Value of digital telethermography for the diagnosis of septic knee prosthesis: a prospective cohort study.

BACKGROUND: Diagnosis of peri-prosthetic infection remains challenging, often requiring a combination of different tests. METHODS: In this prospective, case-control study, the diagnostic accuracy of telethermography was evaluated in a group of seventy patients who had had a total knee replacement and were undergoing a reoperation because of infection or another implant-related problem, after a minimum of one year from implant. RESULTS: An average differential temperature of the affected versus not affected knee of 1.9 °C was observed in infected prosthesis, compared to 0.3 °C in aseptic failures. Considering a normal reference value equal or less than 1.0 °C, telethermography showed an accuracy, sensitivity, specificity, positive and negative predictive value of, respectively: 0.90, 0.89, 0.91, 0.91, 0.88. CONCLUSIONS: Digital telethermography is a reliable option for diagnosing peri-prosthetic knee infection.

A case of a late and atypical knee prosthetic infection by no-biofilm producer Pasteurella multocida strain identified by pyrosequencing.

Prosthetic joint infections due to Pasteurella multocida are rarely but increasingly reported but no data on production of biofilm are available. We report the case of a woman with a late, haematogenous peri-prosthetic infection of cemented total knee arthroplasty caused by a strain of P. multocida identified by pyrosequencing and unable to produce biofilm. Comparison of clinical and laboratory findings with those reported in other patients evidenced differences mainly in the period of symptoms' onset and in the behaviour of some inflammatory markers.

Successful staged hip replacement in septic hip osteoarthritis in osteopetrosis: a case report.

BACKGROUND: Osteopetrosis is a rare, inherited, bone disorder, characterized by osteosclerosis, obliteration of the medullary cavity and calcified cartilage. The autosomal dominant form is compatible with a normal life span, although fractures often result from minimal trauma, due to the pathologic nature of bone. Osteomyelitis is common in patients with osteopetrosis because of a reduced resistance to infection, attributed to the lack of marrow vascularity and impairment of white cell function. Only one case of osteomyelitis of the proximal third of the femur has been previously reported, treated with several repeated debridements and finally with femoral head resection. Here we present for the first time a case of a staged implant of a cementless total hip prosthesis for the treatment of a septic hip in femoral neck nonunion in osteopetrosis. CASE PRESENTATION: A 36-years-old woman, affected by autosomal dominant osteopetrosis was referred to our department because of a septic hip arthritis associated with femoral neck septic non-union, with draining fistulas. The infection occurred early after a plate osteosynthesis for a closed perthrocanteric fracture of the femur and persisted in spite of osteosynthesis removal, surgical debridement and external fixation. In our hospital the patient underwent accurate debridement, femoral head and greater trochanter resection, preparation of the diaphyseal intramedullary canal and implant of an antibiotic-loaded cement spacer. The spacer was exchanged after one month, due to infection recurrence and four months later, a cementless total hip arthroplasty was implanted, with no clinical and laboratory signs of infection recurrence at two years follow-up. CONCLUSIONS: In case of hip septic arthritis and proximal femur septic non-union, femoral head resection may not be the only option available and staged total hip arthroplasty can be considered.

Ankle dorsiflexion after isolated medial versus complete proximal gastrocnemius recession: A cadaveric study.

PURPOSE: Gastrocnemius recession has been described in the treatment of gastrocnemius contracture. The aims of this study were: (1) to assess the change in ankle dorsiflexion after isolated medial gastrocnemius recession performed according to L.S. Barouk's technique; (2) to compare ankle dorsiflexion after isolated medial head with complete proximal gastrocnemius recession. METHODS: A cadaveric study was performed on 15 lower limb adult specimens. Isolated medial gastrocnemius head recession was initially performed, followed by an additional recession of the lateral gastrocnemius head. Ankle dorsiflexion torque was applied with 2 and 4 kg forces on second metatarsal head. Ankle dorsiflexion was measured with the knee both in extension and at 90° of flexion and values were recorded before surgery (T0), after medial head recession (T1) and after both heads recession (T2). Normality of data was assessed using the Shapiro-Wilk test, then measurements were compared in the three conditions with appropriate statistical tests. RESULTS: After isolated medial gastrocnemius recession (Δ = T1-T0), ankle dorsiflexion assessed with the knee in extension significantly increased by 5° ± 3 (range, -2 to 10) with a 2-kg torque (p = 0.02) and by 4.5° ± 3 (range, -4 to 10) with a 4-kg torque (p = 0.04). No significant difference was observed with the knee flexed at 90° (p > 0.05 for all measurements). After both gastrocnemius heads recession (Δ = T2-T1), although a further increase in dorsiflexion was noticed, statistical significance was not reached neither with the knee in extension nor at 90° of flexion (p > 0.05 for all measurements). CONCLUSION: In this study, isolated medial gastrocnemius head recession performed according to LS Barouk's technique was effective in improving ankle dorsiflexion, whereas the additional release of the lateral head did not produce any significant change. LEVEL OF EVIDENCE: Level V, cadaveric study.

Value of debridement and irrigation for the treatment of peri-prosthetic infections. A systematic review.

Debridement and irrigation has been proposed as a salvage procedure for early post-operative and late acute haematogenous periprosthetic hip and knee infections, however the effective ability of this procedure to avoid recurrent infection is still debated. In this systematic review of the literature we reviewed full-text papers published from 1970 through 2011, that reported the success rate of infection eradication after debridement and irrigation with prosthesis retention for the treatment of early septic complications (within six weeks from surgery) or late acute haematogenous infections after hip or knee prosthesis. In all, 14 original articles, reporting the results of 710 patients were retrieved. The average success rate has been, respectively, 45.9% and 52% after a single or repeated debridement and irrigation procedures, at a mean follow-up of 53.3 months. The methodological limitations of this study and the heterogeneous material in the reviewed papers notwithstanding, this systematic review shows that debridement and irrigation procedure is associated with a rather poor outcome, even in a population of patients selected on the basis of symptoms' duration and patients should be adequately informed prior to undergo this salvage procedure.