Japanese Orthopaedic Association Hip Score Research Articles

Long-term outcomes of the mayo conservative hip system in patients aged 30years or less with osteonecrosis of the femoral head: mean follow-up of more than 10years.

Historically, total hip arthroplasty (THA) in very young patients has been associated with lower survivorship. However, the long-term outcomes of THA using short stems for osteonecrosis of the femoral head (ONFH) in very young patients remain unclear. Therefore, this study aimed to investigate the long-term outcomes of the Mayo conservative hip system, a short metaphyseal stabilised stem, in patients with ONFH aged ≦30years. We retrospectively reviewed 104 joints in 76 patients with ONFH who underwent THA using the Mayo conservative hip system with a minimum follow-up of 8years. The mean follow-up period was 12.5 (range, 8-19) years. Patients were categorised into two age groups (≦30years, n = 21 and > 30years, n = 83). Radiographic evaluation was used to assess stem sinking, stress shielding, and spot welds. The clinical evaluations were performed using the Japanese Orthopedic Association (JOA) hip score. Postoperative major complication and revision surgery rates were also assessed. The patient characteristics were similar between the two groups, except for the age. Revision surgeries were performed in five cases, with similar implant survival rates between the groups. Dislocations occurred in the older age group alone (four joints). One case of intra-operative periprosthetic femoral fracture was found in the younger age group. Stem sinking of > 3mm occurred in one and seven joints in the younger and older age groups, respectively. Spot welds were observed in most joints (93.2%) in modified Gruen zones 2 and 6 without significant differences between the groups. Stress shielding showed no significant differences in the frequency of occurrence or location between the two groups. Furthermore,the JOA score showed no significant difference between the two groups. The use of short stems in patients aged ≤ 30years with ONFH showed favourable long-term outcomes.

Association of mid-thigh quadriceps muscle quality with postoperative outcomes in patients with hip osteoarthritis undergoing total hip arthroplasty: a retrospective cohort study.

Muscle quality is more important than muscle mass for assessing physical function. Computed tomography (CT) is used to evaluate intramuscular fatty infiltration. The mid-thigh quadriceps CT attenuation values (CTV) expressed in Hounsfield units (HU) negatively correlate with physical function. Patients with hip osteoarthritis (HOA) have lower extremity muscle atrophy, including decreased cross-sectional area (CSA), CTV, and muscle strength. Using preoperative CT images, we investigated the association between mid-thigh quadriceps CSA, CTV, and postoperative outcomes in patients with HOA. This study included 62 patients who had unilateral HOA (62 hips) and underwent total hip arthroplasty (THA). We investigated the association between preoperative and postoperative Japanese Orthopaedic Association (JOA) hip scores, 12-item Short Form survey (SF-12), mid-thigh quadriceps CSA, and CTV. The mean age was 64.7 ± 10.1years, with 15 men (24.2%), and the mean body mass index was 24.3 ± 4.3kg/m2. Secondary HOA was present in 79.0% of patients. The mean CSA and CTV of the mid-thigh quadriceps on the operative side were 38.8 ± 9.8 cm2 and 40.3 ± 7.8 HU, respectively. Multiple regression analyses adjusted for age and sex showed that preoperative mid-thigh quadriceps CSA was not associated with preoperative and postoperative JOA hip scores or SF-12. The preoperative mid-thigh quadriceps CTV was associated with the postoperative JOA hip score in the gait ability domain and SF-12 in the physical component summary domain. Preoperative muscle quality is associated with postoperative outcomes in patients who have HOA regardless of age and sex.

Long-Term Outcome of Metal-on-Metal Total Hip Arthroplasty with Modular Neck Stem.

