Periprosthetic fractures are a devastating complication of total hip arthroplasty (THA) and are associated with significantly higher mortality rates in the postoperative period. Given the strain that periprosthetic fractures place on the patient as well as the healthcare system, identifying and optimizing medical comorbidities is essential in reducing complications and improving outcomes.All THA with primary indications of osteoarthritis from 2007 to 2020 were queried from the National Surgical Quality Improvement Program database. Demographic data, preoperative laboratory values, medical comorbidities, hospital course, and acute complications were collected and compared between patients with and without readmission for a periprosthetic fracture. A multivariate logistic regression analysis was performed to determine associated independent risk factors for periprosthetic fractures after index THA.The analysis included 275,107 patients, of which 2539 patients were readmitted for periprosthetic fractures. Patients with postoperative fractures were more likely to be older (>65 years), females, BMI >40, and increased medical comorbidities. Preoperative hypoalbuminemia, hyponatremia, and abnormal estimated glomerular filtration rates were independent risk factors for sustaining a periprosthetic fracture and readmission within 30 days. Modifiable patient-related factors of concurrent smoking and chronic steroid use at the time of index THA were also independent risk factors for periprosthetic fractures. Inpatient metrics of longer length of stay, operative time, and discharge to rehab predicted postarthroplasty fracture risk. Readmitted fracture patients subsequently had increased risks of developing a surgical site infection, urinary tract infection, and requiring blood transfusions.Patients with hypoalbuminemia, hyponatremia, and abnormal estimated glomerular filtration rate are at increased risk for sustaining periprosthetic fractures after THA. Preoperative optimization with close monitoring of metabolic markers and modifiable risk factors may help not only prevent acute periprosthetic fractures but also associated infection and bleeding risk with fracture readmission.
O-GlcNAc modification (O-GlcNAcylation) is required for survival in mammalian cells. Genetic and biochemical experiments have found that increased modification inhibits apoptosis in tissues and cell culture and that lowering O-GlcNAcylation induces cell death. However, the molecular mechanisms by which O-GlcNAcylation might inhibit apoptosis are still being elucidated. Here, we first synthesize a new metabolic chemical reporter, 6-Alkynyl-6-deoxy-GlcNAc (6AlkGlcNAc), for the identification of O-GlcNAc-modified proteins. Subsequent characterization of 6AlkGlcNAc shows that this probe is selectively incorporated into O-GlcNAcylated proteins over cell-surface glycoproteins. Using this probe, we discover that the apoptotic caspases are O-GlcNAcylated, which we confirmed using other techniques, raising the possibility that the modification affects their biochemistry. We then demonstrate that changes in the global levels of O-GlcNAcylation result in a converse change in the kinetics of caspase-8 activation during apoptosis. Finally, we show that caspase-8 is modified at residues that can block its cleavage/activation. Our results provide the first evidence that the caspases may be directly affected by O-GlcNAcylation as a potential antiapoptotic mechanism.
Although long term pain and mobility outcomes in total knee arthroplasties (TKA) are successful, many patients experience significant amount of debilitating pain during the immediate post-operative period that necessitates narcotic use. Percutaneous cryoneurolysis to the infrapatellar saphenous and anterior femoral cutaneous nerves may help to better restore function and rehabilitation after surgery while limiting narcotic consumption. A retrospective chart review of primary TKA patients receiving pre-operative cryoneurolysis from 2019 to 2020 was performed to assess total opioid morphine milligram equivalents (MME) consumed inpatient and at interval follow-up. Demographics and medical comorbidities were compared between cryoneurolysis and age-matched control patients to assess baseline characteristics. Functional rehabilitation outcomes, including knee range of motion (ROM), ambulation distance, and Boston AM-PAC scores, as well as patient reported outcomes using the KOOS JR and SF-12 scores were analyzed using STATA 17 Software. The analysis included 29 cryoneurolysis and 28 age-matched control TKA patients. Baseline demographics and operative technique were not significant between groups. Although not statistically significant, cryoneurolysis patients had a shorter length of stay (2.5 vs. 3.5 days) and overall less inpatient and outpatient MME requirements. Cryoneurolysis patients had statistically significant improved 6-week ROM and 1-year follow-up KOOS JR and SF-12 mental scores compared to the control. There were no differences in complication rates. Cryoneurolysis is a safe, effective treatment modality to improve active functional recovery and patient satisfaction after TKA by reducing MME requirements. Patients who underwent cryoneurolysis had on average fewer MME prescribed during the perioperative period, improved active ROM, and improved patient-reported outcomes with no associated increased risk of infections, deep vein thrombosis, or neurologic complications.
