Myxofibrosarcoma involving the sciatic nerve: From ultrasonography to histopathology.

Myxofibrosarcoma (MFS) is a unique soft tissue (fibroblastic) sarcoma, characterized by malignant with a locally infiltrative behavior. In this case image, we aimed to report an uncommon/challenging scenario of MFS involving the scatic nerve in which the potential contribution of ultrasound examination has been touched upon.

Effectiveness of RF ablation and cementoplasty in enhancing functional capacity in pelvic malignant bone metastases.

PURPOSE: Pelvic and sacral bone metastases cause significant morbidity. The primary aim of the study is to thoroughly evaluate the increase in functional capacity resulting from combined RF ablation and cementoplasty surgery applied to malignant bone metastases of the pelvic bones. METHODS: Twenty patients who underwent RF ablation and cementoplasty for malign pelvic bone and sacrum metastases between January 2014 and December 2021 were retrospectively identified. The inclusion criteria were having a life expectancy of more than 1 month, being > 18 years old, and having at least 1 month of follow-up. The Visual Anlogue Scale (VAS) pain, Karnofsky Performance Status (KP), and Musculoskelatal Tumor Society (MSTS) scores were calculated. RESULTS: VAS pain values decreased, and KP values increased postoperatively (p = 0.006 and p = 0,013). There was no statistically significant increase in MSTS (p > 0.05). The correlation relationships between lesion filling ratio and VAS pain, KP, and MSTS scores were not statistically significant (p > 0.05). Cement leakage was observed in 5 patients (25.0%), and no symptoms related to this leakage were observed. CONCLUSION: The pelvic region, given its close proximity to blood vessels, nerves, and joint areas, along with the distinct challenges associated with its surgery, requires separate evaluation. In studies evaluating applications in the isolated pelvic ring region, as in our study, functional gains have been most comprehensively assessed in this study, demonstrating that the procedure results in significant functional improvements.

Early results of a novel modular knee arthrodesis implant after uncontrolled periprosthetic knee joint infection.

AIM: The aim of this study is to evaluate the functional outcomes and complications after non-fusion knee arthrodesis with a modular segmental intramedullary implant used for infected total knee arthroplasty revisions. METHODS: A retrospective review of the patients who had been surgically treated with a modular intramedullary arthrodesis implant for recurrent infection after revision TKA between January 2016 and February 2020 were included. The indications for arthrodesis were failed infected TKA with massive bone loss, deficient extensor mechanism and poor soft tissue coverage that precluded joint reconstruction with revision TKA implants. Clinical outcomes were assesed with visual analogue scale for pain (pVAS), Oxford knee score (OKS) and 12-item short form survey (SF-12). Full-length radiographs were used to verify limb length discrepancies (LLD). RESULTS: Fourteen patients (4 male and 10 female) patients with a mean age of 69.3 (range, 59 to 81) years at time of surgery were available for final follow-up at a mean of 28.8 months (range, 24-35 months). All clinical outcome scores improved at the final follow-up (pVAS, 8.5 to 2.6, p = .01; OKS, 12.6 to 33.8, p = .02; SF-12 physical, 22.9 to 32.1, p = .01 and SF-12 mental, 27.7 to 40.2, p = .01). The mean LLD was 1.0 cm (range, + 15 - 2.3 cm). Re-infection was detected in three patients (21.4%). Two patients were managed with suppressive antibiotic treatment and a third patient required repeat 2-stage revision procedure. In one patient, a periprosthetic femur fracture was observed and treated with plate osteosynthesis. CONCLUSION: Uncontrolled infection after total knee arthroplasty can be effectively treated with arthrodesis using a modular intramedullary nail and satisfactory functional results can be obtained. LEVEL OF EVIDENCE: Level 4, Retrospective cohort study.

Different Attenuation Models of Diffusion-Weighted MR Imaging for the Differentiation of Benign and Malignant Musculoskeletal Tumors.

BACKGROUND: Several functional imaging techniques, including monoexponential diffusion-weighted imaging (m-DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis (DK) imaging, have been used in differentiating benign and malignant musculoskeletal tumors. Combining all three techniques in the same study population may improve differentiation. PURPOSE: To compare the diagnostic performance of m-DWI, IVIM, and DK models and their combinations in differentiating benign and malignant musculoskeletal tumors. STUDY TYPE: Prospective. POPULATION: Fifty patients with benign and malignant musculoskeletal tumors divided into nonmyxoid and nonchondroid and myxoid and/or chondroid subgroups. FIELD STRENGTH/SEQUENCE: A 1.5 T/m-DWI, IVIM, and DK single-shot spin-echo echo-planar sequences. ASSESSMENT: Minimum and volumetric values of apparent diffusion coefficient (ADC), pure molecular diffusion (Divim ), pseudodiffusion (D*), perfusion fraction (f), diffusion coefficient for kurtosis model (DK ), and Kurtosis (K) were compared between all benign and malignant tumors. Subgroup analysis was also performed for nonmyxoid and nonchondroid and myxoid and/or chondroid tumors. STATISTICAL TESTS: Independent samples t-test, Mann-Whitney U test, intraclass correlation coefficient, ROC analysis, and logistic regression analysis. A P value < 0.05 was considered statistically significant. RESULTS: ADCmin , Divim-min , D*vol , DK-min, Kvol, and Kmin values showed statistically significant differences between all benign and malignant tumors and nonmyxoid and nonchondroid tumor subgroup. Kmin showed the highest diagnostic performance in differentiating benign and malignant tumors with AUCs of 0.760 for "all tumors" and 0.825 for the nonmyxoid and nonchondroid tumor subgroup. No significant differences were detected in m-DWI-, IVIM-, and DK-derived parameters for differentiating benign and malignant myxoid and/or chondroid tumors. Only three of 63 combinations of prediction models demonstrated a higher diagnostic performance than Kmin ; however, improvements were not significantly different. DATA CONCLUSION: ADCmin , Divim-min , D*vol , DK-min , Kvol , and Kmin values can be used to differentiate benign and malignant musculoskeletal tumors. Our findings suggest that the added value of multiparametric approach in such differentiation is not significant. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

