Bone morphology and physical characteristics of the pro-cyclist hip joint.

PURPOSE: This study aimed to investigate the radiographic findings for the hip joint and hip range of motion in professional cyclists, and to determine their bone morphology and physical characteristics. The effects of physical characteristics on athletic performance were examined in terms of metabolic efficiency using simulation analysis. METHODS: We performed a case-control research study on 22 hips in 11 male professional cyclists (average age 28.5, height 1.73 m, weight 77.6 kg). Thirty hips in 15 healthy male volunteers were selected as controls. As radiographic evaluations, acetabular dysplasia was assessed on standardized radiographs. During physical evaluations, the hip range of motion was examined. We used simulation analysis to investigate the metabolic efficiency in the different cycling forms. RESULTS: The radiographic evaluations showed a significant difference in the incidence of acetabular dysplasia (p = 0.01): 59% (13/22 hips) in the pro-cyclist group versus 10% (3/30 hips) in the control group. The physical evaluations revealed significant differences in the hip internal rotation angle (p = 0.01), with greater ranges of internal rotation in the pro-cyclist group versus the control group. The simulation analyses showed that metabolism was reduced in the cycling form with hip internal rotation, especially in the lower extremities. CONCLUSIONS: Pro-cyclists showed a high frequency of acetabular dysplasia and superior hip internal rotation. According to the cycling model analyses, hip internal rotation allowed pedaling with reduced metabolic power.

Life Course Epidemiology of Hip Osteoarthritis in Japan: A Multicenter, Cross-Sectional Study.

BACKGROUND: The incidence of developmental dysplasia of the hip (DDH) in Japanese newborns has reduced drastically following a primary prevention campaign initiated around 1972 to 1973; this perinatal education campaign promoted maintaining the hips of newborns in the naturally flexed-leg position. The purpose of the present study was to describe the life course epidemiology of hip osteoarthritis (OA) in adolescent and adult patients and to assess its association with exposure to the primary prevention campaign for DDH. METHODS: We included new patients with hip OA diagnosed from January 1, 2022, to December 31, 2022, at 12 core hospitals (8 special-function hospitals and 4 regional medical care support hospitals). The trend in the percentage of hips with a history of DDH treatment in childhood was estimated with use of a centered moving average using the birth year of the patient. We compared the prevalence of severe subluxation (Crowe type II, III, or IV) between patients with secondary hip OA due to hip dysplasia who were born in or before 1972 and those who were born in or after 1973. RESULTS: Overall, 1,095 patients (1,381 hips) were included. The mean age at the time of the survey was 63.5 years (range, 15 to 95 years). A total of 795 patients (1,019 hips; 73.8% of hips) were diagnosed with secondary OA due to hip dysplasia. Approximately 13% to 15% of hips among patients born from 1963 to 1972 had a history of DDH treatment in childhood; however, the percentage decreased among patients born in or after 1973. The prevalence of severe subluxation (Crowe type II, III, or IV) among patients born in or after 1973 was 2.4%, which was significantly less than that among patients born in or before 1972 (11.1%; odds ratio, 0.20; p < 0.001). CONCLUSIONS: As of 2022, secondary hip OA due to hip dysplasia is still responsible for most new cases of adolescent and adult hip OA seen in core hospitals in Japan. However, the perinatal education campaign initiated 50 years ago, which utilized a population approach and advocated for maintaining the hips of newborns in the naturally flexed-leg position, may have improved the environmental factors of DDH, as indicated by the apparently reduced need for treatment of DDH in childhood and the associated severe subluxation. This may result in a reduced need for challenging hip surgery later in life. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Successful treatment of severe splenic lymphoma­associated hemophagocytic syndrome by splenectomy and subsequent chemotherapy: A case report.

