Total knee arthroplasty revision with trabecular tantalum cones: Preliminary retrospective study of 51 patients from two centres with a minimal 2-year follow-up.

BACKGROUND: Successful management of large bone defects is of crucial importance when performing revision total knee arthroplasty (TKA). Trabecular tantalum cones may improve prosthesis fixation via their potential for reconstructing a stable metaphyseal support. The objective of this study was to evaluate the clinical and radiological outcomes and the complications of tantalum cones in revision TKA. HYPOTHESIS: Trabecular tantalum cones provide stable and durable metaphyseal reconstruction when used during revision TKA. MATERIAL AND METHODS: Trabecular Metal™ cones (Zimmer, Warsaw, IN, USA) were used for 52 revision TKAs in 51 patients (mean age, 68±9 years) managed in two centres between 2008 and 2013. A rotating hinge prosthesis was chosen for 38 (73%) knees and a condylar constrained knee prosthesis for 14 (27%) knees, with 37 tibial and 34 femoral cones. The two most common reasons for revision surgery were aseptic loosening (n=22, 42%) and infection (n=19, 37%). The bone loss was severe in most cases. At each centre, after a mean follow-up of 34 months (range, 24-52 months), two independent observers assessed the Knee Society Score (KSS), range of motion, mechanical axis, and osteo-integration for each patient. RESULTS: Mean KSS increased from 46 preoperatively to 77 (P=0.001) at last follow-up and the mean KSS function from 39 to 57 (P=0.007). Mean range of motion improved from 93° (45°-120°) to 110° (65°-130°) (P=0.001). Mean postoperative mechanical axis was 180° (172°-190°). Radiographic evaluation showed evidence of osteo-integration for all cones. Four revisions were performed for recurrence of infection but none for mechanical failure. DISCUSSION: The findings of our study confirm the biomechanical and biological reliability of Trabecular Metal™ cones used to fill metaphyseal bone defects during revision TKA. LEVEL OF EVIDENCE: IV, retrospective therapeutic study.

Long-term results of compartmental arthroplasties of the knee: Long term results of partial knee arthroplasty.

Partial knee arthroplasty (PKA), either medial or lateral unicompartmental knee artroplasty (UKA) or patellofemoral arthroplasty (PFA) are a good option in suitable patients and have the advantages of reduced operative trauma, preservation of both cruciate ligaments and bone stock, and restoration of normal kinematics within the knee joint. However, questions remain concerning long-term survival. The goal of this review article was to present the long-term results of medial and lateral UKA, PFA and combined compartmental arthroplasty for multicompartmental disease. Medium- and long-term studies suggest reasonable outcomes at ten years with survival greater than 95% in UKA performed for medial osteoarthritis or osteonecrosis, and similarly for lateral UKA, particularly when fixed-bearing implants are used. Disappointing long-term outcomes have been observed with the first generation of patellofemoral implants, as well as early Bi-Uni (i.e., combined medial and lateral UKA) or Bicompartmental (combined UKA and PFA) implants due to design and fixation issues. Promising short- and med-term results with the newer generations of PFAs and bicompartmental arthroplasties will require long-term confirmation.

Is knee function better with contemporary modular bicompartmental arthroplasty compared to total knee arthroplasty? Short-term outcomes of a prospective matched study including 68 cases.

BACKGROUND: Bicompartmental knee arthroplasty (BKA) was developed to treat medial tibiofemoral and patellofemoral osteoarthritis while preserving the anterior cruciate ligament to optimise knee kinematics. Our objective here was to compare the probability of achieving forgotten knee status and the functional outcomes at least two years after BKA versus total knee arthroplasty (TKA). We hypothesised that contemporary modular BKA produced better functional outcomes than TKA after at least two years, for patients with similar pre-operative osteoarthritic lesions. MATERIAL AND METHODS: We conducted a two-centre prospective controlled study of 34consecutive patients who underwent BKA between January 2008 and January 2011. Each patient was matched on age, gender, body mass index, preoperative range of knee flexion, centre, and surgeon to a patient treated with TKA. An independent observer evaluated all 68 patients after six and 12months then once a year. Forgotten knee status was defined as a 100/100 value of the Forgotten Joint Score (FJS-12) and each of the five KOOS subscales. We also compared the two groups for knee range of motion, Knee Society Scores (KSSs), Timed Up-and-Go test (TUG), and UCLA Activity Score. RESULTS: At a mean follow-up of 3.8±1.7 years, the probability of forgotten knee status was significantly higher in the BKA group (odds ratio, 4.64; 95% confidence interval, 1.63-13.21; P=0.007, Chi(2) test). Mean post-operative extension was not significantly different between the groups, whereas mean range of knee flexion was significantly greater in the BKA group (130°±6° vs. 125°±8° after TKA; P=0.03). The BKA group had significantly higher mean values for the knee and function KSSs, TUG test, and UCLA score (P<0.04 for all four comparisons). CONCLUSION: After at least two years, contemporary unlinked BKA was associated with greater comfort during everyday activities (forgotten knee) and better functional outcomes, compared to TKA. These short-term results require validation in randomised trials with longer follow-ups. LEVEL OF EVIDENCE: III, case-control study.

Can we achieve bone healing using the diamond concept without bone grafting for recalcitrant tibial nonunions?

