BACKGROUND: Brucellosis, historically endemic to northern China, has recently shown a southward spread into previously nonendemic regions. Although brucellar spondylitis represents one of the most disabling complications...BACKGROUND: Brucellosis, historically endemic to northern China, has recently shown a southward spread into previously nonendemic regions. Although brucellar spondylitis represents one of the most disabling complications of the disease, its clinical and epidemiologic characteristics in these emerging southern regions remain poorly defined, warranting further investigation. QUESTIONS/PURPOSES: Among patients diagnosed with brucellar spondylitis from nonendemic regions of southern China, we asked: (1) What are the predominant clinical and laboratory findings? (2) For focal lesion aspiration cultures and blood cultures, what proportion of patients had positive cultures and what factors were associated with having positive cultures? (3) What are the characteristic imaging findings? (4) At a minimum 1-year follow-up, what were the proportions of patients with mild sequelae (exertional pain without functional impairment), moderate sequelae (neurologic deficits or work interference), treatment failure, and infection recurrence? METHODS: Between January 2015 and April 2025, we treated 47 patients with brucellar spondylitis at a tertiary medical center in a nonendemic region of southern China. Two patients were excluded because of incomplete clinical records, leaving 45 patients for the baseline analyses. An additional seven patients were excluded from the evaluation of clinical outcomes and sequelae: three because follow-up after completion of therapy was shorter than 1 year and four because they were lost to follow-up after completion of therapy before reaching the minimum 1-year follow-up threshold; this left 38 patients for outcome evaluation. The baseline cohort had a mean ± SD age of 55 ± 11 years; 49% (22 of 45) were women, 58% (26 of 45) lived in rural areas, and 38% (16 of 42) had high-risk occupations. Diagnosis required compatible imaging findings on CT or MRI (including vertebral destruction, disc involvement, or localized abscess formation) together with laboratory confirmation (positive blood culture or focal lesion aspiration culture for Brucella or a standard agglutination test titer of at least 1:100). Demographic, epidemiologic, clinical, laboratory, microbiologic, and imaging data were extracted from electronic medical records. CT and MRI were used to assess vertebral destruction, disc involvement, and abscess formation. All 45 patients received doxycycline-based combination antimicrobial therapy; 76% (34 of 45) were treated nonoperatively with antibiotics and external bracing, whereas 24% (11 of 45) underwent surgery. Clinical outcomes assessed at a minimum of 1 year included recovery, treatment failure, recurrence, and sequelae; recovery was defined as no clinical evidence of ongoing infection at final follow-up. Categorical and continuous variables were compared using the Fisher exact test and independent-samples t-test, respectively, with Bonferroni correction for multiple comparisons. RESULTS: The most common clinical manifestations were low back pain (82% [37 of 45]) and fever (58% [26 of 45]). In addition, 42% (19 of 45) of patients presented with localized neck or back pain, sometimes with radicular symptoms, but without prominent systemic manifestations; inflammatory markers generally were elevated despite largely normal white blood cell counts. Brucella species were isolated more often from focal lesion aspiration cultures than from blood cultures (62% [21 of 34] versus 48% [12 of 25]). Prior antibiotic exposure was less common among patients with positive blood cultures than among those with negative blood cultures (25% [3 of 12] versus 77% [10 of 13], OR 0.1 [95% confidence interval (CI) 0.02 to 0.63]; p = 0.02), whereas positive focal lesion aspiration cultures were associated with higher C-reactive protein levels (56 ± 29 mg/L versus 30 ± 26 mg/L, mean difference 26 [95% CI 6.26 to 46.20]; p = 0.01) and lower albumin levels (30 ± 5 g/L versus 36 ± 4 g/L, mean difference -6 [95% CI -8.80 to -2.34]; p = 0.001). Because only the association between lower albumin level and positive focal lesion aspiration culture met the Bonferroni-adjusted threshold, the associations with prior antibiotic exposure and C-reactive protein level should be interpreted as exploratory. Imaging showed vertebral destruction with sclerosis on CT in 89% (40 of 45) of