Caliper-verified unrestricted kinematically aligned total knee arthroplasty in Asian patients showed efficacious mid- to long-term results regardless of postoperative alignment categories.

PURPOSE: There have been insufficient data regarding the long-term results of unrestricted kinematically aligned total knee arthroplasty (unKATKA) in Asian patients. We investigated mid- to long-term clinical and radiological follow-up data of Korean patients after caliper-verified unKATKA of minimum 7.4-10 years including categorised data of postoperative tibial component, limb and knee alignment. Additionally, we analysed the preoperative distribution and postoperative restoration of coronal plane alignment of knee (CPAK) phenotypes. METHODS: This study is a retrospective analysis of 63 patients: 96 osteoarthritic underwent consecutive caliper-verified unKATKA between October 2013 and May 2016 by a single surgeon. Implant survivorship was investigated for revision for any reason. Each knee was categorised into an in-range or outlier group by three postoperative alignment parameters: tibial component, knee and limb alignment. Statistical analyses were done for any significant differences in clinical scores and implant survival rates between groups. Finally, all knees were classified into CPAK classification postoperatively and postoperatively. The CPAK restoration rate was calculated. RESULTS: Among 85 knees in the clinically confirmed group, implant survival was 98.8%. There was one case of revision due to periprosthetic fracture. The percentage postoperatively aligned in the varus (valgus) outlier range was 100% (0%) for tibial component, 16.7% (24.8%) for the knee alignment and 51% (0%) for the limb alignment. All three categories did not affect implant survival or clinical scores. Eighty one out of 96 knees (84.4%) were restored to their CPAK phenotype postoperatively. CONCLUSION: With the limitation of a case series having a small number of patients and gender deviation, our study suggests that caliper-verified unKATKA could be a good option regardless of geographical variation of constitutional alignment in patients with osteoarthritis (OA). LEVEL OF EVIDENCE: Level IV, therapeutic study.

Current Incidence and Future Projection of Periprosthetic Fractures in South Korea: A Study Based on National Claim Database.

OBJECTIVE: To evaluate the current incidence and economic cost and to estimate the future burden of periprosthetic fracture (PF) after joint arthroplasties in South Korea. METHODS: This study was a retrospective registry-based study of patients who were diagnosed as periprosthetic fractures (PFs) in South Korea. Cases of PF from 2010 to 2017 in South Korea using Health Insurance and Review and Assessment (HIRA) database, which contains all medical claims for all South Korean patients, were identified. The operational definitions of PFs were identified from the Electronic Data Interchange (EDI) code of the Korean National Health Insurance Program (KHNIP). The annual incidence and medical costs during the period were calculated and the future increase of PF and its cost were projected through 2030 using generalized linear model with quasi-poisson link. RESULTS: During the 8-year period, 14,456 patients were treated due to PFs. The annual number of patients with PF remarkably increased from 1,322 in 2010 to 2,636 in 2017. The increment was prominent in age groups of 70-79 and ≧80. Total number of patients with PF were 9752 in women and 4704 in men during the study period. Mean personal costs were 1,155.4 USD in women and 1,185.5 USD in men. The total cost of PFs increased from 779,533 USD in 2010 to 3,888,402 USD in 2017. The personal cost of PFs also increased from 589.7 USD in 2010 to 1,475.1 USD in 2017. In 2017, the number of PF patients exponentially increased after 50 years of age especially in women. Estimated with our projection model, the number of PFs will increase by 2.5 times and the cost will increase by 10 times in the next 10 years. CONCLUSION: The incidence and cost of PFs are rising and will represent a serious socioeconomic burden in South Korea.

Cementless Hip Arthroplasty in Patients with Subchondral Insufficiency Fracture of the Femoral Head.

