Long-term antibacterial activity of silver-containing hydroxyapatite coatings against Staphylococcus aureus in vitro and invivo.

BACKGROUND: The potential of silver-containing hydroxyapatite (Ag-HA) coatings to prevent orthopaedic implant-associated infection was explored previously; however, the resistance of Ag-HA coatings to late-onset orthopaedic infections is unknown. This study aimed to evaluate the long-term Ag+ elution and antibacterial properties of the Ag-HA coatings through in vitro and in vivo experiments. METHODS: Ag-HA-coated disc specimens were immersed in fetal bovine serum (FBS) for six months. Ag concentration was measured over time using inductively coupled plasma-mass spectrometry to evaluate Ag release. The hydroxyapatite (HA)- or Ag-HA-coated disc specimens were immersed in FBS for 3 months to elute Ag+ for in vitro experiments. Methicillin-resistant Staphylococcus aureus (MRSA) suspensions were inoculated onto each disc; after 48 h, the number of colonies and the biofilm volume were measured. HA- or Ag-HA-coated disc specimens were inserted under the skin of Sprague-Dawley rats for three months for in vivo experiments. In in vivo experiment 1, specimens were inoculated with MRSA and the number of colonies was counted after 48 h. In in vivo experiment 2, the specimens were inoculated with bioluminescent S. aureus Xen36 cells, and bioluminescence was measured using an in vivo imaging system. RESULTS: The Ag-HA-coated disc specimens continued to elute Ag+ after six months. The biofilm volume in the Ag-HA group was lower than in the HA group. In in vitro and in vivo experiment 1, the bacterial counts in the Ag-HA group were lower than those in the HA group. In in vivo experiment 2, the bioluminescence in the Ag-HA group was lower than that in the HA group on days 1-7 after inoculation. CONCLUSIONS: The Ag-HA-coated discs continued to elute Ag+ for a long period and exhibited antibacterial activity and inhibition of biofilm formation against S. aureus. The Ag-HA coatings have the potential to reduce late-onset orthopaedic implant-associated infections.

Total knee arthroplasty for neuropathic arthropathy in a patient with leprosy.

Patients with leprosy are known to tend to develop neuropathic arthropathy, known as Charcot joint. There are no case reports of total knee arthroplasty (TKA) in patients with leprosy with polyarticular neuropathic arthropathy, and the results are unknown. In this study, we report a case of TKA in a patient with leprosy with polyarticular neuropathic arthropathy and discuss its outcomes and indications. Right TKA using the NexGen Legacy Constrained Condylar Knee implant was performed in a 62-year-old man with neuropathic arthropathy in multiple joints with clinical symptoms, particularly in the right knee. Seven years post-operation, the American Knee Society Score-knee and -function, which represent knee function and activities of daily living on a scale of 100 points, were significantly improved compared with preoperative values, from 30 to 99 points and 0 to 60 points, respectively. Indications for arthroplasty for neuropathic arthropathy should be carefully considered in each individual case. In this case, the patient had neuropathic arthropathy in multiple joints; however, TKA was performed because recovery of function in the right knee was expected to significantly improve the patient's activities of daily living, and a good mid-term clinical outcome was achieved. Therefore, indications for arthroplasty should be considered in patients with systemic neuropathic arthropathy such as leprosy, and with accurate assessment and appropriate implant selection, good long-term outcomes may be expected.

Clinical results of periacetabular osteotomy with structural bone allograft for the treatment of severe hip dysplasia.

Aims: To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia. Methods: We reviewed patients with severe hip dysplasia, defined as Severin IVb or V (lateral centre-edge angle (LCEA) < 0°), who underwent TOA with a structural bone allograft between 1998 and 2019. A medical chart review was conducted to extract demographic data, complications related to the osteotomy, and modified Harris Hip Score (mHHS). Radiological parameters of hip dysplasia were measured on pre- and postoperative radiographs. The cumulative probability of TOA failure (progression to Tönnis grade 3 or conversion to total hip arthroplasty) was estimated using the Kaplan-Meier product-limited method, and a multivariate Cox proportional hazard model was used to identify predictors for failure. Results: A total of 64 patients (76 hips) were included in this study. The median follow-up period was ten years (interquartile range (IQR) five to 14). The median mHHS improved from 67 (IQR 56 to 80) preoperatively to 96 (IQR 85 to 97) at the latest follow-up (p < 0.001). The radiological parameters improved postoperatively (p < 0.001), with the resulting parameters falling within the normal range in 42% to 95% of hips. The survival rate was 95% at ten years and 80% at 15 years. Preoperative Tönnis grade 2 was an independent risk factor for TOA failure. Conclusion: Our findings suggest that TOA with structural bone allografting is a viable surgical option for correcting severely dysplastic acetabulum in adolescents and young adults without advanced osteoarthritis, with favourable mid-term outcomes.

