Arthrofibrosis in Robotic Total Knee Arthroplasty: An Investigation Into How Robotic Assistance May Contribute to a Tight Knee.

INTRODUCTION: Arthrofibrosis after total knee arthroplasty (TKA) can lead to pain and restricted range of motion. Matching native knee kinematics is crucial in avoiding arthrofibrosis postoperatively. However, manual jig-based instruments have demonstrated variability and inaccuracy during primary TKA. Robotic-arm-assisted surgery was developed to increase the precision and accuracy of bone cuts and component alignment. In the literature, limited information on arthrofibrosis after robotic-assisted TKA (RATKA) exists. The purpose of this study was to compare the incidence of arthrofibrosis after manual TKA (mTKA) with RATKA by examining the need for manipulation under anesthesia (MUA) postoperatively and evaluating preoperative and postoperative radiographic parameters. METHODS: A retrospective analysis of patients who underwent primary TKA from 2019 to 2021 was conducted. Rates of MUA were evaluated and perioperative radiographs were analyzed to determine posterior condylar offset ratio, Insall-Salvati Index, and posterior tibial slope (PTS) in patients who underwent mTKA versus RATKA. Range of motion was recorded for patients who required MUA. RESULTS: A total of 1234 patients were included, of which 644 underwent mTKA, and 590 underwent RATKA. Thirty-seven RATKA patients compared with 12 mTKA patients required MUA postoperatively (P < 0.0001). A significant decrease in PTS postoperatively was seen in the RATKA (7.10° ± 2.4° preoperatively versus 2.46° ± 1.2° postoperatively), with a mean decrease of the tibial slope of -4.6° ± 2.5° (P < 0.0001). In patients requiring MUA, a larger decrease was seen in the RATKA group when compared with the mTKA group (mean -5.5 ± 2.0 versus -5.3 ± 0.78, P = 0.6585). No significant difference was seen in the posterior condylar offset ratio and Insall-Salvati Index in both groups. DISCUSSION: When conducting RATKA, it is important to match PTS close to the native tibial slope to decrease the incidence of arthrofibrosis postoperatively, as a decrease in PTS can lead to decreased postoperative knee flexion and poor functional outcomes.

1.5-Stage Versus 2-Stage Exchange Total Hip Arthroplasty for Chronic Periprosthetic Joint Infections: A Comparison of Survivorships, Reinfections, and Patient-Reported Outcomes.

BACKGROUND: Management of periprosthetic joint infection after total hip arthroplasty (THA) has traditionally consisted of a 2-stage approach. However, 1.5-stage exchange has garnered recent interest. We compared 1.5-stage to 2-stage exchange recipients. Specifically, we assessed (1) infection-free survivorship and risk factors for reinfection; (2) 2-year surgical/medical outcomes (eg, reoperations, readmissions); (3) Hip Disability and Osteoarthritis Outcome Scores for Joint Replacement (HOOS-JR); and (4) radiographic outcomes (ie, progressive radiolucent lines, subsidences, and failures). METHODS: We reviewed a consecutive series of 1.5-stage or planned 2-stage THAs. A total of 123 hips were included (1.5-stage: n = 54; 2-stage: n = 69) with mean clinical follow-up of 2.5 years (up to 8 years). Bivariate analyses assessed incidences of medical and surgical outcomes. Additionally, HOOS-JR scores and radiographs were evaluated. RESULTS: The 1.5-stage exchange had 11% greater infection-free survivorship at final follow-up compared to 2 stages (94% versus 83%, P = .048). Morbid obesity was the only independent risk factor demonstrating increased reinfection among both cohorts. No differences in surgical/medical outcomes were observed between groups (P = .730). HOOS-JR scores improved markedly for both cohorts (1.5-stage difference = 44.3, 2-stage difference = 32.5; P < .001). A total of 82% of 1.5-stage patients did not demonstrate progressive femoral or acetabular radiolucencies, while 94% of 2-stage recipients did not have femoral radiolucencies and 90% did not have acetabular radiolucencies. CONCLUSION: The 1.5-stage exchange appeared to be an acceptable treatment alternative for periprosthetic joint infections after THAs with noninferior infection eradication. Therefore, this procedure should be considered by joint surgeons for treatment of periprosthetic hip infections.

