Is there a reduction in hip destruction under a treat-to-target strategy in patients with rheumatoid arthritis?

OBJECTIVES: The treatments for rheumatoid arthritis (RA) have been greatly improved, and the tight control of disease activity yields superior clinical outcomes. This study aimed to elucidate the accompanying changes in hip destruction following the implementation of a treat-to-target strategy for patients with RA. METHODS: We extracted 190 hips over two periods, i.e. the early period (1998-2003) and the late period (2013-19), with 103 and 87 hips, respectively. The observed rheumatic changes, such as inward migration, upward migration, and femoral head collapse, were quantitatively evaluated, while osteoarthritic changes, such as the formation of a capital drop, were investigated from radiographs before primary total hip arthroplasty. RESULTS: A comparison of the two periods' data showed that the degree of inward migration (-3.44 vs. -7.45 mm; P < .001) and upward migration (+4.3 vs. +0.95 mm; P < .001) significantly decreased in the late-period group. The collapse of the femoral head was not significantly different. The incidence of capital drops was significantly higher in the late-period group (7.8% vs. 27.5%; P < .001). CONCLUSIONS: The degree of inward and upward migration representative of rheumatic changes reduced, whereas the frequency of capital drops as osteoarthritic changes increased during the late period.

Autoreactivity of Peripheral Helper T Cells in the Joints of Rheumatoid Arthritis.

Autoreactive CD4 T cells are thought to play pivotal roles in the pathogenesis of rheumatoid arthritis (RA). Recently, a subset of CD4 T cells that express high levels of programmed death-1 (PD-1) but are distinct from follicular helper T cells have been identified in the joints of RA patients and named peripheral helper T (Tph) cells. Because PD-1 is expressed on T cells chronically stimulated with the Ags, we tested a hypothesis that Tph cells are the pathogenic autoreactive CD4 T cells in RA. We found that human Tph cells in RA joints produce proinflammatory effector cytokines, including IFN-γ, TNF-α, and GM-CSF, in addition to B cell-helping cytokines, such as IL-21 and CXCL13. Flow cytometric analysis showed different bias of TCR Vß usage between PD-1high Tph cells and PD-1low/neg CD4 T cells, including Th1 cells, in the joint or memory CD4 T cells in the peripheral blood, whereas there was little difference between the latter two subsets. In line with this, deep sequencing of TCR demonstrated an overlap of expanded clones between peripheral blood memory CD4 T cells and PD-1low/neg CD4 T cells but not Tph cells in the joint. Interestingly, Tph cells preferentially exhibited autologous MLR in vitro, which required recognition of self-MHC class II and was pronounced by blocking PD-1 signaling. Taken together, these results suggest that Tph cells are the pathogenic autoreactive CD4 T cells in RA, which expand locally in the joints and are regulated by PD-1 signaling.

Complications After Orthopedic Surgeries in Patients with Rheumatoid Arthritis Treated with Janus Kinase Inhibitors: a Retrospective Observational Study.

OBJECTIVES: The current study compared the outcome after orthopedic surgeries in patients with RA receiving JAKi versus biologic disease-modifying anti-rheumatic drugs (bDMARDs). METHODS: This was a retrospective observational study of Japanese patients with RA. Sixty-two patients with RA using JAKi preoperatively underwent orthopedic surgeries. Using propensity score matching, these 62 patients were matched with 62 patients using bDMARDs preoperatively. The number of adverse events was counted. We also examined whether the drug-withholding period in the JAKi-treated group was associated with the occurrence of major postoperative adverse events, namely inflammatory flares and delayed wound healing (DWH). RESULTS: JAKi-treated patients had a higher incidence of postoperative flares than bDMARDs-treated patients (29% vs 12.1%, p=0.01). The incidences of postoperative complications other than flares were not significantly different between the two groups. Among the JAKi-treated group, a longer perioperative drug-withholding period (≥11 days) was associated with a higher incidence of postoperative flares (p=0.04). The incidences of DWH and SSI were not associated with the duration of the JAKi withholding period. CONCLUSION: JAKi-treated patients had a higher incidence of postoperative flares than bDMARDs-treated patients. A total of 11 days or more of drug withdrawal was associated with postoperative flares.

