Search Results (8)

Juvenile idiopathic arthritis (JIA) represents the most common cause of chronic arthritis in childhood; however, not all early-onset arthropathies are inflammatory in origin. We report the case of a 4-year-old girl initially diagnosed with oligoarticular JIA and treated with methotrexate followed by a tumor necrosis factor inhibitor, without significant clinical improvement and despite persistently normal inflammatory markers. Clinical reassessment raised suspicion of a non-inflammatory arthropathy, supported by characteristic radiographic findings including metaphyseal flaring of the distal femora and proximal tibiae. Genetic analysis identified compound heterozygous pathogenic variants in the PRG4 gene, confirming the diagnosis of camptodactyly–arthropathy–coxa vara–pericarditis (CACP) syndrome (OMIM #208250). PRG4 encodes lubricin, a mucin-like glycoprotein essential for boundary lubrication of articular cartilage and maintenance of synovial joint homeostasis. Loss-of-function variants disrupt joint lubrication, leading to mechanical synovial hyperplasia and chronic non-inflammatory joint effusion. This case highlights common diagnostic pitfalls in pediatric rheumatology and underscores the importance of considering genetic causes of chronic arthropathy when clinical and laboratory features are atypical for inflammatory disease. Early molecular diagnosis prevents unnecessary immunosuppressive therapy and enables appropriate multidisciplinary management. Full article

Background: Fibrous dysplasia (FD) is a rare condition in which normal spongy and cortical bone is replaced by non-neoplastic fibrous tissue, leading to weakened bone matrix and increased risk of pathological fractures and deformities. Treating these deformities poses a significant challenge for surgeons. While various cases of surgical stabilization and limb lengthening using intramedullary nails have been reported, there is limited evidence on the use of Motorized Intramedullary Limb-Lengthening Nails (MILLNs) in FD patients. This case report presents the clinical history of a patient with FD who underwent multiple surgical interventions to address severe lower limb length discrepancy (LLD) and angular deformity caused by multiple fractures. Case presentation: A sixteen-year-old Caucasian girl with polyostotic FD developed a severe post-traumatic LLD of 10 cm on the right side, associated with coxa vara, valgus knee, and patellar instability. The deformity of the proximal femur was addressed with a valgus and derotational femoral osteotomy. However, this procedure exacerbated the knee’s valgus deformity and only partially corrected the LLD, leading to the decision to proceed with femoral lengthening. A retrograde magnetic intramedullary nail (PRECICE, NuVasive) was utilized for this purpose. Approximately three months postoperatively, radiographs revealed the loosening of the proximal anchoring screw, while the nail had reached maximum distraction. We then proposed reactivating the previously implanted nail. Nine months after the final surgery, standing long-leg radiographs showed a residual shortening of 1 cm, with excellent healing at the fracture sites and the nail and screws remaining securely in place. The patient was monitored regularly, with the latest follow-up occurring four years and five months after the conclusion of the last lengthening procedure. Conclusions: This case report describes the reactivation of a MILLN in a patient with polyostotic fibrous dysplasia. While nail reactivation has been previously described in the literature, to our knowledge, it has not been reported for treating complications arising from FD. In cases of mechanical complications, this approach can equalize leg length discrepancies and correct deformities, avoiding additional invasive surgeries and reducing healthcare costs. As this is an off-label treatment, preoperative consent from both the patient and the parents is required. Full article

Background: Hip stability remains a major preoccupation during femoral lengthening in Congenital Femoral Deficiency (CFD). We aimed to review hip stability in Paley type 1a CFD patients undergoing femoral lengthening. Methods: A total of 33 patients with unilateral CFD, who were treated between 2014 and 2023, were retrospectively reviewed. In 20/33 cases (60.6%) the SUPERhip preparatory surgery was performed at a mean age of 4.3 years (range 2.7–8.1). The femoral lengthening using an external fixator was performed at a mean age of 7.8 years (range 4.3–14.3). Results: All patients presented with a stable hip joint after preparatory surgery and during femoral lengthening. Six cases of hip instability at a mean of 637 days after the external fixator removal were observed (range 127 to 1447 days). No significant differences between stable and unstable hips were noted for (1) Center-Edge Angle: 23.7 vs. 26.1 deg; (2) Acetabular Inclination: 12.8 vs. 11.7 deg; and (3) Ex-Fix Index: 35.6 days/cm vs. 42.4 days/cm; p > 0.05. Late hip instability was related to Coxa Vara and decreased femoral antetorsion before lengthening. Conclusions: Late hip joint instability in Paley type 1a CFD patients may occur long after femoral lengthening despite hip morphology appearing to be normal on radiograms before and at the end of femoral lengthening. Coxa Vara, femoral torsional deformity, and posterior acetabular deficiency might be risk factors for hip instability. Full article