Joint awareness following periacetabular osteotomy in patients with hip dysplasia.

Aims: The aims of this study were to validate the Forgotten Joint Score-12 (FJS-12) in the postoperative evaluation of periacetabular osteotomy (PAO), identify factors associated with joint awareness after PAO, and determine the FJS-12 threshold for patient-acceptable symptom state (PASS). Methods: Data from 686 patients (882 hips) with hip dysplasia who underwent transposition osteotomy of the acetabulum, a type of PAO, between 1998 and 2019 were reviewed. After screening the study included 442 patients (582 hips; response rate, 78%). Patients who completed a study questionnaire consisting of the visual analogue scale (VAS) for pain and satisfaction, FJS-12, and Hip disability and Osteoarthritis Outcome Score (HOOS) were included. The ceiling effects, internal consistency, convergent validity, and PASS thresholds of FJS-12 were investigated. Results: The median follow-up was 12 years (interquartile range 7 to 16). The ceiling effect of FJS-12 was 7.2%, the lowest of all the measures examined. FJS-12 correlated with all HOOS subscales (ρ = 0.72 to 0.77, p < 0.001) and pain and satisfaction-VAS (ρ = -0.63 and 0.56, p < 0.001), suggesting good convergent validity. Cronbach's α was 0.95 for the FJS-12, which indicated excellent internal consistency. The median FJS-12 score for preoperative Tönnis grade 0 hips (60 points) was higher than that for grade 1 (51 points) or 2 (46 points). When PASS was defined as pain-VAS < 21 and satisfaction-VAS ≥ 77, the FJS-12 threshold that maximized the sensitivity and specificity for detecting PASS was 50 points (area under the curve (AUC) = 0.85). Conclusion: Our results suggest that FJS-12 is a valid and reliable assessment tool for patients undergoing PAO, and the threshold of 50 points may be useful to determine patient satisfaction following PAO in clinical settings. Further investigation of the factors influencing postoperative joint awareness may enable improved prediction of treatment efficacy and informed decision-making regarding the indication of PAO.

Whole body vibration accelerates the functional recovery of motor nerve components in sciatic nerve-crush injury model rats.

This study aimed to investigate the effect of whole body vibration (WBV) on the sensory and motor nerve components with sciatic nerve injury model rats. Surgery was performed on 21 female Wister rats (6-8 weeks) under intraperitoneal anesthesia. The nerve-crush injuries for the left sciatic nerve were inflicted using a Sugita aneurysm clip. The sciatic nerve model rats were randomly divided into two groups (n=9; control group, n=12; WBV group). The rats in the WBV group walked in the cage with a vibratory stimulus (frequency 50 Hz, 20 min/day, 5 times/wk), while those in the control group walked in the cage without any vibratory stimulus. We used heat stimulation-induced sensory threshold and lumbar magnetic stimulation-induced motor-evoked potentials (MEPs) to measure the sensory and motor nerve components, respectively. Further, morphological measurements, bilateral hind-limb dimension, bilateral gastrocnemius dimension, and weight were evaluated. Consequently, there were no significant differences in the sensory threshold at the injury side between the control and WBV groups. However, at 4 and 6 weeks postoperatively, MEPs latencies in the WBV group were significantly shorter than those in the control group. Furthermore, both sides of the hind-limb dimension at 6 weeks postoperatively, the left side of the gastrocnemius dimension, and both sides of the gastrocnemius weight significantly increased. In conclusion, WBV especially accelerates the functional recovery of motor nerve components in sciatic nerve-crush injury model rats.

Analgesic Effect of Passive Range-of-Motion Exercise on the Healthy Side for Pain after Total Knee Arthroplasty: A Prospective Randomized Trial.