Have the radiographic characteristics of total knee arthroplasty recipients in rheumatoid arthritis changed after the induction of biologic disease modifying antirheumatic drugs?

OBJECTIVES: Whether the characteristics of patients with rheumatoid arthritis (RA) undergoing total knee arthroplasty (TKA) have changed in the era of biologic disease-modifying antirheumatic drugs (bDMARDs) is unclear. We compared the radiographic findings of the knees in TKA recipients with RA before and after the introduction of bDMARDs. METHODS: Consecutive patients who underwent primary TKA between 1999 and 2002 (115 knees; 79 patients, group A) and between 2013 and 2017 (117 knees; 95 patients, group B) were retrospectively evaluated. Clinical data, including disease duration, medication, C-reactive protein, erythrocyte sedimentation rate, and rheumatoid factor, were collected. The Larsen classification, joint space narrowing (JSN), bone erosion, and geode and osteophyte formation were evaluated on preoperative radiographs. RESULTS: Osteophyte formation was significantly increased, and bone erosion and geode formation were significantly decreased in group B. In addition, medial-dominant JSN was significantly increased, and bicompartmental JSN was significantly decreased in group B. Medial-dominant JSN was positively and bone erosion was negatively associated with osteophyte formation. CONCLUSIONS: Following the introduction of bDMARDs, typical radiographic findings of rheumatoid knees have decreased, and secondary osteoarthritis-like changes, characterized by osteophyte formation and medial-dominant JSN, have increased in the knees of TKA recipients.

Clinical features and outcomes of spine surgery in patients with ankylosing spondylitis.

OBJECTIVES: The study aimed to comprehend the clinical features and outcomes of surgical treatments for spinal disorders in patients with ankylosing spondylitis. METHODS: This retrospective study enrolled patients with ankylosing spondylitis who underwent spine surgery between 2000 and 2019 in our facility. RESULTS: Thirteen patients with ankylosing spondylitis underwent spine surgeries. The mean age was 56.2 years, and the mean disease duration was 25.1 years at the time of surgery. Nine patients had vertebral fracture, two had kyphotic deformity, and two had myelopathy due to the spinal ligament ossification. Fracture cases included five patients with secondary pseudarthrosis/delayed palsy due to conservative treatment failure. Spinal fixation was performed in all patients. Pedicle subtraction osteotomy for kyphosis and laminectomy for myelopathy were also conducted. All patients improved after surgeries. One patient with kyphotic deformity underwent additional surgery of bilateral hip prosthesis, which resulted in better spine alignment. Four cases of perioperative complications were observed. CONCLUSION: Myelopathy was newly found as the aetiology requiring surgery in patients with ankylosing spondylitis. This summarized case series could help physicians to identify patients with surgically treatable spinal disorders among patients with ankylosing spondylitis.

Preoperative Japanese Society for the Surgery of the Foot Lesser toe score and erythrocyte sedimentation rate influence wound healing following rheumatoid forefoot surgery.

OBJECTIVES: Delayed wound healing is one of the most common complications following forefoot surgery in patients with rheumatoid arthritis. We aimed to identify the risk factors for delayed wound healing following rheumatoid forefoot surgery. METHODS: Consecutive patients who underwent primary rheumatoid forefoot surgery (86 feet; 53 patients) between April 2008 and February 2019 were retrospectively evaluated. Clinical data, including smoking history, duration of the disease, presence of diabetes mellitus, medication, white blood cell count, erythrocyte sedimentation rate (ESR), C-reactive protein, the surgical procedure performed, and the Japanese Society for Surgery of the Foot (JSSF) scores, were collected. RESULTS: Delayed wound healing was identified in 20 of 86 (23.3%) feet. In univariate analysis, participants showing delayed healing were older at the time of surgery (p = .04), their ESR was higher (p = .0006), and their total (p = .019) and pain (p = .016) scores on the JSSF Lesser toe scale were lower than those showing normal healing. In multivariable analysis, both the total preoperative JSSF Lesser toe scale score (p = .0239) and ESR (p = .0126) remained significant risk factors for delayed wound healing. CONCLUSIONS: After rheumatoid forefoot surgery, surgeons should pay more attention to wound care in patients with lower preoperative JSSF Lesser toe score and high ESR.

