Knee arthrodesis using a compression clamp and a single-plane external fixator to treat infection.

BACKGROUND: In patients with knee infection, arthrodesis by external fixation is a limb-salvage procedure appropriate in highly selected patients. No hardware that might lead to infection is left in situ. However, the fusion rate is limited. Use of a device that applies compression in the coronal plane has been suggested in combination with sagittal external fixation to increase the fusion rate but has not been the focus of published studies. The objectives of this retrospective study were to determine: 1) the fusion rate and, 2) the rate of infection eradication. HYPOTHESIS: Knee arthrodesis using an external fixator and a compression clamp provides higher fusion rates compared to reports of external fixation without compression. MATERIAL AND METHODS: We retrospectively studied 30 patients who underwent knee arthrodesis using external fixation and a compression clamp. The reason for arthrodesis was recurrent infection after total knee arthroplasty in 18 patients and septic arthritis in 12 patients. There were 16 females and 14 males with a mean age of 66.0±11.6 years (range, 30-83 years). Mean follow-up was 42.5±23.6 months (range, 24-106 months). RESULTS: Fusion was achieved in 25 (83%) patients, after a mean of 7.5 months (range, 6-12 months). Of the 8 patients with severe bone loss (≤25% bone contact), 4 experienced non-union, compared to 1 of the 22 patients whose bone loss was moderate or mild (50% and >50% bone contact, respectively) (p=0.01). After at least 2 years of follow-up, the infection was eradicated in 28 (93%) patients. Complications occurred in 9 patients and consisted of pin-site infection managed by lavage (n=3), recurrent infection requiring revision surgery for debridement and lavage combined with material exchange and antibiotic therapy (n=2), and femoral shaft fracture (n=3) or traumatic fracture of the arthrodesis (n=1) treated by changing the clamp and fixator assembly. DISCUSSION: The fusion rate achieved using this combined technique is high and better than obtained with external fixation alone. Our results confirm that infection eradication is obtained more often than with nailing. This one-stage, simple, reproducible procedure does not leave any foreign material in situ. LEVEL OF EVIDENCE: IV, retrospective observational cohort study.

Fully hydroxyapatite-coated distal locking cementless femoral modular implant for revision total hip arthroplasty: A retrospective study of 94 Renaissance™ stems at a minimum 10 years' follow-up.

INTRODUCTION: Modular locking revision total hip arthroplasty femoral implants have been little assessed over the long term. We therefore conducted a retrospective assessment of the Renaissance™ fully hydroxyapatite-coated distal locking cementless femoral modular revision implant at a minimum 10 years' follow-up, analyzing: 1) survivorship, 2) complications, 3) radiologic and functional results, and 4) prevalence of thigh pain. HYPOTHESIS: This implant shows more than 90% 10-year survival. MATERIAL AND METHOD: Between December 2002 and December 2008, 213 implant exchanges were performed in 206 patients, including 97 Renaissance™ stems in 93 patients. Three patients were excluded for missing data. Survival was analyzed for 94 stems in 90 patients at a mean 11.2±3 years' follow-up; radiographic and clinical assessment was performed for 48 stems in 45 patients. The survival criterion was implant fracture and/or femoral stem removal. RESULTS: Survival was 93.5% at 10 years (95% CI: 86-97) and 91.3% at 15 years (95% CI: 82.9-96). Eight stems (8.5%) were exchanged or removed by last follow-up: 5 for infection (5.3%) and 3 for implant breakage (3.2%). The complications rate was 18.1% (N=17, including the 8 stem revisions): 3 stem exchanges for breakage (3.2%), 9 stem infections (9.6%), 3 dislocations (3.2%), and 2 traumatic greater trochanter fractures (2.1%). For the 45 patients with long-term clinical assessment, the mean Postel Merle d'Aubigné and Harris Hip scores were respectively 15±3 and 80 ±19 at last follow-up. Metaphysis reconstruction was satisfactory in 36/48 cases (75.0%). Seven of the 48 stems (14.6%) assessed at longest follow-up, in 45 patients, were causing thigh pain, unrelated to stress-shielding, distal locking screws or metaphyseal filling index. DISCUSSION: The Renaissance™ fully hydroxyapatite-coated modular locking stem with curved nail showed 90% 10-year survival, with satisfactory functional results and little thigh pain. LEVEL OF EVIDENCE: IV; case study without control group.