Background: Exercise can reduce the pain threshold momentarily and induce analgesia, which is called exercise-induced hypoalgesia (EIH). Exercise therapy for inducing EIH may be an effective treatment option for pain. We aimed at investigating whether continuous passive motion (CPM) on both healthy and affected sides could induce EIH and reduce pain in the operated knee in patients after unilateral total knee arthroplasty (TKA). Patients and Methods. In this prospective randomized controlled trial, participants were randomly assigned to two groups: a bilateral group that received bilateral exercise on the operated and healthy sides and a unilateral group that received exercise therapy only on the affected side. We enrolled 40 patients aged ≥60 years who were scheduled to undergo unilateral TKA. Visual analogue scale (VAS) scores and range of motion (ROM) on the operated side were measured immediately before and after CPM on postoperative days 2, 4, 7, and 14. The primary outcome was the difference in the VAS scores before and after CPM on postoperative day 14. The secondary outcome was the difference in the ROM before and after CPM on postoperative day 14. Results: Comparison of VAS scores before and after CPM showed no significant intergroup differences on all measurement dates. However, there was a significant difference in values on day 14 (P < 0.05). Both groups showed an increase in ROM after CPM, with significant increments observed on days 2 and 4 in the bilateral group and on day 14 in the unilateral group. There was no significant difference in values on postoperative day 14. Conclusion: Post-TKA pain was reduced by performing the same exercise on the healthy knee during CPM therapy. This could be due to EIH, and the results indicated that EIH can also influence postoperative pain immediately after surgery.

Short-Term Collagen Nerve Wrapping Facilitates Motor and Sensory Recovery from Nerve Degeneration in a Sciatic Nerve Injury Rat Model.

Purpose: This study used a sciatic nerve injury rat model to investigate the short-term effects of a polyglycolic acid (PGA)-collagen tube for nerve injury in continuity. Materials and Methods: Sixteen female Wistar rats (6-8 weeks) were used, and the left sciatic nerve was crushed with a Sugita aneurysm clip. Sciatic nerve model rats were randomly categorized into two groups (n = 8; control group, n = 8; nerve wrapping group). Then, we measured four sensory thresholds, magnetically stimulated the lumbar region to induce motor-evoked potentials (MEPs), and evaluated the sciatic nerve histopathologically. Results: In the sensory thresholds, there were significant differences for the main effect in 250 and 2000 Hz stimulation (p = 0.048 and 0.006, respectively). Further, a significant difference was observed with 2000 Hz stimulation at 1 week (p = 0.003). In the heat stimulation, there were significant differences for the main effect in both weeks and groups (p = 0.0002 and 0.0185, respectively). The post-hoc test showed a significant difference between groups only in 2W (p = 0.0283). Three weeks after the surgery, both 2nd and 3rd MEPs waves-related latencies in the nerve wrapping group were significantly shorter than those in the control group (p = 0.0207 and 0.0271, respectively). Histological evaluation of the sciatic nerve revealed considerable differences in the number of axons between the two groups (p = 0.0352). Conclusion: The short-term PGA-collagen tube nerve wrapping facilitated motor and sensory recovery from nerve degeneration in the sciatic nerve injury rat model.

Changes of the coronal lumbar-pelvic-femoral alignment after conversion total hip arthroplasty in patients with unilateral ankylosed hip.

