Martin Buttaro

Frozen sections of samples taken intraoperatively for diagnosis of infection in revision hip surgery

Background The diagnosis of a suspected infected prosthesis is often difficult, but is important for the choice of treatment. Even at surgery, it is not easy to assess whether the prosthesis is infected or not—even though this may be important for the choice of surgical procedure. Patients and methods We assessed the sensitivity, specificity, predictive value, and reliability of the results of the analysis of frozen sections from samples of tissues taken during revision hip surgery of 136 probably infected prostheses. Samples of tissues were taken to be analyzed immediately from frozen sections, to be processed on a routine basis later, and to be referred for bacteriological cultures. A finding of 5 or more polymorphonuclear leukocytes per field at a magnification of 400× was considered positive for infection. Results The analysis of frozen sections for infection was in agreement with the results of routine histopathology in 134 of 136 cases. Comparison with the results of culture showed a sensitivity of 85%, a specificity of 87%, a PPV of 79%, an NPV of 91%, and a Kendall’s tau correlation coefficient of 0.72. Interpretation We believe that the method we have tested is of value in revision surgery when infection cannot be ruled out.

High active local levels of vancomycin without nephrotoxicity released from impacted bone allografts in 20 revision hip arthroplasties

Background Cancellous bone can act as a delivery vehicle for vancomycin without impairment of graft incorporation. However, local and systemic antibiotic levels, biological activity of vancomycin, interaction with antibiotic-loaded cement, and also nephrotoxicity of these composites have not yet been studied clinically. Material and methods Blood, drainage and urine samples of 20 consecutive patients undergoing revision total hip arthroplasties with impaction grafting technique utilizing 1 g of vancomycin per femoral head were studied. Plain PMMA cement was used in 10 cases, while PMMA with gentamycin was used in 5 cases and tobramycin was used in the remaining 5 cases. Biological activity of vancomycin was studied using kinetic killing curves in three ATCC organisms (methicillin-sensitive Staphylococcus aureus,methicillin-resistant Staphylo-coccus aureusand Pseudomonas aeruginosas).Quantification was done with fluorescent polarized immunoassay. Renal function was evaluated with preoperative and postoperative urea and creatinine. Results Local active bactericidal levels of vancomycin reached 1 400 μg/mL (average 5-point level = 367 μg/mL) without nephrotoxicity. Vancomycin was present in urine until the fifteenth day. Both aminoglycosides in the cement had activity against Pseudomonas aeruginosas. Interpretation Local levels of vancomycin were 35 times greater than the highest levels reported with vancomycin-loaded PMMA. A synergistic effect was observed between vancomycin released from impacted allografts and aminoglycoside-loaded PMMA.

No need for routine closed suction drainage in elective arthroplasty of the hip A prospective randomized trial in 104 operations

BACKGROUND The purpose of this study was to determine the utility of closed suction drainage (CSD) in elective total hip arthroplasty (THA). PATIENTS AND METHODS We randomized 104 elective, consecutive THAs to receive drainage (53) or no drainage (51). 60 arthroplasties were cemented and 44 hybrid. RESULTS In the drainage group, 2 hematomas and 2 superficial wound infections occurred; there were no wound complications in the undrained group (p = 0.04). Patients receiving drainage had a greater reduction in hematocrit (10.4 vs 7.4) (p = 0.03), and longer hospital stay (5.1 days vs 4.7) (p = 0.01). At the 3-month follow-up, we found no deep wound infections in either group. INTERPRETATION We no longer use CSD in elective, primary, routine THA.

Incorporation of vancomycin-supplemented bone allograftsRadiographical, histopathological and immunohistochemical study in pigs

We compared the incorporation of bone allografts with or without vancomycin in tibial defects of 18 pigs. High-quality radiographs, histological examination, immunological expression of metalloproteinase-13 (MMP-13) and transforming growth factor-beta 2 (TGFß2) indicated that there was no significant difference in bone allograft incorporation between up to 220 times the MIC (minimum inhibitory concentration) in bone allografts with 1 g of vancomycin in each 300 g of allograft or without this supplement.

Combining C-reactive Protein and Interleukin-6 May Be Useful to Detect Periprosthetic Hip Infection

BackgroundThe sensitivity and specificity to detect periprosthetic infection of the different methods have been questioned, and no single laboratory test accurately detects infection before revision arthroplasty.Questions/purposesWe asked whether preoperative C-reactive protein (CRP) and interleukin-6 (IL-6) could lead to similar sensitivity, specificity, and predictive values as our previous results obtained with intraoperative frozen section (FS) in revision total hip arthroplasty (THA).MethodsWe prospectively followed 69 patients who had undergone revision THA for failure of a primary THA. The definitive diagnosis of an infection was determined on the basis of positive histopathologic evidence of infection or growth of bacteria on culture.ResultsEleven of the 69 hips were infected. The combination of an elevated CRP and IL-6 was correlated with deep infection in all the cases and showed a sensitivity of 0.57 (0.13–1.00), a specificity of 1.00 (0.99–1.00), a positive predictive value of 1.00 (0.87–1.00), and a negative predictive value of 0.94 (0.87–1.00). FS showed a sensitivity of 0.81 (0.54–1.00), a specificity of 0.98 (0.94–1.00), a positive predictive value of 0.90 (0.66–1.00), and a negative predictive value of 0.96 (0.91–1.00). Combining CRP and IL-6 provided similar sensitivity, specificity, and positive predictive values as the FSs.ConclusionsOur data suggest the combination of CRP and IL-6 would be a useful serologic tool to complement others when diagnosing periprosthetic infection.Level of EvidenceLevel I, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Irrigation and Debridement