BACKGROUND: Subchondral insufficiency fracture of the femoral head (SIFFH) occurs in elderly patients and might be confused with osteonecrosis of the femoral head (ONFH). Subchondral insufficiency fracture of the femoral head is an insufficiency fracture at the dome of the femoral head and has been known to be associated with osteoporosis, hip dysplasia, and posterior pelvic tilt. This study's aims were to evaluate (1) surgical complications, (2) radiological changes, (3) clinical results, and (4) survivorship of THA in patients with SIFFH. METHODS: From November 2010 to June 2017, 21 patients (23 hips); 5 men (5 hips) and 16 women (18 hips) underwent cementless THA due to SIFFH at our institution. Their mean age was 71.9 years (range, 57 to 86) at the time of surgery, and mean T-score was -2.2 (range, -4.2 to 0.2). The mean lateral center-edge angle, abduction, and anteversion of the acetabulum were 29.9° (range, 14.8° to 47.5°), 38.5° (range, 31° to 45°), and 20.0° (range, 12° to 25°), respectively. The mean pelvic incidence, lumbar kyphotic angle and posterior pelvic tilt were 56.4° (range, 39° to 79°), 14.7° (range, -34° to 43°), and 13.0° (range, 3° to 34°), respectively. RESULTS: An intraoperative calcar crack occurred in 1 hip. The mean anteversion and abduction of cup were 29.0° (range, 17° to 43°) and 43.3° (range, 37° to 50°), respectively. One patient sustained a traumatic posterior hip dislocation 2 weeks after the procedure, and was treated with open reduction. At a mean follow-up of 35.4 months (range, 24 to 79 months), no hip had prosthetic loosening or focal osteolysis. At the latest follow-up, the mean modified Harris hip score was 79.1 (range, 60 to 100) points, and mean UCLA activity score was 4.2 (range, 2 to 7) points. The survivorship was 95.7% (95% CI, 94.9% to 100%) at 6 years. CONCLUSIONS: Cementless THA is a favorable treatment option for SIFFH in elderly patients. LEVEL OF EVIDENCE: 3.

Burden and future projection of revision Total hip Arthroplasty in South Korea.

BACKGROUND: The annual number of hip arthroplasties is increasing combined with the aging population worldwide. In accordance with the increasing number of primary hip arthroplasties, the number of revision total hip arthroplasties (THAs) is expected to increase. The incidence and burden of revision THAs in the United States and have been reported by registry studies. To identify potential differences according to ethnics and regional practice, it is important to obtain data from East Asia. Nevertheless, there has been a lack of studies on the burden and future projection of revision THA based on a large-scale database in East Asia. The purpose of this study was to evaluate annual incidence and burden of revision THAs and to project the future burden in South Korea. METHODS: We identified primary THAs, primary hemiarthroplasties (HAs) and revision THAs, which were performed from 2010 to 2018, using database of Health Insurance and Review and Assessment (HIRA); nation-wide medical claim system of South Korea. The annual incidence rates (per 100,000) of primary THA, primary HA and revision THA, and the annual burden of revision THA; the number of revision THAs divided by the sum of primary hip arthroplasties and revision THAs, were calculated. The future burden of revision THAs were projected through 2030 using generalized linear model with Quasi-poisson regression. RESULTS: During the 9-year period, the annual incidences of primary THA, primary HA and revision THA increased by 47, 29 and 3%, respectively, while the revision burden decreased from 0.13 to 0.10. Compared to 2018, the annual incidences of primary THA, HA, and revision THA were projected to increase by 7.2, 2.3 and 1.1% per year, respectively, whereas the burden of revision THA was projected to decrease to 0.07 in 2030. CONCLUSION: Trends of revision THA in South Korea were similar with those of national registry studies from the United States. The annual incidence of revision THA has steadily increased, whereas its burden has decreased. Findings of our study could be used for epidemiological comparison between Western countries and East Asia as well as for the establishment of medical policies of revision THA in East Asian countries.

No Clinically Important Differences in Thigh Pain or Bone Loss Between Short Stems and Conventional-length Stems in THA: A Randomized Clinical Trial.