To elucidate the changes in coronal lumbar-pelvic-femoral alignment after conversion total hip arthroplasty (THA) in patients with unilateral ankylosed hip. A retrospective radiologic study of 48 patients (48 hips) with unilateral hip arthrodesis who underwent conversion THA was conducted. Cobb's angle of lumbar scoliosis (LS), the pelvic obliquity (PO) angle, and the hip adduction angle (HAA) on standing anterior-posterior spine-pelvis-hip radiographs were measured before and after THA. The differences of LS, PO, and HAA before and after THA were defined as ΔLS, ΔPO, and ΔHAA, respectively. A paired samples t-test or the Wilcoxon signed-rank test were used to compare the absolute values of the LS, PO, and HAA between preoperative and postoperative groups. The Pearson's correlation coefficient (r) or Spearman's correlation coefficient (ρ) was calculated to assess the relationship between ΔLS, ΔPO, and ΔHAA and possible associated factors. Significant differences were found in the preoperative LS (mean, 10.8° vs. 8.2°, p = 0.004), PO (median, 6.8° vs. 2.0°, p < 0.001), and HAA (median, 10.0° vs. 6.0°, p = 0.003). ΔLS was correlated with the preoperative LS (ρ =  - 0.621, p < 0.001), PO (ρ =  - 0.580, p < 0.001), and HAA (ρ =  - 0.467, p < 0.001). ΔPO was correlated with the preoperative LS (r =  - 0.596, p < 0.001), PO (ρ =  - 0.892, p < 0.001), and HAA (ρ =  - 0.728, p < 0.001). ΔHAA was correlated with the preoperative LS (r =  - 0.583, p < 0.001), PO (ρ =  - 0.751, p < 0.001), and HAA (ρ =  - 0.824, p < 0.001). LS, PO, and HAA were significantly improved after conversion THA. Greater improvement in LS, PO, and HAA can be expected in patients with larger preoperative LS, PO, and HAA values.

Osteoconductivity and neurotoxicity of silver-containing hydroxyapatite coating cage for spinal interbody fusion in rats.

Background: The use of spinal instrumentation is an established risk factor for postoperative infection. To address this problem, we prepared silver-containing hydroxyapatite coating, consisting of highly osteoconductive hydroxyapatite interfused with silver. The technology has been adopted for total hip arthroplasty. Silver-containing hydroxyapatite coating has been reported to have good biocompatibility and low toxicity. However, no studies about applying this coating in spinal surgery have addressed the osteoconductivity and direct neurotoxicity to the spinal cord of silver-containing hydroxyapatite cages in spinal interbody fusion. Aim: In this study, we evaluated the osteoconductivity and neurotoxicity of silver-containing hydroxyapatite-coated implants in rats. Materials & Methods: Titanium (non-coated, hydroxyapatite-coated, and silver-containing hydroxyapatite-coated) interbody cages were inserted into the spine for anterior lumbar fusion. At 8 weeks postoperatively, micro-computed tomography and histology were performed to evaluate the osteoconductivity of the cage. Inclined plane test and toe pinch test were performed postoperatively to assess neurotoxicity. Results: Micro-computed tomography data indicated no significant difference in bone volume/total volume among the three groups. Histologically, the hydroxyapatite-coated and silver-containing hydroxyapatite-coated groups showed significantly higher bone contact rate than that of the titanium group. In contrast, there was no significant difference in bone formation rate among the three groups. Data of inclined plane and toe pinch test showed no significant loss of motor and sensory function in the three groups. Furthermore, there was no degeneration, necrosis, or accumulation of silver in the spinal cord on histology. Conclusions: This study suggests that silver-hydroxyapatite-coated interbody cages produce good osteoconductivity and are not associated with direct neurotoxicity.

Comparison of the clinical outcomes following total knee arthroplasty in osseous ankylosed and non-ankylosed knees using propensity-score matching.

OBJECTIVES: Few studies have compared the clinical outcomes and complications of total knee arthroplasty (TKA) in patients with and without osseous ankylosed knees. Thus, we investigated the clinical outcomes and complications of TKA in patients with osseous ankylosed knees, using a propensity-score matching method. METHODS: Thirteen knees in the osseous ankylosed-knees group and 13 knees in the non-ankylosed-knees group were included after excluding those with less than two years of follow-up or a lack of data and after propensity-score matching. The American Knee Society Score-knee (AKSS-knee), American Knee Society Score-function (AKSS-function), knee-flexion angle, knee-extension angle, knee range of motion (ROM) before and after TKA, and the number of knees with postoperative complications were evaluated as primary outcomes. RESULTS: The AKSS-knee, AKSS-function, knee-flexion angle, and knee ROM in the osseous ankylosed-knees group after TKA were significantly lower than those in the non-ankylosed-knees group. The knee-extension angle after TKA and number of knees with postoperative complications within two years were not significantly different between the two groups. CONCLUSIONS: The clinical results of TKA in patients with osseous ankylosed knees were inferior to those in patients with non-ankylosed knees.

Limited Active Metacarpophalangeal Extension of the Ring Finger Due to Scarring of the Juncturae Tendinum: A Case Report.