Background: This study aimed to report the long-term outcomes of total hip arthroplasty (THA) using a Conserve Plus (Wright Medical, Japan) metal-on-metal (MoM) acetabular prosthesis with a modular neck stem. Methods: This study enrolled 50 patients (10 men and 40 women; mean age, 65.8 (39-87) years) who underwent primary THA using a Conserve Plus MoM acetabular prosthesis with a modular neck stem. The preoperative diagnosis in most patients was osteoarthritis. Clinical function of hip joint outcomes was investigated using the Japanese Orthopedic Association (JOA) hip score preoperatively and at the final follow-up. The perfect JOA hip score was 100, while the worst score was 0. Radiological analyses were evaluated during the final follow-up visit. Magnetic resonance imaging (MRI) images were evaluated to screen for pseudotumors in 43 hips postoperatively. Results: Six patients did not visit before their 10-year follow-up for unknown reasons. Therefore, 44 patients were evaluated at a mean of 11-years of follow-up (10-12 years). The mean (±SD) preoperative JOA hip score of 44.2 (±15.5) improved significantly to 85.1 (±12.9) postoperatively at the final follow-up (n = 36 hips, excluding eight revision cases). One patient underwent femoral fixation for a periprosthetic fracture due to trauma that occurred 4 years postoperatively. Spot welds were identified in 93.2% (41/44 hips) of cases. Severe (third- and fourth-degree) stress shielding was identified in 40.9% (18/44 hips) of cases. Twenty-two patients (51.2%) had pseudotumors attributable to MoM articulation based on MRI results, 2 to 10 years after arthroplasty. Three hips showed cup osteolysis (7%) and three showed trochanteric region osteolysis (7%). There were seven cup and/or three stem revisions for aseptic loosening and/or osteolysis at 4 months (with trauma) and 3.3 to 11 years (with pseudotumor) postoperatively. The Kaplan-Meier survivorship for the THA construct in this group was constant at 93.0% and 75.9% at 10 and 12 years after arthroplasty, respectively. The rates of survivorship of revision and loss of follow-up at 10 and 12 years were 83.9% and 66.8%, respectively. Conclusions: In summary, we reported on the long-term treatment results of MoM THA, precautions based on our cohort's findings, and the measures taken to address these issues, such as revision replacement and its outcomes. Clinical scores revealed good outcomes during the mean 11-year follow-up period. However, the prevalence of pseudotumors (PTs) was 51.2%. Some cases required revisions even after the 10 years following surgery. This is because in MoM THA, PT occurrence increases over time, and as a result, there were cases in which revised THA was required even after 10 years.

Five-year clinical and radiographic outcomes of Accolade TMZF and Accolade II stem use

PurposeAlthough good mid-term results of the first- and second-generation cementless stems have been reported, no study has compared outcomes between generations. This study aimed to compare the mid-term results of Accolade Ti–12Mo–6Zr–2Fe (TMZF) and Accolade II over a 5-year period. MethodsThis retrospective, single-institution, single-surgeon observational study included patients who underwent primary total hip arthroplasty using the Accolade TMZF (n ​= ​71, group I) or Accolade II (n ​= ​73, group II) between January 2009 and July 2015. Revision and conversion cases were excluded. Functional evaluations were performed using the Japanese Orthopaedic Association hip (JOA) score. Radiographic evaluations were performed using anteroposterior radiographs. Spot welds, radiolucency, cortical hypertrophy, and stress shielding around the stem were assessed for each Gruen zone. Subsidence and stem alignment were evaluated. ResultsThe 5-year postoperative stem survival rate was 100% in both groups. The JOA score improved from 44.0 ​± ​10.2 to 90.6 ​± ​7.6 in group I and from 49.1 ​± ​10.1 to 91.7 ​± ​6.6 in group II. There were no significant differences in preoperative and postoperative JOA scores and subscale scores in either group. Significant spot welds were observed in group II in Gruen zones 3 and 5. Stress shielding progressed over time in both groups, and the prevalence of grade 3 shielding was significantly lower in group II (p ​= ​0.028). ConclusionBoth stems had a survival rate of 100%. The incidence of severe stress shielding seemed to be lower with Accolade II, but further investigations should be needed.