The Association of Patient and Procedural Factors on Improved Outcomes: A Cluster Analysis on 853 Total Knee Arthroplasty Patients.

Many studies involving robotic-assisted total knee arthroplasty (RATKA) have demonstrated superiority regarding soft tissue balance and consistency with alignment target achievement. However, studies investigating whether RATKA is associated with improved patient outcomes regarding physical function and pain are also important. Therefore, we performed a cluster analysis and examined factors that contributed to differences in patient-reported outcome measures (PROMs). Specifically, we analyzed: (1) reduced WOMAC (rWOMAC) scores regarding pain and function; (2) usage of RATKA; (3) common patient comorbidities; as well as (4) patient demographic factors. The rWOMAC score is an abbreviated PROM that includes pain and physical function domains. This study analyzed 853 patients (95 conventional and 758 robotic-assisted) who had completed preoperative, 6-month, and 1-year postoperative rWOMAC surveys. Two clusters were constructed using rWOMAC pain and function scores at 1 year. Cluster 1 included 753 patients who had better outcomes at 1 year (mean rWOMAC pain = 0.9, mean rWOMAC function = 1.4), and cluster 2 included 100 patients who had worse outcomes at 1 year (mean rWOMAC pain = 7.7, mean rWOMAC function = 10.4). The clusters were compared to determine (1) how scores improved and (2) what patient characteristics were significantly different between clusters. Cluster 1 demonstrated greater improvement from preoperative to 6 months or 1 year (p = 0.0013 for pain preoperative to 6 months, p< 0.0001 for other measures) and 6 months to 1 year (p< 0.0001). Comparisons demonstrated that cluster 1 had older patients (67 vs. 65 years, p = 0.0479) who had lower body mass index or BMIs (31.8 vs. 33.9 kg/m2, p = 0.0042) and no significant differences in sex (p = 0.7849). Cluster 1 also had a significantly higher percentage of RATKA patients (90 vs. 79%, p< 0.001). Cluster analyses provided differentiating factors which were associated with improved postoperative rWOMAC pain and function scores at 1 year. Patients undergoing robotic-assisted TKA were associated with better rWOMAC pain and function scores from preoperative to 6 months and 1 year.

Unicompartmental Knee Arthroplasty Has Lower Infection, Conversion, and Complication Rates Compared to High Tibial Osteotomy.

INTRODUCTION: Isolated medial knee osteoarthritis can be surgically treated with either unicompartmental knee arthroplasty (UKA) or high tibial osteotomy (HTO). Proponents of UKA suggest superior survivorship, while HTO offers theoretically improved alignment and joint preservation delaying total knee arthroplasty (TKA). Therefore, we compared complications in a large population of patients undergoing UKAs or HTOs. We specifically assessed 90 days, 1 year, and 2 years: (1) periprosthetic joint infection (PJI) rates, (2) conversion to TKA rates, as well as (3) complication rates. METHODS: A review of an administrative claims database was used to identify patients undergoing primary UKA (n = 13,674) or HTO (n = 1,096) from January 1, 2010 to December 31, 2019. Complication rates at 90 days, 1 year, and 2 years were compared between groups using unadjusted odds ratios (ORs) with 95% confidence intervals. Subsequently, multivariate logistic regressions were performed for PJI and conversion to TKA rates. RESULTS: At all time points, patients who underwent UKA were associated with lower rates of infection compared with those who underwent HTOs (all OR ≤ 0.51, all p ≤ 0.010). After 1 year, patients who received UKAs were found to have lower risk of requiring a conversion to a TKA versus those who received HTOs (all OR ≤ 0.55, all p < 0.001). Complications such as dislocations, periprosthetic fractures, and surgical site infections were found at lower odds in UKA compared with HTO patients. CONCLUSION: This study provides large-scale analyses demonstrating that UKA is associated with lower infection rates and fewer conversions to TKA compared with patients who have undergone HTO. Dislocations, periprosthetic fractures, and surgical site infections were also found to be lower among UKA patients. However, with careful patient selection, good results and preservation of the native knee are achieved with HTOs. Therefore, UKA versus HTO may be an important discussion to have with patients in an effort to lower the incidence of postoperative infections and complications.

Early Experience With New Femoral and Tibial Cones in Revision Total Knee Arthroplasty: A Case Series.

