/wk (320 g/wk, any type of alcoholic beverage) of pure ethanol for more than 6 months; (2) ONFH should be diagnosed within 1 year after alcohol intake of this dose; and (3) patients should not have other risk factor(s). CONCLUSION: ARCO-established classification criteria to standardize clinical studies concerning AA-ONFH.

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.

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.

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.

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.

A quantitative method to assess focal acetabular overcoverage resulting from pincer deformity using CT data.

BACKGROUND: Current assessment techniques for focal acetabular overcoverage are neither consistent nor quantitatively accurate. QUESTIONS/PURPOSES: We propose: (1) a method to precisely quantify the amount of focal acetabular overcoverage in a patient's pincer deformity based on CT data; (2) to evaluate the consistency of this method; and (3) to compare the method with conventional radiographic assessments. METHODS: We developed a method to assess focal acetabular overcoverage using points selected from CT scans along the acetabular rim after realigning the pelvis into a neutral position. Using four resampled and segmented pelvic CT scans of cadaveric specimens with virtually induced impingement, two observers independently tested the algorithm's consistency. Our algorithm assessed the amount of focal acetabular overcoverage using CT data and projected data from reconstructed radiographs. RESULTS: (1) We successfully showed the feasibility of the software to produce consistent, quantitative measurements. (2) Testing showed the average difference between observers in aligning the pelvis was 0.42°, indicative of a consistent approach. (3) Differences between measurements on three-dimensional (3-D) CT and simulated radiographs were significant. CONCLUSIONS: The proposed method represents a new avenue in consistently quantifying focal acetabular overcoverage using CT models while correcting for pelvic tilt and rotation. Our analysis confirms AP hip radiograph simulations overestimate the amount of overhanging acetabular rim in a pincer deformity. CLINICAL RELEVANCE: This technique has potential to improve preoperative diagnostic accuracy and enhance surgical planning for correction of a pincer deformity resulting from focal acetabular overcoverage.

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.

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.

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.

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.

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.