Total Hip Revision with a Custom Acetabular Component and Femoral Allograft-Prosthetic Composite as Salvage for Failed Unstable Megaprosthesis in an Adolescent Patient: A Case Report at 19-Year Follow-up Duration.

CASE: A 13-year-old girl presented after a right proximal femur replacement after proximal femoral resection for treatment of an Ewing sarcoma. She presented after multiple episodes of recurrent instability with her hip endoprosthesis chronically dislocated. Her hip was revised to a custom, constrained metal-on-metal acetabular component with a small iliac flange. The femoral component was revised to an allograft-prosthetic composite. She has been free of malignancy recurrence, implant failure, or dislocation at 19-year follow-up duration. CONCLUSION: Dislocation of the prosthetic hip can be a challenging postoperative complication, particularly when associated with a tumor megaprosthesis in a pediatric age group. This is further compounded in the presence of deficient pelvic bone stock. Restoration of bone stock is optimal, but when impossible, custom components may be necessary to establish hip stability.

What is the Effect of Posterior Osteophytes on Flexion and Extension Gaps in Total Knee Arthroplasty? A Cadaveric Study.

BACKGROUND: Posterior compartment knee osteophytes may pose a challenge in achieving soft-tissue balance during total knee arthroplasty (TKA). Obtaining symmetry of flexion and extension gaps involves balance of both bony and soft-tissue structures. We hypothesize that space-occupying posteromedial femoral osteophytes affect soft-tissue balance. METHODS: Five cadaveric limbs were acquired. Computed tomography scans were obtained to define the osseous contours. Three-dimensionally printed, specimen-specific synthetic posterior femoral osteophytes were fabricated in 10-mm and 15-mm sizes. TKAs were implanted. Medial and lateral compartment contact forces were measured during passive knee motion using pressure-sensing technology. For each specimen, trials were completed without osteophytes and with 10-mm and 15-mm osteophytes affixed to the posteromedial femoral condyle. Contact forces were obtained at full extension, 10°, 30°, 45°, 60°, and 90° of flexion. These were recorded across each specimen in each condition for three trials. Tukey post hoc tests were used with a repeated measures ANOVA for statistical data analysis. RESULTS: The presence of posteromedial osteophytes increased asymmetric loading from full extension to 45° of flexion, with statistically significant differences observed at full extension and 30°. A reduction in lateral compartment forces was noted. The 25%-75% bounds of variability in the contact force was less than 3.5 lbs. CONCLUSIONS: Posteromedial femoral osteophytes caused an asymmetric increase in medial contact forces from full extension continuing into mid-flexion. The soft-tissue imbalance created from these osteophytes supports their removal before performing ligament releases to obtain desired soft-tissue balancing during TKA.

Usefulness of Perioperative Laboratory Tests in Total Hip and Knee Arthroplasty: Are They Necessary for All Patients?

BACKGROUND: Laboratory studies are routinely obtained preoperatively and postoperatively for total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study evaluates the necessity of routine, perioperative laboratory tests and identifies risk factors for laboratory-associated interventions. METHODS: This retrospective review evaluated 967 consecutive patients scheduled for primary, unilateral TKAs (n = 593) or THAs (n = 374) over an 18-month period at a single institution. Preoperative prothrombin time (PT) and International Normalized Ratio (INR), complete blood count (CBC), complete metabolic panel (CMP), and postoperative CBC and basic metabolic panel (BMP) were recorded along with any laboratory-associated intervention. Patient demographics and comorbidities identified risk factors for abnormal or actionable laboratory studies. RESULTS: Preoperatively, the actionable rates for PT/INR, CMP, and CBC were 0.3%, 1.4%, and 0.5%, respectively. Vascular, renal, and immunologic diseases were risk factors for an actionable CBC. Risk factors for an actionable CMP include cardiac arrhythmia and diabetes. There were no risk factors for an actionable PT/INR. Postoperatively, only 1.5% of BMPs and 1.5% of CBCs were actionable. Congestive heart failure, renal disease vascular disease, or history of cancer (P = .030) were risk factors for an actionable CBC. There were no risk factors for an actionable BMP. Patients with an abnormal preoperative lab were 2.4 times more likely to have an actionable postoperative lab. Patients with an actionable preoperative lab were 11.3 times more likely to have an actionable postoperative lab. CONCLUSION: Routine preoperative and postoperative labs may not be necessary on all patients undergoing a TKA or THA. Comorbid risk factors and abnormal or actionable preoperative CMPs and CBCs can help determine the usefulness of postoperative laboratory assessments.