An Alternative Fixation Option for Subtrochanteric Femur Fractures in Children: Adult Proximal Humerus Plate.

BACKGROUND: Subtrochanteric femur fractures are unstable injuries due to strong muscle forces on the proximal femur. The ideal fixation device is controversial in the treatment of subtrochanteric femur fractures in children. The aim of this study is to evaluate the clinical and radiological outcomes of subtrochanteric femur fractures in children treated with an adult proximal humerus plate. METHODS: A total of 9 patients [mean age at surgery, 8.3 years (range: 7 to 12); mean follow-up period, 28.1 months (range: 12 to 56)] who underwent surgery due to a subtrochanteric femur fracture and treated with an adult proximal humerus between January 2017 and December 2021 were retrospectively evaluated. Four of the patients had a pathological fracture associated with a benign bone tumor while 5 patients had a nonpathological fracture. The clinical and radiological outcomes were assessed using the Flynn scoring system at the latest follow-up. Time to union and complications were recorded. RESULTS: All patients demonstrated a solid fusion of the fracture site and were able to bear full weight at the latest follow-up. The mean time to union was 8.2 weeks (range: 6 to 10). Based on the Flynn scoring system at the latest follow-up, seven patients had excellent clinical outcomes and two patients had satisfactory outcomes. Two patients had limb length discrepancy, and one patient had coxa valga and a limb length discrepancy of 16 mm. There were no patients with nonunion, infection, implant failure, osteonecrosis of the femoral head, and heterotopic bone formation. CONCLUSION: This study suggests that the adult proximal humerus plate may be an effective alternative fixation option in the treatment of subtrochanteric femur fractures in children, including pathological fractures. LEVEL OF EVIDENCE: Level IV, Case series.

Clinical Outcomes of 3-column Osteotomy at Growing Rod Graduation.

BACKGROUND: Several different strategies were described on how to graduate a patient when skeletal maturity is reached after growing rod treatment. A final instrumentation and fusion is commonly performed, but the stiffness of the spine after numerous lenghthenings can be a major problem. When correction is needed in a severe and rigid curve, 3-column osteotomies (3CO) can be used as a method of bringing the spine back to a well-balanced position. This study aims to evaluate the clinical outcomes of 3CO osteotomies at growing rod graduation. METHODS: A retrospective search of the database was performed between 1996 and 2018. Inclusion criteria were: diagnosis of early-onset scoliosis, underwent 3CO at the final fusion procedure, and ≥1 year of follow-up. Indications for this osteotomy were: significant sagittal and/or coronal off-balance or severe crankshaft deformity or significant distal and/or proximal adding-on. Clinical, radiographic, and operative data were analyzed. Complications were classified according to the modified Clavien-Dindo-Sink system. RESULTS: Eight patients were included in the study with a mean age of 13.5 at graduation (male/female: 2/6). The mean scoliosis angle significantly reduced from 65.6 to 39 degrees (P=0.012). Mean T1-T12 height increased from 19 to 20.5 (P=0.084) and T1-S1 from 29.6 to 31.6 (P=0.144). Five patients had a staged surgery. Average operative time was 338 minutes and blood loss was 1321 mL. Four grade 1, 1 grade 2, and 1 grade 3 complications occurred. CONCLUSIONS: This is the first case-series in the literature reporting on the use of 3CO at growing rod graduation. These procedures can be safely and effectively used to overcome significant multiplanar deformity and/or off-balance in the graduation of patients with early-onset scoliosis and significant correction can be achieved on these severe and rigid curves. LEVEL OF EVIDENCE: Level IV-case series.

Posterior Instrumentation and Fusion in Multiple-segment Adolescent Congenital Scoliosis: When Are Posterior Column and Concave Rib Osteotomies Needed?

