The use of uncemented stems in femoral neck fractures in elderly patients: A comparative study of 671 cases.

INTRODUCTION: The use of cemented stems in elderly patients is associated with the risk of intraoperative embolic complications. Uncemented stems eliminate this risk, but their use is controversial because of the risk of mechanical complications, with estimated subsidence between 3.6 and 30% and periprosthetic fractures between 2.1 and 11% at 6 weeks. A retrospective multicenter comparative study was conducted using a propensity score analysis to evaluate mechanical performances of uncemented stems in femoral neck fractures in elderly patients to (1) compare the risk of mechanical complications and (2) assess the use of metaphyseal-anchored stems for this indication. HYPOTHESIS: There is no difference in the risk of mechanical complications, intraoperatively or postoperatively, between these stems. MATERIALS AND METHODS: We conducted a multicenter retrospective comparative study including 358 uncemented and 313 cemented stems. The mean age was 84.5 years [83.9-85.1]. The inclusion criteria were patients 70 years and older and a follow-up of at least 6 weeks. The primary endpoint was a composite endpoint comprised of stem subsidence≥2mm or periprosthetic fracture (up to 3 months postoperatively). The secondary endpoints were infection, stem subsidence≥2mm, and operative time. These endpoints were analyzed using a propensity score to control confounding factors. A secondary analysis used the same endpoints to compare metaphyseal-anchored (short stems) versus Corail-like stems. RESULTS: After adjusting for the propensity score, we found 11.17% mechanical complications in the uncemented group (n=40, 5.59% subsidence, and 5.59% fractures) versus 13.42% for the cemented group (n=42, 7.99% subsidence, and 5.43% fractures). There was no statistically significant difference between the 2 values (Odds Ratio [OR]=0.64 [95% Confidence Interval [CI]: 0.14-2.85] [p=0.7]). The mortality rate due to cement embolism was 1%. There was no difference in the rate of subsidence (OR=0.55 [95% CI: 0.02-12.5] [p=0.7]), periprosthetic fracture (OR=0.65 [95% CI: 0.13-3.12] [p=0.7]) or infection (OR=0.71 [95% CI: 0.32-1.55] [p=0.4]). However, the operative times were longer in the cemented group (p=0.03 for hemiarthroplasties [mean additional time 16minutes] and p=0.02 for total hip arthroplasties [mean additional time 22minutes]). No difference was observed between the metaphyseal-anchored (short stems) and Corail-like stems regarding operative time, rate of infection, and rate of stem subsidence or periprosthetic fractures. DISCUSSION: This is one of the first studies to highlight cemented stem subsidence when used for femoral neck fractures in elderly patients. Using uncemented stems in this indication is still warranted, especially since they do not bring about more mechanical complications in the first few months. Metaphyseal-anchored short stems seem to give the same results as "standard" stems. However, these findings need to be assessed in the longer term. LEVEL OF EVIDENCE: III; retrospective comparative study.

Induced-membrane treatment of refractory humeral non-union with or without bone defect.

INTRODUCTION: Treatment of humeral non-union with or without bone defect is complex, with non-negligible rates of complication and failure. Few reports focused on management of treatment failure. OBJECTIVE: The study hypothesis was that the induced-membrane technique associated in a 2-stage strategy to internal fixation provides systematic bone healing in refractory humeral non-union. MATERIAL AND METHODS: The study included 15 patients, with a median age of 46.6 years, with humeral non-union of a mean 24 months' progression and mean history of 3 attempted revision surgeries. Seven patients showed bone defect, exceeding 5cm in 2 cases. Six had history of radial palsy. RESULTS: Consolidation was achieved in all cases, at a mean 4.6 months. Ten patients underwent radial nerve transposition, 6 of whom had shown radial motor nerve palsy; all recovered within 2 to 5 months. There was 1 case of superficial infection, and 1 of seroma. DISCUSSION: The induced-membrane technique ensures bone healing due to the biological properties of the membrane; the main drawback is the need for 2-stage surgery. When bone defect exceeds 5cm, a multi-perforated fibula segment can be placed inside the membrane to increase primary stability and enhance bone integration. CONCLUSION: The induced-membrane technique is suited to humeral non-union, with or without bone defect. The 2-stage strategy is mandatory in case of suspected latent infection. In the 2-stage procedure, anteromedial radial nerve transposition facilitates the bone-graft stage. LEVEL OF EVIDENCE: IV, retrospective study.

