Aidin Eslam Pour

Total Hip Prostheses in Standing, Sitting and Squatting Positions: An Overview of Our 8 Years Practice Using the EOS Imaging Technology

More total hip arthroplasty (THA) is performed worldwide and especially in younger and more active patients compared to earlier decades. One of the focuses of THA research in the future will be on optimizing the radiological follow-up of these patients using 2D and 3D measurements of implants position while reducing the radiation dose delivered. Low-dose EOS® imaging is an innovative slot-scanning radiograph system providing valuable information in patient functional positions (standing, sitting and even squatting positions). EOS has been proven accurate and reliable without significant inconvenience caused by the metallic artifacts of implants. The ability to obtain precise data on implant orientation according to the patient posture opens new perspectives for a comprehensive analysis of the pelvic frontal and sagittal balance and its potential impact on implants function and failures. We report our 8 years experience on our first 300 THA patients using this technology routinely for pre and post op evaluation. Our results will be compared and confronted with the actual literature about this innovative technology. We shall especially emphasize our experience about patients with abnormal posture and the evolution of the subject over time, because the phenomenon of an aging spine is frequently associated with the process of aging hips.

Measuring extension of the lumbar-pelvic-femoral complex with the EOS® system.

IntroductionSagittal balance of the coxofemoral joint in standing position and its extension capacity determine hip/spine adaptation, especially in relation to pelvic retroversion, which may be age-associated or follow either spinal arthrodesis or vertebral osteotomies. The concept of extension reserve is essential for assessing posterior hip impingement. The global visualization of the lumbar–pelvic–femoral complex obtained by EOS® imaging enables this sagittal analysis of both the subpelvic region and lumbar spine by combining the reference standing position and the possibility of dynamic tests.Materials and methodsWe studied 46 patients and their 92 hips. The EOS® radiography was performed in neutral standing position and with one foot on a step, alternately the right and left feet. Pelvic incidence, sacral slope, pelvic version, and femoral version were measured twice by two operators. The global extension reserve (GER) was defined by the sum of the intrinsic extension reserve (allowed by the hips, IER) and the extrinsic extension reserve (allowed by the spine, EER). The IER for each hip corresponds to the difference in the sacrofemoral angle (SFA) for each of the two positions. The EER was measured by the difference in the sacral slope. A descriptive study was performed, together with studies of inter- and intra-observer reproducibility, right/left symmetry, and an analysis according to age, sex, and BMI.ResultsThe mean femoral version in the reference position was 11.7° (SD 14.3°). The reproducibility of the SFA measurement was statistically verified. The IER (mean 8.8°), EER (mean −0.7°), and GER (mean 8.2°) all differed significantly between the two sides for each patient and were not associated with age, sex, or BMI.DiscussionThe femoral axis is not perpendicular to the ground in neutral position, contrary to the conventional view of this position. The measurements proposed for dynamic sagittal analysis of the hip are reproducible and make it possible to identify the IER within the GER of the spinal–pelvic–femoral complex.ConclusionThe assessment of the lumbar–pelvic–femoral complex by EOS imaging makes it possible to define the intrinsic and extrinsec extension reserves to describe the reciprocal adaptive capacities of the hips and spine.Level of evidenceIV.

Post-operative medical and surgical complications after primary total joint arthroplasty in solid organ transplant recipients: a case series

PurposeIn a series of solid organ transplant (SOT) recipients who underwent a subsequent primary total joint arthroplasty (TJA) procedure, this study aimed to determine: (1) 90-day morbidity and mortality after primary total knee or hip arthroplasty (TKA and THA), (2) overall post-operative infection rates, and (3) how complication and infection rates compared across primary TJA procedure and type of transplant organ.MethodsThe University of Michigan Health System database was retrospectively searched using current procedural terminology codes for any primary TKA or THA performed at the institution in years 2000–2012 in a patient who previously received a successful SOT at any hospital.ResultsThe search yielded 44 arthroplasties performed in 29 SOT recipients (average age 54.8 years, average follow-up about 30 months for both groups). No deaths were reported, but 13/27 (48.1%) THA patients and 2/6 (33.3%) TKA patients experienced a total of 29 complications within 90 days of surgery. One patient (3.7%) [1/27 patients, 1/37 joints] underwent revision hip arthroplasty to correct limb length. One THA patient and two TKA patients developed infection requiring revision surgery (3.7% and 33%, respectively). Type of transplant did not affect complication rates (P=0.65), and infection was more common after TKA (P=0.01).ConclusionsA series of SOT recipients demonstrated increased rates of infection and other complications following TJA. Surgical and medical teams should work closely to optimize this population for TJA surgery and minimize peri-operative complications.Level of evidence & study designLevel IV, Prognostic Case-Series.

