Owen, Aaron R.

AimsContemporary outcomes of total femoral arthroplasties (TFAs) in the non-oncological setting are limited. This study aimed to assess implant survival free from revision and reoperation, clinical outcomes, and radiological results associated with TFAs for non-oncological conditions.MethodsWe identified 24 patients who received TFAs between 1 January 2007 and 31 December 2021 through our institutional total joint registry. The patients’ mean age was 66 years (48 to 83), mean BMI was 33 kg/m2 (21 to 54), and median follow-up was four years (IQR 2 to 5). Bearings used included eight flat-faced polyethylene bearings, seven dual-mobility constructs, six constrained liners, and three face-changing liners. Of the 24 patients, 17 had a previously documented periprosthetic joint infection (PJI) and 12 were treated with chronic antibiotic suppression following their TFAs.ResultsThe two-, five-, and ten-year survivals free of any revision were 66%, 51%, and 34%, respectively. There were 12 revisions: five for hip dislocation, four for PJI, one for aseptic tibial loosening, one for prosthetic knee dislocation, and one for acetabular loosening with pelvic discontinuity. The two-, five-, and ten-year survivals free of any reoperation were 53%, 47%, and 34%, respectively. In addition to the stated TFA revisions, one patient required open reduction of a hip dislocation, and two patients required superficial irrigation and debridement procedures for wound complications. Mean Harris Hip Scores improved from a mean score of 48 to 69 (p = 0.002), and Knee Society Scores improved from a mean score of 56 to 71 (p = 0.110). At final follow-up, 20 patients had TFAs in situ, but four patients had been treated with hip disarticulation due to recalcitrant infection. All but one tibial and all non-revised acetabular components were radiologically well-fixed at final follow-up.ConclusionThe use of TFAs in the non-oncological setting, mostly for salvage of multiply revised hips with previous PJI, had a low five-year survival free from any revision of 51%, mostly for hip dislocation and infection. Nevertheless, clinical outcomes improved in this challenging cohort of patients.Cite this article: Bone Joint J 2025;107-B(4):449–454.

Background: Tibiotalar arthrodesis (TTA) is a common operation for end-stage ankle arthritis. Elevated body mass index (BMI) is believed to contribute to complications following TTA. Previous studies involved national registries or small, underpowered cohorts. This study aimed to determine the effects of elevated BMI on nonunion and complication rates following TTA with a large cohort from a single academic institution. Methods: A retrospective study identified 514 patients (527 ankles) who underwent primary TTA from 2005-2017. Mean age was 60 years. Patients were stratified by BMI according to the World Health Organization classification. A reference group of 203 patients (208 ankles) included normal weight or mildly overweight patients (BMI 18.5 to <30). Ankle radiographs were evaluated to determine union or nonunion. Other outcomes included revision TTA, reoperations, subsequent adjacent joint arthrodesis, infection, and readmission. Data were analyzed using Pearson χ 2 and odds ratios for categorical variables. Analysis of variance and Kaplan-Meier estimation assessed continuous variables and time-to-event outcomes, respectively. Mean follow-up was 34.3 months. Results: Obesity class III patients had elevated risk of complications compared with normal weight patients including nonunion (odds ratio [OR] 3.96, P = .002), revision (OR 3.69, P = .03), superficial infection (OR 9.36, P = .002), and readmission (OR 10.90, P = .01). Superficial infection rates were elevated in class I (OR 6.36, P = .007) and readmissions in class II (OR 9.98, P = .01). No differences were found in reoperation ( P = .448), symptomatic implant removal ( P = .805), adjacent joint arthrodesis ( P = .353), or deep infection ( P = .507) rates. Discussion: In this retrospective review after TTA, increased rates of nonunion, revision, superficial infection, and readmission were found in obesity class III patients, compared with the reference group of normal weight or mildly overweight patients. Superficial infection rates were likewise relatively elevated in class I and readmission rates in class II patients.