Effects of anterior capsule repair during total hip arthroplasty using the anterolateral approach in the supine position

PurposeSoft-tissue tension is an important factor for preventing dislocations after total hip arthroplasty. The purpose of this study was to evaluate the effects of anterior capsule repair for preventing dislocation during primary total hip arthroplasty using the anterolateral approach in the supine position (ALS). MethodsThis study retrospectively compared the clinical and radiographic outcomes between patients who underwent total hip arthroplasty via the ALS with or without anterior capsule repair at our institute. The cup (radiographic inclination and radiographic anteversion) and stem alignment, operative time, clinical score, and complication were evaluated. ResultsAmong the 393 hips evaluated, 193 and 200 belonged to the resection and repair groups, respectively. There were significant differences in the inclination and anteversion of the cup and flexion insertion of the stem (42.3° vs. 40.3°, 15.8° vs. 19.8°, and 27.5% vs. 34.0%, respectively). No significant differences in operative time and postoperative Japanese Orthopedic Association hip score were noted. Early dislocation was more common in the resection group compared to the repair group (2 hips vs. 0 hip, respectively), albeit not significantly (1.03% vs. 0%, p ​= ​0.241). ConclusionOur results demonstrated that the clinical benefit of the anterior capsule repair for preventing dislocation was limited in ALS.

Long-term results of Chiari pelvic osteotomy on the preservation of hip function with mean follow-up of more than 30 years and its prognostic factors

BackgroundClinical outcomes of Chiari pelvic osteotomy for acetabular dysplasia, including conversion to total hip arthroplasty (THA), have not been adequately explored. The purpose of this study was to examine the long-term results and clinical outcomes of Chiari pelvic osteotomy as the primary outcome and to analyze its prognostic factors as the second outcome. MethodsThis study was a multicenter, retrospective cohort study. Ninety-seven patients underwent Chiari pelvic osteotomy at three hospitals between March 1975 and October 1997. The long-term clinical outcomes of Chiari pelvic osteotomy, including conversion to THA and hip pain, were analyzed using the Kaplan–Meier method. In addition, the prognostic factors for conversion to THA after Chiari pelvic osteotomy were evaluated with clinical variables and radiographic parameters. ResultsThe study included 51 hips in 45 patients (4 men and 41 women) with long-term follow-up. The survival rates assessed by Kaplan–Meier analysis with conversion to THA as an endpoint, were 90.2% (95% confidence interval (CI) 82.0–98.4%) at 20 years and 73.5% (95% CI 61.1–86.0%) at 30 years. In contrast, the Kaplan–Meier survival rates with the Japanese Orthopaedic Association hip score for pain ≤20 as an endpoint, were 86.3% (95% CI 76.8–95.7%) at 20 years and 65.6% (95% CI 52.3–79.0%) at 30 years. Only older age at osteotomy was the significantly poor prognostic factor for conversion to THA, with a hazard ratio of 1.11/year, 95% CI 1.06 to 1.18, (p < 0.01). ConclusionChiari pelvic osteotomy may still be a good alternative to bony reconstructive surgery for acetabular dysplasia especially in young patients. Only older age at the osteotomy was related to the poor prognosis of preserving hip function.

Case Series of Silver Oxide–Containing Hydroxyapatite Coating in Antibacterial Cementless Total Hip Arthroplasty: Clinical Results of 50 Cases at 5-Year Follow-Up

BackgroundProsthetic joint infection, which is caused by implant treatment, is a severe complication. Consequently, silver-containing hydroxyapatite (Ag-HA)-coated implants have been developed to prevent prosthetic joint infection by combining Ag with HA. The Ag-HA-coated total hip prosthesis, which combines the antibacterial activity of Ag and the osteoconductivity of HA, is the first antibacterial cementless total hip prosthesis worldwide. This study aimed to evaluate the short-term outcomes of total hip arthroplasty (THA) with Ag-HA-coated implants. MethodsOverall, 50 hips with various disabling hip diseases and postoperative infection risks that underwent a primary THA using an Ag-HA total hip prosthesis were enrolled. The patients included 37 women (41 hips) and 8 men (9 hips), and the mean age at the time of surgery was 77 years. The clinical outcomes and hip function before and at 5 years postoperatively were measured using the Japanese Orthopaedic Association hip score. Implant stability was assessed, and postoperative complications were also examined. ResultsThe Japanese Orthopaedic Association score increased in all cases and improved from 41 to 86 points after the THA (P < .001). Radiography revealed no implant failure. Dislocation and deep vein thrombosis also occurred in 1 case each. However, there were no adverse reactions associated with Ag, and argyria was not observed in any case. Additionally, none of the patients experienced infection following the surgery. ConclusionsSilver-containing hydroxyapatite–coated implants significantly enhanced patients’ daily activities without any adverse effects on the human body attributed to Ag, and they are expected to reduce postoperative infections.

