Mallett, Katherine E.

ABSTRACT Introduction The proximal tibia is a common location for bone tumors. Two contemporary reconstruction techniques for limb salvage are endoprosthetic replacement (EPR) and allograft‐prosthesis composite (APC). This study aimed to compare the long‐term oncologic and functional outcomes of EPR and APC reconstructions. Methods Thirty‐eight (19 APC and 19 EPR) patients underwent oncologic proximal tibia resection and reconstruction were reviewed. Patients undergoing APC reconstruction were younger than the EPR group (31 vs. 44 years, p = 0.049), and patients in the EPR group were more likely to have a diagnosis of metastatic disease (32% vs. 0%, p = 0.019). Results For all patients, the 10‐year disease‐specific survival was 63%. With death a competing risk, there was no difference in the 10‐year cumulative risk of failure (41% vs. 26%, p = 0.171) or amputation (11% vs. 19%, p = 0.690) between APC or EPR. There was no difference comparing EPR to APC in the proportion of patients with an extensor lag > 10° (42% vs. 26%, p = 0.495) or 10‐year knee society scores (85 vs. 85, p = 0.710). Conclusion EPR and APC have a similar complication profile and functional outcomes following proximal tibial resection and reconstruction.

Aim Cefazolin, a first generation cephalosporin, is the standard of care for perioperative antibiotic prophylaxis in hip and knee arthroplasty patients. Research has shown that prosthetic joint infection (PJI) rates are significantly higher when non-cefazolin antibiotics are used for perioperative TKA and THA prophylaxis. Cefazolin contains an R1 side chain that has not shown cross reactivity with other cephalosporins. Despite these data, the declaration of a cephalosporin allergy causes uncertainty regarding the optimal antibiotic choice in these patients. The purpose of this study was to determine the safety of administering perioperative cefazolin in patients with a cephalosporin allergy undergoing joint arthroplasty. Methods We identified all patients (n=1267) with a documented cephalosporin allergy who underwent total hip or knee arthroplasty at a high volume academic medical center from 2016-2024. We compared patients who received perioperative cefazolin despite the presence of a cephalosporin allergy (n=481) to patients who received alternative antibiotic prophylaxis (n=786). The primary outcome measure was the incidence of IgE mediated allergic reactions within the first 72 hours postoperatively. Secondary outcomes included 90-day complication rates including PJI, C. difficile infection, adverse events and readmission. Results The incidence of allergic reaction in cephalosporin allergic patients who received cefazolin was 0.0% (0/481) compared to 0.51% (4/786) in patients who received alternative antibiotics prophylaxis (p=0.12). There were no significant differences in the incidences of PJI (0.23% vs. 0.30%; p=0.83), C. difficile infection (0.0% vs. 0.0%) or readmission (3.95% vs. 4.34%; p=0.75) within 90 days. There was one adverse event related to cefazolin administration which was urethral irritation and was self-limited. There were three adverse events related to alternative antibiotic prophylaxis including cutaneous manifestations, GI distress and headache in a patient with idiopathic intracranial hypertension. All four allergic reactions in the alternative antibiotic prophylaxis cohort required supportive treatment with IV corticosteroids, fluids and antihistamines. Conclusion In this cohort of hip and knee arthroplasty patients, cefazolin administration in the setting of a cephalosporin allergy resulted in a 0.0% incidence of IgE mediated allergic reactions. These data and the fact that cefazolin's unique R1 side chain is not shared by any other cephalosporins suggests that cefazolin can safely be administered to most patients with a documented cephalosporin allergy.

AimsDual-mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a rare complication of DM that is believed to have decreased with contemporary implants. This study aimed to report incidence, treatment, and outcomes of contemporary DM IPD.MethodsA total of 1,453 DM components were implanted at a single academic institution between January 2010 and December 2021: 695 in primary and 758 in revision THA. Of these, 49 presented with a dislocation of the large DM head and five presented with an IPD. At the time of closed reduction of the large DM dislocation, six additional IPDs occurred. The mean age was 64 years (SD 9.6), 54.5% were female (n = 6), and mean follow-up was 4.2 years (SD 1.8). Of the 11 IPDs, seven had a history of instability, five had abductor insufficiency, four had prior lumbar fusion, and two were conversions for failed fracture management.ResultsThe incidence of IPD was 0.76%. Of the 11 IPDs, ten were missed either at presentation or after attempted reduction. All ten patients with a missed IPD were discharged with a presumed reduction. The mean time from IPD to surgical treatment was three weeks (0 to 23). One patient died after IPD prior to revision. Of the ten remaining hips with IPD, the DM head was exchanged in two, four underwent acetabular revision with DM exchange, and four were revised to a constrained liner. Of these, five (50%) underwent reoperation at a mean 1.8 years (SD 0.73), including one additional acetabular revision. No patients who underwent initial acetabular revision for IPD treatment required subsequent reoperation.ConclusionThe overall rate of IPD was low at 0.76%. It is essential to identify an IPD on radiographs as the majority were missed at presentation or after iatrogenic dissociation. Surgeons should consider acetabular revision for IPD to allow conversion to a larger DM head, and take care to remove impinging structures that may increase the risk of subsequent failure.Cite this article: Bone Joint J 2024;106-B(5 Supple B):98–104.

