Intervertebral disc (IVD) degeneration occurs with aging, leading to low back pain (LBP), which is one of the leading conditions of disability worldwide. With the lack of effective treatment, decellularized extracellular matrix (dECM) – based biomaterials have been proposed for IVD regeneration. However, the impact of donor ages on tissue repair had never been explored before in the disc field. Therefore, we aimed to address this question.

For that, a decellularization protocol for bovine nucleus pulposus (NP) of different aged donors (fetus, young and old) was optimized by testing several detergents (SDS and Triton). The process efficiency was evaluated in terms of DNA and cell removal, as well as ECM preservation. Afterwards, dECMs were repopulated with bovine NP cells and cultured ex vivo. At day 7, cell behavior, ECM de novo synthesis and remodeling were evaluated [1]. Moreover, dECMs’ inflammatory response was assessed after in vivo CAM assay. Finally, inflammatory and angiogenic cytokines were analyzed in the conditioned media-derived from dECMs by using a cytokine array.

As results, an optimal decellularization protocol (SDS 0.1%, 1h), efficient at removing cells and DNA from bovine NPs, while preserving ECM cues of native tissues, was developed. After repopulation, aggrecan increased in younger NPs, while collagen 2 decreased which may be indicative of matrix remodeling [1]. After in vivo CAM assay, fetal dECMs showed the highest inflammatory response. Finally, no statistically significant changes of cytokines were detected in the matrices, despite for a trend of higher IFN-α, IFN-γ and LIF in fetal dECMs, IL-1β in young dECMs and Decorin in old dECMs.

Overall, this work uncovered the importance of tissue donor ages for tissue regenerative purpose, opening new avenues for the development of appropriate therapeutic strategies for IVD degeneration.

Acknowledgments: FCT, EUROSPINE, ON Foundation.

Acute septic arthritis of the knee can lead to joint damage or sepsis, if early diagnosis and treatment fail to occur, which includes drainage of the joint, adequate antibiotic coverage and resting of the knee. Classically, drainage of the knee was performed either with multiple aspirations or open arhtrotomy. The arthroscopic approach has becoming widely accepted, as it allows adequate drainage of the pus and debridement with partial or total sinovectomy of the joint.

The aim of this study was to evaluate the differences between arthroscopy and open arthrotomy in the clinical outcomes and rate of recurrence in patients with septic arthritis of the knee joint.

We reviewed patients with acute septic arthritis of the knee admitted in our center between January 2010 and December 2014. The criteria for diagnosis was report of purulent material when arhtrotomy or arthroscopy was performed or a positive culture of the joint fluid. Patients with recent surgery or documented osteomyelitis of the femur or tíbia were excluded.

We used the Oxford Knee Score (OKS) to classify the clinical outcomes in the end of follow-up, and registered the rate of recurrence in each group. The statistical evaluation of the results was performed using Student's t-test.

65 patients were treated during this period, 37 by an open arthrotomy through a lateral supra-patellar aproach, and 28 by arthroscopy through 2 standard anterior portals. All the patients were imobilized with a cast or orthosis in the immediate post-operation period for a mean period of 13 days in the arthrotomy group (8–15) and 9 days in the arthroscopy group (6–12) and received endovenous antibiotics for at least 10 days, followed by oral antibiotics for a mean total of 36 days in the the arthrotomy group (30–48) and 32 days in the arthroscopy group (22–36). The mean follow-up was 22 months in the arthrotomy group (8–28 months) and 18 months in the arthroscopy group (14–24). The mean OKS was 31 in the the arthrotomy group (21–39) and 35 in the arthroscopy group (25–44). There was 1 recurrence in the arthrotomy group and 1 recurrence in the arthroscopic group, both managed by knee arthrotomy.

Drainage is a key step in treatment of knee pyoarthrosis, either through an open or an arthroscopic approach. Both seem to be equally effective, with no significant statistical difference in terms of recurrence. The functional results tend to favour the arthroscopic approach, but with no statistical significance.

The aim of this study was to assess the incidence of low-grade infections in total hip arthroplasty revisions and the clinical outcomes after two-time revision surgery.