The purpose of this study was to evaluate the efficacy and safety of a combination of recombinant human bone morphogenetic protein 7 (rhBMP-7) and resorbable calcium phosphate bone substitute (rCPBS) as a salvage solution for recalcitrant tibial fracture nonunions. Twenty consecutive patients, 16 male and four female, with a mean age of 46.8±15.7 years (21-78) and a mean body mass index (BMI) of 24.2±5.3kgm(-2) (21.5-28.5), suffering from 20 recalcitrant tibial fracture nonunions were included. The mean number of operations performed prior to the procedure was 3.3, with homolateral iliac crest bone grafts being used for all of the patients. All patients were treated with a procedure including debridement and decortications of the bone ends, nonunion fixation with a locking plate, and filling of the bony defect with a combined graft of rhBMP-7 (as osteoinductor) with an rCPBS (as scaffold). The mean follow-up was 14±2.7 months. Both clinical and radiological union occurred in 18 cases, within a mean time of 4.7±3.2 months. A recurrence of deep infection was diagnosed for one of the non-consolidated patients. No specific complication of rCPBS or rhBMP-7 was encountered. This study supports the view that the application of rCPBS combined with rhBMP-7, without any bone grafting, is safe and efficient in the treatment of recalcitrant bone union.

Treatment of type B periprosthetic femur fractures with curved non-locking plate with eccentric holes: Retrospective study of 43 patients with minimum 1-year follow-up.

INTRODUCTION: Periprosthetic femur fracture (PFF) is a serious complication after total hip arthroplasty that can be treated using different internal fixation devices. However, the outcomes with curved non-locking plates with eccentric holes in this indication have not been reported previously. The objectives of this study were to determine: (1) the union rate; (2) the complication rate; (3) autonomy in a group of patients with a Vancouver type B PFF who were treated with this plate. HYPOTHESIS: Use of this plate results in a high union rate with minimal mechanical complications. MATERIALS AND METHODS: Forty-three patients with a mean age of 79 years ± 13 (41-98) who had undergone fixation of Vancouver type B PFF with this plate between 2002 and 2007 were included in the study. The time to union and Parker Mobility Score were evaluated. The revision-free survival (all causes) was calculated using Kaplan-Meier analysis. The average follow-up was 42 months ± 20 (16-90). RESULTS: Union was obtained in all patients in a mean of 2.4 months ± 0.6 (2-4). One patient had varus malunion of the femur. The Parker Mobility Score decreased from 5.93 ± 1.94 (2-9) to 4.93 ± 1.8 (1-9) (P = 0.01). Two patients required a surgical revision: one for an infection after 4.5 years and one for stem loosening. The survival of the femoral stem 5 years after fracture fixation was 83.3% ± 12.6%. CONCLUSION: Use of a curved plate with eccentric holes for treating type B PFF led to a high union rate and a low number of fixation-related complications. However, PFF remains a serious complication of hip arthroplasty that is accompanied by high morbidity and mortality rates.

Titanium-titanium modular neck for primary THA. Result of a prospective series of 170 cemented THA with a minimum follow-up of 5 years.

BACKGROUND: Although they have been in use since the end of the 1980s, modular titanium neck components are associated with a risk of wear or fracture, and their safety has recently become a subject of debate and has never been evaluated in a consecutive series of patients. The goal of this study was to evaluate: revision-free survival of these implants after a minimum follow-up of 5 years; clinical and radiographic results; and the potential complications associated with the use of modular titanium neck components. HYPOTHESIS: The use of titanium modular neck on cemented titanium THA is safe at a minimum follow-up of 5 years. PATIENTS AND METHODS: Between January 2006 and December 2008, we prospectively followed 170 patients (170 hips) who underwent primary anatomical THA with a modular cemented titanium stem design implant. The indications were unilateral THA for primary (n=160) or secondary (n=10) hip osteoarthritis (aseptic osteonecrosis of the femoral head or hip dysplasia). Mean age of patients was 75.4±5.8 years old (52-85), and mean BMI was 26.1±4.5 kg/m(2) (16.6-42.1). Patients were operated on by a modified Watson-Jones anterolateral approach based on preoperative 2D planning. All patients underwent annual clinical and radiological follow-up by an independent observer. RESULTS: At a mean follow-up of 71±8 months (60-84), 5 patients died and 7 were lost to follow-up. There was no revision of THA after a maximum follow-up of 84 months. The Harris score improved significantly from 50.4±11.3 (0-76) preoperatively to 84.5±15.2 (14-100) at the final follow-up. There was no difference in postoperative femoral offset or the position of the center of rotation compared to the opposite side. On the other hand, the neck-shaft angle (NSA) and limb length were corrected (2±5° [-11 to +14°] and 2.16±3.6 mm [-7.4 to +12.7 mm]) respectively. Fifteen patients (9%) had limb length discrepancies of more than 5 mm and 4 patients (2%) of more than 10 mm. There were no complications due to the modular implant design. DISCUSSION: Our study suggests that the use of cemented titanium implants with a modular titanium stem is safe at a follow-up of 5 years. The modular design does not prevent limb length discrepancies but restores femoral offset. LEVEL OF EVIDENCE: IV: prospective, non-comparative study.

[Prosthetic hip infection due to Listeria monocytogenes: review of the literature and case report]. / Infection prothétique de hanche à Listeria monocytogenes.

With the ageing of the population, articular prosthetic replacements are becoming more and more frequent. One of the most feared complications is prosthetic infection, mostly due to bacteria of the cutaneous flora. Listeria monocytogenes is rarely the cause. This paper describes the management of a hip prosthetic infection due to Listeria monocytogenes. The patient was cured with antimicrobial therapy and a two-stage exchange. This case report creates an opportunity to review the literature in the aim of determining the risk factors and the optimal care.