Highly porous metaphyseal cones have proven useful in revision total knee arthroplasty in providing surgeons with improved metaphyseal fixation when large contained and uncontained bony defects are encountered. In this case series, we demonstrate three patients who received the latest generation of metaphyseal cones. Specifically, these cases will highlight this new system description and its operative techniques as well as the indications for metaphyseal cone use with various real-world applications. These newer-generation porous-coated cones are excellent options for large bone defects in the absence of infection, providing adequate metaphyseal fixation without constraining final implant positioning.

Cefadroxil-Induced Clostridium difficile Infection Following Total Knee Arthroplasty.

Perioperative infection prophylaxis is a fundamental element of total knee arthroplasty (TKA). There has been a recent trend toward the use of extended postoperative oral antibiotics in high-risk patients. We describe a case report of a patient who underwent a primary TKA and subsequently developed Clostridium difficile colitis after an extended course of postoperative prophylactic oral cefadroxil. Following the C. difficile infection, the patient eventually developed bacteremia and a multidrug-resistant Escherichia coli prosthetic joint infection which required multiple debridements. Extended use of postoperative prophylactic oral cefadroxil may increase the risk of C. difficile-associated diarrhea. Additionally, our case suggests that C. difficile infection may subsequently increase the risk of bacteremia which could lead to prosthetic joint infection. More evidence is required to further define this risk.

Rare septic arthritis of the wrist and carpus primary osteoarticular manifestation of Mycobacterium tuberculosis: A case report.

Mycobacterium tuberculosis is one of the oldest and most studied infections, yet it remains one of the most common causes of infection-related death worldwide. The majority concern pulmonary tuberculosis. Therefore, extrapulmonary cases are rare and are often neglected in the differential diagnosis, especially in chronic musculoskeletal complaints. Nevertheless, osteoarticular manifestation of tuberculosis can cause disabling destruction of bone, cartilage, and surrounding soft tissues which may be exacerbated by a delay in diagnosis. This case report documents a case of primary osteoarticular tuberculosis causing septic arthritis of the wrist and carpus. In our case, the patient had no pulmonary burden of tuberculosis, which further delayed diagnosis and lead to irreversible damage to the wrist as well as carpus. This case illustrates the need to consider this diagnosis in at risk populations in order to prevent a delay in diagnosis and treatment.

Improving Postoperative Acute Kidney Injury Rates Following Primary Total Joint Arthroplasty.

BACKGROUND: Perioperative hip and knee arthroplasty complications remain a significant clinical and financial burden. Our institution has shifted to developing protocols to decrease these perioperative complications. This study focuses on acute kidney injury (AKI) rate status post primary total joint arthroplasty (TJA). Current literature demonstrates a 2%-15% incidence of AKI following TJA. However, there is a paucity of published literature on protocols that have effectively reduced AKI rates following TJA. The purpose of this study is to evaluate the effect that our institutionally developed perioperative renal protocol had on the postoperative AKI rates. METHODS: A retrospective cohort study was performed. Patient demographics, baseline creatinine, and postoperative creatinine values during the patient's hospitalization were collected and analyzed. The preintervention cohort data contained all patients at our institution who underwent a primary TJA from November 1, 2016 to January 1, 2018. The postintervention cohort included all primary TJA patients from July 1, 2018 to February 2, 2020. AKI was defined using the AKI Network classification system comparing baseline and postoperative creatinine values. A multivariate analysis was performed to determine the statistical significance of our results. RESULTS: Before intervention 1013 patients underwent a primary TJA with 68 patients developing an AKI postoperatively. After intervention 2169 patients underwent primary TJA with 90 patients developing an AKI (6.71% vs 4.15%; P = .0015, odds ratio = 0.59, 95% confidence interval = 0.42-0.82). CONCLUSION: This study demonstrated that implementation of a perioperative renal protocol can significantly reduce AKI rates. A reduction in AKI rates following TJA will result in improved outcomes and secondarily decrease the financial impact of postoperative complications seen following TJA.

Intraoperative Hardware Failure of the Fassier-Duval Rescue System in a Pediatric Patient with Osteogenesis Imperfecta.