BACKGROUND: Short-length stems were developed to reduce bone loss of the proximal femur and potentially decrease the incidence of thigh pain after cementless THA. However, it remains unknown whether short stems indeed reduce bone loss or the frequency of thigh pain. QUESTIONS/PURPOSES: Is there a difference between short- and standard-length stems in terms of: (1) the frequency or severity of thigh pain, (2) modified Harris hip scores, (3) implant loosening, or (4) bone mineral density as measured by dual-energy x-ray absorptiometry? METHODS: Between March 2013 and January 2014, three surgeons performed 205 primary THAs. To be eligible, patients needed to be at least 20 years of age, have not undergone previous history of hip surgery, and have no metabolic bone disease. A total of 100 patients were randomized to receive THA either with a short stem (n = 56) or with a standard-length stem (n = 44). Both stems were proximally coated, tapered, cementless stems. Compared with standard stems, short stems typically were 30- to 35-mm shorter. A total of 73% (41 of 56) and 77% (34 of 44) of those groups, respectively, were accounted for at a minimum of 5 years and were analyzed. The presence of thigh pain during activity was evaluated using a 10-point VAS, and the modified Harris hip score was calculated by research assistants who were blinded to the treatment groups. Plain radiographs were taken at 6 weeks, 6 months, and 12 months postoperatively, and every 1 year thereafter; loosening was defined as subsidence > 3 mm or a position change > 3° on serial radiographs. Radiological assessment was performed by two researchers who did not participate in the surgery and follow-up evaluations. Bone mineral density of the proximal femur was measured using dual-energy x-ray absorptiometry at 4 days, 1 year, 2 years, and 5 years postoperatively. The primary endpoint of our study was the incidence of thigh pain during 5-year follow-up. Our study was powered at 80% to detect a 10% difference in the proportion of patients reporting thigh pain at the level of 0.05. RESULTS: With the numbers available, we found no difference between the groups in the proportion of patients with thigh pain; 16% (9 of 56) of patients in the short-stem group and 14% (6 of 44) of patients in the standard-stem group experienced thigh pain during the follow-up period (p = 0.79). In all patients, the pain was mild or moderate (VAS score of 4 or 6 points). Among the 15 available patients who reported thigh pain, there was no difference between the implant groups in mean severity of thigh pain (4.3 ± 0.8 versus 4.2 ± 0.7; p = 0.78). There were no between-group differences in the short versus standard-length stem groups in terms of mean modified Harris hip score by 5 years after surgery (89 ± 13 versus 95 ± 7 points; p = 0.06). No implant was loose and no hip underwent revision in either group. Patients in the short-stem group showed a slightly smaller decrease in bone mineral density in Gruen Zones 2, 3, and 5 than those in the standard-stem group did; the magnitude of the difference seems unlikely to be clinically important. CONCLUSION: We found no clinically important differences (and few differences overall) between short and standard-length THA stems 5 years after surgery in a randomized trial. Consequently, we recommend that clinicians use standard-length stems in general practice because standard-length stems have a much longer published track record in other studies, and short stems can expose patients to the uncertainty associated with novelty, without any apparent offsetting benefit. LEVEL OF EVIDENCE: Level I, therapeutic study.

Hip and Subtrochanteric or Femoral Shaft Fractures after Bisphosphonate Use in Korean Women, Using Korean National Sample Cohort.

BACKGROUND: Concern about bisphosphonate-associated subtrochanteric and femoral shaft (ST/FS) fractures has been raised. However, its real risk is still debatable, because there is no study to estimate risk and benefit of bisphosphonate. The objective of this study was to evaluate the risk of typical hip fractures and ST/FS fractures among bisphosphonate users using nationwide database. METHODS: We performed a retrospective cohort study using National Health Insurance Service-National Sample Cohort. We evaluated occurrence of the ST/FS and femoral neck and intertrochanteric (FN/IT) fractures among female bisphosphonate new users. Incidence rate of ST/FS and FN/IT fractures were compared between long-term users (≥ 1 year) and short-term users (< 1 year). Number needed to harm (NNH) for ST/FS and number needed to treat (NNT) for typical hip fracture were analyzed. RESULTS: Among 46,420 bisphosphonate users, we identified 14,689 long-term users and 21,840 short-term users. During the study period, 61 long-term users and 36 short-term users had ST/FS fractures, while 204 long-term users and 511 short-term users had FN/IT fractures. The long-term user showed higher incidence rate of ST/FS fractures (67.1/100,000 person-years; 95% confidence interval [CI], 50.3-83.9) comparing with 31.2/100,000 person-years (95% CI, 21.0-41.4) in the short-term users. The incidence rate of FN/IT fractures was 225.5/100,000 person-years (95% CI, 194.6-256.5) in the long-term users and 448.6/100,000 person-years (95% CI, 409.7-487.5) in the short-term users. The NNH for ST/FS was 400, while the NNT for typical hip fracture was 105. CONCLUSION: Our study suggested that physicians keep the significant benefit of bisphosphonate to prevent typical hip fracture in mind, even the concerns about bisphosphonate-associated ST/FS fractures.