Does the use of intraoperative fluoroscopy improve postoperative radiographic component positioning and implant size in total hip arthroplasty utilizing a direct anterior approach?

BACKGROUND: The direct anterior approach (DAA) for total hip arthroplasty (THA) has gained recent popularity, with 1 purported benefit being access to intraoperative fluoroscopy. However, there are limited data demonstrating improved component position with the use of intraoperative fluoroscopy. The aim of this study is to compare radiographic implant positioning on 2 consecutive cohorts of patients undergoing DAA THA performed by 1 surgeon either utilizing intraoperative fluoroscopy or not. We hypothesized that there would be no relevant radiographic differences between the cohorts. METHODS: Forty-two consecutive patients underwent DAA THA utilizing fluoroscopy (IFC), and 42 consecutive patients then underwent DAA THA without fluoroscopy (NFC). Using preoperative pelvis radiographs and 6-week postoperative pelvis radiographs, acetabular anteversion, inclination, femoral offset, and templated component sizes vs final intraoperatively selected sizes were recorded and compared between cohorts. RESULTS: Acetabular inclination was 45.0° for IFC and 45.6° for NFC (P = .629). Femoral offset difference preoperatively and postoperatively was 0.8 mm for IFC and 1.3 mm for NFC (P = .734). Number of hips within the so-called safe zone was 32 for IFC and 33 for NFC (P = .794). These all demonstrated no significant difference between the cohorts. However, acetabular anteversion was 13.7° for IFC and 11.2° for NFC (P = .02). CONCLUSIONS: In this limited series, the routine use of intraoperative fluoroscopy did not improve implant positioning or sizing. This may be surgeon-specific or due to the result of the use of acetabular landmarks to guide placement of the components without fluoroscopy.

Management of Bone Defects in Revision Total Knee Arthroplasty with Use of a Stepped, Porous-Coated Metaphyseal Sleeve.

BACKGROUND: Revision total knee arthroplasty is a costly operation associated with many challenges including bone loss in the distal end of the femur and proximal end of the tibia1,2. Reconstruction of bone defects remains a difficult problem that may require more extensive reconstruction techniques to restore mechanical stability and ensure long-term fixation. Use of porous-coated metaphyseal sleeves is a modern technique to address bone deficiency in revision total knee arthroplasty3,4. Midterm reports have shown excellent survivorship and osseointegration5-7. DESCRIPTION: The use of a porous-coated metaphyseal sleeve begins with intramedullary canal reaming to determine the diameter of the diaphyseal-engaging stem. Bone loss is assessed followed by broaching of the tibial and/or femoral metaphyses. Broaching continues until axial and rotational stability are achieved. The sleeve typically occupies most, if not all, of the proximal tibial and distal femoral cavitary osseous defects often encountered during revision total knee arthroplasty. However, a sleeve does not address all distal and posterior femoral condylar bone loss, for which augments are often required. ALTERNATIVES: Previously described methods to address various bone deficiencies include use of morselized or structural bone-grafting, reinforcing screws within cement, metal augments, and metaphyseal cone fixation8-17. RATIONALE: Structural allografts or metal augments remain a suitable option for uncontained metaphyseal defects. Metaphyseal structural allografts may undergo stress-shielding, resorption, and late fracture. Metaphyseal sleeves offer long-term biologic fixation to host bone while creating a stable platform to receive a cemented femoral and/or tibial component7. This hybrid combination may provide mechanically protective properties to decrease the loads at the cement-bone interfaces and enhance loads to metaphyseal bone to ensure long-term implant fixation in the setting of substantial bone deficiencies18-20.

Does the Method of Sterile Glove-Opening Influence Back Table Contamination? A Fluorescent Particle Study.

