Should we rely on frozen section during the reimplantation stage of revision knee arthroplasty?

OBJECTIVE: To compare Frozen Section (FS) results during the reimplantation stage of revision knee arthroplasty, in patients without clinical signs of infection but with preoperative inconclusive serum inflammatory markers. METHODS: Sections were revisited the day after surgery. Intraoperative FS (iFS) was accepted as positive when the presence of >5 polymorphonuclear neutrophils (PMNLs) in 5 separate high-power fields was determined according to the consensus criteria of the International Consensus on Musculoskeletal Infection. The clinical outcomes, cultures and diagnostic values of iFS and review FS (rFS) were analyzed. RESULTS: No complications developed after reimplantation in 66 (84.6%) of the 78 evaluated patients. Complications developed in 12 patients, six of whom were treated with re-explantation, four with arthrodesis and two with above-the-knee amputation. Both iFS and rFS yielded insignificant sensitivity and specificity (25% and 45.5%, 25% and 45%, respectively). There was no statistically significant difference between definitive culture and iFS and rFS. CONCLUSION: iFS evaluation is insufficient to exclude recovery from periprosthetic joint infection (PJI). Diagnosis of recurrence of infection in patients with indefinite serum inflammatory markers between the explantation and reimplantation interval remains challenging due to massive fibrosis that makes proper tissue sampling difficult. The attending physician should closely monitor clinical findings.

An evaluation of the effect on lower extremity fracture healing of collagen-based fusion material containing 2 different calcium phosphate salts: An experimental rat model.

BACKGROUND: Collagen-based synthetic bone grafts which contain tricalcium phosphate (TCP) and hydroxyapatite (HA), and collagen-based synthetic bone grafts containing only TCP have some advantages compared to autografts. Therefore, these grafts are frequently used to fill bone defects and pseudoarthrosis. OBJECTIVES: The aim of this study was to evaluate and compare the clinical, radiological and histopathological effects of TCP-HA and TCP alone + Type-1 collagen in healing lower extremity fractures in a pseudoarthrosis model in rat femurs. MATERIAL AND METHODS: A total of 36 female Wistar rats were randomly separated into 4 groups. Group 1 (n = 10) was the control group. A femur pseudoarthrosis model was created in Groups 2, 3 and 4. On the 90th day after the 1st surgery in Group 2 (n = 10), TCP-HA + Type-1 collagen was applied, in Group 3 (n = 10), TCP alone + type-1 collagen was applied, and in Group 4 (n = 6, the placebo group), saline solution was applied. Fixation was performed with an intramedullar pin. After 60 days and clinical and radiological scoring, all animals were sacrificed and a histopathological evaluation of the pseudoarthrosis areas was conducted. RESULTS: In all the clinical, radiological and histopathological measurements used in the evaluations of the differences between the groups, a higher rate of union was determined in Group 2 (TCP-HA). No significant difference was determined between Group 3 and Group 4 in terms of union rates. CONCLUSIONS: The clinical, radiological and histopathological results of this study showed that TCP alone was less effective than TCP-HA in the union of a femur pseudoarthrosis model in rats. The reason for this difference was considered to be hydroxyapatite (HA).

Minimally invasive percutaneous plate osteosynthesis does not increase complication rates in extra-articular distal tibial fractures.

BACKGROUND: Selection of a treatment method in cases of unstable, nonarticular distal tibial fractures is still a matter of discussion. Intramedullary nailing, which is a "gold standard" for tibial shaft fractures, does not always work for this specific transition area between diaphysis and metaphysis. Instead, new minimally invasive techniques with special implants are popular. AIMS: To determine the functional and radiological results of distal tibial fractures treated with minimally invasive percutaneous plate osteosynthesis (MIPPO) technique. STUDY DESIGN: Retrospective cohort analysis. METHODS: Thirty distal tibial fractures treated with MIPPO method, between January 2006 and December 2010, were evaluated retrospectively. All patients were classified according to AO/OTA classification. Period of hospital stay, time of fracture union, time to allow full weight bearing, early and late complications were inquired. Functional outcomes were assessed by AOFAS scores. RESULTS: There were 13 male and 17 female patients with an average age of 44.26 (range, 22-77 years). One superficial infection and one malunion were observed. Two patients were revised for the loss of reduction and healed uneventfully. According to the AO/OTA classification, 23 patients were 43-A1 (76.6%), 3 were 43-A2 (10%) and 4 were 43-A3 (13.3%). Post-operative mean stay of patients at the hospital was 2.6 ± 1.42 days (range, 1-7 days). Mean full weight-bearing period of the patients was found out as 13.16 ± 2.6 weeks (range, 10-22 weeks). The mean period of union of fracture for patients was found out as 19.8 ± 2.99 weeks (range, 16-34 weeks). CONCLUSION: Treatment of distal tibial fractures with MIPPO method provides a successful treatment strategy as long as used as per the technique, and it respects and does not harm soft tissues which allows early callus formation and rapid healing that enable the patient to walk as early as possible after the operation. The overall clinical and functional outcome is still good despite minor complications.