The use of telescopic intramedullary rods for the treatment of lower extremity deformity in children with osteogenesis imperfecta has been well described. The reinforcement of these weakened weightbearing bones with intramedullary devices leads to improvements in mobility that progress into adulthood. Although the current telescopic intramedullary rod systems are an upgrade from earlier systems, they are still associated with high rates of reoperation and complication. We describe a unique complication encountered during a revision which involved the male retriever system for the Fassier-Duval rod (FDR) (Pega Medical, Quebec, CA) experienced intraoperatively. To our knowledge, this mechanism of failure has not been previously described in the literature.

Failure at the femoral stem extension-condylar interface in a rotating hinge knee without radiographic evidence of loosening.

Modular stem extensions have become ubiquitous in revision total knee arthroplasty systems. Although stem extensions are valuable in addressing bone deficiencies and improving implant fixation, the stem extension-condylar interface may be a point of implant failure. We report a case of failure at the femoral stem extension-condylar interface in a Zimmer NexGen Rotating Hinge Knee (Zimmer, Warsaw, IN). Currently, several published case reports describe failure at the femoral stem extension-condylar interface but only 1 case describes loosening at a taper junction without evidence of set screw failure or taper fracture. Furthermore, no published cases describe this type of failure in the Zimmer NexGen Rotating Hinge Knee (Zimmer).

Long-term factor structure of the Rivermead Post-Concussion Symptom Questionnaire in mild traumatic brain injury and normative sample.

BACKGROUND: Previous studies of the Rivermead Post-Concussive Questionnaire(RPQ)'s factor structure were conducted within 1 year post-injury. Post-concussive symptoms may persist, and are common in the general population, so determining if the factor structure in mild-TBI and controls differ is important. This study examined factor structure of the RPQ in adults 4 years post-mild-TBI and in age-/gender-matched controls. METHOD: A total of 232 adults 4 years post-mild-TBI and 232 age-/gender-matched controls completed the RPQ. RESULTS: Both samples produced a three-factor solution (57.98% and 56.44% of variance in the RPQ). Factor 1 for both samples included all RPQ items and accounted for the majority of variance explained (42.6% and 40.7%). After mild-TBI factor 2 included dizziness, vomiting/nausea, irritability, and double vision; whilst in controls it involved headache, dizziness, vomiting/nausea, and slowed thinking. Factor 3 for mild-TBI included vomiting/nausea, blurred vision, slowed thinking, and poor memory; while for controls it was restricted to visual symptoms (blurred vision, light sensitivity, double vision). CONCLUSION: The RPQ factor structure was similar for both groups, although differences were identified in lesser factors. This suggests those with mild-TBI differ minimally from matched controls in the very long term after injury.

Depression and anxiety across the first 4 years after mild traumatic brain injury: findings from a community-based study.

BACKGROUND: Emotional disorders are considered to contribute to persistent difficulties after mild traumatic brain injury (TBI). Few studies have examined anxiety after mild TBI, and fewer have examined comorbid depression and anxiety and their trajectories over time. This study describes depression and anxiety across 48-months after mild TBI in adults (aged >15 years at injury). METHODS: Depression and anxiety were assessed using the Hospital Anxiety and Depression Scale in a sample of 341 adults with mild TBI within 2 weeks of injury and then at 6-, 12- and 48-months post-injury. RESULTS: Mean anxiety and depression total scores decreased significantly over time. Prevalence of depression ranged from 0% to 7.7%, whilst anxiety was present in 3.7-29.5% of cases. Comorbid anxiety and depression prevalence ranged from 10.2% to 20.7%. At each time of assessment, the greatest proportion of individuals had neither depression nor anxiety (range 28-49%). The findings suggest multiple trajectories over time. CONCLUSIONS: The findings indicate that both anxiety and depression need to be screened regularly after mild TBI. Furthermore, it cannot be assumed that someone who initially presents without depression or anxiety will remain free of these as they negotiate life after injury.

Factor structure of the Rivermead Post-Concussion Symptoms Questionnaire over the first year following mild traumatic brain injury.