Retrospective study of total hip arthroplasty revision surgery between January of 2012 and December of 2013. Inclusion criteria: two-time revision surgery, PCR (pre and post-op) white blood cells count and microbiological culture. The diagnosis of low-grade infection was based on the Academy of Orthopedic Surgeons’ (AAOS) guidelines. All patients were evaluated with the Harris Hip Score (HHS).

Between this period were revised a total of 79 hips, none of them bilateral, of these fourteen full-filled the inclusion criteria, eight women and six men. The mean time between primary arthroplasty and revision surgery was 4.5 years. The interface was metal-on-polyethilene in thirteen and metal-on-metal in one. All patients had at least three episodes at the urgency department with permanent hip pain in the last six months. Ten have done a course of antibiotics previous to surgery. Intra-articular pus was present in four patients. The agent isolated was S. Aureus in five and S. Epidermidis in two. An elevated PCR and leucocytosis was present in all patients. The mean PCR was 18.1 and leucocytes countage 7600. The HHS was good in four patients, fair in seven patients and poor in three. These three patients with poor had another surgical intervention due to recurrent dislocation.

Periprosthetic joint infection is a common complication after total hip arthroplasty (THA). The incidence is approximately 1% after primary replacement and about 4% revision arthroplasty. As stated by Hanssen successful treatment outcomes require precise assessment of the infecting organism, the immune status of the patient, and the condition of the bone and soft tissues around the joint. With this study we tried to establish a protocol in our service: patient with a THA, interface metal-on-polyethilene, persistent coxalgia and elevated PCR will be diagnosed with low-grade infection, however we need further revision of our experience.

Knee joint infection after an ACL reconstruction procedure is infrequently but might be a devastating clinical problem, if not diagnosed promptly and treated wisely.

The results of functional outcomes in these patients are not well known because there aren't large patient series in the literature.

The objective of this study was to evaluate the prevalence and determine the adequate management of septic arthritis following ACL reconstruction and to assess the patient functional outcomes.

The authors conducted a retrospective multicentric analysis of septic arthritis cases occurring after arthroscopically assisted ACL reconstructions (hamstrings and BTB), in patients submitted to surgery between 2010 to 2014. The study reviewed patients submitted do ACL reconstruction, that presented objective clinical suspicion of joint infection, in post-operative acute and sub-acute phases, associated with high inflammatory seric parameters (CRP >=10,0, ESR>=30,0) and synovial effusion laboratory parameters highly suggestive (PMN >=80, leucocytes >=3000).

All this patients were treated with antibiotic empiric suppressive therapy and then directed antibiotherapy according to antibiotic sensitivity profile, then the patients were submitted to arthroscopic lavage procedure, without arthropump, but with debris and fibrotic tissue removal preserving always the ACL plasty. The functional outcomes analyzed were the Lysholm and the IKDC score.

Eleven (2.2 %) out of 490 patients analyzed in the sudy were diagnosed with a post-operative septic arthritis. The microbiologic exams showed coagulase-negative Staphylococcus was present in 5 patients (S. lugdunensis in 4 cases and S. capitis in 1 case), Staphylococcus Aureus in 2 patients (1 MSSA and 1 MRSA). In four patients, the micro-organism was not identified.

The studied patients had a mean follow-up of 28 ± 16 months, the Lysholm score was 74.8 ± 12.2, the IKDC score was 66.4 ± 20.5.

Functional outcomes in the control group were better than those obtained in the infected group.

(Lysholm score 88.2 ± 9.4 (NS); IKDC score 86.6 ± 6.8 (NS). All patients retained their reconstructed ACL. None of the patients relapsed or need other intervention because of ACL failure and chronic instability.

The prevalence of septic arthritis after an ACL reconstruction in this series was 2.2 %, slightly higher than other international series (0.14 to 1.7 %). Arthroscopic lavages along with antibiotic treatment showed to be a secure procedure and allowed the preservation of the ACL plasties, without infection relapse. But the functional outcomes after active intra-articular infection were largely inferior to those obtained in patients without infection, probably to uncontrolled and intense inflammatory local response.

Surgical treatment of distal tibia fractures is usually associated with extensive soft tissue compromise and high complication rates (infection, delayed or non-union, ankle stiffness and osteoarthritis). Wound infection is one of the most common complication (deep infection rates up to 15%) and can develop into an infected non-union.