Urinary retention after total joint arthroplasty of hip and knee: Systematic review.

PURPOSE: Postoperative urinary retention (POUR) is a common complication after total joint arthroplasties (TJAs). The POUR is managed with urinary catheterization, which is associated with a risk of urinary tract infection and subsequent periprosthetic joint infection. The purpose of this review was to afford a comprehensive understanding of POUR and its management. METHODS: We identified 15 original articles concerning POUR after TJA, which were published from January 2010 to February 2019. The diagnostic method, incidence, risk factors, and management of POUR of the 15 studies were reviewed. RESULTS: The incidence of POUR was ranged from 4.1% to 46.3%. Ultrasound was used for the detection of POUR among the total of the 15 studies. The following factors of old age, male gender, benign prostatic hypertrophy, history of urinary retention, spinal/epidural anesthesia, excessive fluid administration, patient-controlled analgesia, the use of opiates, underlying comorbidities, and poor American Society of Anesthesiologists (ASA) grade were risk factors for POUR. Most of the studies did not use indwelling catheterization during surgery. The POUR patients were managed with intermittent catheterization. The most common volume criterion for bladder catheterization was 400 mL. In inevitable use of an indwelling catheter, it should be removed within 48 h. CONCLUSIONS: This review provided an up-to-date guide for the detection and management of POUR. LEVEL OF EVIDENCE: Level III.

Anterior Cortical Window Technique Instead of Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty: A Minimum 10-Year Follow-up.

BACKGROUND: The anterior cortical window technique was developed to facilitate stem removal in revision total hip arthroplasty (THA). In this technique, only the anterior cortex of the proximal femur is osteomized; the trochanter, lateral cortex, and medial cortex remain intact. Therefore, a new stem can be press-fitted into the femur and mediolateral stability can be obtained. However, the long-term results of revision THA using this technique are unknown. We report the outcome and survivorship at a minimum of 10-year follow-up. METHODS: From May 2003 to April 2006, 69 patients (75 hips) underwent revision THA using an anterior cortical window and a cementless distal interlocking stem. Of these, 50 patients (56 hips) were followed up for 10 to 13 years (mean, 11.5 years). There were 26 men (29 hips) and 24 women (27 hips) with a mean age of 51.2 years (range, 29 to 82 years) at the time of revision arthroplasty. We evaluated radiographs, Harris hip score, University of California at Los Angeles (UCLA) activity score, Koval category, and survivorship. RESULTS: Nonunion of the osteotomy occurred in one hip (2%). Five stems (8.9%) subsided 5 mm or more. At the final evaluation, the mean Harris hip score, UCLA activity score, and the Koval category were 82.5, 4.6, and 1.5, respectively. Survivorship with any operations as the end point was 80.4% and that with stem-revision as the end point was 91.1%. CONCLUSIONS: With use of an anterior cortical window, a well-fixed stem can be easily removed, and a new stem can be inserted with firm mediolateral stability in the proximal femur in revision THA. We recommend using this technique instead of the extended trochanteric osteotomy in revision THA.

Oncostatin M, a muscle-secreted myokine, recovers high-glucose-induced impairment of Akt phosphorylation by Fos induction in hippocampal neuron cells.

Oncostatin M is a muscle-secreted myokine that has various effects on neuronal function, however, the underlying molecular mechanism has been poorly defined. In this study, we showed that Oncostatin M increased the phosphorylation of Akt and ERK, proteins crucial for neuron cell survival and proliferation. Furthermore, Oncostatin M increased the expression of c-Fos, a protein with significant involvement in neuronal cell proliferation and survival, through both Akt and ERK. Oncostatin M also increased intracellular calcium concentrations that act upstream of Akt and ERK. Treatment with Oncostatin M led to the recovery of high-glucose-induced impairment of Akt phosphorylation. Thus, Oncostatin M can protect neuronal cell damage related to high-glucose conditions, showing potential as a therapeutic agent.