What is the impact of a spinal fusion on acetabular implant orientation in functional standing and sitting positions

BACKGROUND This study used EOS imaging of primary total hip arthroplasty (THA) patients, with and without predating spinal fusion, to investigate (1) the impact of spinal fusion on acetabular implant anteversion and inclination, and (2) whether more extensive spinal fusion (fusion starting above the thoracolumbar junction or extension of fusion to the sacrum) affects acetabular implant orientation differently than lumbar only spinal fusion. METHODS Ninety-three patients had spinal fusion (case group), and 150 patients were without spinal fusion (controls). None of the patients experienced dislocation. The change in sacral slope (SS) and cup orientation from standing to sitting was measured. RESULTS Mean SS change from the standing to sitting positions was -7.9°in the fusion group vs -18.4°in controls (P = .0001). Mean change in cup inclination from the standing to sitting positions was 4.9°in the fusion group vs 10.2°in controls (P = .0001). Mean change in cup anteversion from standing to sitting positions was 7.1°in the fusion group vs 12.1°in controls (P = .0001). For each additional level of spinal fusion, the change in SS from standing to sitting positions decreased by 1.6(95% confidence interval [CI], 2.2073-1.0741), the change in cup inclination decreased by 0.8(95% CI, 0.380-1.203), and the change in cup anteversion decreased by 0.9(95% CI, 0.518-1.352; P < .001 in all cases). CONCLUSION Patients with spinal fusion demonstrated less adaptability of the lumbosacral junction. Longer spinal fusion or inclusion of the pelvis in the fusion critically impacts hip-spine biomechanics and significantly affects the ability to compensate in the standing-to-sitting transition.

High Risk of Failure With Bimodular Femoral Components in THA

BackgroundThe bimodular femoral neck implant (modularity in the neck section and prosthetic head) offers several implant advantages to the surgeon performing THAs, however, there have been reports of failure of bimodular femoral implants involving neck fractures or adverse tissue reaction to metal debris. We aimed to assess the results of the bimodular implants used in the THAs we performed.Questions/purposesWe asked: (1) What is the survivorship of the PROFEMUR® bimodular femoral neck stems? (2) What are the modes of failure of this bimodular femoral neck implant? (3) What are the major risk factors for the major modes of failure of this device?MethodsBetween 2003 and 2009, we used one family of bimodular femoral neck stems for all primary THAs (PROFEMUR® Z and PROFEMUR® E). During this period, 277 THAs (in 242 patients) were performed with these implants. One hundred seventy were done with the bimodular PROFEMUR® E (all are accounted for here), and when that implant was suspected of having a high risk of failure, the bimodular PROFEMUR® Z was used instead. One hundred seven THAs were performed using this implant (all are accounted for in this study). All bearing combinations, including metal-on-metal, metal-on-polyethylene, and ceramic-on-ceramic, are included here. Data for the cohort included patient demographics, BMI, implant dimensions, type of articular surface, length of followup, and C-reactive protein serum level. We assessed survivorship of the two stems using Kaplan-Meier curves and determined the frequency of the different modes of stem failure. For each of the major modes of failure, we performed binary logistic regression to identify associated risk factors.ResultsSurvivorship of the stems, using aseptic revision as the endpoint, was 85% for the patients with the PROFEMUR® E stems with a mean followup of 50 months (range, 1–125 months) and 85% for the PROFEMUR® Z with a mean followup of 50 months (range, 1–125 months)(95% CI, 74–87 months). The most common modes of failure were loosening (9% for the PROFEMUR® E), neck fracture (6% for the PROFEMUR® Z and 0.6% for the PROFEMUR® E), metallosis (1%), and periprosthetic fracture (1%). Only the bimodular PROFEMUR® E was associated with femoral stem loosening (odds ratio [OR] =1.1; 95% CI, 1.04–1.140; p = 0.032). Larger head (OR = 3.2; 95% CI, 0.7–14; p = 0.096), BMI (OR = 1.19; 95% CI, 1–1.4; p = 0.038) and total offset (OR = 1.83; 95% CI, 1.13–2.9; p = 0.039) were associated with neck fracture.ConclusionBimodular neck junctions may be potentiated by long neck lengths, greater offset, and larger head diameters. These factors may contribute to bimodular neck failure by creating a larger moment about the neck’s insertion in the stem. The PROFEMUR® E implant is associated with high periprosthetic loosening. Based on our experience we cannot recommend the use of bimodular femoral neck implants.Level of EvidenceLevel III, therapeutic study.