Minimum 10-Year Results of Modular Metal-On-Metal Total Hip Arthroplasty.

this study aimed to assess the long-term outcomes of (a minimum of 10-years) total hip arthroplasty with a metal-on-metal acetabular prosthesis. Eighty-nine primary total hip arthroplasties (82 patients) were performed using a Pinnacle modular metal-on-metal acetabular prosthesis. Clinical hip function outcomes were evaluated using the Japanese Orthopaedic Association hip score preoperatively and at the final follow-up. Radiological analysis was performed at the final follow-up and magnetic resonance imaging in all hips postoperatively. Out of 82 patients, 17 were excluded who were followed up for &lt;10 years. Of the remaining 65 patients (70 hips), 19 (20 hips) developed pseudotumors during 2-10 years postoperatively. After 10 and 13 years, the survival rates of revision endpoint were 93.6% and 90.4%, respectively. Clinical hip function outcomes had improved significantly at the final follow-up. In the radiological analysis, the mean cup angle of inclination and mean ratio of femoral offset on the operated hip to the contralateral hip was highest in patients with revision surgery for adverse reactions to metal debris. This study showed a 29.0% prevalence of pseudotumors. Some cases required revisions even after 10 years following surgery. Regular clinical surveillance is recommended for the early detection of adverse reactions to metal debris.

Visualization of acetabular coverage with radar chart before and after curved periacetabular osteotomy in dysplastic hips

BackgroundCurved periacetabular osteotomy (CPO) is indicated for patients with developmental dysplasia of hip (DDH) to prevent progressive osteoarthritis. Patients with DDH have not only lateral acetabulum dysplasia but also anterior and posterior dysplasia. The full circumference acetabular coverage angle (ACA) of the femoral head should be evaluated preoperatively. This study aimed to determine the full circumference ACA in the patients with DDH before and after CPO compared with the coverage in normal patients. MethodsTwenty-three patients (a total of 24 hips) with DDH undergoing CPO between February 2006 and March 2014 were included in this study. The normal group was defined as the normal side in patients with unilateral osteonecrosis of the femoral head (ONFH) and the non-collapsed femoral head side in patients with bilateral ONFH. Pre- and postoperative hip functions were evaluated using the Japanese Orthopedic Association (JOA) hip score. ACA was measured using pre- and postoperative three-dimensional computed tomography (3DCT) and described as a clock using a radar chart. The ACA of the normal group was evaluated in the same manner as that for patients who underwent CPO. The ACA before CPO was compared with the ACA after CPO, the ACA before CPO was compared with that of the normal group and the ACA after CPO was compared with that of the normal group at each location. ResultsThe mean JOA hip scores improved significantly from 69 preoperatively to 88 postoperatively. The superior, posterior, and anterior ACA after CPO significantly increased and the inferior ACA decreased compared with ACA before CPO. The superior, posterior, and anterior ACA before CPO were significantly smaller than ACA in the normal group. The ACA after CPO were similar to the normal group. ConclusionsCPO improved the anterosuperior coverage of the femoral head but reduced its inferior coverage. The radar chart could visualize acetabulum full circumference and was useful for three-dimensional pre-postoperative evaluation.

Functional Impairment of Hip Joint and Activities of Daily Living Failure in Patients with Multiple Hereditary Exostoses.