patients, whereas all patients evaluated with MRI (100% [43 of 43]) had abnormal vertebral signal, often with paravertebral abscesses (30% [13 of 43]) or epidural abscesses (44% [19 of 43]). The lumbar spine (42% [19 of 45]) and lumbosacral junction (33% [15 of 45]) were the most commonly involved regions, and 64% (29 of 45) of patients had lesions confined to two adjacent vertebrae. At a minimum 1-year follow-up, 95% (36 of 38) of patients recovered, 5% (2 of 38) experienced treatment failure, and no patient had recurrence; mild and moderate sequelae were observed in 32% (12 of 38) and 11% (4 of 38) of patients, respectively. CONCLUSION: In nonendemic regions, clinicians may wish to consider brucellar spondylitis earlier in patients with unexplained back pain, elevated inflammatory markers, and a relatively normal white blood cell count, even when systemic symptoms are limited. Early serologic screening and, whenever feasible, microbiologic sampling before empirical antimicrobial therapy may help support the diagnosis. Because outcome analyses were restricted to patients who completed at least 1 year of follow-up, the reported outcomes may be overly favorable. Future multicenter prospective studies are needed to better define factors associated with culture positivity and early predictors of clinical outcomes and sequelae. LEVEL OF EVIDENCE: Level IV, therapeutic study.
BACKGROUND: Implantation of titanium alloys (Ti-6Al-4V) or cobalt-chromium-molybdenum alloys (Co-Cr-Mo) for long-segment spinal fixation is the standard surgical treatment for adolescent idiopathic scoliosis (AIS), but l...BACKGROUND: Implantation of titanium alloys (Ti-6Al-4V) or cobalt-chromium-molybdenum alloys (Co-Cr-Mo) for long-segment spinal fixation is the standard surgical treatment for adolescent idiopathic scoliosis (AIS), but long-term presence of the implants in the body may lead to the release of metal nanoparticles. Unlike orthopaedic internal fixation surgeries, spinal implants generally remain in the human body for a lifetime. The release of metal nanoparticles remains a potential clinical issue, but currently there is a lack of strong data on the topic. This study aimed to fill this crucial knowledge gap by providing longitudinal evidence on the dynamics of metal ion release. This is the first step in determining safety characteristics and clinical thresholds. QUESTIONS/PURPOSES: (1) Are serum Ti, Co, and Cr concentrations in patients with AIS after implantation elevated compared with in patients without implantation over a 4-year period? (2) Does surgical removal of implants lead to a reduction in systemic metal nanoparticle load? (3) Is there a correlation between metal ion levels and implant burden? (4) Does implant type (Ti-6Al-4V versus Co-Cr-Mo) influence serum metal concentrations? METHODS: This was a single-center retrospective cohort study performed at an urban tertiary referral hospital from January 2018 to December 2020. A total of 336 patients with AIS were included, including 60% (201 of 336) who underwent surgical treatment and 40% (135 of 336) who received nonsurgical treatment. Among the 201 patients who underwent AIS operations, 6% (13 of 201) were excluded because of the presence of metal implants in other parts (ulna and radius [n = 5], around the elbow joint [n = 4], femoral shaft [n = 4]), and 15% (31 of 201) were excluded because they were lost to follow-up, resulting in incomplete clinical data. Forty-eight percent (96 of 201) of the patients only received spinal implant treatment without revision surgery (implant group), 23% (46 of 201) of the patients received spinal implant treatment and underwent revision surgery but did not have the implants removed (revision group), and 7% (15 of 201) of the patients received spinal implant treatment, underwent revision surgery, and had the implants removed (removal group). Among the 135 patients with AIS who did not undergo surgery, 6% (8 of 135) were excluded because of the presence of metal implants in other parts (ulna and radius [n = 3], around the elbow joint [n = 3], femoral shaft [n = 2]), and 16% (22 of 135) were excluded because they were lost to follow-up, resulting in incomplete clinical data. Seventy-eight percent (105 of 135) of the patients who did not undergo surgery who met the inclusion criteria were ultimately included in the control group. Since 2015, according to a standardized protocol, serum samples from patients undergoing surgery for AIS and from the nonsurgical control group have been collected. This is part of