Background: Congenital femoral deficiency (CFD) is a challenging and complex condition that causes limb lengthening. We focused on the clinical and radiographic results of SUPERhip procedures in patients with congenital femoral deficiency type 1b, according to Paley’s classification, prior to femoral lengthening. Methods: We reviewed all records and radiographs of patients who underwent this procedure between 2005 and 2020. We included 26 patients, with clinical and radiographic assessments performed during pre- and post-operative evaluations. Results: There were twenty-six patients (15 right vs. 11 left), with a mean age of 7 years (1–18). Most of the patients were female (17 patients; 65.4%). Twenty (76.9%) patients were undergoing their first procedure and six (23.1%) had already undergone a previous surgery. There was a significant improvement in all radiographic parameters, with the mean preoperative and postoperative Neck-Shaft Angle (NSA) being 72.3 ± 7.1° vs. 133.1 ± 12.7°, the Center-Edge Angle (CEA) 16.8 ± 9.8° vs. 33.5 ± 14.1°, and the Acetabular Index (AI) 27.8 ± 6.9° vs. 16.4 ± 6.8°, respectively. The complication rate was 15.4%, predominantly affecting patients under 5 years old. Conclusions: The SUPERhip procedure is an effective and reproducible technique for clinical and radiographic correction to a significant degree in patients with Paley’s type 1b CFD, in preparation for bone lengthening surgery. Full article

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome leads to diarthrodial joint arthropathy and is caused by the absence of lubricin (proteoglycan 4—PRG4), a surface-active mucinous glycoprotein responsible for lubricating articular cartilage. In this study, mice lacking the orthologous gene Prg4 served as a model that recapitulates the destructive arthrosis that involves biofouling of cartilage by serum proteins in lieu of Prg4. This study hypothesized that Prg4-deficient mice would demonstrate a quadruped gait change and decreased markers of mitochondrial dyscrasia, following intra-articular injection of both hindlimbs with recombinant human PRG4 (rhPRG4). Prg4^−/− (N = 44) mice of both sexes were injected with rhPRG4 and gait alterations were studied at post-injection day 3 and 6, before joints were harvested for immunohistochemistry for caspase-3 activation. Increased stance and propulsion was shown at 3 days post-injection in male mice. There were significantly fewer caspase-3-positive chondrocytes in tibiofemoral cartilage from rhPRG4-injected mice. The mitochondrial gene Mt-tn, and myosin heavy (Myh7) and light chains (Myl2 and Myl3), known to play a cytoskeletal stabilizing role, were significantly upregulated in both sexes (RNA-Seq) following IA rhPRG4. Chondrocyte mitochondrial dyscrasias attributable to the arthrosis in CACP may be mitigated by IA rhPRG4. In a supporting in vitro crystal microbalance experiment, molecular fouling by albumin did not block the surface activity of rhPRG4. Full article

Background: Slipped capital femoral epiphysis is due to proximal femur physis failure in adolescent patients. Early iatrogenic closure of proximal growth cartilage in children with significant residual growth potential causes complications such as coxa breva, coxa vara, and lower limb length inequalities. The Free-Gliding SCFE Screw System is a self-extending cannulated screw used in Slipped Capital Femoral Epiphysis (SCFE) fixation and femoral neck fractures. Materials and Method: We conducted a retrospective study on 16 patients. All patients under 11 years old were treated by telescopic cannulated screws fixation. The youngest patient was 7 years old. Results: Out of the 22 operated hips, 2 screws have failed, thus resulting in a lack of telescoping of the screw. We discovered an average lengthening of approximately 10 mm at 24 months postoperative check-up in 20 hips in which lengthening took place. According to the Notzli method, none of the patients had an alpha angle value greater than 48 degrees. Conclusion: Fixation with telescopic screw for SCFE in patients less than 11 years old, with mild to moderate slippage, allows the continuous growth and remodeling of the proximal femur, thus avoiding deformities such as coxa breva, coxa vara, FAI, AVN, limb length discrepancies and also allows good range of motion. Full article