Hemophagocytic lymphohistiocytosis (HLH) represents a fatal immunopathology derived from excessive inflammatory reactions. In particular, lymphoma-associated hemophagocytic syndrome (LAHS) is associated with a dismal prognosis. The current study presented a challenging case of splenic LAHS. A 71-year-old man presented with fatigue and anorexia. Laboratory test results revealed anemia, thrombocytopenia, lactate dehydrogenase elevation and markedly elevated levels of ferritin (6,210 ng/ml) and soluble interleukin 2 receptor (sIL-2R; 11,328 U/ml). Abdominal computed tomography revealed marked splenomegaly, while fluorodeoxyglucose positron emission tomography revealed increased tracer uptake in the spleen. An elective splenectomy was performed, which led to the diagnosis of B-cell splenic lymphoma with transformation from indolent to aggressive lymphoma. Prior to the splenectomy, thrombocytopenia and hepatic dysfunction with rapidly progressing jaundice appeared, accompanying further elevation of ferritin (25,197 ng/ml) and sIL-2R levels (30,420 U/ml). On postoperative day 5, the patient was transferred to a tertiary care institution and corticosteroid pulse therapy was immediately initiated after establishing the diagnosis of LAHS. Liver dysfunction gradually recovered and subsequent chemotherapy resulted in complete remission with improved performance status. At eight months after the onset, the patient remains alive without any signs of residual lymphoma. Although splenic lymphoma typically manifests with low-grade lymphoma, it can transform into high-grade lymphoma associated with severe complications, such as HLH and multiple organ failure. In this case, splenectomy assisted in not only establishing the diagnosis but also in tumor cytoreduction before commencing chemotherapy. Through interdisciplinary collaboration, the patient was successfully treated by performing a timely splenectomy, followed by steroid pulse therapy and chemotherapy.

Assessment of the Hip Flexor Muscles Shortly after Curved Periacetabular Osteotomy using Magnetic Resonance Imaging.

BACKGROUND: Curved periacetabular osteotomy requires detachment and retraction of the hip flexors. In this study, we evaluated hip flexor muscle status by magnetic resonance imaging (MRI) shortly after curved periacetabular osteotomy. METHODS: We retrospectively evaluated 60 hips of 56 patients by MRI 1 week and 3 months after curved periacetabular osteotomy performed from August 2017 to December 2019. We classified the condition of the flexors as follows: Grade 0, normal; Grade I, strain/edema; Grade II, partial tear; and grade III, complete tear. RESULTS: At 1 week after surgery, the iliacus muscle was classified as grades I and II in 12.0 and 88.0% of hips; psoas as grades 0, I and II in 22.0, 72.0, and 6.0%; sartorius muscle as grades 0, I and II in 6.0, 62.0, and 32.0%; and rectus femoris muscle as grades 0 and I in 86.0 and 14.0%, respectively. At 3 months, 82.0, 88.0, and 96.0% of psoas, sartorius, and rectus femoris muscles, respectively, had improved to grade 0, whereas the iliacus was grades I and II in 94.0 and 6.0%, respectively. These changes in the iliacus muscle at 3 months were not significantly associated with patient characteristics, radiographic data, or clinical scores. CONCLUSIONS: All the iliacus, 78% of psoas, 94% of sartorius, and 14% of rectus femoris muscles appeared abnormal on MRI 1 week after curved periacetabular osteotomy. However, at 3 months, only 18% of psoas, 12% of sartorius, and 4% of rectus femoris muscles appeared abnormal, whereas all iliacus muscles still appeared abnormal. These abnormalities did not significantly affect clinical scores.

A case of total hip arthroplasty for nonunion after femoral trochanteric fracture surgery with complete breakage of only the compression screw of the InterTAN nail.