Previous studies have sought to determine the effects of total knee arthroplasty (TKA) using kinematic alignment (KA) versus mechanical alignment (MA) to reproduce the native knee alignment and soft tissue envelope for improved patient satisfaction. There are limited studies that compare acute perioperative outcomes between KA and MA patients as it pertains to pain-related opioid consumption and hospital length of stay (LOS). This study aims to compare early KA and MA in restoring function and rehabilitation after surgery to reduce hospitalization and opioid consumption.A retrospective review of 42 KA and 58 MA primary TKA patients performed by a single surgeon between 2020-2021 was conducted. Demographics were controlled between groups and radiographic measurements and functional outcomes were compared. Pain was evaluated with inpatient/outpatient morphine milligram equivalents (MME) and visual analogue scale (VAS) scores. Mobility was assessed using multiple measures by a physical therapist. Mean preoperative and 3-month postoperative flexion range of motion (ROM) were analyzed, and overall complications, LOS, and non-home discharge between groups compared. Continuous variables were compared using the Wilcoxon rank-sum test, and categorical variables were compared using the chi-square or Fisher exact test. Statistical significance was set at P < 0.05.KA patients had shorter LOS (1.8 vs 3.1 days) and less cumulative opioid requirements compared to MA patients (578 vs 1253 MME). On postoperative day 0, KA patients ambulated on average twice the distance of MA patients (20 vs 6.5 feet). KA patients had residual tibia component in varus (1.4° vs -0.3°), femoral component in valgus (-1.9° vs 0.2°), and valgus joint line obliquity compared with MA (-1.5° vs 0.2°). There were no significant differences between 3-month postoperative flexion arc motion, discharge destination, KOOS or SF-12 outcomes, and surgical complication rates between groups.By restoring the native joint line obliquity and minimizing the frequency of ligament releases, KA for TKA may improve pain relief, early mobility, and decreased length of stay compared with traditional methods of establishing neutral limb axis by MA.
Objective Fibrin sealants are routinely used for intra-articular surgical fixation of cartilage fragments and implants. However, the mechanical properties of fibrin sealants in the context of cartilage repair are unknown. The purpose of this study was to characterize the adhesive and frictional properties of fibrin sealants using an ex vivo model. Design Native bovine cartilage-bone composites were assembled with a single application of Tisseel or Vistaseal. Composites were tested in tension and lap shear. In addition, the coefficient of friction (COF) was measured in a native cartilage annulus model alone and with minced cartilage. Finally, the effect of a double application of fibrin sealant was evaluated. Results There were no significant differences in tensile modulus, ultimate tensile strength (UTS), shear modulus, or ultimate shear strength (USS) between the 2 fibrin sealants. Both fibrin sealants demonstrated a UTS and USS of <8 and <30 kPa, respectively. There were no differences in COF between the sealants when tested alone or with minced cartilage. A double application of fibrin sealant did not alter the mechanical properties compared with a single application of fibrin sealant. Conclusions Fibrin sealant adhesive properties are not affected by the sealant type studied or the number of applications in a bovine cartilage-bone model. Fibrin sealant tribological properties are not affected by sealant type or the addition of minced cartilage. The adhesive properties of Tisseel and Vistaseal were less than those desired for the in vivo fixation of cartilage repair implants. These findings motivate the development of an improved cartilage-specific adhesive for cartilage repair applications.
