Increased failure rates after the introduction of the TFNA proximal femoral nail for trochanteric fractures: implant related or learning curve effect?

Background and purpose — Trochanteric fractures are often treated using intramedullary fixation. In our institution, the TFN-Advanced Proximal Femoral Nailing System (TFNA) was introduced as replacement for the Gamma Trochanteric Nail (GTN3) for the treatment of these fractures as a result of a hospital-driven change of trauma implant supplier. We compared trochanteric fracture fixation failure rate between these 2 intramedullary nails. Patients and methods — All trochanteric fractures treated surgically from 2011 to 2019 were retrospectively reviewed for fixation failure. From 2016 only the TFNA was used. Fixation failure was defined as implant cut-out, implant breakage, non-union, malpositioning of the screw/blade requiring reoperation, new fracture around the nail, or miscellaneous. Propensity score matching was used to balance distribution of covariates and to compare failure rates between TFNA and GTN3 groups. Learning curve analyseswere performed. Results — After exclusion, 797 GTN3s (779 patients) and 542 (536 patients) TFNAs were available for analysis. A higher risk of fixation failure was found in the TFNA group (14%) compared with the GTN3 group (7.0%) (hazard ratio [HR] 2.0, 95% confidence interval [CI] 1.2–3.5). This was mainly attributed to a higher risk of cut-out (HR 2.2; CI 0.9–5.7), malpositioning (HR 4.7; CI 0.7–34), and new fracturearound the nail (HR 4.0; CI 1.0–16). Learning curve analyses indicated no clear learning curve effect. Interpretation — Failure of fixation increased after a switch from the GTN3 to the TFNA proximal femoral nail for the treatment of trochanteric fractures. Cut-out and malpositioning of the calcar screw or blade appeared to be the most dominant failure mechanisms. Modifications in implant design may have played a role in this increased risk of failure of fixation. In our institution a new implant device was introduced without solid clinical evidence behind it. This study may help to underline the need for medical doctors with acritical and scientific background to be involved in implant choices.

Multiple Cannulated Screw Fixation of Femoral Neck Fractures with Comminution in Young and Middle Age Patients

Objective To investigate the distribution and influence of comminutions on femoral neck fracture (FNF) patients after cannulated screw fixation (CSF). Methods From January 2019 to June 2020, a total of 473 patients with FNF treated by CSF, aged 23–65 years, were included in present study. Based on location of the cortical comminution, the FNF patients were assigned as comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) and without comminution group. The incidence of postoperative complications, quality of life and functional outcomes were recorded in different groups at 1 year-follow up. Results The comminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), while occurrence rate of comminution was also closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P<0.05). Besides, the incidence of osteonecrosis of femoral head (ONFH, 11.3% vs 2.9%, P<0.05), nonunion (7.5% vs 1.7%, P<0.05), femoral neck shortening (21.6% vs 13.4%, P<0.05) and internal fixation failure (11.8% vs 2.9%, P<0.05) in FNF patients with comminutions, especially with multiple comminutions, was significantly higher than those in FNF patients without comminution. Furthermore, there was a prominently difference in Harris hip score (HHS, 85.6±15.6 vs 91.3±10.8, P<0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85±0.17 vs 0.91±0.18, P<0.05) score between FNF patients with comminution and FNF patients without comminution, whereas there was seem to be no significantly difference in Visual analogue scale (VAS, 1.46±2.49 vs 1.13±1.80, P>0.05) score between two groups at 1 year after surgery. Conclusion In our view, the comminution, easily happened in displaced FNF and Pauwel type III FNF, which was deemed to be a risk factor for postoperative complications in young and middle-aged patients underwent CSF, consequently causing an influence on recovery of hip function and life quality. However, further evaluation with better study design, larger sample and long-term follow-up was still imminently applied.

Case Report: Treatment of Femoral Non-union With Rib and Iliac Crest Autografts and rhBMP-2 in a Cat

A 5-year-old, intact male Bengal cat weighing 5.2 kg was referred for the fixation failure of a right femoral fracture. Multiple surgical revisions failed, and atrophic non-union was diagnosed. The cat was then admitted for a final revision surgery using locking plate fixation in conjunction with rib and iliac crest autografts and recombinant human bone morphogenetic protein 2 (rhBMP-2). The fracture site was debrided and stabilized before filling the defect with 1.8 cm of rib bone autograft. The residual space in the defect was then filled with an iliac crest autograft. Finally, a 3 ×5 cm absorbable collagen sponge soaked with 0.5 mL of 0.2 mg/mL rhBMP-2 solution was placed around the defect. No significant complications were noted postoperatively. Bone healing was noted 2 months postoperatively, and it continued for 12 months. Although mild lameness remained, the cat's ambulatory function and quality of life were good. To the authors' knowledge, this is the first case report of a clinical transplantation of a rib segment as an autograft in combination with rhBMP-2 in a cat with a large bone defect.