Intramedullary nails are an effective treatment for common femoral trochanteric fractures. However, one of their complications is implant breakage due to poor reduction and nonunion after surgery. We herein report a case of a 54-year-old man who underwent total hip arthroplasty for nonunion after internal fixation of a femoral trochanteric fracture. The femoral trochanteric fracture was treated by internal fixation using the Trigen InterTAN nail. The patient developed symptoms of hip pain 6 months after internal fixation. Nine months after internal fixation, hip radiographs and computed tomography scans showed breakage of only the compression screw. During total hip arthroplasty, we were unable to remove the lag screw and compression screw before the femoral head dislocation because no gap was present between the two screws. Thus, we removed these screws with the femoral head after dislocation of the femoral head. The removed nail was partially damaged at the lag screw hole. This change was retrospectively observed on the preoperative computed tomography scan. Three months after total hip arthroplasty, the patient was able to walk unaided and the hip pain had resolved. If only the compression screw is completely broken after internal fixation with the Trigen InterTAN nail, both the lag screw and compression screw will be difficult to remove with preservation of the femoral head. We effectively managed such a case by not only revision internal fixation but also total hip arthroplasty.

Sequential Intraoperative Evaluation of Rotational Stability of Cementless Stem in Total Hip Arthroplasty: A Broach-Based Study.

In cementless total hip arthroplasty, the rotational stability of the stem is generally confirmed in a one-time manual evaluation by the surgeon. This study was performed to evaluate the sequential intraoperative changes in rotational stability using a torque wrench. Primary total hip arthroplasty was performed on 52 consecutive hips using a single wedge stem design. Intraoperative evaluation of rotational stability was uniformly performed using a torque wrench. Evaluations were performed immediately after broach insertion and immediately before the final insertion of the stem (after placement of the acetabular cup). Immediately after the insertion of the broach, rotational stability was checked and confirmed to be fully stabilized using a torque wrench in all cases, and the stability was maintained in 17 of 52 (33%) hips immediately before the final insertion of the stem. Among the hips showing instability, 11 of 35 (31%) broaches were upsized, while the remaining 24 hips achieved stabilization through deeper insertion of the broach. In conclusion, the rotational stability achieved immediately after the insertion of the broach was not necessarily maintained during surgery, indicating that rotational stability may need to be checked at multiple time points intraoperatively.

Short-term outcomes of curved periacetabular osteotomy and factors influencing patient dissatisfaction.

This study aimed to evaluate clinical outcomes based on patient-reported outcome measures and to analyze factors influencing patient dissatisfaction at 1 year after curved periacetabular osteotomy (CPO). This retrospective review involved 98 hips of 98 consecutive patients with symptomatic acetabular dysplasia who underwent CPO from March 2016 to June 2020. The clinical outcomes were evaluated based on the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire, the Medical Outcomes Study 36-Item Short-Form Health Survey and the Harris Hip Score. Patients were divided into satisfied and unsatisfied groups according to the 85th percentile cut-off on the postoperative visual analog scale (VAS) for dissatisfaction. A multiple logistic regression analysis was performed to investigate the factors impacting patient dissatisfaction after CPO; the explanatory variables were age, body mass index, postoperative Tönnis grade of ≥2, postoperative VAS score for pain, lateral femoral cutaneous nerve (LFCN) injury and radiographic complications (non-union of the pubis, non-union of the ischium after posterior column fracture and ischial ramus stress fracture). The 85th percentile of the postoperative VAS score for dissatisfaction was 60 mm. The unsatisfied group comprised 15 patients at 1 year after CPO. The multiple logistic regression analysis results showed that the postoperative VAS scores for pain [odds ratio (OR), 1.064; 95% confidence interval (CI), 1.026-1.104; P = 0.001] and LFCN injury (OR, 6.775; 95% CI, 1.308-33.256; P = 0.018) were associated with postoperative dissatisfaction. LFCN injury and the postoperative VAS score for pain independently impacted postoperative dissatisfaction at 1 year after CPO.

A Laparoscopically Treated Case of Peritoneal Dissemination Mimicking Liver Metastases from Distal Cholangiocarcinoma Four Years After the Initial Pancreaticoduodenectomy.