Effects of anterior boundary of the necrotic lesion on the progressive collapse after varus osteotomy for osteonecrosis of the femoral head.

BACKGROUND: Anterior localization of the necrotic lesion was recently proposed as an important factor for the occurrence of collapse even in medially located osteonecrosis of the femoral head (ONFH). We examined the effects of the anterior boundary of the necrotic lesion on progressive collapse after varus osteotomy for ONFH. METHODS: We reviewed the outcomes of 31 hips in 27 patients with ONFH treated by transtrochanteric curved varus osteotomy (CVO) from 2000 to 2012 with a mean follow-up of 10.5 years. The occurrence of progressive collapse of the anterior necrotic lesion was defined as the presence of ≥2 mm collapse using follow-up lateral radiographs. Postoperative osteoarthritic change was defined as ≥1 mm progression of joint space narrowing on follow-up radiographs. The location of the anterior boundary of the necrotic lesion was assessed using the anterior necrotic angle (the angle between the midline of the femoral neck shaft and the line passing from the femoral head center to the anterior boundary of the necrotic lesion on a mid-slice oblique magnetic resonance image). RESULTS: All hips had a postoperative intact ratio of ≥34% (percentage of the transposed intact articular surface of the femoral head to the weight-bearing area of the acetabulum after femoral osteotomy). Progressive collapse of the anterior necrotic lesion was seen in five hips (16%) during a mean of 2.2 years after CVO. Of these, four hips (80%) proceeded to develop osteoarthritic change at an average of 4.3 years after the collapse. Multivariate analysis revealed that the anterior necrotic angle was independently associated with progressive collapse of the anterior necrotic lesion as well as the postoperative intact ratio. CONCLUSIONS: This study suggests that hips with anterior localization of the necrotic lesion have a possible risk of progressive collapse of the anterior necrotic lesion after CVO, which can frequently lead to subsequent osteoarthritic change.

Modified lateralized head sign: An accurate marker in diagnosing adult hip dysplasia.

BACKGROUND: Although lateralized head sign (LHS) is considered indicative of structural instability, it lacks reproducibility, and its usefulness in diagnosing adult hip dysplasia is unknown. In this study, we proposed a modified LHS and aimed to determine its reliability and accuracy in diagnosing adult hip dysplasia. METHODS: We reviewed anteroposterior pelvic radiographs of 94 patients (134 hips) with hip dysplasia. As controls, 133 normal hips were evaluated. We defined the modified lateralization distance (LD) as the horizontal distance between the medial aspect of the femoral head to the acetabular fossa. The sensitivity, specificity, and cutoff value of modified LD in diagnosing hip dysplasia were calculated using receiver operating characteristic curve analysis. RESULTS: The sensitivity and specificity of the modified LD (79% and 87%, respectively) were higher than those of the conventional LD (63% and 80%, respectively). Diagnostic accuracy was further improved when patients were divided on the basis of sex. The sensitivity and specificity of the modified LD in men were 89% and 97%, respectively, with a cutoff value of 12 mm, while in women, they were 80% and 96%, respectively, with a cutoff value of 9.7 mm. Therefore, we defined the modified LHS as presentation with a modified LD ≥ 12 mm in men and ≥10 mm in women. Between three observers, the kappa value for intraobserver reliability was ≥0.9, while that for interobserver reliability was >0.8. The mean sensitivity and specificity of the modified LHS in diagnosing hip dysplasia were 85% and 99%, respectively. CONCLUSIONS: Modified LHS-a horizontal distance between the medial aspect of the femoral head and the acetabular fossa ≥12 mm in men and ≥10 mm in women-is a clinically useful marker in detecting lateral femoral head subluxation indicative of hip dysplasia or structural hip instability.