a broader and ongoing research project for patients with AIS. Between February and April 2025, we determined the metal ion concentrations in the collected blood samples. Serum Ti, Co, and Cr levels were measured via inductively coupled plasma mass spectrometry at multiple postoperative time points. The correlation between metal ion levels and rod length as well as the number of screws were evaluated using correlation analysis. Linear regression analysis was employed to assess the relationship between implant types (Ti-6Al-4V and Co-Cr-Mo), rod diameter, and serum metal concentrations. The extracted implants were subjected to scanning electron microscopy (SEM) combined with energy-dispersive x-ray spectroscopy analysis to examine the surface morphology and elemental composition of the implants. RESULTS: Serum concentrations of Ti, Co, and Cr were higher in patients with spinal implants than in nonsurgical controls at all postoperative time points. At 48 months, the mean ± SD serum Ti was 1.1 ± 0.3 μg/L in the implant group versus 0.2 ± 0.1 μg/L in controls (mean difference 0.9 μg/L [95% confidence interval (95% CI) 0.8 to 1.0]; p < 0.001), for Co it was 0.3 ± 0.2 μg/L versus 0.2 ± 0.1 μg/L (mean difference 0.1 μg/L [95% CI 0.1 to 0.2]; p < 0.001), and for Cr it was 1.0 ± 0.5 μg/L versus 0.1 ± 0.1 μg/L (mean difference 0.9 μg/L [95% CI 0.6 to 0.7]; p < 0.001). Metal levels peaked at 12 months postoperatively and remained elevated for 48 months. Implant removal was associated with a reduction in serum metal concentrations. At 6 months after removal, Ti levels decreased by 1.8 μg/L (95% CI -2.1 to -1.6; p < 0.001), Co levels by 0.4 μg/L (95% CI -0.5 to -0.3; p < 0.001), and Cr levels by 1.2 μg/L (95% CI -1.4 to -1.0; p < 0.001) compared with the removal group. At 12 months after removal surgery, there was no difference in Ti ion concentration between the removal group and the control group (0.2 ± 0.2 versus 0.2 ± 0.1, mean difference 0.0 [95% CI -0.2 to 0.1]; p = 0.38). Similarly, no difference was observed in Co ion concentration (0.2 ± 0.1 versus 0.2 ± 0.1, mean difference 0.0 [95% CI -0.1 to 0.1]; p = 0.62). Additionally, Cr ion concentration did not differ between groups (0.2 ± 0.1 versus 0.1 ± 0.1, mean difference 0.1 [95% CI -0.2 to 0.1]; p = 0.45). Serum metal concentrations correlated positively with implant load (rod length r = 0.85 to 0.87, number of screws r = 0.87 to 0.88; all p < 0.001) and rod diameter (β = 0.54 to 0.58; all p < 0.001).The serum Co concentration had a substantial positive correlation with the use of Co-Cr-Mo implants (β = 0.54; p < 0.001). Similarly, the serum Cr concentration had a substantial positive correlation with the use of Co-Cr-Mo implants (β = 0.58; p < 0.001). SEM analysis confirmed implant surface corrosion and nanoscale defects consistent with metal release. CONCLUSION: Serum levels of Ti, Co, and Cr increase after posterior spinal fusion in patients with AIS, reaching a peak at 12 months after operation, and remaining elevated for at least 4 years, which suggests continuous release of metal ions from the implants. Removal of the implants was associated with a reduction in serum metal ion levels, confirming that the implants are the main source of metal nanoparticle release. The concentration of metal ions is related to the burden of the implant (such as the length of the rod and the number of screws) and the type of implant. However, the clinical importance of elevated metal ions needs further confirmation. Our findings are preliminary and do not support routine metal ion tests or imaging examinations in patients with AIS treated surgically or recommendations regarding implant removal; however, future research may attempt to correlate ion levels with symptoms or imaging results in the study environment. LEVEL OF EVIDENCE: Level III, therapeutic study.
BACKGROUND: Proximal femoral valgus osteotomy is a recognized salvage procedure for managing hinge abduction in Perthes disease. Although proximal femoral valgus osteotomy aims to improve joint congruency, previous studi...BACKGROUND: Proximal femoral valgus osteotomy is a recognized salvage procedure for managing hinge abduction in Perthes disease. Although proximal femoral valgus osteotomy aims to improve joint congruency, previous studies have been limited by heterogeneous methodologies and concomitant procedures, making it difficult to determine its isolated effect. Furthermore, no study of which we are aware has specifically examined how proximal femoral valgus osteotomy influences acetabular