Prevalence of Cam Deformity with Associated Femoroacetabular Impingement Syndrome in Hip Joint Computed Tomography of Asymptomatic Adults.

PURPOSE: Femoroacetabular impingement (FAI) is considered an important cause of early degenerative arthritis development. Although three-dimensional (3D) imaging such as computed tomography (CT) and magnetic resonance imaging are considered precise imaging modalities for 3D morphology of FAI, they are associated with several limitations when used in out-patient clinics. The paucity of FAI morphologic data in Koreans makes it difficult to select the most effective radiographical method when screening for general orthopedic problems. We postulate that there might be an individual variation in the distribution of cam deformity in the asymptomatic Korean population. MATERIALS AND METHODS: From January 2011 to December 2015, CT images of the hips of 100 subjects without any history of hip joint ailments were evaluated. A computer program which generates 3D models from CT scans was used to provide sectional images which cross the central axis of the femoral head and neck. Alpha angles were measured in each sectional images. Alpha angles above 55° were regarded as cam deformity. RESULTS: The mean alpha angle was 43.5°, range 34.7-56.1°(3 o'clock); 51.24°, range 39.5-58.8°(2 o'clock); 52.45°, range 43.3-65.5°(1 o'clock); 44.09°, range 36.8-49.8°(12 o'clock); 40.71, range 33.5-45.8°(11 o'clock); and 39.21°, range 34.1-44.6°(10 o'clock). Alpha angle in 1 and 2 o'clock was significantly larger than other locations (P<0.01). The prevalence of cam deformity was 18.0% and 19.0% in 1 and 2 o'clock, respectively. CONCLUSION: Cam deformity of FAI was observed in 31% of asymptomatic hips. The most common region of cam deformity was antero-superior area of femoral head-neck junction (1 and 2 o'clock).

Does femoral offset recover and affect the functional outcome of patients with displaced femoral neck fracture following hemiarthroplasty?

BACKGROUND: Restoring preoperative horizontal femoral offset (FO) promised good functional outcome in patients receiving total hip arthroplasty. However, relatively little was known regarding the clinical relevance of restoring the offset in patients with bipolar hemiarthroplasty to treat displaced femoral neck fracture. Therefore, the objective of this study was to evaluate postoperative FO accurately and verify its relation with functional outcome. METHODS: One hundred elderly patients who received bipolar hemiarthroplasty to treat displaced femoral neck fracture were identified. Preoperative CT scanning of contralateral hip joint and reconstruction of images led to rotation-free FO. By referencing postoperative implant specification and comparing to measured values in Picture Archive and Communication System, rotation-free postoperative FO and the amount of change were acquired. Postoperative Harris Hip Score (HHS) and Modified Barthel Index (MBI) were evaluated to measure functional outcome at 12-month after the surgery. Patients with significant FO change were identified. Multiple regression analysis was conducted to determine if the FO change might independently affect the outcome regardless of confounding factors. RESULTS: The mean preoperative offset was 37.4±2.5 increased by 12.7±9.6% after the surgery. Only 25.0% of postoperative offset after hemiarthroplasty was changed within ±5% of preoperative offset. A total of 45.0% of postoperative offset changed within ±10% while 77.0% of postoperative offset changed within ±20%. 23% of patients whose FO changed more than 20% showed significantly worse outcome score than the patients whose FO change remained within ±20% of initial value. Mean MBI and HHS were negatively correlated with FO change. After adjusting for confounding factors, significant correlation remained between modification of FO and MBI, but not between FO change and HHS (B=4.576; ß=0.235; 95% confidence interval of B: 0.534 to 8.135). CONCLUSIONS: FO was not properly restored in 23% of subjects receiving bipolar hemiarthroplasty due to femoral neck fracture. FO restoration independently predicted fair MBI after the surgery. Therefore, surgeons should pay attention to restoring FO with meticulous templating.