Cross-cultural adaptation, reliability and validity of the Japanese version of the Hospital for Special Surgery Hip Replacement Expectations Survey.

BACKGROUND: The Hospital for Special Surgery Hip Replacement Expectations Survey (HSS-THRES) is used in many countries to determine patient expectations before surgery. This study aimed to assess the reliability and validity of the Japanese version of HSS-THRES. METHODS: A total of 134 patients scheduled for total hip arthroplasty (THA) underwent a self-administered preoperative survey questionnaire. Patient's expectation and quality of life (QOL) were measured using the Japanese version of HSS-THRES, overall expectations for THA, Oxford hip score (OHS), and EuroQol-5D (EQ-5D). Some patients completed the Japanese version of HSS-THRES and the overall expectations for THA after a ten-day interval. Cross-cultural adaptation was validated by an expert committee comprising health professionals, a methodologist, language experts, and orthopedic specialists. The internal consistency was evaluated by the Cronbach α coefficient. The test-retest reliability was examined using the intraclass coefficient correlation (ICC) and the Bland and Altman analysis. To test the construct validity, nine priori hypotheses were tested by correlation analysis between the Japanese version of HSS-THRES and two QOL scales, and by examining the association with demographic variables. RESULTS: A total of 116 patients completed four scales. Patients were predominantly female (75.9%), with an average age of 62.2 ± 11.7. In the cross-cultural adaptation, all patients responded to the questionnaire without problems. The Japanese version of HSS-THRES showed good internal consistency (Cronbach α: 0.9). ICC was 0.94 and Bland-Altman analysis indicated no bias. The correlation between Japanese HSS-THRES and overall expectations for THA was high (r = 0.67). Similarly, the correlation with the OHS was higher than that with EQ-5D. A total of 77.8% of the hypotheses were confirmed. CONCLUSIONS: The Japanese version of HSS-THRES showed good cultural acceptability, high reliability, and validity to evaluate preoperative expectations for THA patients.

Does Preparation of the Subtalar Joint for Primary Union Affect Clinical Outcome in Patients Undergoing Intramedullary Nail for Rheumatoid Arthritis of the Hindfoot and Ankle?

This study aimed to evaluate whether preparation of the subtalar joint affects the clinical outcomes after tibiotalocalcaneal arthrodesis using an intramedullary nail with fins for rheumatoid ankle/hindfoot deformity. Fifty-three joints in 51 patients who underwent tibiotalocalcaneal arthrodesis using an intramedullary nail with fins for rheumatoid arthritis at 2 institutions were included. Ten patients were male and 41 were female, with a mean age at surgery and follow-up period of 61.3 years and 71.6 months, respectively. Radiographic bone union was evaluated at the most recent visit. Univariate and multivariable analyses were performed to determine the risk factors associated with nonunion. The mean postoperative Japanese Society for Surgery of the Foot ankle/hindfoot scale was 65.3 (range, 5-84). The tibiotalar nonunion rate was 0%, whereas the subtalar nonunion rate was 43.3% (23 joints). Revision surgery was performed in 5, all of which were due to painful subtalar nonunion. Absence of subtalar curettage and earlier postoperative weightbearing were significantly associated with subtalar nonunion (p = .0451 and p = .0438, respectively). Subtalar nonunion after tibiotalocalcaneal arthrodesis for rheumatoid hindfoot is associated with higher revision rate. To decrease the risk of subtalar nonunion after tibiotalocalcaneal arthrodesis with an intramedullary nail in rheumatoid patients, curettage for the subtalar joint should be performed, and full weightbearing should be delayed until at least 26 days postoperatively.

Does high hip centre affect dislocation after total hip arthroplasty for developmental dysplasia of the hip?