development or lower limb alignment over time. QUESTIONS/PURPOSES: (1) Is isolated proximal femoral valgus osteotomy associated with improvements in femoral sphericity and proximal femur development at skeletal maturity? (2) Is it associated with promotion of acetabular development? (3) Is it associated with changes in the lower limb mechanical axis? METHODS: Between November 2000 and December 2020, we treated 33 patients using proximal femoral valgus osteotomy for painful hinge abduction deformity associated with Perthes disease, which was initially suspected through serial clinical examinations and confirmed during examination under anesthesia combined with arthrographic findings. All 33 patients who met diagnostic criteria during the study period were treated with the same operation (except as specified below), and all were accounted for at a minimum of 5 years of follow-up and considered potentially eligible for study here. Of these, eight patients were excluded for prespecified reasons (bilateral surgery, use of shelf procedure or limb lengthening procedure, or skeletal immaturity at the most recent follow-up), leaving 25 patients, with a mean ± SD follow-up of 13 ± 5 years; two of those patients had not been evaluated within the past 5 years, although both had achieved skeletal maturity at their most recent follow-up (19 and 20 years of age, respectively). The mean ± SD age was 9 ± 2 years at the time of surgery and 22 ± 5 years at the most recent follow-up. Femoral head morphology was assessed using the sphericity deviation score, a continuous measure that quantifies the shape of the femoral head, with values < 10 considered spherical. Proximal femoral alignment was evaluated using the neck-shaft angle and the articulotrochanteric distance, with higher neck-shaft angles indicating coxa valga, lower angles indicating coxa vara, and reduced articulotrochanteric distances indicating relative overgrowth or proximal migration of the greater trochanter. Acetabular development was assessed using the center-edge angle and the Sharp angle, with lower center-edge angles and higher Sharp angles associated with acetabular dysplasia. The alignment of the lower limb was assessed at the most recent follow-up. The hip shape at the most recent follow-up was assessed using both the Stulberg classification and the head-acetabulum-trochanter (HAT) system. The Stulberg classification categorizes hips at skeletal maturity as from Class I (a normal hip) to Class V (a flattened femoral head with a normal neck and acetabulum). The HAT classification assesses the femoral head, acetabulum, and greater trochanter, with higher scores indicating greater residual deformity (≤ 3 is considered a "good" outcome). Pain was assessed using the VAS during activities of daily living. Hip ROM was measured at the most recent follow-up. RESULTS: Proximal femoral valgus osteotomy was associated with improvement in femoral head sphericity, as the mean ± SD sphericity deviation score improved from 62 ± 19 before surgery to 34 ± 22 at the most recent follow-up (mean difference 28 [95% confidence interval (CI) 16 to 41]; p < 0.001). The neck-shaft angle increased postoperatively but partially remodeled, while the articulotrochanteric distance returned toward preoperative levels. Proximal femoral valgus osteotomy was also associated with improvements in acetabular development, as the center-edge angle progressively increased and the Sharp angle decreased. The Stulberg classification was Class II in three hips, Class III in 15, Class IV in three, and Class V in four, while 13 hips had a HAT score of ≤ 3, representing a good outcome on that parameter. The mechanical lateral distal femoral angle was 84° ± 2° on the affected side and 86° ± 2° on the contralateral side (mean difference -2° [95% CI -3° to -1°]; p = 0.001), whereas no differences were observed in the other mechanical angles. On the VAS, preoperative scores ranged from 6 to 10, whereas scores at the most recent follow-up ranged from 0 to 2. The overall hip ROM was within normal limits, with internal rotation demonstrating a slight reduction. CONCLUSION: Isolated proximal femoral valgus osteotomy for hinge abduction deformities was associated with improvements in femoral head sphericity and acetabular development in patients with Perthes disease. We recommend a paradigm shift in which proximal femoral valgus osteotomy may be regarded more as a joint preservation procedure than as a salvage operation. Future research is warranted to evaluate the potential influence of patient age and disease stage on outcomes and to further define the indications for additional acetabular procedures in hinge abduction deformities. LEVEL OF EVIDENCE: Level IV, therapeutic study.