BACKGROUND/AIM: Operable peritoneal dissemination from distal cholangiocarcinoma after pancreaticoduodenectomy is rare. Furthermore, peritoneal dissemination mimicking liver metastasis has scarcely been reported. CASE REPORT: An 81-year-old woman received pancreaticoduodenectomy for distal cholangiocarcinoma. She was diagnosed with stage IIA (T3a N0 M0) and received curative resection. She did not receive adjuvant chemotherapy. As a result of the examination in our department, she showed two tumors, 20 mm and 8 mm in segments 7/8 and 7, respectively, in the subphrenic liver surface four and half years after the initial pancreaticoduo-denectomy. The larger tumor was slow-growing, and cystic degeneration was inside. Plain computed tomography imaging revealed an isodense tumor with a marginal high ring and weak early enhancement, and prolonged peripheral enhancement was recognized at the marginal portion. Magnetic resonance imaging showed a heterogeneous mass with peripheral hypointensity ring that may be caused by fibrous tissue. Although the smaller tumor was diagnosed only after admission, it presented similar imaging findings to the larger tumor. The preoperative diagnosis was suspected to be liver metastases from DCC or inflammatory pseudotumor. Laparoscopic partial liver resection with diaphragm dissection was performed for both tumors. Pathologically, the tumors were diagnosed as peritoneal dissemination from distal cholangiocarcinoma. In the disseminated cancer cells, the expression of Ki67 was decreased, which was suspected to be one of the reasons for the long recurrence-free interval. The patient is doing well without any recurrence three months after the second operation. CONCLUSION: Laparoscopic surgery can provide excellent results for diagnosing and treating unknown subphrenic tumors.

Clinical Outcomes for Total Hip Arthroplasty with and without Previous Curved Periacetabular Osteotomy.

There are currently no reports on the clinical outcomes after total hip arthroplasty (THA) with previous curved periacetabular osteotomy (CPO), although the outcomes after THA with non-CPO types of periacetabular osteotomy have been reported. This study aimed to clarify the differences in clinical outcomes and radiographic features after THA with or without previous CPO. We performed a retrospective case-control with individual matching study. The participants were 10 patients with 11 hips that underwent cementless THA between October 1998 and October 2018 with previous CPO (osteotomy group). For the control group, we matched age, sex, and follow-up period, and included 32 patients with 33 hips that underwent cementless THA without previous CPO at a 1:3 ratio. The Harris Hip Score (HHS), cup size, position, and alignment, global offset (GO), operative time, perioperative blood loss, frequency of osteophyte removal, and major complications were compared between the two groups. The osteotomy group had no cases with revision surgery and dislocation. No significant differences were found between the two groups as follows: mean HHS, 94.9 points in the osteotomy group versus 92.7 points in the control group at the final follow-up; mean GO, 70.1 mm in the osteotomy group versus 71.4 mm in the control group; cup size, position, and alignment after THA; operative time; and perioperative blood loss. The frequency of osteophyte removal was higher in the osteotomy group. The take-home messages were that the clinical outcomes, including HHS, and radiographic features, including GO, after THA were equivalent in the two groups.

Utility of anterior wall of greater trochanter in predicting femoral anteversion angle: a three-dimensional computed tomography-based simulation study.

BACKGROUND: The femoral anteversion angle is an important factor in performing surgery in the proximal part of the femur. Predicting the femoral anteversion angle based on the morphology of the proximal femur is clinically useful. The purpose of this study was to investigate whether an anatomical landmark can be used to predict the femoral anteversion angle intraoperatively. MATERIALS AND METHODS: We analysed CT data obtained from 100 hips in 69 patients with osteonecrosis of the femoral head with no more than 2 mm collapse and no evidence of osteoarthritic changes. The measured variables were the femoral anteversion angle, the femoral neck-shaft angle, and the AW angle (defined as the angle between the femoral shaft axis and the tangential line of the anterior wall of the greater trochanter). The correlations between variables were also investigated. Multiple regression analysis by the forced input method was performed for the degree of femoral anteversion angle, using sex and the AW angle as explanatory variables. RESULTS: On CT, the mean femoral anteversion angle was 14.8° ± 10.8°, the mean AW angle was 17.5° ± 8.0°, and the mean femoral neck-shaft angle was 127.3° ± 5.4°. There was a positive correlation between the femoral anteversion angle and the AW angle. The approximation equations based on the multiple regression analysis were as follows: male femoral anteversion angle = AW angle × 0.7 - 0.7 and female femoral anteversion angle = AW angle × 0.7 + 4.3. CONCLUSIONS: Femoral anteversion angle can be predicted based on the AW angle of the greater trochanter.