Reconstruction of the abductor mechanism remains a primary challenge with contemporary proximal femoral replacement (PFR) surgery. Previously, techniques such as trochanteric preservation or direct repair to the implant have been described; however, these strategies are limited in their ability to tension the repair and reattach other muscles of the hip girdle. The aim of this study was to evaluate the outcomes of patients undergoing oncologic PFR using a novel technique of mesh augmentation for soft tissue repair. Methods: We reviewed 18 (mean age 64 years; 8 female: 10 male) consecutive patients undergoing PFR with Marlex mesh augmentation between 2018 and 2023 at a single institution. The most common indication was metastatic disease (n = 13). The mean follow-up in the 14 surviving patients was 27 months (range 12–34). Results: All patients were ambulatory at final follow-up. There were no post-operative dislocations, infections, or wound issues. At the final follow-up, the mean total MSTS score was 77%. Conclusion: Mesh augmentation of PFRs allowed for adequate soft tissue tensioning and muscular attachment to the body of the implant. In our series, this technique was durable, with no dislocations and no mesh-related complications. In summary, mesh augmentation of PFRs may be considered during reconstruction for oncologic indications.

OBJECTIVES: To evaluate tranexamic acid (TXA) when administered immediately on hospital presentation in patients with extracapsular peritrochanteric hip fractures to determine its effect on (1) transfusion rates, (2) estimated blood loss, and (3) complications. METHODS: Design: Prospective, double-blinded, randomized clinical trial. Setting: Single-center, Level 1 trauma center. Patient Selection Criteria: All patients with isolated OTA/AO 31-A fracture patterns from 2018 to 2022 were eligible for inclusion. Study drug was administered in the emergency department at the time of presentation—1-g bolus over 10 minutes followed by a 1-g infusion over 8 hours. Outcome Measures and Comparisons: The primary outcome was the rate of red blood cell transfusion hospital days 1–4. Secondary outcomes included estimated blood loss and complications including venous thromboembolic events, stroke, myocardial infarction, all-cause 90-day readmissions, and all-cause mortality. RESULTS: One hundred twenty-eight patients were included—64 patients were randomized to intravenous TXA and 64 patients to intravenous normal saline (ie, placebo). There was no difference in the rate of red blood cell transfusion between treatment arms between hospital days 1–4 (27% in the TXA arm vs. 31% in the placebo arm, P = 0.65). Patients randomized to placebo who required transfusion received a mean of 2.30 units compared with 1.94 units in the TXA cohort (P = 0.55). There was no difference in the estimated blood loss between hospital days 1–4. There was no difference in the incidence of postoperative complications including venous thromboembolic events, stroke, myocardial infarction, 90-day readmission, or death. CONCLUSIONS: The results of this study do not support the use of preoperative TXA for reducing blood loss for geriatric patients with extracapsular hip fractures. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

AbstractArthrofibrosis, which causes joint motion restrictions, is a common complication following total knee arthroplasty (TKA). Key features associated with arthrofibrosis include myofibroblast activation, knee stiffness, and excessive scar tissue formation. We previously demonstrated that adiponectin levels are suppressed within the knee tissues of patients affected by arthrofibrosis and showed that AdipoRon, an adiponectin receptor agonist, exhibited anti‐fibrotic properties in human mesenchymal stem cells. In this study, the therapeutic potential of AdipoRon was evaluated on TGFβ1‐mediated myofibroblast differentiation of primary human knee fibroblasts and in a mouse model of knee stiffness. Picrosirius red staining revealed that AdipoRon reduced TGFβ1‐induced collagen deposition in primary knee fibroblasts derived from patients undergoing primary TKA and revision TKA for arthrofibrosis. AdipoRon also reduced mRNA and protein levels of ACTA2, a key myofibroblast marker. RNA‐seq analysis corroborated the anti‐myofibrogenic effects of AdipoRon. In our knee stiffness mouse model, 6 weeks of knee immobilization, to induce a knee contracture, in conjunction with daily vehicle (DMSO) or AdipoRon (1, 5, and 25 mg/kg) via intraperitoneal injections were well tolerated based on animal behavior and weight measurements. Biomechanical testing demonstrated that passive extension angles (PEAs) of experimental knees were similar between vehicle and AdipoRon treatment groups in mice evaluated immediately following immobilization. Interestingly, relative to vehicle‐treated mice, 5 mg/kg AdipoRon therapy improved the PEA of the experimental knees in mice that underwent 4 weeks of knee remobilization following the immobilization and therapy. Together, these studies revealed that AdipoRon may be an effective therapeutic modality for arthrofibrosis.