BACKGROUND: Medial meniscus posterior root (MMPR) tears are more commonly observed in female patients with preexisting osteoarthritis (OA); however, the histopathologic basis for medial root predilection and female predo...BACKGROUND: Medial meniscus posterior root (MMPR) tears are more commonly observed in female patients with preexisting osteoarthritis (OA); however, the histopathologic basis for medial root predilection and female predominance remains unclear. QUESTIONS/PURPOSES: (1) Is histopathologic degeneration associated with knee OA that selectively affects the MMPR? (2) Is greater histologic degeneration of the meniscus root insertion observed in female patients compared with male patients? (3) Do patients with varus alignment and severe OA exhibit greater tissue degeneration at the meniscus root insertion? METHODS: This histologic study analyzed menisci harvested from patients with OA undergoing TKA between August 2024 and July 2025. Patients with a history of prior meniscal surgery, rheumatologic or gouty arthritis, or previous cruciate or collateral ligament injury and those who declined participation were excluded. Of 122 eligible patients, 1% (1) declined, the meniscal root could not be retrieved in 18% (22), and tissue quality was insufficient in 11% (13). The final cohort included 86 patients, yielding 138 posterior meniscal roots: 69 MMPR and 69 lateral (LMPR). Of those, 63% (54) of patients were female. Mean ± SD age did not differ between the MMPR and LMPR groups (72 ± 7 versus 73 ± 7 years; p = 0.28). The severity of OA, assessed by Kellgren-Lawrence (KL) grade, was similarly distributed (MMPR Grade III 35% [24 of 69], Grade IV 65% [45 of 69] versus LMPR Grade III 38% [26 of 69], Grade IV 62% [43 of 69]; p = 0.85). Mean ± SD hip-knee-ankle angle was comparable (MMPR 7° ± 6° varus, LMPR 8° ± 6° varus; p = 0.33). American Society of Anesthesiologists (ASA) classification was similar, with 17% of patients with MMPR and 14% of those with LMPR classified as having ASA III, and the remainder as having ASA II. Sagittal root insertions were stained with hematoxylin and eosin and Masson trichrome. Meniscal degeneration was evaluated using the modified Pauli score, a semiquantitative histologic grading system ranging from 0 to 12, with higher scores indicating greater tissue degeneration. Paired comparisons were performed in a subgroup of 52 patients in whom both menisci were analyzed. Linear regression was used to assess associations between histologic degeneration, demographic and clinical variables, and lower-limb alignment within each root group. RESULTS: Histologic degeneration was more severe in MMPRs than LMPRs (mean ± SD modified Pauli score 6.6 ± 2.6 versus 2.7 ± 1.6; p < 0.001), particularly in female patients (6.3 ± 2.5 versus 2.9 ± 2.1; p < 0.001). In 52 patients with paired samples, medial roots again showed more severe degeneration (5.3 ± 2.6 versus 2.2 ± 1.9; p < 0.001), with the shiny white fibers of the medial insertion most severely affected, especially in female patients. A moderately strong correlation was observed between the degree of varus alignment and the severity of MMPR degeneration, with greater varus associated with more severe degeneration (r = 0.54; p < 0.001). After controlling for potentially confounding variables such age, severity of preexisting OA, and lower-limb alignment, we found that male sex was associated with less severe degeneration (β = -2.63 [95% confidence interval (CI) -3.90 to 1.36]; p < 0.001), whereas KL grade IV was associated with more advanced root degeneration (β = 1.87 [95% CI 0.59 to 3.13]; p < 0.001). CONCLUSION: OA was associated with more severe MMPR degeneration, particularly within the shiny white fibers, with the greatest degree of degeneration observed in female patients with advanced OA and in varus-aligned knees. CLINICAL RELEVANCE: These OA-related histopathologic changes may contribute to the higher incidence of medial root tears in female patients presenting with preexisting OA and varus malalignment. Moreover, highlighting the histopathologic changes of root insertional degeneration in the presence of additional risk factors may help identify, prevent, and manage MMPR injuries more effectively. These findings may ultimately contribute to improved patient care and long-term success in meniscal root repair.