In this study, we focused on the hip joints and examined pain and functional impairment, and their relationship with anatomical characteristics in MHE patients. Patients with MHE followed up in our hospital from January 2020 to December 2020 were enrolled. Clinical hip functional outcomes were evaluated using the Japanese Orthopedic Association (JOA) hip score and hip range of motion (ROM). Proximal femur geometric measurements were evaluated using radiography. A total of 39 patients (78 hips) with a median age of 25.6years and average JOA score of 94.0 ± 10.5 were included. Eight patients felt pain in their hip joints. The average ROM score was 18.2 ± 2.5, and 47.4% of the patients with MHE had ROM limitation. The average score of ability to walk was 19.6 ± 1.8, and three patients had some problems with walking. The average ADL score was 18.2 ± 2.5, and 51.3% of patients with MHE had some failures in ADL. The hip flexion and internal rotation were markedly restricted compared with the normal values. When patients were grouped according to their ADL scores, we found that the ADL failure group had a significantly lower ROM score than the no ADL failure group (p < 0.0001), and there were significant differences between the groups in terms of femoral neck widening (p = 0.0001). We found that half of MHE patients had some failures in their ADL due to hip functional impairment. The study results also suggest that femoral neck widening affected ADL failure and ROM limitation.

Total hip arthroplasty after rotational acetabular osteotomy for developmental dysplasia of the hip: a retrospective observational study

BackgroundTotal hip arthroplasty after osteotomy is more technically challenging than primary total hip arthroplasty, especially concerning cup placement. This is attributed to bone morphological abnormalities caused by acetabular bone loss and osteophyte formation. This study aimed to investigate the clinical and radiological outcomes of total hip arthroplasty after rotational acetabular osteotomy compared with those of primary total hip arthroplasty, focusing mainly on acetabular deformity and cup position.MethodsThe study included 22 hips that had undergone rotational acetabular osteotomy and 22 hips in an age- and sex-matched control group of patients who underwent total hip arthroplasties between 2005 and 2020. We analyzed cup abduction and anteversion; lateral, anterior, and posterior cup center–edge angle; hip joint center position; femoral anteversion angle; and presence of acetabular defect using postoperative radiography and computed tomography. Operative results and clinical evaluations were also analyzed.ResultsThe clinical evaluation showed that the postoperative flexion range of motion was lower in total hip arthroplasty after rotational acetabular osteotomy than in primary total hip arthroplasty, although no significant difference was noted in the postoperative total Japanese Orthopedic Association hip score. The operative time was significantly longer in the rotational acetabular osteotomy group than in the control group, but there was no significant difference in blood loss. The lateral cup center–edge angle was significantly higher and the posterior cup center–edge angle was significantly lower in the total hip arthroplasty after rotational acetabular osteotomy, suggesting a posterior bone defect existed in the acetabulum. In total hip arthroplasty after rotational acetabular osteotomy, the hip joint center was located significantly superior and lateral to the primary total hip arthroplasty.ConclusionsIn total hip arthroplasty after rotational acetabular osteotomy, the cup tended to be placed in the superior and lateral positions, where there was more bone volume. The deformity of the acetabulum and the high hip center should be considered for treatment success because they may cause cup instability, limited range of motion, and impingement.

Predictive factors for discharge destination after total hip arthroplasty

BackgroundThis study aimed to investigate factors affecting discharge to an inpatient rehabilitation facility or home following total hip arthroplasty, using a clinical pathway in Japan. MethodsFive hundred hips with osteoarthritis who underwent unilateral total hip arthroplasty at our institution, with no deviation from the pathway, were included in this retrospective study. The variables were examined by univariate analysis. Multivariate logistic regression analysis was used to identify the independent factors that influenced the discharge outcome. ResultsFour hundred and thirty-four hips were discharged home directly, and 66 were discharged to an inpatient rehabilitation facility. Patients discharged to an inpatient rehabilitation facility were significantly older, shorter, lighter, and more likely to live alone. Additionally, the preoperative clinical score was significantly lower in the inpatient rehabilitation facility Group for all items. Logistic regression analysis showed a significant association between being discharged to an inpatient rehabilitation facility and higher age [odds ratio 3.87, 95% confidence interval 2.03–7.38, P < 0.001], lower total score in the preoperative Japanese Orthopaedic Association hip score [odds ratio 2.42, 95% confidence interval 1.38–4.23, P = 0.002] and living alone [odds ratio 1.84, 95% confidence interval 1.01–3.35, P = 0.046]. ConclusionsIn this study, age, the preoperative Japanese Orthopaedic Association hip score, and living arrangement impacted the discharge destination after THA.