BACKGROUND: To achieve sufficient socket coverage by the native bone, high placement of cementless acetabular cup is often required. We previously reported, using computer simulation, that higher hip centre improved the bone coverage but decreased the range of motion in total hip arthroplasty (THA) for patients with hip dysplasia. However, in a clinical setting, the correlation between the hip centre height and dislocation after primary THA is still unclear. We examined whether a high hip centre affects dislocation after THA. METHODS: A total of 910 patients, with 1079 dysplastic hips, who underwent primary THA were retrospectively reviewed. The age at THA averaged 63.0 years and mean follow-up was 74.3 months. Vertical centre of rotation (V-COR) was defined as the distance from the head centre to the interteardrop line. Uni- and multivariate logistic regression models were applied to identify significant factors affecting dislocation. RESULTS: Ten hips in nine patients (0.9%) had dislocation after THA. In univariate analysis, age at surgery and V-COR were significant risk factors for dislocation. Multivariate analysis identified advanced age at operation (odds ratio [OR] 1.8/5 years), Crowe classification (OR 15.6), V-COR (OR 3.1/5 mm), and femoral head size (OR 11.6) as independent risk factors for dislocation. Receiver operating characteristic curve analysis revealed the cutoff value of the V-COR for dislocation as 23.9 mm. CONCLUSIONS: A higher hip centre with the V-COR > 23.9 mm affected dislocation after THA for DDH. Our results would be useful for reconstruction of the hip centre, particularly with cementless acetabular cups.

Serum IgG ACPA-IgM RF immune complexes were detected in rheumatoid arthritis patients positive for IgM ACPA.

OBJECTIVES: Since the presence of IgM antibodies is a hallmark of ongoing immune response, we aimed to identify immunologically active rheumatoid arthritis (RA) patients by detecting IgM anti-citrullinated protein antibody (ACPA) levels. METHODS: IgM ACPA levels were determined in the serum of 176 RA patients by enzyme-linked immunosorbent assay, in which parameters of reactivity against citrullinated and non-citrullinated peptides were compared to ensure the specificity. Influence of IgM rheumatoid factor (RF) on IgM ACPA detection was examined by removing IgG, using protein G-conjugated beads, or by purifying ACPA, using citrullinated peptide-conjugated beads. RESULTS: Although IgM specific for citrullinated proteins was detected in some patients (11%), IgM molecules reactive to both citrullinated and non-citrullinated peptides were detected in a substantial number of patient samples (12%). IgM ACPA-positive reactions were associated with the presence of IgG ACPA and IgM RF. Surprisingly, protein G-mediated removal of IgG from the serum eliminated positivity for IgM ACPA, suggesting that IgG ACPA-IgM RF complex was being detected. This assumption was confirmed by the detection of IgM RF in the eluate of protein G beads and citrullinated peptide-conjugated beads. CONCLUSIONS: In an attempt to detect IgM ACPA, we mostly revealed false positive reactions due to the presence of IgM molecules, which were not specific for citrullinated proteins, and IgG ACPA-IgM RF immune complex. The latter complex had been proposed to play a role in the pathogenesis of RA, and here, for the first time, we have demonstrated its presence in the sera of RA patients.

Streptococcus pyogenes-purpura fulminans as an invasive form of group A streptococcal infection.

BACKGROUND: Streptococcus pyogenes is an uncommon pathogen of purpura fulminans, and the pathogenesis of S. pyogenes-purpura fulminans remains unclear because of paucity of cases. We reported a pediatric case of S. pyogenes-purpura fulminans with literature review of the disease. CASE PRESENTATION: A 3-year-old boy showed limping, lethargy and acral gangrene within 24 h. A diagnosis of S. pyogenes-purpura fulminans was made for bacterial isolation from throat and peripheral blood. Intensive therapy led to a survival with amputation of the left distal metatarsal bone, and normal development. The isolated M12 carried no mutation of csrS/R or rgg. Thrombophilia or immunodeficiency was excluded. DISCUSSION: Twelve-reported cases (9 pediatric and 3 elderly) of S. pyogenes-purpura fulminans started with shock and coagulopathy. Five patients age < 8 years had no underlying disease and survived. One youngest and two immunocompromised patients died. CONCLUSION: Streptococcus pyogenes-acute infectious purpura fulminans is a distinctive rare form of aggressive GAS infections.