BACKGROUND: Surgical site infections (SSI) may result from inadvertent intraoperative contamination events. This study investigated the method of opening surgical gloves onto the operative field (OF) and potential contamination rates. METHODS: Twenty surgical glove packets were coated with a commercially available fluorescent particle powder. Two methods of glove openings (10 surgical glove packets in each cohort) were investigated: direct drop (DD) onto the OF vs opening and direct hand-off (DH) to a sterile intermediary (SI). Ultraviolet black light was used to quantify fluorescent particles for dispensed glove packets and the OF in both cohorts. The gloves of the SI were inspected in the DH cohort. A previously used contamination scale for fluorescent particle model contamination was employed: 0: no detectable fluorescent particle specks, 1: 1-5 specks, 2: 5-10 specks, 3: 11-100 specks, 4: >100 specks. RESULTS: The DD cohort had a median OF contamination of 4 (range, 3-4) vs 3 for the DH trials (range, 1-3; P = .001). Likewise, the median glove contamination was higher in the DD cohort, 3 (range, 2-4) vs 1 for DH (range, 0-3; P = .007). Minimal contamination was found on the hands of the SI. Total fluorescent contamination rates, including the gloves of SI in the DH cohort, revealed greater overall contamination in DD (median, 3.5; range, 2-4) vs DH cohort (median, 1; range, 0-3); (P < .001). CONCLUSION: Using a fluorescent particle model, there is a greater burden of potential contamination from dispensed glove packets and OF with DD vs DH. The DH method did not show significant fluorescent particle contamination on the SI gloves. These data support the use of the opening of gloves via DH over the DD method in total joint arthroplasty to decrease the risk of potential contamination.

Total Knee Arthroplasty Kinematics.

Knee kinematics is an analysis of motion pattern that is utilized to assess a comparative, biomechanical performance of healthy nonimplanted knees, injured nonimplanted knees, and various prosthetic knee designs. Unfortunately, a consensus between implanted knee kinematics and outcomes has not been reached. One might hypothesize that the kinematic variances between the nonimplanted and implanted knee might play a role in patient dissatisfaction following TKA. There is a wide range of TKA designs available today. With such variety, it is important for surgeons and engineers to understand the various geometries and kinematic profiles of available prostheses. The purpose of this review is to provide readers with the pertinent information related to TKA kinematics.

What Is the Value of Component Loosening Assessment of a Preoperatively Obtained Bone Scan Prior to Revision Total Knee Arthroplasty?

BACKGROUND: Bone scintigraphy (BS) is frequently ordered to investigate cause of failure following total knee arthroplasty (TKA). Its correlation of component loosening with intraoperative findings (IFs) at the time of revision TKA (rTKA) has not been well studied. This study investigated correlations between the preoperatively obtained radiologist report (RR) of BS, preoperatively documented surgeon prediction (SP) of component loosening, and operative reports documenting IFs. METHODS: Our institutional database was retrospectively reviewed for all rTKA done after BS and revealed 96 eligible cases. The RR and SP cohorts were subdivided into all potential combinations of component loosening and were then compared with each other as well as IF. In addition to calculating the percentage correct of RR and SP compared with IF, the levels of agreement between RR and SP were compared using the kappa statistic. RESULTS: Of the 96 cases, the RR correctly correlated with IF in 35 cases (37%), whereas the SP was correct in 66 cases (69%), indicating the preoperative interpretation of the surgeon regarding component loosening at rTKA was correct more frequently (P < .001). The kappa statistic between RR and IF was only 0.23 (95% confidence interval [CI] = 0.15-0.32), indicating minimal agreement. The kappa statistic between SP and IF was 0.57 (95% = CI 0.46-0.68), indicating weak agreement. Furthermore, the kappa statistic between RR and SP was 0.36 (95% CI = 0.27-0.45), also indicating minimal agreement. CONCLUSIONS: In rTKA, there is weak agreement regarding component loosening between a radiologist's opinion of a preoperatively obtained bone scan and the surgeon's preoperative interpretation of clinical and radiographic data. While neither reliably accurately predicts what is found at the time of rTKA, the surgeon's preoperative interpretation is more closely correlated with actual IFs of component loosening.

A retrospective analysis of the merits and challenges associated with simultaneous bilateral THA using the direct anterior approach.