In 1973, Papineau described a staged technique for treating infected non-union of long bones, consisting of (1) surgical debridement of necrotic tissue, temporary splinting, specific antibiotic treatment, postoperative wet-to-dry wound dressing changes; (2) packing of the bone defect with cortico-cancellous autograft; (3) closure of the soft-tissue wound by a flap or secondary intent.

The authors aim to report a clinical case of a successful treatment of a distal tibia infected non-union with the Papineau technique and negative-pressure wound therapy.

Woman, 56 years-old, referred to Orthopaedic consultation on October 2013 for wound dehiscence and infection with a methicillin-resistant Staphylococcus aureus, one month after open reduction and internal fixation of an open distal tibia fracture.

On November 2013 she underwent surgical debridement, removal of osteosynthesis material, osteotaxis with external fixator, negative-pressure wound therapy and antibiotic treatment with intravenous vancomycin 1g 12/12h (1st stage of Papineau procedure)

On December, she underwent autologous iliac crest cancellous bone grafting and wound care, daily irrigated with saline solution (2nd stage).

On February 2014, she underwent a partial thickness skin graft for wound closure (3rd stage).

On April, the external fixator was removed and there was still no evidence of union. She had pain, disuse osteoporosis, ankle and midfoot stiffness, and was sent to physical therapy.

On April 2015, she can full weight bear with mild pain, the soft tissue envelope is in good condition, the fracture has united and she has an Ankle AOFAS Score of 83.

The Papineau technique has been used for the management of infected non-unions with bony defects, with high success rates. Complete necrotic tissue debridement and targeted antibiotics are fundamental for obtaining a viable and healthy tissue, able to receive the bone graft. Negative-pressure wound therapy is important in reducing the bacterial load, improving the microcirculation and enhancing the granulation tissue.

In the present case, the combination of the two techniques probably acted together in achieving successful eradication of the infection, reconstruction of the bone defect and soft tissue closure.

Acute septic arthritis of the knee may be a challenging diagnosis in the emergency department and must always be excluded in any patient with knee pain and local or systemic signs of infection. Arthrocentesis of the suspected knee is mandatory, since the analysis of the synovial fluid gives useful information like the white blood cell count (WBC)/mm3 or the polymorphonuclear cell percentage (PMP). These parameters will help the clinician to make the decision to drain the joint in the operation room, without having to wait for the culture or Gram stain, which may take several days to be available. The classical cutoff of 50,000 WBC/mm3 with more than 90% of PMP may fail to include all the septic arthritis of the knee, since significant variation have been described in recent years. The aim of this study was to evaluate the accuracy of WBC/mm3 and PMP in the synovial fluid in the diagnosis of acute septic arthritis of the knee.

We reviewed the clinical data of patients diagnosed with acute septic arthritis of the knee admitted in our center between January 2010 and December 2014, specifically the WBC/mm3 and the PMP of the synovial joint fluid. The criteria for diagnosis of an acute septic arthritis of the knee was report of purulent material when arhtrotomy or arthroscopy was performed or a positive culture of the joint fluid. The statistical evaluation of the results was performed using Student's t-test.

48 patients matched the inclusion criteria. The mean WBC/mm3 was 44.333 (14.610–182.640) and the mean PMP was 91,89% (86,4%–98,1%). 28 patients (58,33%) had a WBC/mm3 below 50.000 and 44 patients (91,67%) had a PMP above 90%, both with no statistical significance.

Knee arthrocentesis is mandatory in every patient suspected to have an acute knee pyoarthrosis, since the joint fluid analysis may show several abnormal findings. Our results show that a considerable number of patients may show a relatively low WBC/mm3 in the joint fluid in the presence of a knee pyoarthrosis. The PMP may be a better criteria, but again failed to achieve statistical significance, probably because of the low number of patients. The synovial fluid analysis alone is probably misleading in the diagnosis of an acute septic arthritis of the knee if the clinician is guided by the classical guidelines. The physical examination, medical history, laboratory and imagiologic tests are all key elements in this challenging diagnosis.

Surgical Site Infection (SSI) is one of the most frequent nosocomial infections and depends on many factors: patient, microorganism, antiseptic solution use, antibiotic prophylaxis, hand scrubbing, wound care or hospital stay lenght.

With the present paper the authors aim to study the SSI incidence after Total Knee (TKA) or Hip Arthroplasty (THA).

