Patient Satisfaction, Functional Outcomes, and Survivorship in Patients with a Customized Posterior-Stabilized Total Knee Replacement.

BACKGROUND: In this study, we assessed implant survivorship, patient satisfaction, and patient-reported functional outcomes at approximately 2 years for patients who had received a customized posterior-stabilized (PS) knee replacement system. We hypothesized that the customized PS implant would have high overall patient-reported outcomes because of its patient-specific design. METHODS: Ninety-three patients (100 knees) who had received the customized total knee replacement system were enrolled at 2 centers. The patients' length of hospitalization and preoperative pain intensity were assessed. At a single follow-up time-point, we assessed patient-reported outcomes utilizing the Knee injury and Osteoarthritis Outcome Score Joint Replacement (KOOS JR), satisfaction rates, implant survivorship, and patients' perception of their knee. RESULTS: At an average follow-up time of 1.9 years (range, 1.5 to 2.4 years), implant survivorship was found to be 100%. From an average preoperative baseline pain rating of 6.5 (range, 3 to 10) until the time of follow-up, we observed an average decrease of 5.2 on the numeric pain rating scale to an average of 1.3 (range, 0 to 8), indicating satisfactory pain relief after the procedure. The satisfaction rate was found to be high, with 90% of patients being satisfied or very satisfied and 88% of patients reporting a "natural" perception of their knee either some or all of the time. The evaluation of the patient-reported outcome measure showed satisfactory results with a high KOOS JR average score of 90 (range, 34 to 100) at the time of follow-up. CONCLUSIONS: Based on our results, we believe that the customized PS implant provides patients with excellent postoperative outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Intravenous Iron May Improve Outcomes in Elderly Patients With Operative Hip Fractures.

INTRODUCTION: Hip fractures are common injuries with high morbidity and mortality rates. These patients often become anemic and require allogenic blood transfusion. Transfusions are costly with potential complications. This study examines the effect of intravenous (IV) iron on patients with hip fractures, undergoing surgery within 48 hours, and being treated with a highly restrictive transfusion protocol. MATERIALS AND METHODS: A retrospective chart review performed on patients admitted to a level 1 tertiary care center with fractures of the proximal femur from December 2015 to December 2017 included 239 patients. Patients who received 300 mg of IV iron when their hemoglobin fell below 11 g/dL were compared to a control group of patients who never received IV iron with respect to transfusion rate, 30-day readmission rate, nosocomial infections, length of stay, and hospital costs. RESULTS: There were no significant differences in transfusion rates (P = .118). There was a trend toward decreased length of stay (P = .063) and 30-day readmission rates (P = .051) with a 59% reduction in the odds of 30-day readmission when a patient received IV iron. There were no differences in nosocomial infection rates or cost of hospitalization. DISCUSSION: This study presents a compelling argument for further research regarding the use of IV iron in elderly patients undergoing surgery for a hip fracture. Length of stay and transfusion rates are increased in patients with intertrochanteric fractures and undergoing intramedullary nailing. A higher number of these patients in the IV iron group may have falsely increased these rates. A prospective, randomized, controlled trial is needed to assess the true effects of perioperative IV iron. CONCLUSIONS: This study showed no significant benefit to IV iron use in elderly patients undergoing surgical treatment of hip fracture. The decrease in 30-day readmission rate should be further examined with a prospective randomized controlled trial.

What Is the Possible Impact of High Variability of Distal Femoral Geometry on TKA? A CT Data Analysis of 24,042 Knees.

BACKGROUND: Previous studies analyzing femoral components of TKAs have demonstrated the limited ability of these components to accommodate size variations seen in the patient population, particularly width and femoral offset. QUESTIONS/PURPOSES: The purpose of this study was to use a large data set of knee CT scans (1) to determine the variations in the distal and posterior femoral geometries and to determine whether there is a correlation between distal condylar offset and posterior femoral offset as a potential parameter for symmetry/asymmetry; and (2) to evaluate what proportion of knees would have a substantial mismatch between the implant's size or shape and the patient's anatomy if a femoral component of a modern standard TKA of symmetric (sTKA) or asymmetric (asTKA) designs were to be used. METHODS: A retrospective study was performed on 24,042 data sets that were generated during the design phase for a customized TKA implant. This data set was drawn from European and US-American patients. Measurements recorded for the femur included the overall AP and mediolateral (ML) widths, widths of the lateral condyle and the medial condyle, the distal condylar offset (DCO) between the lateral and medial condyles in the superoinferior direction, and the posterior femoral offset (PFO) as the difference between the medial and lateral posterior condylar offset (PCO) measured in the AP direction. A consecutively collected subset of 2367 data sets was further evaluated to determine the difference between the individual AP and ML dimensions of the femur with that of modern TKA designs using two commercially available implants from different vendors. RESULTS: We observed a high degree of variability in AP and ML widths as well as in DCO and PFO. Also, we found no correlation between DCO and PCO of the knees studied. Instances of a patient having a small DCO and higher PCO were commonly seen. Analysis of the DFOs revealed that overall, 62% (14,906 of 24,042) of knees exhibited DCO > 1 mm and 83% (19,955 of 24,042) of femurs exhibited a > 2-mm difference between the lateral and medial PCO. Concerning AP and ML measurements, 23% (544 of 2367) and 25% (592 of 2367) would have a mismatch between the patient's bony anatomy and the dimensions of the femoral component of ± 3 mm if they would have undergone a modern standard sTKA or asTKA design, respectively. CONCLUSIONS: Analysis of a large number of CT scans of the knee showed that a high degree of variability exists in AP and ML widths as well as in DCO and PFO. CLINICAL RELEVANCE: These findings suggest that it is possible that a greater degree of customization could result in surgeons performing fewer soft tissue releases and medial resections than now are being done to fit a fixed-geometry implant into a highly variable patient population. However, as an imaging study, it cannot support one approach to TKA over another; comparative studies that assess patient-reported outcomes and survivorship will be needed to help surgeons decide among sTKA, asTKA, and customized TKA.

Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy.

BACKGROUND: Historically, knee arthroplasties have been designed using average patient anatomy. Recent advances in imaging and manufacturing have facilitated the development of customized prostheses designed to fit the unique shape of individual patients. The purpose of this study is to determine if improving implant design through customized total knee arthroplasty (TKA) improves kinematic function. METHODS: Using state-of-the-art mobile fluoroscopy, tibiofemoral kinematics were analyzed for 24 subjects with a customized individually made (CIM), cruciate-retaining TKA, and 14 subjects having an asymmetric condylar cruciate-retaining TKA. Subjects performed a weight-bearing deep knee bend and a rise from a seated position. Each patient was evaluated for weight-bearing range of motion, femorotibial translation, femorotibial axial rotation, and condylar liftoff occurrence. RESULTS: Subjects having a CIM TKA experienced greater weight-bearing knee flexion compared with the traditional posterior cruciate-retaining (PCR) TKA design. During flexion, the CIM TKA subjects consistently exhibited more posterior femoral rollback than the traditional PCR TKA subjects. The CIM TKA was found to have statistically greater axial rotation compared with the traditional PCR TKA (P = .05). Of note, only the CIM TKA patients experienced femoral internal rotation at full extension, as exhibited in a normal knee. Compared with the traditional PCR TKA, the CIM TKAs demonstrated minimal occurrences of paradoxical sliding and reverse rotation during flexion and extension. The CIM TKA subjects showed minimal liftoff and hence better stability in earlyflexion to midflexion compared with the traditional PCR subjects. CONCLUSION: The CIM TKA demonstrated kinematics more similar to a normal knee. Therefore, using customized implant technology through CIM TKA designs affords benefits including more normal motion compared with a traditional PCR TKA.

In situ leg length measurement technique in hip arthroplasty.

In situ femoral preparation refers to implanting a femoral component before the femoral neck osteotomy and without dislocating the hip joint, which allows the implanted femoral component to be used to measure leg length and offset. One hundred hip arthroplasty surgeries among 93 patients were compared with a control group of 15 patients. A modular neck femoral component was implanted in a technique similar to implanting a femoral nail. The differences between the in situ measurements and the preoperative and postoperative radiograph measurements averaged -0.1 mm for leg length (r = 0.89) and -0.37 mm for offset (r = 0.57). In situ leg length measurement allows accurate measurement of leg length and offset and guides surgeons in selecting appropriate modular components to attain a near anatomical hip arthroplasty.

Factors affecting bony impingement in hip arthroplasty.

Computer modeling of 10 patients' computed tomographic scans was used to study the variables affecting hip arthroplasty range of motion before bony impingement (ROMBI) including acetabular offset and height, femoral offset, height and anteversion, and osteophyte removal. The ROMBI was compared with the ROM before component impingement and the native hip ROM. The ROMBI decreased with decreased total offset and limb shortening. Acetabular offset and height had a greater effect on ROMBI than femoral offset and height. The ROMBI lost with decreased acetabular offset was not fully recoverable with an increase in femoral offset or osteophyte removal. Bony impingement increased and component impingement decreased with decreased acetabular offset and increased head diameter.

Fixation of femoral head fractures using the modified heuter direct anterior approach.

Large displaced fractures of the femoral head require open reduction and internal fixation. If the displaced fragments are small, open reduction may not be possible and excision of the fragment or nonoperative care may be the treatment of choice. Surgical approaches that have been used for open reduction and internal fixation include the Smith-Petersen approach, Watson-Jones approach, Kocher-Langenbeck approach, a posterior approach with a trochanteric flip osteotomy, and surgical dislocation of the hip. Here, we describe the use of the modified Heuter direct anterior approach for open reduction and internal fixation of femoral head fractures in 2 patients.

Specificity of a Bacteroides thetaiotaomicron marker for human feces.

A bacterial primer set, known to produce a 542-bp amplicon specific for Bacteroides thetaiotaomicron, generated this product in PCR with 1 ng of extracted DNA from 92% of 25 human fecal samples, 100% of 20 sewage samples, and 16% of 31 dog fecal samples. The marker was not detected in 1 ng of fecal DNA from 61 cows, 35 horses, 44 pigs, 24 chickens, 29 turkeys, and 17 geese.