Delegates: Craig A. Aboltins, MD, Olivier Borens, MD, John J. Callaghan, MD, Pedro Ivo de Carvalho, MD, Yuhan Chang, MD, Pablo Corona, MD, Ferdinando Da Rin, MD, Silvano Esposito, MD, Thomas K. Fehring, MD, Xavier Flores Sanchez, MD, Gwo-Chin Lee, MD, J. Carlo Martinez-Pastor, MD, S.M. Javad Mortazavi, MD, Nicolas O. Noiseux, MD, Kuo-Ti Peng, MD, Harold Delano Schutte, MD, Daniel Schweitzer, MD, Rihard Trebse, MD, Eleftherios Tsiridis, MD, Leo Whiteside, MD

Squeaking in a Delta Ceramic-on-Ceramic Uncemented Total Hip Arthroplasty

Squeaking is one of the main concerns related to the use of ceramic-on-ceramic total hip arthroplasty. Although it has received much recent publicity, most of the previous reports on this complication have been related to the use of the second generation of alumina ceramics combined with a cup having an elevated metal rim to protect the ceramic liner from neck impingement. We report a patient with a third-generation Biolox Delta (CeramTec AG, Plochingen, Germany) ceramic-on-ceramic uncemented total hip arthroplasty without an elevated metal rim in the cup who presented with a squeaking hip at 23 months postoperative. Although this complication was mainly related to a specific design in the literature, this case demonstrates that newer generation of ceramics can also present squeaking.

Early bead shedding of the Vitalock acetabular cup--a report on 7 cases.

No Abstract available

Displacement of a cemented polished tapered stem during closed reduction of a dislocated total hip arthroplasty--a case report.

A 96-year-old woman was admitted with a right dislocated femoral neck fracture. She underwent total hip arthroplasty with a cemented Exeter stem (Howmedica International, Staines, United Kingdom) through a posterolateral approach. The stem was cemented with Simplex bone cement (Howmedica, Rutherford, NJ, USA). No distal plug was implanted to prevent escape of procoagulants to the peripheral venous system (Maltry et al. 1995). The short external rotators and the joint capsule were repaired, using Pellicci et al.’s method (1998). Immediate postoperative radiographs showed a stem in a neutral position, with a homogeneous cement mantle. The polyethylene acetabular cup had 42° of inclination and 29o of planar anteversion (Ackland et al. 1986). The postoperative course was uneventful and the patient was discharged after 6 days, mobilized with a walker. 14 days after surgery, while standing up from the high toilet seat, her hip dislocated. Radiographs showed a postero-superior dislocation with a normal cement-stem interface (Figure 1). We tried to perform a closed reduction without sedation. A click was heard, and the leg-length equalized; however, passive hip motion was still limited and painful. Additional radiographs showed that the joint remained dislocated and that the stem had separated from the cement mantle, and migrated 12 mm proximally (Figure 2). We therefore performed an open reduction. At surgery, failure of the posterior soft tissue repair was seen with the tagging sutures pulled-out from the tendons and capsule. We removed the femoral component. The femoral head, cement mantle, and polyethylene cup were macroscopically intact. The same stem was reimplanted using the cement-within-cement technique (Lieberman et al. 1993) and leaving the stem 5 mm higher to exert more tension on the soft Displacement of a cemented polished tapered stem during closed reduction of a dislocated total hip arthroplasty—a case report

Primary Total Hip Arthroplasty With Fourth-Generation Ceramic-on-Ceramic: Analysis of Complications in 939 Consecutive Cases Followed for 2-10 Years

BACKGROUND Delta ceramics may be the bearing of choice for younger and active patients due to its improved toughness and wear characteristics, provided there is no risk of fracture. However, ceramic fracture is the most serious complication related to this type of bearing. Although millions of Delta ceramics have been implanted worldwide, short to midterm results have been scarcely reported in the literature. The purpose of this study was to report the complication rate at short to midterm follow-up associated with the bearing surface used in a series of primary total hip arthroplasties with Delta ceramic-on-ceramic bearings performed in a single institution. METHODS A total of 939 cases (880 patients) undergoing primary total hip arthroplasty with fourth-generation Delta ceramic-on-ceramic bearings were retrospectively reviewed. They were followed for an average of 5.3 years (2-10 years). RESULTS One hip experienced a liner fracture, 2 cups presented early loosening due to friction between the acetabular screw and the backside of the liner, one femoral ball head had a fracture; one case of squeaking was reported, which is impending revision. Considering revision or impending revision in relationship with the bearing surface as the end point, the mean survival rate was 99.3% (confidence interval 95%, 98.3%-99.7%) at 2-10 years. CONCLUSION This study showed a low rate of ceramic fracture compared with others; however, it was much higher than the complication rate presented by the manufacturers. The complications observed were directly related to technical errors that surgeons should avoid when using this type of surface.