Patient Acceptable Symptom State Thresholds for the Knee Society Score, Oxford Knee Score, and 36-Item Short Form Survey Ten Years Following Unicompartmental Knee Arthroplasty.

BACKGROUND: The patient acceptable symptom state (PASS) refers to a cutoff value on any patient-reported outcome measures (PROMs) scale, beyond which patients consider themselves as having achieved an acceptable outcome. This study aimed to identify PASS thresholds for knee-specific and generic PROMs at 10 years post-unicompartmental knee arthroplasty (UKA). METHODS: There were 269 patients who underwent UKA for medial osteoarthritis from 2004 to 2007 at a single institution and were surveyed preoperatively and 10 years postoperatively using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), 36-Item Short Form Survey (SF-36) Mental Component Score (MCS), and SF-36 Physical Component Score (PCS). Treatment outcomes and expectations were assessed using an anchor question, and PASS attainment was determined using the Youden index on a receiver operating characteristic (ROC) curve. Also, a similar study that identified 2-year long-term PROM PASS thresholds for UKA was referenced and compared. RESULTS: Overall, 91.1% reported acceptable outcomes. The area under the curve for ROCs of KSKS, OKS, and PCS were 0.80, 0.75, and 0.71, respectively. The area under the curve for ROCs of KSFS and MCS were both 0.64. The PASS thresholds were 67.5 for KSFS, 70.5 for KSKS, 39.5 for OKS, 44.6 for PCS, and 43.8 for MCS. Patients who achieved a PASS were at least 3 times more likely to have satisfactory outcomes. CONCLUSIONS: To our knowledge, this is the first study that identified 10-year long-term PROM PASS thresholds for UKA. Accounting for our finding that a decade-long follow-up yielded lower PASS thresholds, time-specific UKA PROM PASS thresholds should be considered. LEVEL OF EVIDENCE: III.

Excess mortality after hip fracture: fracture or pre-fall comorbidity?

Comorbidity and hip fracture independently increased mortality risk for 9 years in both sexes, with a significant additive interaction in the first year among women and through 6 years among men. INTRODUCTION: Hip fracture is associated with a persistently elevated mortality risk, but it is unknown whether the elevated risk is due to the fracture or to pre-fracture comorbidity. METHODS: In a population-based study in Singapore with 9 years of follow-up, patients age > 50 with first hip fracture from 2008 to 2017 were pair-matched to a cohort without hip fracture by age, sex, ethnicity, and pre-fracture Charlson Comorbidity Index (CCI). We investigated additive interaction using the relative excess risk due to interaction (RERI) and multiplicative interaction using the ratio of relative risks. RESULTS: Twenty-two thousand five hundred ninety of 22,826 patients with a first hip fracture in 2008-2017 were successfully matched. Hip fracture and comorbidity independently increased mortality risk for 9 years in both sexes. After adjustment for comorbidity, excess mortality risk continued to persist for 9 years post-fracture in both men and women. Women with a hip fracture and pre-fracture CCI > 4 had a higher relative risk (RR) of mortality at 9 years of 3.29 [95% confidence interval (CI) 3.01, 3.59] than those without comorbidity (RR 1.51, 95%CI 1.36, 1.68) compared to the referent without hip fracture or comorbidity. An additive interaction between hip fracture and pre-fracture CCI > 4 was observed in the first post-fracture year` [relative excess risk due to interaction (RERI) 1.99, 95%CI 0.97, 3.01]. For men with CCI ≥ 4, the positive additive interaction was observed through 6 years. CONCLUSIONS: Excess mortality risks post-fracture are attributable to both the fracture and pre-fracture comorbidity. Early interventions in hip fracture patients with high comorbidity could reduce their excess mortality.

Retrieval analysis of metal and ceramic femoral heads on a single CoCr stem design.

OBJECTIVES: The use of ceramic femoral heads in total hip arthroplasty (THA) has increased due to their proven low bearing wear characteristics. Ceramic femoral heads are also thought to reduce wear and corrosion at the head-stem junction with titanium (Ti) stems when compared with metal heads. We sought to evaluate taper damage of ceramic compared with metal heads when paired with cobalt chromium (CoCr) alloy stems in a single stem design. METHODS: This retrieval study involved 48 total hip arthroplasties (THAs) with CoCr V40 trunnions paired with either CoCr (n = 21) or ceramic (n = 27) heads. The taper junction of all hips was evaluated for fretting/corrosion damage and volumetric material loss using a roundness-measuring machine. We used linear regression analysis to investigate taper damage differences after adjusting for potential confounding variables. RESULTS: We measured median taper material loss rates of 0.210 mm3/year (0.030 to 0.448) for the metal head group and 0.084 mm3/year (0.059 to 0.108) for the ceramic group. The difference was not significant (p = 0.58). Moreover, no significant correlation between material loss and implant or patient factors (p > 0.05) was found. CONCLUSIONS: Metal heads did not increase taper damage on CoCr trunnions compared with ceramic heads from the same hip design. The amount of material released at the taper junctions was very low when compared with available data regarding CoCr/Ti coupling in metal-on-metal bearings.Cite this article: A. Di Laura, H. Hothi, J. Henckel, I. Swiatkowska, M. H. L. Liow, Y-M. Kwon, J. A. Skinner, A. J. Hart. Retrieval analysis of metal and ceramic femoral heads on a single CoCr stem design. Bone Joint Res 2017;6:-350. DOI: 10.1302/2046-3758.65.BJR-2016-0325.R1.

MRI findings in cervical spinal cord type II neurological decompression sickness: a case report.

Decompression illness affecting the cervical spinal cord is uncommon. We report a case that presented with mixed signs and symptoms of cervical myelopathy and Type II neurological decompression sickness. This presented a diagnostic dilemma that required the use of magnetic resonance imaging (MRI) scan to elucidate the underlying cause. Cervical spine MRI revealed the presence of tiny hypointensities and edema within the spinal cord that corresponded to the clinical findings. The patient recovered with residual neurological deficits after hy-perbaric oxygen (HBO2) therapy. To our knowledge, these MRI findings have yet to been described in literature and we recommend the use of MRI to assist diving physicians in the management of complex cases as long as it does not delay recompression.

A tale of three divers: recompression therapy for divers with severe Type II decompression sickness with neurological deficits.

Decompression sickness (DCS) is manifested in a myriad of symptoms, and can affect any part of the body. It is attributed to the formation of inert gas bubbles in the blood and tissues. Following a diving incident, the pathogenesis of DCS is a result of mechanical obstruction caused by the inert gas bubbles and the body's immunological response to the bubbles. Neurological DCS may present with unusual sensory/motor symptoms that may lead to paralysis. This report describes three divers who suffered severe neurological Type II DCS and underwent recompression therapy at the Naval Hyperbaric Centre in 2007.

Intravascular lymphomatosis: contribution of cerebral MRI findings to diagnosis.

Intravascular lymphomatosis (IL) is a rare variant of non-Hodgkin's lymphoma with an unusual predilection for the central nervous system (CNS). Most cases are not diagnosed until postmortem because of variable clinical presentation and nonspecific laboratory findings. Neuroimaging findings vary widely and range from diffuse involvement of the deep white matter to infarct-like lesions. Cerebral magnetic resonance imaging (MRI) may show parenchymal and meningeal gadolinium enhancement. The authors describe brain MRI findings of linear, punctate, and patchy enhancement suggestive of CNS IL in two patients confirmed by brain biopsy/histologic studies. High index of clinical suspicion and careful interpretation of MRI (including gadolinium contrast studies) may contribute to premortem diagnosis and early intervention of this often-missed disease.