Effects of porous tantalum on periprosthetic bone remodeling around metaphyseal filling femoral stem: a multicenter, prospective, randomized controlled study

Periprosthetic bone loss due to adaptive bone remodeling is an important unresolved issue in cementless total hip arthroplasty (THA). The use of porous tantalum on the proximal surface of the femoral stem is expected to decrease postoperative bone loss around the prosthesis through early fixation. We conducted a multicenter randomized controlled study to determine if porous tantalum could reduce periprosthetic bone loss after THA. From October 2012 to September 2014, 118 patients (mean age, 61.5 years; 107 females and 11 males) were prospectively enrolled and were randomly allocated at a ratio of 1:1 to either a metaphyseal filling stem with a proximal porous tantalum coating (Trabecular Metal) or a conventional metaphyseal filling stem with fiber mesh coating (VerSys). Patients underwent dual-energy x-ray absorptiometry scans within 1 week after surgery (baseline) and at 6, 12, and 24 months after surgery to assess periprosthetic bone mineral density (BMD) in the 7 Gruen zones. In addition, the Japanese Orthopaedic Association hip score was assessed before surgery and at 6, 12, and 24 months after surgery. In the proximal periprosthetic region (zones 1 and 7), the Trabecular Metal group had significantly smaller reductions in BMD than the VerSys group throughout the study period. In the VerSys group, significant reductions in BMD compared to baseline were seen at each measurement point in all regions, except in zone 6 at 24 months. In the Trabecular Metal group, no significant reductions in BMD relative to baseline were seen in zones 1, 5, or 6 throughout the study period. Both groups demonstrated similar improvement in Japanese Orthopaedic Association hip scores over the study period. This study demonstrated that a proximally coated stem with porous tantalum has superior results over a conventional stem with titanium fiber mesh in terms of periprosthetic bone remodeling.

Revision total hip arthroplasty using a Kerboull-type acetabular reinforcement device and allogeneic structural bone graft.

One of the major problems in revision total hip arthroplasty (THA) is severe acetabular bone loss. The aim of our study was to evaluate the clinical outcomes of revision THA using a Kerboull-type reinforcement device (KT plate) and allogeneic structural bone graft. This retrospective study evaluated 48 hips that underwent revision THA using a KT plate and allogeneic structural bone graft between 2008 and 2016, with a median follow-up of 6.2years (range 3-12.6years). Functional outcome was assessed using the Japanese Orthopaedic Association (JOA) hip score. Postoperative and follow-up radiographs were compared to assess migration and breakage of the implant. The mean JOA hip score improved from 45.6 (±16.3) points before surgery to 72.1 (±11.9) points at the most recent follow-up examination (p < 0.001). Two hips (4.2%) underwent re-revision THA because of cup loosening due to breakage of the KT plate. A total of 13 hips (27.1%) were classified as radiological failures. Binomial logistic regression analysis showed that a Kawanabe classification of stage 4, which indicates massive bone defects in the weight-bearing area, was a risk factor for radiological failure (odds ratio: 4.57; 95% confidence interval: 1.01-26.35). A KT plate with an allogeneic structural bone graft is a useful method of acetabular reconstruction in revision THA that restores bone stock and improves hip function. Our findings indicated that a Kawanabe classification of stage 4 was a risk factor for radiological failure of the implant.

Pelvic incidence affects postoperative dislocation rate in total hip arthropalsty patients with spinal fusion.