Measurement of particulate matter 2.5 in surgical smoke and its health hazards.

PURPOSE: Surgical smoke is generated during the cauterization, coagulation, and incision of biological tissues by electrocautery, ultrasonic coagulation, incising devices, and lasers. Surgical smoke comprises water, water vapor, steam, and some particulate matter, including bacteria, viruses, cell fragments, and volatile organic compounds, which can pose health risks to the operating room personnel. In this study, we measured the concentration of particulate matter 2.5 (particles with a diameter of ≤ 2.5 µm) in surgical smoke. METHODS: We used digital dust counters for real-time monitoring of particulate matter 2.5 generated intraoperatively in breast and gastrointestinal surgeries performed at our hospitals between 2019 and 2020. RESULTS: Concentrations of particulate matter 2.5 were measured in surgical smoke generated when performing 14 different surgeries. Immediately after electrocautery, the concentration of particulate matter 2.5 increased to 2258 µg/m3 and then, when we stopped using the devices, it decreased rapidly to the initial levels. Interestingly, the concentrations increased after each intermittent electrocautery procedure. Higher concentrations of particulate matter 2.5 were observed during breast surgeries than during laparoscopic procedures. CONCLUSION: Surgical smoke poses potential health risks to operating room personnel by contaminating their breathing zone with high concentrations of particulate matter 2.5. A local exhaust ventilation system is needed to reduce exposure.

Rate of Return to Work After Periacetabular Osteotomy and Its Influencing Factors.

BACKGROUND: Periacetabular osteotomy (PAO) has been reported as a treatment for patients with symptomatic developmental dysplasia of the hip (DDH). Several studies have investigated the rate of return to sports activities after PAO, but few studies have evaluated the rate of return to work. In the present study, we aimed to identify the rate of return to work at 1 year after PAO and its affecting factors. METHODS: We retrospectively evaluated 83 patients (85 hips) with symptomatic DDH who had undergone PAO between December 2015 and June 2020. Patients who had returned to work at 1 year after PAO were classified into the returnee group, and those who had not were classified into the non-returnee group. The returnee group included patients who could return to their original job (original) or to a different job (non-original). The non-returnee group included patients who could not return to work because of hip symptoms (hip) and those who did not return for reasons other than hip symptoms (non-hip). We analyzed clinical parameters, including the Harris hip score, Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire, 36-Item Short Form Survey, and radiographic parameters, as well as the type of work. RESULTS: Sixty-eight patients (70 hips; 82.4%) returned to work at 1 year after PAO (returnee group), and 15 patients (15 hips; 17.6%) were in the non-returnee group. Among the 15 patients in the non-returnee group, 7 were classified into the non-hip subgroup and 8 were classified into the hip subgroup. No significant differences were observed between the returnee group and the hip subgroup in terms of clinical parameters or type of work. CONCLUSIONS: One year after PAO, 8 patients (8 hips; 9.4%) could not return to work because of hip symptoms; both clinical parameters and the type of work showed no direct relationship with postoperative working status. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Hybrid Assistive Limb improves restricted hip extension after total hip arthroplasty.

The Hybrid Assistive Limb (HAL) was developed as an exoskeleton robot that supports gait training. The purpose of this study was to assess the usefulness of training using the HAL after total hip arthroplasty (THA). We targeted 16 consecutive patients who underwent THA via the posterior approach. We randomized patients to the HAL group (8 hips), in which the HAL was used as part of physical therapy, or the control group (8 hips), in which only typical physical therapy was performed. Gait analysis was performed before and after surgery, and comparisons were made between the two groups. We evaluated the single support time (%), double support time (%), cadence (steps/min), velocity (cm/s), stride length (cm), and anteroposterior and lateral variability, and assessed the hip and knee joint range of motion in the sagittal plane. The results showed improvements in the hip extension angle and other gait parameters in the HAL group. Among gait-related problems after THA, a decreased peak hip extension angle is reported to be a significant factor that affects gait disability. This study revealed that HAL usage after THA seems to be a useful method to obtain sufficient extension angle.

