Posterior clearance increases the knee extension angle in cruciate retaining type total knee arthroplasty: Intraoperative evaluation using a navigation system

BackgroundPosterior osteophyte of the femur can impinge on the tibia insert in total knee arthroplasty (TKA). Although osteophyte removal [posterior clearance (PC)] improves the flexion angle, its influence on the gaps and extension angle are unclear. This study investigated the effect of PC on the gaps and range of motion (ROM) using a navigation system, as well as PC's relationship with osteophyte size.MethodsTwenty-seven knees that underwent cruciate-retaining (CR)-type TKA were examined. Before and after PC, the ROM, hip-knee-ankle (HKA) angle, and flexion and extension gaps were recorded using a navigation system. Osteophyte size was measured in the lateral view in radiographs, and in the sagittal and axial planes of computed tomography (CT) images. The effects of PC on the gaps and ROM were analysed statistically.ResultsPC caused the extension gap to increase by 0.7 ± 0.9 mm in the medial (p < 0.001), and 0.9 ± 1.5 mm in the lateral compartment (p = 0.006). The extension angle increased by 4.9 ± 1.6°, flexion angle increased by 6.5 ± 5.0°, and HKA decreased by 0.3°. The increase in extension angle by PC was significantly correlated with the preoperative HKA angle (r = 0.594) and with the osteophyte area in radiographs and CT (r = 0.626 to 0.681).ConclusionsThe extension and flexion gaps increased less than 1 mm in the medial and lateral compartments. PC achieving an additional 5° extension angle could promote full extension in severely deformed knees with a large posterior osteophyte. The extension angle increase by PC was correlated with the preoperative HKA angle and osteophyte size.     

D-dimer for diagnosis of periprosthetic joint infection: A meta-analysis

BackgroundThe D-dimer test is easily available to detect periprosthetic joint infection (PJI). This study aimed to estimate the diagnostic accuracy of the D-dimer test in PJI diagnosis and identify possible independent factors affecting the diagnostic value of this test.MethodsMEDLINE and EMBASE databases identified literature until February 2020 that utilized the D-dimer test for PJI diagnosis. The pooled sensitivity, specificity, area under the curve (AUC), diagnostic odds ratio (DOR), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated to evaluate the diagnostic accuracy of the D-dimer test. Meta-regression and subgroup analyses were performed to assess potential heterogeneity.ResultsThe databases identified 243 records, and eight studies were included in the final analysis. The pooled sensitivity and specificity of the D-dimer test for PJI diagnosis were 0.78 (95% confidence interval [CI], 0.69–0.84) and 0.74 (95% CI, 0.85–0.99), respectively. The AUCs and DORs of the D-dimer test were 0.83 (95% CI, 0.79–0.86) and 10 (95% CI, 4–24), respectively. The PLR and NLR of the D-dimer test for PJI detection were 3.0 (95% CI, 1.9–4.8) and 0.30 (95% CI, 0.20–0.47), respectively. The results of the meta-regression and subgroup analyses indicated that studies that excluded patients with hypercoagulation disorder had higher sensitivity (0.85 vs 0.86) and specificity (0.83 vs 0.62). The sensitivity of the D-dimer test also improved in studies that excluded patients with inflammatory arthritis (0.81 vs 0.75).ConclusionThe D-dimer test is a practical method for PJI diagnosis, especially in patients without history of hypercoagulation disorder and inflammatory arthritis.     

One-stage oblique lateral corridor antibiotic-cement reconstruction for Candida spondylodiscitis in patients with major comorbidities: Preliminary experience

Fungal spondylodiscitis is rare (0.5%–1.6% of spondylodiscitis) and mainly caused by Candida albicans. Surgical intervention in spondylodiscitis patients is indicated for compression of neural elements, spinal instability, severe kyphosis, failure of conservative management and intractable pain. However, there is no evidence-based optimal surgical approach for spondylodiscitis. There have been only case reports of surgical treatment for Candida spondylodiscitis. We evaluated the preliminary results of the efficacy and safety of one-stage debridement via oblique lateral corridor with interbody fusion (OLIF) using stand-alone cement reconstruction after debridement for the treatment of Candida spondylodiscitis in patients with major co-morbidities. Five patients (4 males, 1 female, mean age: 64.2 years) suffering from Candida albicans lumbar spondylodiscitis who underwent this procedure were studied. Their predominant symptoms were unremitting back and leg pain and all had pre and postoperative anti-fungal therapy under microbiologist supervision. The operative time ranged from 137 minutes to 260 minutes (mean: 213.4 minutes). The mean blood loss was 160 mL (range: 100–200 mL). There were no perioperative complications. At follow-up all showed major improvement in pain and ambulatory status. CT scan showed radiological stability for all patients at 6–12 months. Our preliminary results showed stand-alone anterior debridement and spinal re-construction with cement through mini-open OLIF approach might be a safe and effective option for patients with spinal fungal infection and major comorbidities.     