All patients who underwent primary TKA or THA between January 2011 and May 2012 at our institution were considered. Patients who died within 1 year after the procedure of unrelated causes were excluded. Data collected included ASA classification, type of procedure, total and post-operative hospital stay, type and duration of antibiotic prophylaxis.

Data were collected from the consultation at 1 month and 1 year post-operative, clinical registries and telephone interview. SSI was defined according to the Centers for Disease Control and Prevention criteria. Suspected cases of SSI included antibiotic administration longer than 5 days or absence of antibiotic prescription, hospital stay after the procedure longer than 9 days, patient referring infection symptoms, and clinical data reports of infection or re-intervention.

During the studied period and after exclusion of 5 cases, a total of 251 surgeries (104 TKA, 147 THA) were performed, of which 2 were urgent.

For both TKA and THA, the average total hospital stay was 9 days (8 days post-operative). The majority were American Society of Anesthesiologists (ASA) classification 2 and 3.

There were 4 SSI (1,60%), 2 TKA (1,92%) and 2 THA (1,36%), all of them after discharge. Their average total hospital stay was 10,5 days.

Antibiotic prophylaxis was used in 93% of the patients (97,4% a cephalosporin), with an average length of 5,7 days.

Recommended hospital stay after a TKA or THA is about 5 days. On HELICS-CIRURGIA 2006–2010 report it was 10 days, similar to ours. In infected patients, our total hospital stay was lower (10,5 vs 26).

Recommended duration of antibiotic prophylaxis is 24h. On HELICS-CIRURGIA more than 50% had it for more than 24h, which also happened with us; our antibiotic coverage was similar.

Comparing to HELICS-CIRURGIA, the predominance of ASA 2 and 3 classifications was similar, but the overall SSI rate was lower (1,6% vs 2,24%).

We conclude we must reduce hospital stay and antibiotic duration and keep the surveillance of SSI after TKA or THA.

Introduction: Several studies have compared various plate constructs for distal intra-articular humerus fractures. In our experience osteoporotic bone and fractures that have a transverse component close to the elbow joint have tenuous fixation with traditional plating systems due to, at most, two screws in the distal fragment through the plate. Therefore, the aim of this study was to obtain objective data on the performance of two plating systems used for fixation of intra-articular distal humerus fractures with a low transverse component with only two screws through a 3.5 LC-DCP distally. It was hypothesized that locked plating would be more stable than standard plating after cyclic loading.

Methods: Twenty pairs of fresh matched cadaver humeri of patients older than 65 years old were harvested. DEXA scans of the right forearm from each pair were obtained. Osteotomies were performed to simulate comminuted supracondylar humerus fracture with intercondylar split (OTA 13-C2.3). The specimens were then randomly assigned to locking or non-locking plate fixation.

Ten paired specimens were tested in simulated extension and the remaining ten were tested axially.

Fragment motion relative to the humeral shaft was measured using kinematic analysis at the fracture gap.

Differences in resultant fragment translations and rotations between fixation groups were checked for significance (p< 0.05) using a one-tailed paired t-test. Differences in cycles to failure were checked for significance using a Wilcoxon signed rank test.

Results: On average, during extension tests, the humeri with locking plate fixation did not survive significantly more cycles (4352) than with non-locking (4755) plate fixation. There was no significant difference in fragment translation between locking (0.8 mm) and non-locking (1.7 mm) plates. However, there was a significant difference in fragment rotation between locking (2.8 degrees) and non-locking (3.9 degrees) fixations.

On axial testing, the humeri with locking plates on average survived more loading cycles (4072) than those with non-locking plate fixation (2115), but the difference was not significant. Mean translation for locking plate fixation (3.6 mm) was significantly less than for non-locking plate fixation (5.7 mm) and mean fragment rotation was significantly less for locking plate fixation (13.3 degrees) than for non-locking plate fixation (17.8 degrees).

Conclusions: The results of this study demonstrated that the fixed-angle 3.5 mm locking plate constructs for comminuted intercondylar humerus fractures reduced fracture site motion, sometimes significantly so, relative to the non-locking constructs in osteoporotic bone. The potential benefit of increased fixation survivability and decreased fracture site motion in osteoporotic bone needs to be evaluated clinically.