A limitation of finger extension resulting from scarring of the juncturae tendinum (JT) is a rare condition. We report a patient with limitation in active extension of the metacarpophalangeal joint (MCPJ) of the ring finger due to a scarred JT in a 37-year-old man. Surgical exploration showed a hard, fixed and scarred JT in the third intermetacarpal space. After resection of the scarred JT, the patient achieved full range of active extension of the ring finger MCPJ. Scarring of the JT may decrease excursion of the extensor digitorum communis and must be considered as one of the differentials in patients with limitation in MCPJ extension. Level of Evidence: Level V (Therapeutic).

The relationship between traction spurs, Modic change, vacuum phenomenon, and segmental instability of the lumbar spine.

A thorough understanding of lumbar segmental motion is valuable to treat patients with degenerative lumbar disease, but kinematics associated with indicators of lumbar intervertebral instability [traction spur, Modic changes (MCs) and vacuum phenomenon (VP)] in the lumbar spine have not been well understood. The purpose of this study is to evaluate the relationships between traction spur, MCs and VP to radiographic measurements in the lumbar spine. A total of 525 lumbar discs from L1-2 to L5-S1 of 105 patients were evaluated. The sagittal translation (ST) and sagittal angulation were measured from the radiographs taken flexion-extension. The anterior disc height (ADH) was measured from the lateral radiographs, and ΔADH was measured as the difference from supine to sitting position. Logistic regression analyses were used to detect the association between the existence of traction spur, MCs and VP and related factors. Multivariate analysis showed that the traction spur was significantly related to translational motion (ST > 2 mm, OR 4.74) and the VP was significantly related to vertical motion (ΔADH > 3 mm, OR 1.94). These results suggest that the segments with traction spur and VP should be evaluated carefully because these may be a sign of lumbar intervertebral instability.

A Survey of the Incidence of Constipation in Patients with Chronic Non-cancer Pain Using Opioid Analgesics in Japan.

INTRODUCTION: Although opioids have potent analgesic properties, their use is associated with side effects, including opioid-induced constipation (OIC). This study investigated the incidence of OIC based on the Rome IV diagnostic criteria in patients using opioid analgesics for chronic non-cancer pain and to explore and compare the risk factors for the development of OIC in opioid analgesic users. METHODS: We surveyed patients aged 20 years or more living in Japan via the internet; who had been using opioid or non-opioid analgesics (N = 500 each) for at least 3 months for relief from chronic non-cancer musculoskeletal pain (low back pain or osteoarthritis); and who provided electronic consent to participate in and complete the survey. The groups were matched for age and sex. RESULTS: Of the patients using opioid analgesics, 89% were taking weak opioids. The proportion of patients perceiving constipation was comparable between the opioid and non-opioid analgesic groups (34% vs 29%, respectively); however, a significantly higher proportion of patients in the opioid group, compared to the non-opioid group, reported self-assessed constipation (40% vs 18%, respectively) after using an analgesic and fulfilled two or more symptoms of the Rome IV diagnostic criteria for constipation (28% vs 19%, respectively). A higher proportion of patients were taking prescribed medicine for constipation in the opioid group compared with the non-opioid group (33% vs 18%, respectively). Low back pain, but not opioid strength and scheduled dosing, was identified as a risk factor for OIC among various covariates assessed in the logistic regression analysis in 81 patients with OIC and Rome IV diagnosis vs 419 patients without OIC in the opioid group. CONCLUSION: Use of opioid analgesics, including weak opioids, for treating chronic non-cancer musculoskeletal pain is associated with OIC. This finding highlights the need for appropriate treatment of constipation in patients with chronic non-cancer pain in Japan. TRIAL REGISTRATION: UMIN000043985.

The significant relationship among the factors of pelvic incidence, standing lumbar lordosis, and lumbar flexibility in Japanese patients with hip osteoarthritis: A descriptive radiographic study.