Fixation failure in patients with traumatic diastasis of pubic symphysis: impact of loss of reduction on early functional outcomes

Background Failure of fixation (FF) in pubic symphysis diastasis (SD) ranges between 12 and 75%, though whether it influences functional outcomes is still debated. The objective of this study is to evaluate the impact of anterior pelvic plate failure and loss of reduction on Majeed’s functional scores. Methods Single center retrospective review of consecutive patients with acute SD treated by means of anterior pubic plating. Thirty-seven patients with a mean age 45.7 ± 14.4 years were included. Demographics, AO classification, pelvic fixation and secondary procedures were recorded. Majeed’s functional scores at minimum 6 months follow-up were compared according to the presence of FF and loss of reduction. Results Fifteen patients presented FF. Eight presented an additional loss of symphyseal reduction. Mean Majeed´s score (MMS) in patients with and without FF was 64.4 ± 13.04 and 81.8 ± 15.65, respectively (p = 0.0012). Differences in MMS in patients without FF and those with FF and maintained or loss of anterior reduction were 11.3 [70.5 vs 81.8] (p = 0.092) and 22.7 [59.1 vs 81.8] (p = 0.001), respectively. Significant association of FF with AO classification was noted. (OR 12.6; p = 0.002). Conclusions Differences in MMS in the analyzed groups suggest that loss of reduction might be more relevant than failure of the anterior osteosynthesis in functional outcomes.

Treatment of Pauwels type III femoral neck fracture with medial femoral neck support screw: a biomechanical and clinical study

A femoral neck fracture is currently one of the most common types of fracture in clinical practice. The incidence continues to increase due to traffic accidents, trauma, and osteoporosis. This research includes a biomechanical study and a clinical retrospective study. In the biomechanical studies, three groups’ effects (Control Group: 3CCS, DHS group, and study Group: 3CCS + mFNSS group) were compared by vertical compression tests, torsion tests, and fatigue tests. All the data were collected and analyzed. We subsequently performed a retrospective analysis of 131 patients with femoral neck fractures. The operative time, intraoperative blood loss, quality of postoperative fracture reduction, and follow-up observation of fracture healing, screw retreatment rates and fixation failure rates, as well as femoral head necrosis rates and hip function in two groups with 3CCS and 3CCS + mFNSS were compared. By the biomechanical study, we found that 3CCS + Mfnss group were biomechanically superior to 3CCS group and superior to the DHS group in terms of resistance to torsion. However, it was less effective than the DHS group in compressive strength and fatigue resistance. In terms of clinical application, 3CCS + mFNSS group was found to have lower screw retreatment rates and femoral head necrosis rates, and to have better fracture healing rates than group with 3CCS, indicating that medial support screws can effectively resist the vertical shear forces of fracture ends and promote the stability and healing of fracture ends, as well as to reduce the incidence of postoperative complications.

The Wagner Modular (S2) Prosthesis for Proximal Femur Bone Loss ; Prospective Study of 19 Cases

Background: Wagner proximal femur prosthesis is the versatile modular implant. Study Design: Prospective study Setting: Department of Orthopaedic Surgery Dow University of Health Sciences / Civil Hospital Karachi, from January 2013 to December 2019. Methodology: Total 19 patients of both genders with proximal femur bone loss due to tumor, implant failure for proximal femur fixation, comminuted intertrochanteric fracture, and failed arthroplasty included in the study. After taking written informed consent, detailed demographics including age, gender, indication of wagner prosthesis, and wagner stem type were recorded. Among all the patients 11 patients received total hip replacement and 8 patients received bipolar. Complications associated with procedure were recorded. Outcomes were assessed by Merle D Aubgine scale. Results: Total 19 patients were included in the study who were operated with wagner prosthesis for proximal femur bone deficit problems. 7 (37%) patients were male and 12 (67%) were female , between age of 16 to 70. 13 (68%) patient have proximal femur problem on right side and 6(32%) patient on left side .10 Patient have proximal femur fixation problems and 9 with proximal femur tumor. Modular wagner prosthesis used in all patients . Per-operative one (5%) patient have perforation of cortex and One (5%)patient posterior hip dislocation on next day . Two (11%) patient had per-operative fracture . Maximum follow-up is from 6.3 years to minimum 6 months. One patient with metastasis died within four weeks of surgery. Outcome measured with modified Merle D Aubgine scale showed no excellent , good in 15(79%) , fair 3 (16%), poor 1(5%). Conclusion: Wagner proximal femur modular implant is a versatile implant for proximal femur fixation failure and after proximal femur resection in tumor patients. It is modular with variable options to make stable hip joint. It is cheap as comparative to proximal femur replacement implant for tumor. Keywords: Implant failure, Proximal femur, Tumor, Wagner implant.