The purpose of this study was to compare the clinical outcome of total hip arthroplasty (THA) with and without spinal fusion (SF), and to evaluate the radiographic characteristics of patients with dislocation after THA. A case-controlled study of 53 patients (67 hips) who underwent both THA and SF was performed. The control group was matched to the SF group by age, gender and body mass index, and 106 patients (134 hips) were selected. Hip function was evaluated using the Japanese Orthopaedic Association (JOA) hip score. In addition, the incidence rates of postoperative complications were determined. Radiograph evaluation included lateral inclination and anteversion of the acetabular component. We also analysed sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). The JOA hip score at final follow up was significantly poorer in the SF group compared to the control group. There were 5 cases of dislocations in the SF group and none in the control group. The anteversion of acetabular cup, PT, and PI were significantly higher in the SF group compare to the control group. In particular, the PI of patients with anterior dislocation were significantly higher compare to those of patients without dislocation. Our study showed that SF is a risk factor for a poorer clinical outcome and postoperative dislocation of THA. In addition, the abnormal value of PI may be a risk factor to predict dislocation after THA with SF.

Limited effects on patient outcomes of conjoint tendon release in anterolateral muscle-sparing total hip arthroplasty

BackgroundThe anterolateral muscle-sparing total hip arthroplasty (THA) in the supine position is advantageous owing to the very low-dislocation rate and excellent leg length discrepancy control. However, femur exposure is challenging. Although the conjoined external rotators tendon (CERT) release is effective in improving femoral access, the effects on clinical outcomes remain unclear. The purpose of this study was to evaluate the clinical and radiographic results of CERT release in the anterolateral muscle-sparing THA approach.MethodsThe study was performed as a retrospective cohort study and included 85 hips in 85 patients who underwent primary anterolateral THA. Clinical and radiographic outcomes were investigated 6 months and 1 year after THA (CERT-preserved and non-released patients). The Japanese Orthopaedic Association (JOA) hip score, JOA Hip-disease Evaluation Questionnaire (JHEQ), forgotten joint score (FJS), and the 36 short-form questionnaires (SF-36 mental and physical) were evaluated. The leg length discrepancy, cup inclination and stem orientation were evaluated with radiographs.ResultsAmong all the included hips, 37 patients (43.5%) retained the CERT, and 48 patients (56.5%) included the released CERT. There were no significant differences in the JOA hip scores, JHEQ, FJF-12 and SF-36 between the released and non-released groups. There were significant differences in sagittal stem alignments between groups.ConclusionThe CERT release in anterolateral muscle-sparing THA has a limited effect on post-operative clinical outcomes. The CERT release improved the femur exposure and is more invasive than the preserved CERT. We infer that the CERT should be maintained in patients with a wide range of motions, and release the CERT in inadequate femur canal preparation cases.

Short-term changes in radiographic joint space width after jiggling exercise as conservative treatment for hip osteoarthritis: A retrospective case series of nine patients.

Jiggling exercise is a conservative treatment for hip osteoarthritis, which involves continuous shaking of the foot and leg in small oscillations while seated. Previous studies have shown beneficial effects of jiggling exercises for outpatients with advanced- and terminal-stage hip osteoarthritis when performed for longer than 1 year, including increases in joint space width and remission of symptoms. We aimed to use the data from our own treatment to evaluate the short-term impact of intensive jiggling exercises on inpatients with hip osteoarthritis to further examine the clinical utility of this exercise. This retrospective case series study included nine patients (57 ± 12 years) with nine hip joints with advanced- or terminal-stage hip osteoarthritis who performed continuous daily jiggling exercises, beginning from day of hospitalization to 6 months post-discharge. Jiggling exercise was performed seated, using the KENKO YUSURI® automated heel vibrating machine at 3.3–5.0 Hz. The patients were also instructed against weight-bearing during hospitalization. The values of radiographic joint space width and Japanese Orthopaedic Association hip score for pain at hospital admission, discharge, and at the 6-month post-discharge checkup were evaluated. Although the hospitalization period and daily time spent performing the jiggling exercise varied in each case (27–98 days and 2–6 hours, respectively), the joint space width increased in all patients and there was an improvement in the hip pain scores in eight patients. The mean values of the minimum joint space width and hip pain scores at discharge were the highest compared to those at hospital admission and 6 months post-discharge. Our results suggest that intensive jiggling exercise for inpatients with advanced- and terminal-stage hip osteoarthritis leads to earlier improvement in joint space width and pain. Daily jiggling exercise for an adequate duration or in combination with non-weight-bearing practices may be a feasible conservative treatment for hip osteoarthritis.