OBJECTIVE: To compare clinical and radiographic outcomes following retrograde intramedullary nailing vs locked plating of “extreme distal” periprosthetic femur fractures, defined as those which contact or extend distal to the anterior flange. METHODS Design: Retrospective review Setting: Eight academic level I trauma centers Patient Selection Criteria: adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMNs or LPs. Outcome Measures and Comparisons : The primary outcome was reoperation to promote healing or to treat infection (re-operation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Compared, were patients treated with rIMNs or LPs. RESULTS: 71 patients treated with rIMNs and 224 patients treated with LPs were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 +/- 1.1 vs LP: 6.0 +/- 1.1, p<0.001) and more patients who were allowed to weight-bear as tolerated immediately post-operatively (rIMN: 45%; LP: 9%, p<0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group (p=0.122). There were no significant differences in nonunion (p >0.999), delayed union (p=0.079), fixation failure (p>0.999), infection (p=0.084), or overall reoperation rate (p>0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, p=0.008). CONCLUSIONS: Retrograde intramedullary nailing of extreme distal periprosthetic femur fractures has similar complication rates compared to locked plating, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Posterolateral corner (PLC) reconstruction of the knee involves precise drilling of a single tunnel from anterolateral to posteromedial in the fibular head (FH) to ensure adequate graft fixation. Misplacement of the tunnel in a too lateral or too superior trajectory can lead to cortical breach and inadequate graft fixation.To (1) determine the mechanical consequence of a lateralized FH tunnel in PLC reconstruction and (2) compare the mechanical strength of 3 salvage fixation techniques for a lateralized FH tunnel.Controlled laboratory study.Sawbones models of a uniform density were utilized. FH tunnels (7-mm diameter) were drilled from anterolateral to posteromedial in positive controls (lateral cortex thickness, 7.6 ± 0.7 mm) to represent an improperly placed FH tunnel at risk of lateral cortical breach. For negative controls and salvage experimental groups, FH tunnels were drilled from anterolateral to posterolateral (lateral cortex thickness, 2.7 ± 0.9 mm). Three salvage fixation techniques were compared: suture anchor fixation, tunnel redrilling, and nitinol staple fixation. Samples (n = 5 per group) underwent uniaxial tension testing, and the ultimate tensile strength (UTS) and mode of failure were recorded. Data were analyzed using the 1-sample t test and nonparametric 1-sample Wilcoxon signed-rank test.The negative control group had a 4-fold lower mean UTS relative to the positive control group (1.49 ± 0.17 vs 6.25 ± 1.98 MPa; P < .01) and exhibited failure through the lateral cortex and tunnel. Nitinol staple fixation improved the mean UTS by >16 times compared with the negative control group (24.06 ± 6.49 vs 1.49 ± 0.17 MPa; P < .01). Suture anchors and tunnel redrilling exhibited similar UTS and mode of failure to those of negative controls.Reinforcement of a thinned lateral FH cortex with a single nitinol staple improved graft fixation strength in a sawbones model.A lateralized FH tunnel can be a common intraoperative pitfall during PLC reconstruction. Salvage of a thinned lateral FH cortex with a single nitinol staple may reduce the risk of cortical breach and graft failure.
Recognition and treatment of injuries to the posterolateral (PLC) corner of the knee have increased in recent decades. Despite advancements in surgical technique, complications can occur in up to 20% of PLC reconstructions. Lateralization of the fibular tunnel during drilling is a common intraoperative pitfall and can lead to cortical breach or fibular head fracture after graft tensioning. Compression staples have been increasingly used for fracture fixation in the hand, foot, and ankle. Because of its pseudo-elastic properties, insertion of a low-profile, compressive Nitinol staple could serve as an intraoperative salvage technique to reinforce and prevent failure through a thin lateral cortex of the fibular head. The purpose of this Technical Note is to describe a reproducible technique for the implementation of a Nitinol staple for reinforcement of a lateralized fibular tunnel in posterolateral corner reconstruction.
For the treatment of large chondral and osteochondral defects of the knee, osteochondral allograft transplantation (OCA) is an effective solution with relatively high rates of return to sport. In professional athletes, rehabilitation following OCA is a critical component of the process of returning the athlete to full sports activity and requires a multidisciplinary team approach with frequent communication between the surgical and rehabilitation teams (physical therapists, athletic trainers, coaching staff). In this review, we describe our five-phase approach to progressive rehabilitation of the professional athlete after OCA, which takes into account the biological processes of healing and optimization of neuromuscular function required for the demands of elite-level sport. The principles of early range of motion, proper progression through the kinetic chain, avoidance of pain and effusion, optimization of movement, regimen individuation, and integration of sports-specific activities underlie proper recovery.
Diabetes mellitus (DM) and hypertension (HTN) are increasing in prevalence in the population. Level 1 trauma facilities are often faced with managing these chronic conditions. Recent studies indicated that 12-44% of patients presenting traumas are found to have incidental findings by imaging representing undiagnosed medical conditions, with 10% reported requiring further management [Surendran A, Mori A, Varma DK, Gruen RL. Systematic review of the benefits and harms of whole-body computed tomography in the early management of multitrauma patients: Are we getting the whole picture? J Trauma and Acute Care Surg. 2014;76(4):1122-1130]. Between 2015 and 2016, 852 patients seen at a level 1 trauma center were analyzed. Patients were evaluated who received a new diagnosis of HTN or DM, or had preexisting diagnosis of HTN or DM whose management was changed. Uncontrolled HTN or DM was defined as a need for either a change in medication or primary care optimization prior to discharge. Among the patients evaluated, 6.3% and 3.0% received new diagnoses of HTN and DM, respectively. Additionally, 34.4% and 35.3% of patients were found to have uncontrolled HTN and DM and required medical optimization, respectively. The high prevalence of undiagnosed or suboptimal management for chronic conditions indicates that more research is warranted for defining, screening for, and treating surgical patients with poorly controlled medical conditions with these comorbidities.