Antibiotic Therapy for 6 or 12 Weeks for Prosthetic Joint Infection.

BACKGROUND: The management of prosthetic joint infection usually consists of a combination of surgery and antimicrobial therapy. The appropriate duration of antimicrobial therapy for this indication remains unclear. METHODS: We performed an open-label, randomized, controlled, noninferiority trial to compare 6 weeks with 12 weeks of antibiotic therapy in patients with microbiologically confirmed prosthetic joint infection that had been managed with an appropriate surgical procedure. The primary outcome was persistent infection (defined as the persistence or recurrence of infection with the initial causative bacteria, with an antibiotic susceptibility pattern that was phenotypically indistinguishable from that at enrollment) within 2 years after the completion of antibiotic therapy. Noninferiority of 6 weeks of therapy to 12 weeks of therapy would be shown if the upper boundary of the 95% confidence interval for the absolute between-group difference (the value in the 6-week group minus the value in the 12-week group) in the percentage of patients with persistent infection within 2 years was not greater than 10 percentage points. RESULTS: A total of 410 patients from 28 French centers were randomly assigned to receive antibiotic therapy for 6 weeks (205 patients) or for 12 weeks (205 patients). Six patients who withdrew consent were not included in the analysis. In the main analysis, 20 patients who died during follow-up were excluded, and missing outcomes for 6 patients who were lost to follow-up were considered to be persistent infection. Persistent infection occurred in 35 of 193 patients (18.1%) in the 6-week group and in 18 of 191 patients (9.4%) in the 12-week group (risk difference, 8.7 percentage points; 95% confidence interval, 1.8 to 15.6); thus, noninferiority was not shown. Noninferiority was also not shown in the per-protocol and sensitivity analyses. We found no evidence of between-group differences in the percentage of patients with treatment failure due to a new infection, probable treatment failure, or serious adverse events. CONCLUSIONS: Among patients with microbiologically confirmed prosthetic joint infections that were managed with standard surgical procedures, antibiotic therapy for 6 weeks was not shown to be noninferior to antibiotic therapy for 12 weeks and resulted in a higher percentage of patients with unfavorable outcomes. (Funded by Programme Hospitalier de Recherche Clinique, French Ministry of Health; DATIPO ClinicalTrials.gov number, NCT01816009.).

Poor prognosis for infectious complications of surgery for ankle and hindfoot fracture and dislocation. A 34-case series.

INTRODUCTION: Ankle and hindfoot fractures are associated with high rates of complications, and of infection in particular, for which rates of 1% to 48% are reported. HYPOTHESIS: Treatment of bone and joint infection (BJI) secondary to surgery for ankle or hindfoot fracture is at high risk of failure. We analyzed results of treatment of BJI in this context. MATERIAL AND METHODS: 33 patients (34 cases) were treated for ankle or hindfoot BJI between 2010 and 2015. Cure was defined by absence of fistula and of local or general inflammatory signs and by normal C-reactive protein level, at a minimum 2 years' follow-up. Fusion without infection was counted as success; recurrent infection and amputation were counted as failure. Mean age at trauma was 52 years (range, 16-85 years). Median time to diagnosis of BJI was 44 days (range, 2-830 days). RESULTS: Mean follow-up was 20 months (range, 3-59 months). Twenty-two patients were cured (65%). Seven cases required joint fusion (21%). The failure rate was 15%, including 5 transtibial amputations. Skin cover flap was required for 15 patients (44%), at a median 33 days (range, 0-167 days). DISCUSSION: Despite its retrospective design and small numbers, the present study confirmed the poor prognosis of BJI following surgery for ankle and/or hindfoot fracture. Patients need to be informed of this. TYPE OF STUDY AND LEVEL OF EVIDENCE: IV, retrospective observational.