BACKGROUND: We examined the factor structure of the Rivermead Post-Concussion Symptom Questionnaire (RPQ), the most commonly used measure of post-concussive symptoms, over the first year post-injury. METHOD: Factor analysis (orthogonal rotation) was used to examine the RPQ items that form coherent subsets/factors within 2-weeks, and 1, 6, and 12-months post-mTBI in 527 adults (age >16 years). RESULTS: At baseline, three factors accounted for 63.95% of the variance; factor 1 reflected cognitive and physiological disturbances; factor 2 included items reflecting mood, sleep, and nausea/vomiting; and factor 3 included visual/auditory disturbances, dizziness, and headaches. At 1 month, three factors were again extracted (63.26% variance). Factor 1 reflected cognitive and mood symptoms, factor 2 reflected mood with headache, nausea, and dizziness; and factor 3 reflected visual disturbances. Two factors were obtained at 6 and 12 months (63.7% and 63.38% of variance): factor 1 included mood/cognitive items, restlessness, sleep disturbance, and noise sensitivity; whereas, factor 2 included physiological symptoms. CONCLUSIONS: The factor structure of the RPQ changes over time; however, it was relatively stable from 6 to 12-months post-injury. Subject to further evaluation, assessments conducted from 6 months could consider using these two factors as subscales. Changing the factor structure of RPQ before 6 months suggests that timing of assessment should be considered in applying these factors.

Incidence of spinal epidural lipomatosis in patients with spinal stenosis.

INRODUCTION: Spinal Epidural Lipomatosis (SEL) is believed to be a rare disorder. The incidence and prevalence of clinically symptomatic SEL in patients with spinal stenosis has never been reported in the literature. Our study aims to determine the prevalence, incidence, and associated risk factors of SEL in patients with the diagnosis of spinal stenosis. METHODS: This is a retrospective study. We reviewed the charts of 831 patients with the diagnosis of spinal stenosis over a 30 month period. All patients had spinal MRIs. Grading of SEL was performed using the Borré method. RESULTS: 52 patients (21 female and 31 male) had symptomatic moderate and severe SEL. We found a prevalence of 6.26% and an annual incidence of 2.5%. SEL was most commonly seen at L5-S1 level. 27% had received corticosteroids. All SEL patients were overweight and 79% were obese. CONCLUSIONS: SEL is not uncommon in patients with spinal stenosis. SEL should be considered as a possible diagnosis in those with symptoms of spinal stenosis especially in those with associated risk factors.

Work Limitations 4 Years After Mild Traumatic Brain Injury: A Cohort Study.

OBJECTIVE: To explore employment status, work limitations, and productivity loss after mild traumatic brain injury (TBI). DESIGN: Inception cohort study over 4 years. SETTING: General community. PARTICIPANTS: Adults (N=245; >16y at the time of injury) who experienced a mild TBI and who were employed prior to their injury. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Details of the injury, demographic information, and preinjury employment status were collected from medical records and self-report. Symptoms and mood were assessed 1 month postinjury using the Rivermead Post-Concussion Symptom Questionnaire and the Hospital Anxiety and Depression Scale. Postinjury employment status and work productivity were assessed 4 years postinjury using the Work Limitations Questionnaire. RESULTS: Four years after mild TBI, 17.3% of participants had exited the workforce (other than for reasons of retirement or to study) or had reduced their working hours compared with preinjury. A further 15.5% reported experiencing limitations at work because of their injury. Average work productivity loss was 3.6%. The symptom of taking longer to think 1 month postinjury significantly predicted work productivity loss 4 years later (ß=.47, t=3.79, P≤.001). CONCLUSIONS: Although changes in employment status and difficulties at work are likely over time, the results indicate increased unemployment rates, work limitations, and productivity loss in the longer term after a mild TBI. Identification of cognitive difficulties 1 month after TBI in working aged adults and subsequent interventions to address these difficulties are required to facilitate work productivity.

Accuracy of an International Classification of Diseases Code Surveillance System in the Identification of Traumatic Brain Injury.

BACKGROUND: Use of International Classification of Disease (ICD) codes for traumatic brain injury (TBI) in healthcare administrative databases may underestimate the epidemiology of TBI. The present study examined the use of ICD-10 codes in a population-based New Zealand sample. METHODS: TBI related ICD-codes within the New Zealand health database were examined for all incident cases from a population-based TBI sample (n = 1,369). Impact of age, gender, ethnicity, presence/absence of skull fracture, where the case was located (i.e., hospital) on receipt of an ICD code was examined. RESULTS: Individuals who received a TBI-related ICD-code accounted for 18.6% of the studied population. The most frequent codes were brief loss of consciousness, head injury not otherwise specified, and concussion. Receipt of a code was not impacted by gender. Those with skull fracture (χ2 (1) = 69.983, p < 0.001), and/or attending hospital (χ2 (2) = 81.507, p < 0.001), and of older age (χ2 (1) = 56.473, p < 0.001) were more likely to receive a code. CONCLUSIONS: Reported incidence of TBI, when based upon health registration data, is likely to be a significant underestimate. Specific research needs to be conducted to identify the barriers to medical personnel implementing the ICD head injury codes and to identify ways in which the use of the codes can be improved.