Congenital femoral deficiency (CFD) Paley type 1b is characterized by severe bony deformity of the upper femur, extra-articular contractures of the hip, and_, delayed ossification of the femoral neck and/or subtrochanteric region. The Systematic Utilitarian Procedure for Extremity Reconstruction of the hip (SUPERhip) procedure for the correction of CFD deformities was developed in 1997. Initially, a non-fixed angle device (rush rod) was used for fixation. Late complications of persistent delayed ossification and recurrent varus deformity occurred. In order to reduce and treat such complications, fixation with a fixed angle device and the off-label use of BMP2 to induce ossification of the un-ossified femoral neck were employed. The purpose of this study is to determine if the use of a fixed angle device, and, BMP2 inserted into a drill hole in the cartilage of the femoral neck, decreases the incidence of these late complications. We retrospectively reviewed 72 SUPERhip procedures performed for Paley type 1b CFD between 1997 and 2012. Due to recurrent varus or persistent delayed ossification of the femoral neck, 34 revision SUPERhip procedures were performed. In total, 106 SUPERhip procedures were studied. Sixty-eight SUPERhips were performed using internal fixation without BMP2, while 38 SUPERhips were performed with both internal fixation and the addition of BMP2. Forty-one were performed using non-fixed angle internal fixation while 65 had fixed angle internal fixation. Fixed angle devices significantly reduced the incidence of recurrent varus compared with non-fixed angle devices. Inserting BMP2 in the femoral neck significantly reduced the incidence of persistent delayed ossification. Using only a fixed angle device but no BMP2 did not reduce the incidence of delayed ossification. The combination of both a fixed angle device and BMP2 reduced the incidence of recurrent coxa vara and persistent delayed ossification of the femoral neck. The SUPERhip procedure corrects the pathoanatomy of the proximal femur in CFD Paley type 1b but is associated with a very high risk of recurrence of coxa vara and persistence of femoral neck delayed ossification, unless, a fixed angle internal fixation device is used to prevent recurrent coxa vara and BMP2 is used to induce ossification of the femoral neck. Full article

Deficiency of PRG4 (lubricin), the boundary lubricant in mammalian joints, contributes to increased joint friction accompanied by superficial and upper intermediate zone chondrocyte caspase-3 activation, as shown in lubricin-null (Prg4^−/−) mice. Caspase-3 activity appears to be reversible upon the restitution of Prg4 either endogenously in vivo, in a gene trap mouse, or as an applied lubricant in vitro. In this study we show that intra-articular injection of human PRG4 in vivo in Prg4^−/− mice prevented caspase-3 activation in superficial zone chondrocytes and was associated with a modest decrease in whole joint friction measured ex vivo using a joint pendulum method. Non-lubricated Prg4^−/− mouse cartilage shows caspase cascade activation caused by mitochondrial dysregulation, and significantly higher levels of peroxynitrite (ONOO⁻ and ⁻OH) and superoxide (O⁻₂) compared to Prg4^+/+ and Prg4^+/− cartilage. Enzymatic activity levels of caspase 8 across Prg4 mutant mice were not significantly different, indicating no extrinsic apoptosis pathway activation. Western blots showed caspase-3 and 9 activation in Prg4^−/− tissue extracts, and the appearance of nitrosylated Cys163 in the active cleft of caspase-3 which inhibits its enzymatic activity. These findings are relevant to patients at risk for arthrosis, from camptodactyl-arthropathy-coxa vara-pericarditis (CACP) syndrome and transient lubricin insufficiency due to trauma and inflammation. Full article