Protection From the Second Warm Ischemic Injury in Kidney Transplantation Using an Ex Vivo Porcine Model and Thermally Insulating Jackets

BackgroundKidney transplantation is the optimum treatment for kidney failure in carefully selected patients. Technical surgical complications and second warm ischemic time (SWIT) increase the risk of delayed graft function (DGF) and subsequent short- and long-term graft outcomes including the need for post-transplant dialysis and graft failure. Intraoperative organ thermal regulation could reduce SWIT, minimizing surgical complications due to time pressure, and limiting graft ischemia-reperfusion injury.MethodsA novel ischemic-injury thermal protection jacket (iiPJ) was designed and fabricated in silicone composite and polyurethane (PU) elastomer prototypes. Both were compared with no thermal insulation as controls. Time to reach ischemic threshold (15°C) and thermal energy transfer were compared. A water bath model was used to examine the thermal protective properties of porcine kidneys, as a feasibility study prior to in vivo translation.ResultsIn both iterations of the iiPJ, the time taken to reach the warm ischemia threshold was 35.2 ± 1.4 minutes (silicone) and 38.4 ± 3.1 minutes (PU), compared with 17.2 ± 1.5 minutes for controls (n = 5, P < .001 for both comparisons). Thermal energy transfer was also found to be significantly less for both iiPJ variants compared with controls. There was no significant difference between the thermal performance of the 2 iiPJ variants.ConclusionProtection from SWIT by using a protective insulation jacket is feasible. With clinical translation, this novel strategy could facilitate more optimal surgical performance and reduce transplanted organ ischemia-reperfusion injury, in particular the SWIT, potentially affecting delayed graft function and long-term outcomes.     

The effects of exposure to microgravity and reconditioning of the lumbar multifidus and anterolateral abdominal muscles: implications for people with LBP

BACKGROUND CONTEXTOne of the primary changes in the neuromuscular system in response to microgravity is skeletal muscle atrophy, which occurs especially in muscles that maintain posture while being upright on Earth. Reduced size of paraspinal and abdominal muscles has been documented after spaceflight. Exercises are undertaken on the International Space Station (ISS) during and following space flight to remediate these effects. Understanding the adaptations which occur in trunk muscles in response to microgravity could inform the development of specific countermeasures, which may have applications for people with conditions on Earth such as low back pain (LBP).PURPOSEThe aim of this study was to examine the changes in muscle size and function of the lumbar multifidus (MF) and anterolateral abdominal muscles (1) in response to exposure to 6 months of microgravity on the ISS and (2) in response to a 15-day reconditioning program on Earth.DESIGNProspective longitudinal series.PATIENT SAMPLEData were collected from five astronauts who undertook seven long-duration missions on the ISS.OUTCOME MEASURESFor the MF muscle, measures included cross-sectional area (CSA) and linear measures to assess voluntary isometric contractions at vertebral levels L2 to L5. For the abdominal muscles, the thickness of the transversus abdominis (TrA), obliquus internus abdominis (IO) and obliquus externus abdominis (EO) muscles at rest and on contraction were measured.METHODSUltrasound imaging of trunk muscles was conducted at four timepoints (preflight, postflight, mid-reconditioning, and post reconditioning). Data were analyzed using multilevel linear models to estimate the change in muscle parameters of interest across three time periods.RESULTSBeta-coefficients (estimates of the expected change in the measure across the specified time period, adjusted for the baseline measurement) indicated that the CSA of the MF muscles decreased significantly at all lumbar vertebral levels (except L2) in response to exposure to microgravity (L3=12.6%; L4=6.1%, L5=10.3%; p<.001), and CSAs at L3-L5 vertebral levels increased in the reconditioning period (p<.001). The thickness of the TrA decreased by 34.1% (p<.017), IO decreased by 15.4% (p=.04), and the combination of anterolateral abdominal muscles decreased by 16.2% (p<.001) between pre- and postflight assessment and increased (TrA<0.008; combined p=.035) during the postreconditioning period. Results showed decreased contraction of the MF muscles at the L2 (from 12.8% to 3.4%; p=.007) and L3 (from 12.2% to 5%; p=.032) vertebral levels following exposure to microgravity which increased (L2, p=.046) after the postreconditioning period. Comparison with preflight measures indicated that there were no residual changes in muscle size and function after the postreconditioning period, apart from CSA of MF at L2, which remained 15.3% larger than preflight values (p<.001).CONCLUSIONSIn-flight exercise countermeasures mitigated, but did not completely prevent, changes in the size and function of the lumbar MF and anterolateral abdominal muscles. Many of the observed changes in size and control of the MF and abdominal muscles that occurred in response to prolonged exposure to microgravity paralleled those seen in people with LBP or exposed to prolonged bed rest on Earth. Daily individualized postflight reconditioning, which included both motor control training and weight-bearing exercises with an emphasis on retraining strength and endurance to re-establish normal postural alignment with respect to gravity, restored the decreased size and control of the MF (at the L3-L5 vertebral levels) and anterolateral abdominal muscles. Drawing parallels between changes which occur to the neuromuscular system in microgravity and which exercises best recover muscle size and function could help health professionals tailor improved interventions for terrestrial populations. Results suggested that the principles underpinning the exercises developed for astronauts following prolonged exposure to microgravity (emphasizing strength and endurance training to re-establish normal postural alignment and distribution of load with respect to gravity) can also be applied for people with chronic LBP, as the MF and anterolateral abdominal muscles were affected in similar ways in both populations. The results may also inform the development of new astronaut countermeasures targeting the MF and abdominal muscles.     