DOES CEMENT CURING CAUSE CONCERNING INCREASE OF THE TEMPERATURE WHEN DELIVERED IN THE HUMAN HUMERUS?

For the treatment of humeral fractures, numerous strategies exist to improve the clinical outcome of the reconstruction and to reduce the incidence of fixation failure. Injection of acrylic-based cements to reinforce the bone and/or augment the screws is one option. The heat generated during cement polymerization raises some concerns, as it could cause tissue damage. The first aim of this study was to measure the temperature over time during polymerization when acrylic cements are delivered inside the bone to treat fracture. The second aim was to assess if the ISO-5833:2002 standard can predict what happens in a real bone. Different tests were performed using two acrylic-based cements (Mendec and Cal-Cemex): (i) the ISO-5833:2002 standard (Annex C); (ii) tests on human bones (humeral diaphysis and humeral head) injected with cement to simulate fracture treatment. In the humeri, the highest temperature was measured in the diaphysis (68.6∘C for Mendec, 62.7∘C for Cal-Cemex). These values are comparable with the temperature reached in other consolidated applications (vertebroplasty). Exposure to high temperature was shorter for the diaphysis than for the head. For both cements, in both the diaphysis and the head, temperatures exceeded 48∘C for less than 10[Formula: see text]min. This is within the threshold for tissue necrosis. The ISO-5833:2002 yielded significantly different results in terms of maximum temperature (difference exceeding 15∘C) and exposure to temperature above 48∘C and 45∘C. This discrepancy is probably due to a combination of factors affecting the amount of heat produced and dissipated (e.g., amount and shape of the cement, thermal conductivity).

Failure of internal fixation of the anterior ring for unstable pelvic fractures, the experience of a single institute

Background This study aimed to share our experience of anterior ring fixation failure for unstable pelvic fractures and propose corresponding treatment strategies. Materials From January 2009 to December 2018, 93 charts of patients with pelvic fractures were retrospectively reviewed. Patients with failure of the anterior ring internal fixation within 3 months after initial surgery were analyzed. Quality of reduction was evaluated using the Majeed scoring system. Patients aging ≥ 18 years, with unstable pelvic fractures, Tile classification type B and type C pelvic fractures, combined injury of other organs that did not affect the operation and without important neurovascular damage were included. The exclusion criteria included: (1) pathological fracture, or combined with pelvic bone tumor or severe osteoporosis; (2) femoral fracture and thoracolumbar fracture; (3) open pelvic fracture; (4) Morel-Lavallée injury; (5) complicated acetabular fracture. The quality of the reduction of the anterior pelvic ring injury was evaluated on the x-ray film using the Majeed scoring system. Results According to the Tile classification of fracture, there were 23 cases of type B1, 17 cases of type B2, 11 cases of type B3, 28 cases of type C1, 6 cases of type C2, and 8 cases of type C3. The duration from injury to pelvic internal fixation ranged from 5 to 28 days. Seven out of 93 patients experienced failure of internal fixation of the anterior pelvic ring within 3 months, including 2 patients fixed with an external fixator and 5 patients fixed with a plate. Five patients undergoing revision surgery were followed up for 6–36 months with an average of 18 months. According to Majeed’s score at the last follow-up in the 5 patients undergoing revision surgery, there were 2 cases of excellent, 2 cases of good, 1 case of fair. The excellent and good rate reached 80%. Conclusion The treatment of complicated unstable pelvic fractures requires performing internal fixation surgery within 2 weeks. It is necessary to make a preoperative plan and stabilize the posterior ring first, avoiding a single steel plate crossing the pubic symphysis.