The Results of Total Hip Arthroplasty After Sugioka Transtrochanteric Anterior Rotational Osteotomy for Osteonecrosis.

BACKGROUND: Since Sugioka transtrochanteric anterior rotational osteotomy (ARO) for osteonecrosis of the femoral head (ONFH) changes the morphology of the proximal femur, total hip arthroplasty (THA) after previous ARO is considered a technically demanding procedure. The purpose of this study was to compare the clinicoradiologic outcomes of THA after ARO with those of THA without any antecedent surgery for ONFH. METHODS: Twenty-four hips in 20 patients who underwent cementless THA after ARO (postosteotomy group) were retrospectively reviewed and compared with patients who underwent cementless THA without any antecedent surgery for ONFH during the same period (primary group). In the postosteotomy group, the mean duration from ARO to THA was 19.7 years. All patients were followed for at least 5 years (mean, 8.3 years; follow-up rate, 78.5%). A clinical assessment was performed preoperatively and at the latest follow-up using the Harris Hip Score. A radiographic examination was performed at 3 months after THA and at the latest follow-up. RESULTS: The Harris Hip Score at the latest follow-up in the postosteotomy group was equivalent to that in the primary group, but longer operation time and greater intraoperative blood loss were observed in the postosteotomy group. There were no significant differences in postoperative complications, including dislocation (2 hips in each group). The leg lengthening in the postosteotomy group tended to be longer. No hips showed implant malpositioning, loosening, or required any revision surgery. CONCLUSION: The clinicoradiologic outcomes of THA after ARO are considered to be comparable with those of THA without any antecedent surgery for ONFH.

Management of Intra-Articular Calcaneal Fractures: Clinical Results of Reduction Technique Using a Bone Spreader.

The purpose of the present study was to examine the clinical results of surgery for intra-articular calcaneal fractures using a calcaneal locking plate and a bone spreader as a reduction tool. Ten patients with intra-articular calcaneal fractures were treated. An extended lateral approach was used. The reduction of the intra-articular fragments of the posterior facet was temporarily held using a bone spreader and Kirschner wires. Internal fixation was achieved with a locking calcaneal plate. Böhler's angle and Preiss' angle were assessed on the day of injury and the day of the final follow-up examination. The step off and gap of the posterior facet were assessed on the day of injury and the first week after surgery. The functional outcome was evaluated using the American Orthopaedic Foot and Ankle Society ankle hindfoot scale score. The mean Böhler's angle ranged from 2.1° ± 11.0° to 30.4° ± 5.0° (p < .0001), the mean Preiss' angle ranged from 23.5° ± 4.5° to 15.5° ± 2.9° (p < .0001), the mean step off ranged from 4.0 ± 1.9 mm to 0.1 ± 0.2 mm (p = .0002), and the mean gap ranged from 2.6 ± 1.0 mm to 1.2 ± 0.6 mm (p = .0035). The mean American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale score was 89.2 (range 85 to 100) at a mean of 14.3 months after surgery. Our results suggest that a locking calcaneal plate can be used to restore and reduce an intra-articular calcaneal fracture and achieve good clinical results.

Minimum 10-year results of cementless total hip arthroplasty in patients with rheumatoid arthritis.