INTRODUCTION: Spine stiffness is known to increase the risk of total hip replacement (THR) instability. The sagittal posture and lumbo-pelvic kinematics have therefore become parameters of interest when planning THR. We conducted this study to investigate (1) the distribution and characteristics of the spino-pelvic standing alignment, (2) the relationship between pelvic incidence (PI) and standing lumbar lordosis (LL) and lumbar flexibility, in Japanese hip osteoarthritis patients. HYPOTHESIS: (1) Japanese hip osteoarthritis patients with different sagittal spino-pelvic alignments do not differ markedly in their demographics, PI, or lumbar flexibility; and (2) there is no significant relationship between PI, standing LL, and lumbar flexibility in a population of Japanese hip osteoarthritis patients. MATERIAL AND METHODS: A retrospective study of radiographs from 945 Japanese patients who consecutively received THR for the treatment of hip osteoarthritis. All patients pre-operatively underwent lateral standing and deep-seated lumbo-pelvic radiography on which the spino-pelvic parameters were measured. The difference between the standing and deep-seated LL angles defined the lumbar flexibility and was calculated as the delta (Δ) LL. Individual spino-pelvic standing alignment was stratified based on the difference between the PI and standing LL ('PI-LL mismatch'). 'PI-LL mismatch' of<-10°, between -10° and 10°, and>10° was defined as hyperlordosis, normolordosis, and flatback, respectively. RESULTS: In the present study, the spinal alignment of 115/945 (12.2%), 559/945 (59.2%), and 271/945 (28.6%) patients were classified as hyperlordosis, normolordosis, and flatback, respectively. Hyperlordotic patients had significantly lower PI (47.6°±7.8° vs. 52.7°±10.5°, p<0.001) and higher ΔLL (60.6°±12.6° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. Patients with flatback were significantly older (age, 69.1±9.1 years vs. 62.7±9.8 years, p<0.001) with higher PI (56.9°±11.7° vs. 52.7°±10.5°, p<0.001) and lower ΔLL (35.2°±17.4° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. A significant relationship between PI and the standing LL was found in the whole cohort (r=0.409, p=0.009), hyperlordotic (r=0.785, p<0.001), normolordotic (r=0.857, p<0.001), and flatback (r=0.664, p<0.001) patients. Significant relationships between the PI and ΔLL were also found in normolordotic (r=0.442, p=0.004) and flatback (r=0.449, p=0.003) patients but not hyperlordotic patients (r=0.154, p=0.367). DISCUSSION: A large proportion of Japanese hip osteoarthritis patients have abnormal PI-LL mismatch (12% and 29% have hyperlordosis and flatback, respectively). The PI was a determinant of the standing LL and the lumbar flexibility, especially in the normolordotic and flatback individuals. LEVEL OF EVIDENCE: III; retrospective diagnostic radiographic study.

Fragility fracture following total hip arthroplasty.

BACKGROUND: While periprosthetic fractures following total hip arthroplasty (THA) are a well-known phenomenon for orthopedic surgeons, fragility fractures following THA are also a significant, though less studied, concern. Furthermore, patients who have undergone THA have several additional risk factors for fragility fractures, including motor weakness, bone atrophy, and limping. The aims of this study were to evaluate the incidence of fragility fractures following THA and to clarify the characteristics of these fractures. METHODS: This study included 5678 primary THA procedures in 4589 female patients. This study evaluated body morphology data, disease type leading to THA, Japanese Orthopaedic Association hip score, range of motion of the hip joint, and medical history. Distal radius and patella fractures were defined as fragility fractures. Risk factors for fragility fractures after THA were calculated by comparing the fragility fracture group with the non-fracture group. RESULTS: Fifty-three fragility fractures were confirmed in 53 patients (distal radius fracture: 32 fractures in 32 patients, patella fracture: 21 fractures in 21 patients). In the univariate analysis, the following eight risk factors for fragility fractures were significantly different between the groups: height, weight, follow-up period, developmental dysplasia of the hip, primary osteoarthritis, abduction before THA, internal rotation before THA, and external rotation before THA. Medical histories were not significantly different between the groups. There was no difference in any study factor and in the time of occurrence between the radius fractures and patella fractures analyzed as fragility fractures. CONCLUSIONS: This study revealed that there are significant preoperative factors of fragility fractures following THA. These factors will serve as useful data for THA treatment strategies, preoperative explanations, and future studies.

Mid-term clinical outcomes and complications of primary total knee arthroplasty in hemodialysis patients: a retrospective comparative cohort study.

