Calcium phosphate cement and locked plate augmentation of distal femoral defects: A biomechanical analysis.

PURPOSE: Bone tumors are common in the distal femur and often treated with intralesional curettage. The optimal method of stabilization of large distal femoral defects after curettage remains unclear. The goal of this study is to compare stabilization techniques for large distal femoral defects. METHODS: Large defects (60 cm3) were milled in the distal lateral metaphysis of 45 adult composite sawbone femurs. The defect was either (1) left untreated or reconstructed with (2) locked plate fixation, (3) calcium phosphate cement packing, or (4) locked plate fixation with calcium phosphate cement packing, or (5) polymethylmethacrylate packing. Each specimen then underwent axial and torsional stiffness testing followed by torsional loading to failure. The data were analyzed using ANOVA with Tukey-Kramer post-hoc analysis. RESULTS: The calcium phosphate cement filled defect with a locked plate was the stiffest construct in axial and torsional loading as well as the strongest in torque to failure. However, this difference only reached significance with respect to all other groups in torque to failure testing. The calcium phosphate cement filled defect with a locked plate was significantly stiffer than three of the four other groups in both axial and torsional stiffness testing. CONCLUSIONS: These results indicate that calcium phosphate cement, with or without the addition of locked plate fixation, may provide improved construct stability under time zero testing conditions. This result warrants further testing under cyclic loading condition and consideration for fixation of large femoral metaphyseal defects in future clincal trails.

Quality Measures in Foot and Ankle Care.

BACKGROUND: Quality measures may be operationalized in payment models or quality reporting programs to assess foot and ankle surgeons, but if existing measures allow accurate representation of a foot and ankle surgeon's practice is unclear. METHODS: National quality measures databases, clinical guidelines, and MEDLINE/PubMed were systematically reviewed for quality measures relevant to foot and ankle care. Measures meeting internal criteria were categorized by clinical diagnosis, National Quality Strategy priority, and Donabedian domain. RESULTS: Of 12 quality measures and 16 candidate measures, National Quality Strategy priorities most commonly addressed "Effective Clinical Care" (n = 19) and "Communication and Coordination of Care" (n = 6). Donabedian classifications addressed were process (n = 25) and outcome (n = 3). Diabetic foot care was most commonly addressed (n = 18). CONCLUSIONS: Available foot and ankle quality measures are limited in number and scope, which may hinder appropriate assessment of care, analysis of trends, and quality improvement. Additional measures are needed to support the transition to a value-based system. LEVEL OF EVIDENCE: Level I.

Joint replacement surgery in homeless veterans.

Total joint arthroplasty (TJA) in a homeless patient is generally considered contraindicated. Here, we report our known medical and social (housing and employment) results of homeless veterans who had TJA. Thirty-seven TJAs were performed on 33 homeless patients (31 men) at our hospital between November 2000 and March 2014. This was 1.2% of all TJAs. Average age was 54 years. Average hospital stay was 4.1 days. There were no major inpatient complications. Thirty-four cases had at least 1-year follow-up in any clinic within the Veterans Affairs health care system. There were no known surgery-related reoperations or readmissions. At final follow-up, 24 patients had stable housing and 9 were employed. The extensive and coordinated medical and social services that were provided to veterans from the Department of Veterans Affairs contributed to our positive results.

A comparison of 2 drilling techniques on the femoral tunnel for anterior cruciate ligament reconstruction.

PURPOSE: This cadaveric study was undertaken to characterize the femoral tunnel geometry resulting from commonly used drilling techniques in anterior cruciate ligament reconstruction. METHODS: We randomized 10 matched-pair cadaveric knees (20 knees) into 2 groups with right and left matched pairs from each cadaver. Of the knees, 10 underwent transtibial femoral tunnel drilling from a far-medial starting point on the tibia (group 1) and 10 had the femoral tunnel drilled from a medial arthroscopic portal (group 2). The dimensions and size of the apertures, the volume and length of the tunnels, and the distance of the tunnels from the posterior wall and articular surface were measured by computed tomography. RESULTS: The mean femoral tunnel length was 29.7 mm in group 1 and 15.7 mm in group 2. The mean volume for each tunnel was 2,401 mm(3) in group 1 and 2,071 mm(3) in group 2. The intra-articular aperture area was 94.6 mm(2) in group 1 and 98.6 mm(2) in group 2. In group 2 the intra-articular shape was more elliptical than in group 1, with the long axis averaging 13.5 ± 1.3 mm (P = .004) and short axis averaging 9.7 ± 1.0 mm (P = .002); in group 2 the long axis averaged 12.5 ± 1.7 and short axis averaged 10.3 ± 0.7 (P = .002). Group 2 was closer to the posterior wall and articular surface (6.9 ± 0.6 mm and 9.4 ± 0.6 mm, respectively) than group 1 (10.8 ± 1.0 mm and 11.8 ± 1.9 mm, respectively). CONCLUSIONS: We determined the length and volume of the femoral tunnel to be shorter and smaller, respectively, with a medial arthroscopic portal. In addition, the aperture shape was more of an ellipse with a medial arthroscopic portal. The medial arthroscopic portal also created a femoral tunnel that was closer to the posterior wall and articular surface of the femur. CLINICAL RELEVANCE: Improved characterization of osseous tunnels with 3-dimensional figures will allow for improved matching of graft and incorporation.

A biomechanical comparison of the endobutton cl using transtibial drilling and endobutton direct using anteromedial arthroscopic drilling.

PURPOSE: To compare the biomechanical properties of the EndoButton Direct (Smith & Nephew, Andover, MA) with the EndoButton CL (Smith & Nephew) using 2 different drilling techniques. Only the femoral side (and not the tibial side) of the graft fixation complex (bone-fixation device-anterior cruciate ligament [ACL] graft) was examined in this study. METHODS: ACL reconstructions were performed on 20 cadaveric knees (10 matched pairs), with an age range from 73 to 89 years, by use of a doubled semitendinosus and gracilis tendon graft. Ten knees underwent femoral tunnel drilling from a standard anteromedial arthroscopic portal, and the EndoButton Direct was used for fixation. Ten knees underwent femoral drilling through a medial transtibial approach, and the EndoButton CL was used for fixation. All graft fixation complexes were subjected to 1,000 loading cycles. Graft elongation after 1,000 cycles, stiffness, ultimate load, and mode of failure were determined for each specimen. RESULTS: The mean failure load was significantly higher for the EndoButton CL (959.9 ± 190.4 N) compared with the EndoButton Direct (697.7 ± 341.8 N) (P = .05). There was no significant difference in overall stiffness or graft elongation after 1,000 cycles between the 2 fixation devices. CONCLUSIONS: The maximum load during ultimate failure testing was higher for the EndoButton CL with transtibial drilling when compared with the EndoButton Direct with anteromedial drilling. There were no differences found between the EndoButton Direct and EndoButton CL with regard to overall stiffness or elongation after cyclic loading. CLINICAL RELEVANCE: Reduced ultimate failure strength has implications in reconstructed patients if forces imparted on the ACL exceed the strength of graft fixation.