INTRODUCTION: 15%-20% of patients presenting for total hip arthroplasty (THA) have bilateral disease. While simultaneous bilateral THA is of interest to patients and surgeons, debate persists regarding its merits. The majority of previous reports on simultaneous bilateral THA involve patients in the lateral decubitus position, which require repositioning, prepping and draping, and exposure of a fresh wound to pressure and manipulation for the contralateral THA. The purpose of this study was to compare complications, component position, and financial parameters for simultaneous versus staged bilateral THAs using the direct anterior approach (DAA). METHODS: Medical records were reviewed for patient demographics, medical history, operative time, estimated blood loss (EBL), change in hemoglobin, transfusion, tranexamic acid (TXA) use, length of stay (LOS), discharge disposition, leg length discrepancy, acetabular cup position, and perioperative complications. Cost and reimbursement data were analysed. RESULTS: 44 patients were included in the sequential group and fifteen patients in the simultaneous group. Operative time, EBL, hemoglobin drop, transfusion rate, and LOS were significantly increased for simultaneous group. There was no significant difference in component position, complications, or readmissions between groups. Profit per hip was significantly higher for the simultaneous group. DISCUSSION: While simultaneous DAA THA presents challenges, our results suggest that simultaneous DAA THA may add value to the healthcare system without resulting in increased complications compared to sequential hip arthroplasty.

An Orthopedic-Hospitalist Comanaged Hip Fracture Service Reduces Inpatient Length of Stay.

INTRODUCTION: Hip fractures are common in the elderly patients with an incidence of 320 000 fractures/year in the United States, representing a health-care cost of US$9 to 20 billion. Hip fracture incidence is projected to increase dramatically. Hospitals must modify clinical models to accommodate this growing burden. Comanagement strategies are reported in the literature, but few have addressed orthopedic-hospitalist models. An orthopedic-hospitalist comanagement (OHC) service was established at our hospital to manage hip fracture patients. We sought to determine whether the OHC (1) improves the efficiency of hip fracture management as measured by inpatient length of stay (LOS) and time to surgery (TTS) and (2) whether our results are comparable to those reported in hip fracture comanagement literature. METHODS: A comparative retrospective-prospective cohort study of patients older than 60 years with an admitting diagnosis of hip fracture was conducted to compare inpatient LOS and TTS for hip fracture patients admitted 10 months before (n = 45) and 10 months after implementation (n = 54) of the OHC at a single academic hospital. Secondary outcome measures included percentage of patients taken to surgery within 24 or 48 hours, 30-day readmission rates, and mortality. Outcomes were compared to comanagement study results published in MEDLINE-indexed journals. RESULTS: Patient cohort demographics and comorbidities were similar. Inpatient LOS was reduced by 1.6 days after implementation of the OHC (P = .01) without an increase in 30-day readmission rates or mortality. Time to surgery was insignificantly reduced from 27.4 to 21.9 hours (P = .27) and surgery within 48 hours increased from 86% to 96% (P = .15). DISCUSSION: The OHC has improved efficiency of hip fracture management as judged by significant reductions in LOS with a trend toward reduced TTS at our institution. CONCLUSION: Orthopedic-hospitalist comanagement may represent an effective strategy to improve hip fracture management in the setting of a rapidly expanding patient population.

Incidence of heterotopic ossification in direct anterior vs posterior approach to total hip arthroplasty: a retrospective radiographic review.

PURPOSE: To investigate the prevalence of heterotopic ossification following direct anterior approach total hip arthroplasty compared to posterior approach, performed by a single surgeon at one institution METHODS: All primary THAs performed by the senior author (JEL) over a 70-month period were reviewed, including 235 DAA and 120 posterior THAs. Brooker's system was used to grade HO at a minimum of six months follow-up. RESULTS: Patients undergoing DAA were less likely to develop clinically significant HO compared to posterior THA (p = 0.04). The overall incidence of HO following DAA THA was 24.3 % (3 % grade 3 and 0 % grade 4), and following posterior THA was 27.5 % (4.2 % grade 3 and 3.3 % grade 4). CONCLUSIONS: Lower rates of clinically significant (Brooker grade 3 and 4) HO were observed in DAA THA than in posterior approach THA. This data may be instructive when approaching THA candidates with conditions that predispose them to HO.