OBJECTIVES: To retrospectively evaluate the long-term results of cementless total hip arthroplasty (THA) in patients with rheumatoid arthritis (RA) and postoperative patient mortality after THA. METHODS: This study included 191 hips in 149 RA patients who underwent cementless THA between 1998 and 2005. Mean age at surgery was 54.2 years, and mean follow-up was 12.6 years. Implant and patient survivorships were determined using the Kaplan-Meier method, and the associated influencing factors were determined. RESULTS: Implant survivals at 17 years were 99.5% for stems, 93.9% for cups, and 90.8% for liners. Among the liners used, THAs with highly cross-linked polyethylene showed better survivals compared with those with conventional polyethylene and alumina-bearing surface (93.4%, 90.9%, and 52.2%, respectively). A total of 64 deaths occurred; 45 patients died within 10 years and 19 patients died between 10 and 17 years. Malignancy (25.0%) was the leading cause of death, followed by pneumonia (20.8%) and sepsis (20.8%). The patient survival rate was 36.9% at 17 years after THA. Multivariate analysis exhibited that older age at operation and greater dose of concomitant corticosteroid resulted in shorter patient survivals. CONCLUSIONS: Cementless THA worked well in patients with RA. Mortality remained high among RA patients who needed THA.

Arthroscopic validation of radiographic minimum joint space width associated with the subchondral bone exposure in symptomatic hip dysplasia.

OBJECTIVE: The purpose of this study was to clarify the minimum joint space width (MJSW) that leads to subchondral bone exposure (SBE) in patients with hip dysplasia. METHODS: We included 82 subjects (86 hips) who had hip dysplasia with center-edge angle less than 20° and who underwent periacetabular osteotomy combined with hip arthroscopy. The acetabular and femoral cartilages were divided into three regions: anterosuperior, superior, and posterosuperior; for each region, we analyzed the correlation between the incidence of SBE and the MJSW measured on plain radiographs. The disease stage was defined according to the Kellgren and Lawrence grades (KL grade). RESULTS: SBE was found in 51 hips (59.3%) in total, involved the acetabulum in 49 hips (57.0%), and involved the femoral head in 26 hips (30.2%). SBE was more frequent in the acetabulum, with the highest incidence in the anterosuperior region, followed by the superior region. SBE was present in six hips (22.2%), 17 hips (56.7%), and 28 hips (96.5%), at KL-1, KL-2, and KL-3, respectively. MJSW of hips with SBE was significantly smaller than those without SBE (2.3 vs 4.0 mm, p < 0.001), and the cut-off value for MJSW that led to SBE was 3.7 mm (sensitivity: 0.902, 1 - specificity: 0.343). SBE was present in 23.3% in patients with MJSW ≥3.7 mm, whereas 76.7% in those <3.7 mm. CONCLUSIONS: Cartilage degeneration is more advanced than would be predicted on plain radiographs. The cut-off value of MJSW for SBE was 3.7 mm in patients with symptomatic hip dysplasia.

Transtrochanteric rotational osteotomy for avascular necrosis of the femoral head after unstable slipped capital femoral epiphysis: 10-year clinical results.

BACKGROUND: Avascular necrosis of the femoral head (AVN) is the most serious complication after unstable slipped capital femoral epiphysis (SCFE), and is often unsalvageable. We report a minimum 10 years of clinical results for transtrochanteric rotational osteotomy of the femoral head (TRO) for AVN. METHODS: This study included 7 patients (7 hips) with a mean age at surgery of 13.3 years, and the follow-up period was 15.8 years. All patients had prior treatment via closed reduction and pinning of the unstable SCFE, and showed severely collapsed femoral heads. The direction of rotation was anterior in 3 hips and posterior in 4. The Merle d'Aubigné-Postel score (MDPS) was used for clinical assessment, and joint degeneration was assessed with the Kellgren and Lawrence classification (KL-grade). RESULTS: The spherical intact area of the femoral head was moved to the weight-bearing portion, and subluxation was corrected via rotation combined with intentional varus positioning. The mean MDPS improved from 10.3 points to 15.6 points at 5 years, and it was maintained at 15.0 points by 10 years; 3 hips were excellent, 1 was good, 2 were fair, and 1 showed poor outcomes. No patient experienced re-collapse after TRO or required conversion to hip replacement or arthrodesis. After 10 years, degenerative changes became evident over time, and 2 hips progressed to KL-4 with a decreased MDPS. CONCLUSIONS: Although some joint degeneration is inevitable in the long-term, TRO is an effective salvage procedure for treating AVN after unstable SCFE.