Objectives: To describe a reproducible technique for reduction assessment and percutaneous reduction of unstable intertrochanteric fractures treated with a cephalomedullary nail on a traction table. Design: Retrospective cohort study. Setting: Level-1 trauma center. Patients: Two-hundred 20 consecutive patients with intertrochanteric fractures. Intervention: Initial closed reduction performed on a traction table. Accessory incisions were used to facilitate a reduction in 77 patients (35%). All fractures were stabilized with a cephalomedullary nail. Main Outcome Measurements: Radiographic outcome including union, cutout, and fracture collapse (FC). Surgical outcomes including infection and hematoma were also reported. Results: Mechanical complications (nonunion, cutout, and varus collapse) occurred in 8.8% of patients at 1 year. Eleven of 13 patients who developed these complications had either suboptimal implant placement (tip-to-apex distance >25 mm) or a varus reduction. There was no difference in the incidence of reoperation, nonunion, lag screw cutout, or posttraumatic arthritis based on the use of an accessory incision for fracture reduction. There was a significant increase in FC in patients who received an accessory incision (6.8 mm vs. 5.4 mm, P = 0.04). One patient (1%) developed a hematoma in the accessory incision cohort, and 1 patient (0.7%) who did not have an accessory incision developed a postoperative infection. Conclusions: The current study suggests utilization of accessory incisions assist in reduction is safe and is associated with a low rate of complications. The surgeon should prioritize fracture reduction and optimal implant placement and not hesitate to use an accessory incision to assist with fracture reduction. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Aims As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA). Methods Experimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections. Results Experimental knees immobilized for four weeks demonstrated mean PEAs of 141°, 72°, and 79° after zero, two, and four weeks of remobilization (n = 6 per group), respectively. Experimental knees demonstrated reduced PEAs after two weeks (p < 0.001) and four weeks (p < 0.0001) of remobilization compared to controls. Following eight weeks of immobilization, experimental knees exhibited mean PEAs of 82°, 73°, and 72° after zero, two, and four weeks of remobilization, respectively. Histological analysis demonstrated no cartilage degeneration. Similar trends in biomechanical and histological properties were observed when intra-articular violation was introduced. Conclusion This study established a novel mouse model of robust knee contracture without evidence of OA. This was appreciated consistently after eight weeks of immobilization and was irrespective of length of remobilization. As such, this arthrofibrotic model provides opportunities to investigate molecular pathways and therapeutic strategies. Cite this article: Bone Joint Res 2023;12(1):58–71.

Aims Spinal anaesthesia has seen increased use in contemporary primary total knee arthroplasties (TKAs). However, controversy exists about the benefits of spinal in comparison to general anaesthesia in primary TKAs. This study aimed to investigate the pain control, length of stay (LOS), and complications associated with spinal versus general anaesthesia in primary TKAs from a single, high-volume academic centre. Methods We retrospectively identified 17,690 primary TKAs (13,297 patients) from 2001 to 2016 using our institutional total joint registry, where 52% had general anaesthesia and 48% had spinal anaesthesia. Baseline characteristics were similar between cohorts with a mean age of 68 years (SD 10), 58% female (n = 7,669), and mean BMI of 32 kg/m2 (SD 7). Pain was evaluated using oral morphine equivalents (OMEs) and numerical pain rating scale (NPRS) data. Complications including 30- and 90-day readmissions were studied. Data were analyzed using an inverse probability of treatment weighted model based on propensity score that included many patient and surgical factors. Mean follow-up was seven years (2 to 18). Results Patients treated with spinal anaesthesia required fewer postoperative OMEs (p < 0.001) and had lower NPRS scores (p < 0.001). Spinal anaesthesia also had fewer cases of altered mental status (AMS; odds ratio (OR) 1.3; p = 0.044), as well as 30-day (OR 1.4; p < 0.001) and 90-day readmissions (OR 1.5; p < 0.001). General anaesthesia was associated with increased risk of any revision (OR 1.2; p = 0.021) and any reoperation (1.3; p < 0.001). Conclusion In the largest single institutional report to date, we found that spinal anaesthesia was associated with significantly lower OME use, lower risk of AMS, and lower overall 30- and 90-day readmissions following primary TKAs. Additionally, spinal anaesthesia was associated with reduced risk of any revision and any reoperation after accounting for numerous patient and operative factors. When possible and safe, spinal anaesthesia should be considered in primary TKAs. Cite this article: Bone Joint J 2022;104-B(11):1209–1214.