Long-term rates of bladder dysfunction after decompression in patients with cauda equina syndrome

BACKGROUND CONTEXTCauda equina syndrome (CES) occurs due to compression of the lumbar and sacral nerve roots and is considered a surgical emergency. Although the condition is relatively rare, the associated morbidity can be devastating to patients. While substantial research has been conducted on the timing of treatment, the literature regarding long-term rates of bladder dysfunction in CES patients is scarce.PURPOSEThe aim of this study was to identify long-term rates of bladder dysfunction in CES patients and to compare those rates to non-CES patients who underwent similar spinal decompression.STUDY DESIGN/SETTINGRetrospective database study.PATIENT SAMPLEThe CES cohort was comprised of 2,362 patients who underwent decompression surgery following CES diagnosis with a 5-year follow-up. These patients were matched to 9,448 non-CES control patients who underwent spinal decompression without a diagnosis of CES.OUTCOME MEASURESDiagnosis of bladder dysfunction, surgical procedure to address bladder dysfunctionMETHODSUsing the national insurance claims database, PearlDiver, CES patients who underwent decompression surgery were identified and 1:4 matched to non-CES patients who underwent similar spinal decompression surgery. The 1-year, 3-year, and 5-year rates of progression to a bladder dysfunction diagnosis and surgical intervention to manage bladder dysfunction were recorded. The CES and non-CES groups were compared with univariate testing, and an analysis of risk factors for bladder dysfunction was performed with multivariate logistic regression analysis.RESULTSA total of 2,362 CES patients who underwent decompression surgery were identified and matched to 9,448 non-CES control patients. After 5 years, CES patients had a 10%–12% increased absolute risk of continued bladder dysfunction and a 0.7%–0.9% increased absolute risk of undergoing a surgical procedure for bladder dysfunction, as compared to matched non-CES patients. Multivariate analysis controlling for age, sex, obesity, tobacco use, and diabetes, identified CES as independently associated with increased 5-year risk for bladder dysfunction diagnosis (odds ratio [OR]: 1.72; 95% confidence interaval [CI] 1.56–1.89; p<.001) and procedure (OR: 1.40; 95% CI 1.07–1.81; p=.012).CONCLUSIONSUnderstanding the long-term risk for bladder dysfunction in CES patients is important for the future care and counseling of patients. Compared to non-CES patients who underwent similar spinal decompression, CES patients were observed to have a significantly higher long-term likelihood for both bladder dysfunction diagnosis and urologic surgical procedure.