Intrahepatic Cholangiocarcinoma Coexisting With Multiple Bile Duct Adenoma Treated as Liver Metastasis from a Pancreatic Neuroendocrine Tumor.

BACKGROUND: Bile duct adenomas (BDA) may be precursor lesions of small duct-type, including mass-forming type intrahepatic cholangiocarcinoma (ICC). CASE REPORT: A 68-year-old woman was transferred to our facility for the treatment of a liver tumor, possibly metastasized from a pancreatic neuroendocrine tumor. Finally, two liver tumors were resected and histopathologically diagnosed as "BDA" and "ICC with a BDA-like component". In the BDA-like component, the MUC6 positive rate was notably lower and the Ki-67 positive rate was higher than the other BDAs and ICC component, respectively. The doubling time of the tumor volume in BDA was very long but was shortened (1,510 and 719 days). Distinct enlargement of the tumor and appearance of enhancement through diagnostic imaging was useful in diagnosing the transformation from a BDA to an ICC. CONCLUSION: An "adenoma-carcinoma sequence" may exist in the transformation process from a BDA to an ICC.

Leg Length Change After Curved Periacetabular Osteotomy and Its Impact on the Clinical Outcomes.

BACKGROUND: Curved periacetabular osteotomy (CPO) is one of the periacetabular osteotomies for the treatment of acetabular dysplasia. Several complications have been described after CPO, however, there have been no reports on the leg length change (LLC). This study aimed to investigate the LLC after CPO and its impact on the clinical outcomes. METHODS: This study was a retrospective review of 70 consecutive hips in 67 patients with symptomatic acetabular dysplasia who underwent CPO between March 2016 and April 2019. Preoperative and postoperative leg lengths were measured using anteroposterior radiographs, and the clinical outcomes were evaluated based on the Harris hip score (HHS) and Medical Outcomes Survey 36-item Short Form Health Survey (SF-36). RESULTS: The mean LLC (and standard deviation) after CPO was -0.08 ± 3.10 mm. The mean HHS significantly improved from 73.5 points to 91.9 points (P < .001). The physical component and role component scores of SF-36 significantly improved from 35.1 to 46.1 (P < .001) and from 39.5 to 47.0 (P < .001), respectively. No significant differences were found between the preoperative and postoperative mental component scores of SF-36. In addition, among 70 hips, 35 hips exhibited leg length elongation (0 to plus 6.82 mm) after CPO, whereas 35 hips exhibited leg length shortening (0 to minus 6.23 mm). No significant differences were found in HHS and SF-36 between the leg elongation group and leg shortening group. CONCLUSION: The mean LLC after CPO was -0.08 ± 3.10 mm, and this change does not affect the postoperative clinical outcomes.

Bone union status of all osteotomy sites one year after curved periacetabular osteotomy based on computed tomography.

BACKGROUND: Curved periacetabular osteotomy (CPO) is a joint-preservation surgery to treat acetabular dysplasia. It is performed via an anterior approach with the osteotomy of the anterosuperior iliac spine (ASIS). One of the complications associated with CPO includes non-union of the osteotomy sites. However, all osteotomy sites including the ASIS have not been simultaneously evaluated. Therefore, we investigated: (1) the bone union status of all osteotomy sites; and (2) the predictors of non-union at one year after CPO based on computed tomography (CT). HYPOTHESIS: The bone union status may be different in each osteotomy site. PATIENTS AND METHODS: This retrospective review included 147 hips of 124 patients with symptomatic acetabular dysplasia who underwent CPO from 2011 to 2018. At one year postoperatively, we evaluated the bone union status of all osteotomy sites: the ASIS, ischium, pubis, and ilium using CT and investigated the predictors for achieving bone union. RESULTS: Bone union was confirmed in both the ASIS and ilium in all cases. In contrast, ischial and pubic non-union was confirmed 15/147 hips (10.2%) and 42/147 hips (28.5%), respectively. The multivariate analysis revealed that the predictors of ischial non-union were both large width of the gap at the pubic osteotomy site and small postoperative acetabular roof obliquity, and that the predictor of pubic non-union was large width of the gap at the pubic osteotomy site. DISCUSSION: At one year after CPO, both the ASIS and ilium obtained complete bone union, while ischial and pubic non-union were observed. Large width of the gap at the pubic osteotomy site was the predictor of both ischial and pubic non-union. In CPO, sufficient bone union can be achieved at the ASIS and the ilium, while it is necessary to reduce the width of the gap at the pubic osteotomy site to prevent ischial and pubic non-union. LEVEL OF EVIDENCE: IV; retrospective study.