Trends in Primary and Revision Hip Arthroplasty Among Orthopedic Surgeons Who Take the American Board of Orthopedics Part II Examination

BACKGROUND A certified list of all operative cases performed within a 6-month period is a required prerequisite for surgeons taking the American Board of Orthopaedic Surgery Part II oral examination. Using the American Board of Orthopaedic Surgery secure Internet database database containing these cases, this study (1) assessed changing trends for primary and revision total hip arthroplasty (THA) and (2) compared practices and early postoperative complications between 2 groups of examinees, those with and without adult reconstruction fellowship training. METHODS Secure Internet database was searched for all 2003-2013 procedures with a Current Procedural Terminology code for THA, hip resurfacing, hemiarthroplasty, revision hip arthroplasty, conversion to THA, or removal of hip implant (Girdlestone, static, or dynamic spacer). RESULTS Adult reconstruction fellowship-trained surgeons performed 60% of the more than 33,000 surgeries identified (average 28.1) and nonfellowship-trained surgeons performed 40% (average 5.2) (P < .001). Fellowship-trained surgeons performed significantly more revision surgeries for infection (71% vs 29%)(P < .001). High-volume surgeons had significantly fewer complications in both primary (11.1% vs 19.6%) and revision surgeries (29% vs 35.5%) (P < .001). Those who passed the Part II examination reported higher rates of complications (21.5% vs 19.9%). CONCLUSION In early practice, primary and revision hip arthroplasties are often performed by surgeons without adult reconstruction fellowship training. Complications are less frequently reported by surgeons with larger volumes of joint replacement surgery who perform either primary or more complex cases. Primary hip arthroplasty is increasingly performed by surgeons early in practice who have completed an adult reconstructive fellowship after residency training. This trend is even more pronounced for more complex cases such as revision or management of infection.

Delayed-onset sciatic nerve palsy after periacetabular osteotomy: A case report

Case: A large surgical correction was required for severe hip dysplasia, which was associated with a delayed-onset sciatic nerve injury in an adolescent patient. A cortical bone spur on the outside of the acetabular fragment produced an indirect injury that became symptomatic during mobilization of the patient. Conclusion: The risk of direct injury to the sciatic nerve during a periacetabular osteotomy is quite low when the osteotomy is executed in extension with abduction of the hip and flexion of the knee to reduce tension on the sciatic nerve. Reported injuries have been attributed to direct damage from excessive soft-tissue retraction or during osseous ischial, supra-acetabular, and/or retroacetabular osteotomies.