Dual mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a known rare complication of these implants and has reportedly decreased with modern implants. The purpose of this paper is to report the diagnosis and treatment of modern DM IPD.1453 DM components were implanted between 2010 and 2021. 695 in primary and 758 in revision THA. 49 hips sustained a dislocation of the large head and 5 sustained an IPD at presentation. 6 additional IPD occurred at the time of reduction of large head. The average age was 64, 54% were female and the mean follow-up was three years. Of the 11 IPD, 8 had a history of instability, 5 had abductor insufficiency, 4 had prior lumbar fusion, and 3 were conversions from fracture.The overall IPD incidence was 0.76%. Ten of the 11 DM IPD were missed at initial presentation or at the time of reduction, and all were discharged with presumed reduction. The mean time from IPD to surgical treatment was 3 weeks. One patient died with an IPD at 5 months. A DM head was reimplanted in six, two underwent revision of the acetabular component with exchange of DM head, and four were revised to a constrained liner. The re-revision rate was 55% at a mean 1.8 years. None of the patients who underwent cup revision required subsequent re-revision while half of the constrained liners and exchange of DM heads required re-revision.The overall rate of DM dislocation or IPD is low. It is critical to identify an IPD on radiographs as it was almost universally missed at presentation or when it occurred iatrogenically. For patients presenting with IPD, the surgeon should consider acetabular revision and conversion to a constrained liner or a larger DM, with special attention to removing impinging structures that could increase the risk of re-dislocation.

Background: Dual-mobility (DM) implants reduce the risk of dislocation in patients who have undergone total hip arthroplasty (THA); however, DM implants are at risk for large-head dislocation and intraprosthetic dissociation (IPD), where the inner femoral head dissociates from the outer polyethylene head. This study aimed to report the incidence of DM dislocation and IPD, evaluate the rate of recognition of IPD before and after reduction, investigate the outcomes of these complications, and provide treatment recommendations for their management. Methods: Between 2010 and 2021, 695 primary and 758 revision THAs were performed with DM constructs at a single institution. There were 44 large-head dislocations (3.0%) and 10 IPDs (0.7%). Four additional IPDs occurred during attempted closed reduction, increasing the IPD incidence to 0.96%. We reviewed prior instability history, dislocation management, success of reduction, recognition of IPD, and subsequent rates of revision and complications. The mean follow-up was 2.5 years. Results: Nine of 10 IPDs were missed at presentation and thus not treated as such. Sixty-three percent of attempted closed reductions in the emergency department failed and led to 4 IPDs and 1 periprosthetic fracture. Reduction success was associated with the following factors: use of general anesthesia with paralysis (p = 0.02), having the reduction performed by an orthopaedist (p = 0.03), and undergoing only 1 reduction attempt (p = 0.015). Two-thirds of dislocations required revision. The rate of redislocation was 33%, and 5 hips required subsequent revision at a mean of 1.8 years after the initial dislocation. Conclusions: We present an evaluation of DM-implant dislocation and dissociation along with management recommendations based on these data. Given the low success and high complication rates of attempted closed reduction and the need for eventual revision, we recommend that all patients with dislocated DM implants be brought to the operating room for closed reduction as well as potential revision if the reduction fails. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

AbstractBackgroundCompared to other sarcomas, myxoid liposarcoma (ML) is known to be radiosensitive, with improved oncologic outcomes. Although these tumors “shrink” following radiotherapy, there is a paucity of data examining the degree of radiosensitivity and oncologic outcome. The purpose of the study was to evaluate pre‐ and postradiotherapy tumor volume to determine if size reduction impacts outcome.MethodsWe reviewed 62 patients with ML undergoing surgical resection combined with preoperative radiotherapy, with pre‐ and postradiotherapy MRI. This included 34 (55%) males, with a mean age of 47 ± 14 years. All tumors were deep to the fascia, and 12 (19%) patients had tumors with a >5% round‐cell component.ResultsThe mean volume reduction was 54% ± 29%. Compared to patients with >25% volume reduction, patients with reduction ≤25% had worse 10‐year disease specific survival (86% vs. 37%, p < 0.01), in addition to an increased risk of metastatic disease (HR 4.63, p < 0.01) and death due to disease (HR 4.52, p < 0.01).ConclusionLack of volume reduction is a risk factor for metastatic disease and subsequent death due to disease in patients with extremity ML treated with combined preoperative radiotherapy and surgery. This data could be used to stratify patients for adjuvant therapies and follow‐up intervals.

