Analysis of the Costs and Complications of First Metatarsophalangeal Joint Arthrodesis Comparing Locked and Non-locked Plate Fixation Constructs.

BACKGROUND: The ideal fixation method for the first metatarsophalangeal joint (first MTP) remains uncertain. This study compares nonunion and revision surgery rates of first MTP arthrodesis between nonlocking semitubular plates and precontoured locking plates. METHODS: Demographics, fixation technique, and complications of all patients who underwent primary first MTP arthrodesis between 2013 and 2018 were determined from radiographs and clinical records. Cost data were from a 1-year subset of isolated first MTP fusion surgeries. The primary outcome measures of this study were the nonunion and complication rates, with associated costs of patients undergoing first metatarsophalangeal arthrodesis with either a noncontoured semitubular plate or a precontoured locking plate. RESULTS: The study included 189 patients, with a mean follow-up of 18.7 months. The overall nonunion rate was 10.1%, with no difference between the locking and nonlocking plates. The prevalence of a painful implant was also similar. Surgeries using locking plates cost an average of $1,500 more than those using nonlocked plates. CONCLUSIONS: Because there was no difference in revision between locking and nonlocking plate fixation for primary first MTP arthrodesis, routine use of the more expensive locking plates may not be justified. LEVEL OF EVIDENCE: Level III (Retrospective cohort study).

Selecting a Press-fit Stem for Total Hip Arthroplasty: The Rationale and Evolution of the Modern Femoral Prosthesis.

Noncemented press-fit femoral stems predominate in total hip arthroplasty for all age groups with generally excellent long-term survivorship. The 2021 American Joint Replacement Registry reports that 96% of all elective primary total hip arthroplasties used noncemented femoral implant fixation. 1 Today, there are many styles of press-fit stems, each with supposed benefits, based on a range of design philosophies. Design aspects to consider when selecting a stem are numerous, including stem geometry, stem length, collared or collarless, material properties, and surface structure. Although most stem designs demonstrate excellent results, the differences in stem designs are intimately linked to additional factors such as ease of use/implantation, percentage of surface osseointegration, overall bone removal versus bone stock preservation, subsequent femoral stress shielding, and consideration of complexity of later revision. A surgeon with a broad understanding and appreciation of femoral stem designs should be prepared to select between the multitude of options to best serve individual patients.

Intraoperative Comparative Femoral Rotation Imaging: Do not Overlook Parallax.

OBJECTIVE: To investigate the degree of error due to parallax during intraoperative rotational imaging involving the distal femur. METHODS: Twelve, fresh-frozen, lower-extremity cadaveric specimens were studied. The limbs were positioned supine and rotated until the posterior femoral condyles were superimposed using a C-arm. The C-arm was then repositioned to place the femoral condyles at the anterior and posterior margins of the image intensifier. The rotation necessary to resuperimpose the femoral condyles due to parallax was recorded. A second C-arm was then used from the contralateral side to simulate the rotational imaging technique to determine the magnitude and directionality of combined parallax. RESULTS: All 12 specimens demonstrated parallax, resulting in rotational discrepancies. Compared with central field of view alignment, the mean rotational discrepancy was 5.6 and 5.5 degrees for anterior and posterior positions, respectively. Contralateral imaging resulted in an additive effect with rotational differences of 9.0 and 12.6 degrees for bilateral anterior and posterior positions, respectively. CONCLUSIONS: Parallax causes rotational discrepancies with fluoroscopic imaging of the distal femur when the posterior femoral condyles are off-center in the imaging field of view. If femoral condyles are not centered when obtaining intraoperative rotational imaging of the uninjured and injured femurs, parallax can result in potentially clinically significant rotational deformity even if the femurs seem perfectly matched at the conclusion of surgery. We recommend perfectly centering of the posterior femoral condyles in the imaging field of view when obtaining lateral images of the distal femur to prevent this potentially overlooked contribution to malrotation.

A Novel Fluoroscopic Method for Assessing Rotational Malalignment of the Tibia.

OBJECTIVE: To evaluate the accuracy and reliability of a novel fluoroscopic technique for assessing tibial rotation and compare it with a previously described fluoroscopic method. METHODS: A multiplanar circular ring external fixator was secured to the tibial diaphysis of 5 cadaveric lower extremity specimens. Using deformity correction software, the frame and tibia were programed to randomly rotate 5, 10, 15, 20, 25, and 30 degrees of internal and external rotation. After each rotation, 2 blinded, independent observers measured the degree of tibial rotation using 2 different fluoroscopic methods: the previously described "mortise" method and the novel "intermalleolar" method. A total of 65 measurements were made by each observer. Accuracy and interobserver reliability were calculated. RESULTS: Both intermalleolar and mortise methods had a mean absolute rotational difference from the true torsion of 3 degrees (standard error 1; range, 0-10 degrees intermalleolar vs. 0-18 degrees mortise). We found that 98.5% (128/130) of measurements using the intermalleolar method were less than 10 degrees from the true rotation compared with 93.8% (122/130) using the mortise method. Both the intermalleolar and the mortise methods had excellent interobserver reliability (intraclass correlation coefficient 0.99 and 0.96, respectively). CONCLUSION: Measuring tibial rotation fluoroscopically using the intermalleolar method is both accurate and reliable. Compared with the previously described mortise method, it has similar accuracy and provides a value that approximates the true tibial rotation. Also, it can be used reliably and effectively intraoperatively to identify tibial malrotation and assist in intraoperative rotational corrections.

Total Knee Bartonella henselae Infection: An Unusual Manifestation of Cat Scratch Disease: A Case Report.

CASE: This is the first clinical report of periprosthetic total joint infection caused by Bartonella henselae. A 65-year-old woman developed an acutely painful total knee 3 weeks after a cat scratch. Serial joint aspirations and tissue cultures failed to identify any organism. Diagnosis was performed with polymerase chain reaction analysis. She underwent a 2-stage revision with successful symptom resolution. CONCLUSIONS: Bartonella is an unusual cause of total knee infection requiring alternative techniques for diagnosis because cultures are unlikely to be definitive.