Is the position of dual-mobility cup in THA for femoral neck fractures optimal? A retrospective study.

INTRODUCTION: Few studies have examined the relationship between the indication of total hip arthroplasty (THA) and the quality of its technical achievement. Implants mispositioning could happen more frequently while THA is performed on acute proximal femur fracture cases. The purpose of this study was to compare the frontal inclination (FTA) of double-mobility cups (DMC) in patients undergoing THA for hip osteoarthritis or fracture. MATERIALS AND METHODS: This retrospective study included all patients undergoing THA for hip fracture or hip osteoarthritis. The surgical protocol was identical in all patients and included a systematic DMC implantation. In the postoperative period, the FTA was measured on anteroposterior pelvic radiographs and compared between groups. Malposition was defined for FTA values outside the 35°-55° range. RESULTS: The study included 97 patients: 33 men, mean age: 78.8 years, 45 fractures. The misalignment rate was 55% after THA for fracture versus 33% for hip osteoarthritis (p = 0.02). The mean FTA value was 39° for "fracture" and 43° for "hip osteoarthritis" groups (p = 0.052). The risk for hip dislocation, surgical revision for mechanical or infectious cause was identical in both groups. DISCUSSION: Misalignment was more frequent when THA was achieved for an acute proximal femur fracture. Several explanations can be proposed: lesser bone quality, incomplete removal of upper acetabular osteophytes which can lead to excessive horizontalization of the cup and surgical procedure performed by younger surgeons in "fracture group". These misalignments don't cause more mechanical complications in the first months after surgery.

C-reactive protein levels for early detection of early postoperative complications after proximal femoral fracture surgery.

INTRODUCTION: We have studied the early C-reactive protein (CRP) kinetics after proximal femoral fracture (PFF) surgery and defined a chart of CRP threshold values beyond which early postoperative complications are likely. MATERIALS AND METHODS: We have prospectively followed up a 42-patient cohort for surgical treatment by osteosynthesis or hip arthroplasty, and CRP was dosed at admission, on day 1, day 3, day 5 and then twice weekly for 30 days at the same time as a platelet count control of low molecular weight heparins. Then, we identified postoperative complications (medical complications like infections other than the surgical site, thromboembolic complications, death and surgical complications like surgical site infections, dislocation, haematoma) and established the evolutive profile of CRP in a 'complication' group and a 'no complication' group. We developed a threshold value model for complications detection from our results and compared with Chapman's 500/d formula (d being the postoperative day). RESULTS: CRP in the 'complication' group (20 patients) is on average 19 points higher than the 'no complication' group (22 patients) (p = 0.007). Our model, which corresponds to the formula CRP(d) = e(4.71 - 0.06*d), is valid from day 1 to day 30 and has a threshold value of 105 mg/L at day 1. From day 5, the correlation between our chart and the 500/d chart is 0.84 (p < 10-5). Two successive CRP values strictly above our chart at a 48-h interval have a sensitivity of 65% and a specificity of 85% to detect a postoperative complication while only one CRP value above the chart has a sensitivity and a specificity of 48%. DISCUSSION/CONCLUSION: Early postoperative CRP kinetics of PFF surgical patients can be modelled as a threshold value scale valid between day 1 and day 30. This can be an additional tool in the early detection of postoperative complications, if two CRP values are above the threshold values, without replacing the clinical examination, which remains the 'gold standard'. LEVEL OF EVIDENCE: Prospective observational study.