Antibiotic therapy duration for prosthetic joint infections treated by Debridement and Implant Retention (DAIR): Similar long-term remission for 6 weeks as compared to 12 weeks.

BACKGROUND: The required duration of antibiotic treatment for prosthetic joint infections (PJI) with debridement and retention of the implant (DAIR procedure) is unknown. METHODS: Multicenter retrospective study emphasizing the duration of antibiotic therapy in patients treated with by DAIR. RESULTS: We included 87 hip or knee PJI episodes in 87 patients from three university hospitals in France and Switzerland. All debridements were performed within 3 weeks of symptom onset. After a mean follow-up of 52.1 months, 60 patients with PJI (69%) remained in remission, with no significant difference between hip and knee cases (73.3% vs. 59.3%, 95% confidence interval (CI), 0.20-1.38), or between patients receiving 6 compared with 12 weeks of antibiotic treatment (70.5% vs.67.4%, 95%CI 0.27-2.10, p=0.60). Methicillin-resistant Staphylococcus aureus was isolated from 13.8% of infections and this was the only variable associated with a poorer outcome (remission in 41.7% vs. 73.3% for those with other pathogens, 95%CI 0.05-0.77, p=0.02). CONCLUSIONS: In patients undergoing DAIR for hip or knee PJI, the likelihood of long-term remission was not significantly different for those receiving 6 versus 12 weeks of antibiotic therapy. Prospective randomized trials are required to confirm this observation.

A Retrospective Review of the Clinical Experience of Linezolid with or Without Rifampicin in Prosthetic Joint Infections Treated with Debridement and Implant Retention.

INTRODUCTION: Debridement and prosthesis retention, combined with a prolonged antibiotic regimen including rifampicin, is an accepted therapeutic approach when the duration of symptoms is less than 4 weeks and there are no radiological signs of loosening. The outcome of patients managed with this strategy has been previously assessed in several articles with success rates of 60-90%. This study aims to review the clinical experience with linezolid in 3 different hospitals from Spain and France in patients with prosthetic joint infection (PJI) managed with debridement, retention of the implant and treated with linezolid with or without rifampicin. METHODS: Patients with an acute PJI who underwent open debridement with implant retention treated with linezolid for more than 7 days in 3 hospitals from Barcelona, Tours and Lille between 2005 and 2011 were retrospectively reviewed. Relevant information about demographics, co-morbidity, type of implant, surgical treatment, microorganism isolated, antimicrobial therapy, adverse events (AEs) and outcomes were recorded from patients. RESULTS: A total of 39 patients were retrospectively reviewed. The mean age (SD) was 70.5 (8.8) years and 9 patients had diabetes mellitus (23%). There were 25 (64%) knee prostheses, 13 (33%) hips and 1 shoulder (3%). The median interquartile range (IQR) days from arthroplasty to infection diagnosis was 17 (19-48) and 33 (85%) cases were diagnosed within the first 60 days. The median (IQR) duration of antibiotic treatment was 70.5 (34-96) days and the median (IQR) number of days on linezolid treatment was 44.5 (30-81). AEs were observed in 15 patients (38%), with gastrointestinal complaints in 8 cases and anemia in 5 being the most frequent. After a median (IQR) follow-up of 2.5 (1.8-3.6) years, there were 11 failures (28%) (8 relapses and 3 new infections). The failure rate was higher in the rifampicin group (36% vs. 18%) mainly due to a higher relapse rate (27% vs. 12%) although differences were not statistically significant. CONCLUSION: Management of acute PJIs with debridement and retention of the implant linezolid, with or without rifampicin, is associated with a high remission rate and it is an alternative treatment for infections due to fluoroquinolone and/or rifampicin-resistant staphylococci.