Sports-related brain injury in the general population: an epidemiological study.

OBJECTIVES: To determine the incidence, nature and severity of all sports-related brain injuries in the general population. DESIGN: Population-based epidemiological incidence study. METHODS: Data on all traumatic brain injury events sustained during a sports-related activity were extracted from a dataset of all new traumatic brain injury cases (both fatal and non-fatal), identified over a one-year period in the Hamilton and Waikato districts of New Zealand. Prospective and retrospective case ascertainment methods from multiple sources were used. All age groups and levels of traumatic brain injury severity were included. Details of the registering injuries and recurrent injuries sustained over the subsequent year were obtained through medical/accident records and assessment interviews with participants. RESULTS: Of 1369 incident traumatic brain injury cases, 291 were identified as being sustained during a sports-related activity (21% of all traumatic brain injuries) equating to an incidence rate of 170 per 100,000 of the general population. Recurrent injuries occurred more frequently in adults (11%) than children (5%). Of the sports-related injuries 46% were classified as mild with a high risk of complications. Injuries were most frequently sustained during rugby, cycling and equestrian activities. It was revealed that up to 19% of traumatic brain injuries were not recorded in medical notes. CONCLUSIONS: Given the high incidence of new and recurrent traumatic brain injury and the high risk of complications following injury, further sport specific injury prevention strategies are urgently needed to reduce the impact of traumatic brain injury and facilitate safer engagement in sports activities. The high levels of 'missed' traumatic brain injuries, highlights the importance in raising awareness of traumatic brain injury during sports-related activity in the general population.

Incidence of traumatic brain injury in New Zealand: a population-based study.

BACKGROUND: Traumatic brain injury (TBI) is the leading cause of long-term disability in children and young adults worldwide. However, accurate information about its incidence does not exist. We aimed to estimate the burden of TBI in rural and urban populations in New Zealand across all ages and TBI severities. METHODS: We did a population-based incidence study in an urban (Hamilton) and rural (Waikato District) population in New Zealand. We registered all cases of TBI (admitted to hospital or not, fatal or non-fatal) that occurred in the population between March 1, 2010, and Feb 28, 2011, using multiple overlapping sources of information. We calculated incidence per 100,000 person-years with 95% CIs using a Poisson distribution. We calculated rate ratios [RRs] to compare the age-standardised rates between sex, ethnicity, and residency (urban, rural) groups. We used direct standardisation to age-standardise the rates to the world population. RESULTS: The total incidence of TBI per 100,000 person-years was 790 cases (95% CI 749-832); incidence per 100,000 person-years of mild TBI was 749 cases (709-790) and of moderate to severe TBI was 41 cases (31-51). Children (aged 0-14 years) and adolescents and young adults (aged 15-34 years) constituted almost 70% of all TBI cases. TBI affected boys and men more than women and girls (RR 1·77, 95% CI 1·58-1·97). Most TBI cases were due to falls (38% [516 of 1369]), mechanical forces (21% [288 of 1369]), transport accidents (20% [277 of 1369]), and assaults (17% [228 of 1369]). Compared with people of European origin, Maori people had a greater risk of mild TBI (RR 1·23, 95% CI 1·08-1·39). Incidence of moderate to severe TBI in the rural population (73 per 100,000 person-years [95% CI 50-107) was almost 2·5 times greater than in the urban population (31 per 100 000 person-years [23-42]). INTERPRETATION: Our findings suggest that the incidence of TBI, especially mild TBI, in New Zealand is far greater than would be estimated from the findings of previous studies done in other high-income countries. Our age-specific and residency-specific data for TBI incidence overall and by mechanism of injury should be considered when planning prevention and TBI care services. FUNDING: Health Research Council of New Zealand.