BACKGROUND: Numerous patients who receive hemodialysis (HD) undergo total knee arthroplasty (TKA) due to advanced knee joint arthritis. However, there are few studies that describe the clinical outcomes and complications of TKA in HD patients. This study investigated the mid-term results of TKA in patients undergoing HD. METHODS: This single-center retrospective study compared clinical and surgical outcomes following TKA in patients who were receiving HD with those who were not. We used propensity scores to match 21 knees of 18 patients who received HD to 706 knees of 569 patients who had not received HD, from a total of 727 knees (587 patients) that underwent primary unilateral TKA. The clinical outcomes were evaluated using the American Knee Society Score-knee (AKSS-knee) and AKSS-function scores. The primary surgical outcome measure was the number of knees with postoperative complications. RESULTS: In both the HD and non-HD groups, postoperative AKSS-knee and function scores significantly improved when compared to preoperative values. Postoperative AKSS-knee and function scores were not significantly different between the groups. The number of knees with postoperative complications was larger in the HD group than the non-HD group within the first postoperative month, 0-12 months, 12-24 months, 0-24 months, and two years after surgery. Additionally, in the HD group, more complications occurred in the first month than any subsequent month in the two years after surgery. CONCLUSIONS: TKA improves AKSS-knee and function scores equivalently for HD patients and non-HD patients. However, HD patients develop more complications after TKA, especially within the first month. Therefore, surgeons who perform TKA for HD patients should obtain informed consent after explaining the possible complications, and HD patients should be carefully observed following TKA.

Hydroxyapatite-coated cementless total hip arthroplasty for patients undergoing dialysis: a study of 30 hips with a minimum follow-up period of 5 years.

BACKGROUND: The number of total hip arthroplasties (THAs) performed for patients undergoing dialysis is increasing. However, there are few reports of cementless THA for patients undergoing dialysis. This study investigated the mid-term to long-term results of hydroxyapatite (HA)-coated cementless THA for dialysis patients. METHODS: This single-center, retrospective study enrolled dialysis patients undergoing primary HA-coated cementless THA. A total of 24 patients (30 hips) were included in the final analyses. The Harris hip score and radiographic results were assessed preoperatively and during the final follow-up examination. Postoperative complications and mortality rates were recorded. The mean follow-up period was 109 months (range, 60-216 months). RESULTS: The total Harris hip score significantly improved from 40 to 84 points. The overall cumulative survival rates with revision as the endpoint were 100% at 5 years and 90.4% at both 10 and 15 years. Stress shielding was observed in 24 hips (80%). No deaths were related to the primary THA. Complications included periprosthetic fracture for one patient (3.3%), blood transfusion for nine patients (30%), shunt blockage for two patients (6.7%), deep infection for one patient (3.3%), and dislocation for two patients (6.7%). CONCLUSIONS: HA-coated cementless THA resulted in good mid-term outcomes for patients undergoing dialysis with no mortality risk. However, the procedure involved a relatively high perioperative risk of blood transfusion.

Is dislocation following total hip arthroplasty caused while suffering from delirium?

The mechanisms and pathologies of dislocation following total hip arthroplasty (THA) in patients with postoperative delirium remain unclear. Therefore, we conducted a retrospective study of 738 patients (738 hips) who underwent unilateral THA for the treatment of hip osteoarthritis. The patients were divided into two groups; with (n = 8) and without postoperative delirium (n = 730). Patients with postoperative delirium had a higher rate of dislocation following THA due to falling from a standing position on hospitalization than those without postoperative delirium (1/8 [12.5%] patients vs. 0/730 [0%] patients, p = 0.011). A power of 80.2% was provided for the rate of dislocation following THA due to falling from a standing position on hospitalization. Postoperative delirium after THA could be a cause of falling from standing position, leading to dislocation following THA during hospitalization. Therefore, postoperative delirium and its associated falls and injuries during hospitalization should be avoided by the elimination of patient's preventable conditions and adjustment of the hospital environments, particularly in patients with the risk factors for postoperative delirium (eg, older age, general anesthesia, medications given [intraoperative opioids and ketamine and postoperative ketamine and benzodiazepines], higher comorbidity burden [diabetes mellitus, renal diseases, depression, anxiety, and psychoses], and blood transfusions). Further investigations with a larger cohort are needed to clarify this issue.