Previous arthroscopic repair of femoro-acetabular impingement does not affect outcomes of total hip arthroplasty

BackgroundTotal hip arthroplasty (THA) is commonly elected following failed arthroscopic treatment of femoro-acetabular impingement (FAI). The purpose of this study was to evaluate post-operative outcomes of primary THA in patients who had previously undergone arthroscopic treatment for FAI.MethodsA retrospective, matched case–control study was conducted. The case group included 39 patients who underwent THA after previous hip arthroscopy for FAI. Thirty-nine patients who had a primary THA without previous hip arthroscopy served as a control group and were matched for age, sex and body mass index. Surgical outcomes were assessed based on inpatient hospital metrics and outpatient complication measures. Statistical analyses were performed to identify the significance of outcome variables between case and control groups.ResultsNo statistically significant differences were observed between groups in terms of operative time, haemoglobin drop, intra-operative estimated blood loss, transfusion requirements, amounts of opioids provided, functional mobility assessments on post-operative days one and two, length of hospitalization, discharge location, emergency department visits, post-operative superficial or deep periprosthetic infection, revision rates for dislocation or formation of heterotopic bone (p-values = 0.1–0.8). A statistically significant difference was found between the walking scores on the third post-operative day (p = 0.015).ConclusionsThese findings, while underpowered, are consistent with other previously published reports. Previous hip arthroscopy for FAI does not appear to impact post-operative outcomes of a subsequent THA. Larger datasets from different surgeons and centers are needed to further assess these conclusions.Level of evidenceCase–control level-III.

Complicated Outcomes After Emergent Lower Extremity Surgery in Patients With Solid Organ Transplants.

The complications of emergent or urgent surgery in solid organ transplant recipients are unclear. The goal of this nonrandomized retrospective case study, conducted at a large public university teaching hospital, was to determine the following: (1) 90-day postsurgical complications in solid organ transplant recipients who undergo fracture surgery of the lower extremities; (2) 90-day and 1-year mortality rates for this cohort; (3) correlation of particular postsurgical complications with the 90-day or 1-year mortality rate; and (4) correlation of body mass index with the 90-day or 1-year mortality rate. Subjects included 36 solid organ transplant recipients who underwent surgical treatment for 37 emergent or urgent lower extremity fractures within 72 hours of presentation to the emergency department. Patients were followed for all medical and surgical complications for 90 days and for all-cause mortality for 1 year. Within 90 days of surgery, patients had complications that included acute renal failure (15, 40.5%), deep venous thrombosis (3, 8.1%), pulmonary embolus (2, 5.4%), pneumonia (7, 18.9%), superficial surgical site infection (3, 8.1%), and nonorthopedic sepsis (4, 10.8%). In addition, 3 (8.1%) and 5 (13.9%) patients died within 90 days and 1 year, respectively. Hospital readmission correlated with a higher 1-year mortality rate (odds ratio, 14.000; P=.016). Higher body mass index correlated with higher 90-day (odds ratio, 1.425; P=.035) and 1-year (odds ratio, 1.334; P=.033) mortality rates. Solid organ transplant recipients with lower extremity fracture have high 90-day and 1-year mortality rates and may have multiple complications within 90 days of treatment. [Orthopedics. 2016; 39(6):e1063-e1069.].

Total Hip Arthroplasty in Patients With Parkinson Disease: Improved Outcomes With Dual Mobility Implants and Cementless Fixation

BACKGROUND Parkinson disease (PD) results in severe limitation in ambulation caused by abnormality of gait and posture. The rate of complications, including fractures and dislocation after total hip arthroplasty (THA), can be higher among these patients. The goal of this study was to investigate the long-term outcomes of primary and revision THAs with cementless dual mobility implants. METHODS This retrospective study examines 59 PD patients who had surgery between 2002 and 2012. All the primary cases were performed for osteoarthritis and all patients received cementless acetabular implants with dual mobility bearing surface. The femoral stem was cemented in 4 patients who underwent revision surgery. The mean follow-up time was 8.3 years (4-14 years). RESULTS Good to excellent pain relief was achieved in 53 of 57 patients at the 2-year follow-up and in 40 of 47 patients at their latest follow-up. The most common medical complication was cognitive impairment (12 of 57 patients). One patient sustained an intraprosthetic hip dislocation 9 years after surgery, which required revision. Four patients sustained periprosthetic femoral fractures with well-fixed stem, requiring open reduction and internal fixation. The disability had increased in 68% of the patients in the latest follow-up visit. DISCUSSION Our study shows that elective primary or revision THA using cementless implants with dual mobility bearing surface in patients with PD provides satisfactory long-term outcomes, although many of these patients may see a general worsening of their activities over time due to PD.