Background: When treating upper-extremity infections, clinicians frequently must decide whether to initiate antibiotics or delay them with the goal of optimizing culture yield at the time of surgical debridement. The purpose of this study was to determine whether the administration of preoperative antibiotics affects intraoperative culture yield and whether there is a “safe” interval prior to culture acquisition within which antibiotics can be administered without affecting culture yield. Methods: We conducted a retrospective review of 470 consecutive patients who underwent debridement for a presumed acute infection of the hand, wrist, or forearm at a single tertiary care center between January 2015 and May 2020. Data including patient demographics, mechanism of infection and affected body part(s), and details of antibiotic administration, including type and timing with respect to culture acquisition, were collected. Results: Three hundred and forty-one patients (73%) received preoperative antibiotics prior to debridement and culture acquisition. The rate of positive cultures among patients who received preoperative antibiotics was 81% compared with 95% among patients who did not receive preoperative antibiotics (p < 0.01; odds ratio, 4.73). Even a single dose of antibiotics imparted a significantly increased risk of obtaining negative intraoperative cultures, and an incremental increase in the likelihood of obtaining negative cultures was seen with each preoperative dose given up to 7 doses. We did not identify a “safe” interval of time between antibiotic administration and culture acquisition such that culture yield was not affected. Conclusions: Patients who received preoperative antibiotics for the treatment of upper-extremity infections were approximately 5 times more likely to have negative cultures at the time of debridement than those who did not receive preoperative antibiotics. This effect persisted regardless of the number of doses given or the interval between antibiotic administration and culture acquisition. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background. Limb-salvage surgery combined with radiotherapy has become the primary treatment for soft tissue sarcomas of the extremity. Free functional latissimus flaps (FFLF) are an option to restore function in the setting of volumetric muscle loss. The purpose of the current study was to examine the use of FFLF in patients undergoing resection of thigh sarcoma. Methods. Twelve patients with a sarcoma involving the hamstring (n = 6), quadriceps (n = 5), or combined (n = 1) defects which included multiple muscle groups were reviewed. This included 9 males and 3 females with a mean age and body mass index of 56 ± 12 years and 31.3 ± 5.7 kg/m2. Results. The mean defect volume and operative time was 3,689 ± 2,314 cm3 and 587 ± 73 minutes. Following reconstruction, the mean knee range of motion (ROM), MSTS93 score, and muscle strength was 89 ± 24°, 90 ± 15%, and 4 ± 1; with 75% of patients ambulating without gait aids. Seven (58%) patients sustained a complication, namely, delayed wound healing (n = 2). Conclusion. Although there was a high incidence of complications, FFLF can restore active knee ROM and function, with most patients ambulating without gait aids following reconstruction of large oncologic defects in the thigh.

Abstract Background Foot and ankle soft tissue sarcomas (STS) are challenging for reconstruction due to limited surrounding soft tissue and weight‐bearing requirements. Currently, there is a paucity of data examining the outcome of flap reconstruction following resection of a foot and ankle sarcoma. Methods We reviewed 44 (31 female, 13 male) patients with STS arising from the ankle or foot which required coverage in the form of a free ( n = 21), pedicled ( n = 13), or rotational perforator flap ( n = 10). The mean tumor size was 6 ± 5 cm, with 39 (89%) patients receiving radiotherapy. The mean follow‐up was 10 ± 7 years. Results There were no cases of amputation due to flap failure, with a 10‐year limb salvage rate of 84%. Complications occurred in 19 (43%) patients, most commonly wound infections. There was no difference in the incidence of complications between patients undergoing a free flap and pedicled or perforator flap (odds ratio = 0.97, p = 1.0); with no difference in the mean Musculoskeletal Tumor Society (MSTS) score between patients with a free flap versus a pedicled/perforator flap (84% vs. 76%, p = 0.11). Conclusion Flap reconstruction is an essential part of limb salvage for foot and ankle STS. At final follow‐up nearly all the patients are ambulatory with an acceptable MSTS score.