Background: The specific advantages of spinal anesthesia compared with general anesthesia for primary total hip arthroplasty (THA) remains unknown. Therefore, this study aimed to investigate the pain control, length of stay, and postoperative outcomes associated with spinal anesthesia compared with general anesthesia in a large cohort of primary THAs from a single, high-volume academic institution. Methods: We retrospectively identified 13,730 primary THAs (11,319 patients) from 2001 to 2016 using our total joint registry. Of these cases, 58% had general anesthesia and 42% had spinal anesthesia. The demographic characteristics were similar between groups, with mean age of 64 years, 51% female, and mean body mass index (BMI) of 31 kg/m 2 . Data were analyzed using an inverse probability of treatment weighted model based on a propensity score that accounted for numerous patient and operative factors. The mean follow-up was 6 years. Results: Patients treated with spinal anesthesia had lower Numeric Pain Rating Scale (NPRS) scores (p < 0.001) and required fewer postoperative oral morphine equivalents (OMEs) at all time points evaluated (p < 0.001). Patients treated with spinal anesthesia also had shorter hospital length of stay (p = 0.02), fewer altered mental status events (odds ratio [OR], 0.7; p = 0.02), and fewer intensive care unit (ICU) admissions (OR, 0.7; p = 0.01). There was no difference in the incidence of deep vein thrombosis (p = 0.8), pulmonary embolism (p = 0.4), 30-day readmissions (p = 0.17), 90-day readmissions (p = 0.18), all-cause revisions (p = 0.17), or all-cause reoperations (p = 0.14). Conclusions: In this large, single-institution study, we found that spinal anesthesia was associated with reduced pain scores and OME use postoperatively. Furthermore, spinal anesthesia resulted in fewer altered mental status events and ICU admissions. These data favor the use of spinal anesthesia in primary THAs. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

AbstractArthrofibrosis is characterized by excessive extracellular matrix (ECM) deposition that results in restricted joint motion after total knee arthroplasties (TKAs). Currently, treatment options are limited. Therefore, an in vitro model of knee‐related myofibroblastogenesis is valuable to facilitate investigation of the arthrofibrotic process, diagnostic and therapeutic options. In this study, we obtained intraoperative posterior capsule (PC), quadriceps tendon (QT), and suprapatellar pouch (SP) tissues from the knees of four patients undergoing primary TKAs for osteoarthritis. From these tissues, we isolated primary cells by the outgrowth method and subsequently characterized these cells in the absence and presence of the pro‐myofibroblastic cytokine, transforming growth factor beta 1 (TGFβ1). Light microscopy of knee outgrowth cells revealed spindle‐shaped cells, and immunofluorescence (IF) analysis demonstrated staining for the fibroblast‐specific markers TE‐7 and vimentin (VIM). These knee outgrowth fibroblasts differentiated readily into myofibroblasts as reflected by enhanced α‐smooth muscle actin (ACTA2) mRNA and protein expression and increased mRNA expression of collagen type 1 (COL1A1) and type 3 (COL3A1) with collagenous matrix deposition in the presence of TGFβ1. Outgrowth knee fibroblasts were more sensitive to TGFβ1‐mediated myofibroblastogenesis than adipose‐derived mesenchymal stromal/stem cells (MSCs). While outgrowth knee fibroblasts isolated from three anatomical regions in four patients exhibited similar gene expression, these cells are distinct from other fibroblastic cell types (i.e., Dupuytren's fibroblasts) as revealed by RNA‐sequencing. In conclusion, our study provides an in vitro myofibroblastic model of outgrowth knee fibroblasts derived from patients undergoing primary TKA that can be utilized to study myofibroblastogenesis and assess therapeutic strategies for arthrofibrosis.