Total hip arthroplasty using a three-dimensional porous titanium acetabular cup: an examination of micromotion using subject-specific finite element analysis

BackgroundWe investigated the mid-term clinical and radiological results of total hip arthroplasty (THA) using a three-dimensional (3D) porous titanium cup and analyzed the micromotion at the interface of the cup using subject-specific finite element (FE) analysis.MethodsWe evaluated 73 hips of 65 patients (6 men and 59 women; mean age at the time of surgery, 62.2 years; range, 45–86 years) who had undergone THA using a 3D porous titanium cup. Clinical evaluations were performed using the Japanese Orthopaedic Association (JOA) hip score system. We assessed the fixation of the acetabular component based on the presence of radiolucent lines and cup migration using anteroposterior radiographs. Subject-specific FE models were constructed from computed tomography data.ResultsThe JOA score improved from a preoperative mean of 52.2 (range, 23–82) to a mean of 87.8 (range, 71–100) at the final follow-up. None of the patients underwent revisions during the follow-up period. Radiolucent lines were observed in 26 cases (35.6%) and frequently appeared at DeLee and Charnley Zone 3. Following the FE analysis, the micromotion at DeLee and Charnley Zone 3 was significantly larger than that at Zone 2. Furthermore, micromotion was large in the groups in which radiolucent lines appeared at Zone 3.ConclusionsThe mid-term clinical outcome of THA using a 3D porous titanium cup was excellent. However, radiolucent lines frequently appeared at DeLee and Charnley Zone 3. FE analysis indicated that micromotion was large at the same site, strongly suggesting that it contributes to the emergence of radiolucent lines. The 3D porous titanium cups are useful in THA, and with improvements focused on micromotion, we anticipate better long-term outcomes.

Fragility fracture following total hip arthroplasty

BackgroundWhile 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. MethodsThis 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. ResultsFifty-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. ConclusionsThis 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.

The Effects of Rasp Oversize on the Clinical and Radiographic Outcomes of Total Hip Arthroplasty With a Collared Satin-Finished Composite Beam Cemented Stem

BackgroundThis study aimed to compare the clinical and radiographic outcomes of using two different oversized rasps in total hip arthroplasty (THA) with a composite beam cemented stem (DCM-J). MethodsA consecutive series of 105 hips underwent hybrid THA using the DCM-J stem between 2006 and 2010. Among the patients with a minimum 10-year follow-up, a 1.5-mm oversized rasp was used in 38 hips (group S), whereas a 0.5-mm oversized rasp was used in 36 hips (group M). The Japanese Orthopedic Association hip score and radiographic findings were evaluated, including cement mantle thickness, stress shielding, and cortical hypertrophy. ResultsThe Japanese Orthopedic Association hip score was significantly improved postoperatively with 100% of the implant survival rate in both groups when septic loosening was excluded. Radiographic assessment performed immediately postoperatively revealed that the cement mantle thickness was significantly larger in group M than group S in Gruen zone 1 but did not differ between groups in zones 2-7. Stress shielding was significantly more frequent in group M than group S at 2 years (P = .011), 5 years (P = .012), and ≥10 years postoperatively (P = .038). Cortical hypertrophy appeared in a time-dependent manner; however, the prevalence did not significantly differ between groups at final follow-up at a mean of 11.7 years (range 10-14 years) postoperatively. ConclusionsThe DCM-J stem achieved good clinical results in both groups. Stress shielding was significantly more frequent in THA using the 0.5-mm rasp than the 1.5-mm rasp, indicating that sufficient cement mantle room should be prepared for the cemented stem.