Incidence and clinical outcome of lateral femoral cutaneous nerve injury after periacetabular osteotomy.

AIMS: Injury to the lateral femoral cutaneous nerve (LFCN) is one of the known complications after periacetabular osteotomy (PAO) performed using the anterior approach, reported to occur in between 1.5% and 65% of cases. In this study, we performed a prospective study on the incidence of LFCN injury as well as its clinical outcomes based on the Harris Hip Score (HHS), Short-Form 36 Health Survey (SF-36), and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ). METHODS: The study included 42 consecutive hips in 42 patients (three male and 39 female) who underwent PAO from May 2016 to July 2018. We prospectively evaluated the incidence of LFCN injury at ten days, three months, six months, and one year postoperatively. We also evaluated the clinical scores, including the HHS, SF-36, and JHEQ scores, at one year postoperatively. RESULTS: LFCN injury was observed in 31 of 42 (74%) patients at ten days, of which 11 resolved completely by one year. Incidence decreased gradually, to 25 of 42 (60%) patients at three months, 24 of 42 patients (57%) at six months, and 20 of 42 (48%) patients at one year postoperatively. There was no significant difference in the HHS between patients with and without LFCN injury at one year postoperatively. Regarding the SF-36 and JHEQ, a significant difference in the mental score was recognized between patients with and without LFCN injury, but there were no significant differences in the other clinical scores. CONCLUSION: The incidence of LFCN injury was 74% at ten days after PAO, and subsequently decreased to 48% at one year. LFCN injury did not influence the hip function as assessed by the HHS, but had a negative impact on mental health at one year. Cite this article: Bone Joint J 2021;103-B(4):659-664.

Femoral Neck Fracture in a Hemodialysis Patient after Liver Transplantation: A Case Report.

BACKGROUND: Surgical treatment of femoral neck fractures is usually performed as an urgent procedure so that restoration of the ability to stand and walk can be achieved as quickly as possible. However, orthopedic surgeons need to be aware of undertreated or untreated diseases in their patients. Organ transplant recipients require immunosuppressive agents and steroids postoperatively. Hemodialysis patients also exhibit immunological deterioration and are included among immunocompromised patients. We report a case in which conservative treatment was chosen for a hepatic transplant recipient on hemodialysis who suffered a femoral neck fracture because signs of inflammation of unknown etiology were intermittently seen. CASE: The patient was a 70-year-old man who had undergone liver transplantation from a living donor as treatment for hepatocellular cancer and hepatic failure with cirrhosis. Dialysis for end-stage renal failure was initiated at approximately 1 year postoperatively. Cyclosporine was administered as an immunosuppressive agent. The patient subsequently fell off a bicycle and was unable to walk because of right hip pain. He was brought to our hospital by ambulance, and a right hip radiograph revealed a femoral neck fracture. His white blood cell count and C-reactive protein levels were intermittently elevated with unknown etiology. Conservative treatment was finally adopted, although a bipolar hip arthroplasty was planned. At 5 months after the injury, the patient was able to walk alone in a stable manner using a pair of crutches and was discharged. DISCUSSION: Conservative treatment for a femoral neck fracture, which generally requires surgery, may be acceptable in organ transplant recipients on hemodialysis.