BACKGROUND: No clear guidelines exist for appropriate surgical treatment of congenital scoliosis. The spectrum varies from isolated posterior instrumentation and fusion (PIF-only) to vertebral column resections. Multiple posterior column osteotomies (PCOs) with and without concave rib osteotomies have previously been suggested as an alternative to invasive 3-column osteotomies. The aim of the study is to analyze outcomes of spinal surgery in congenital scoliosis patients for a new treatment algorithm based on a traction radiograph under general anesthesia (TruGA). METHODS: Surgical intervention was determined according to flexibility with TruGA: patients with >40% correction underwent PIF-only; patients with <40% of correction underwent PCO. Patients, who had <30% of correction in TruGA and/or more than 5 vertebral levels with failure of segmentation, underwent additional concave rib osteotomies. The radiologic and clinical results were compared. RESULTS: Forty-three patients met inclusion criteria (14M). The mean age was 13.8 (10 to 17) years, average follow-up 67 (24 to 107) months. Fourteen patients were in the PIF-only group, 29 in the PCO group. PCO patients were significantly older (14.5 vs. 12.3, P=0.001). Mean operative time and blood loss of PCO group were significantly greater than those of PIF-only group. Nine patients required concave rib osteotomies. While the curve magnitude of patients in the PIF-only and PCO groups did not differ significantly (54.6 vs. 63 degrees, P=0.067), curve rigidity was significantly higher in the patients of PCO group (51.2% vs. 32%, P=0.001). Despite this, postoperative correction rates for 2 groups were similar (51.1% vs. 47.8%, P=0.545). CONCLUSIONS: The number of anomalous segments and the curve flexibility on TruGA play important roles in the decision-making process in congenital scoliosis and <40% flexibility of the major curve could be an important indicator of the need for PCO. Curves with more than 5 anomalous vertebral segments might be more likely to need additional concave rib osteotomies for adequate correction. LEVEL OF EVIDENCE: Level III.

Proximal Humerus Tumors: Higher-than-Expected Risk of Revision With Constrained Reverse Shoulder Arthroplasty.

BACKGROUND: The treatment of proximal humerus tumors with endoprostheses is associated with a high risk of implant-related surgical complications. Because of extensive soft-tissue resection and muscular detachment during surgery, instability is the most common serious complication. A reverse total shoulder arthroplasty with a highly constrained design is one option to mitigate instability, but few studies have reported the results of this prosthesis for proximal humerus tumor resections. QUESTIONS/PURPOSES: (1) What are the short-term functional results of the constrained reverse total shoulder prosthesis in terms of Musculoskeletal Tumor Society (MSTS), DASH, and Constant-Murley scores and ROM values? (2) What is the frequency of revision, using a competing-risks estimator to assess implant survival, and what were the causes of the revisions that occurred? (3) What proportion of patients experienced dislocations at short-term follow-up? METHODS: Between January 2014 and June 2017, we treated 55 patients with proximal humeral resections and reconstructions for malignant tumors. Of those, 33% (18) of patients were treated with the constrained, reverse total shoulder arthroplasty implant under study here. During that period, no other constrained reverse total shoulder implant was used; however, 13% (seven) of patients were treated with conventional (unconstrained) reverse total shoulder implants, 27% (15) had hemiarthroplasties, 15% (eight) of patients had biologic reconstructions with auto- or allografts and 13% (seven) underwent amputation. During the period in question, our general indications for use of the constrained device under study here were resection of the deltoid muscle/axillary nerve or the deltoid insertion on the humerus due to tumor invasion, or extensive rotator cuff and surrounding soft tissue resection that might result in shoulder instability. During this period, these indications were adhered to consistently. Four of 18 patients treated with the study implant died (three died with the implant intact) and none were lost to follow-up before 2 years, leaving 14 patients (seven women and seven men) for study at a median (range) follow-up of 35 months (25 to 65). Two authors evaluated the clinical and functional status of each patient with ROM (flexion, extension, internal and external rotation, abduction, and adduction) and MSTS, (range 0% to 100%), Constant-Murley (range 0% to 100%), and DASH (range 0 points to 100 points) scores. For the MSTS and Constant-Murley scores, higher percentage scores mean better functional outcome; and for the DASH score, a higher score means more severe disability. Radiographs were obtained at each visit and were used to look for signs of loosening, which we defined as progressive radiolucencies between visits, prosthetic component migration, and fragmentation/fracture of the cement. The Sirveaux classification was used to determine scapular notching. A competing risks analysis with 95% confidence intervals was performed to estimate the cumulative incidence of revision surgery, which we defined as any reoperation in which the implant was removed or changed for any reason, with patient mortality as a competing event. RESULTS: At the most recent follow-up, the median (range) MSTS score was 78% (50 to 90), the DASH score was 20 (8 to 65), and the Constant-Murley score was 53% (26 to 83). The median ROM was 75° in forward flexion (40 to 160), 78° in abduction (30 to 150), 35° in internal rotation (10 to 80), and 33° in external rotation (0 to 55). Postoperatively, two of 14 patients underwent or were supposed to undergo revision surgery, and the cumulative incidence of revision surgery was 18% for both 30 and 48 months (95% CI 2 to 45). During the study period, no patients reported instability, and no dislocations occurred. CONCLUSIONS: Our findings are concerning because the revision risk with this constrained reverse total shoulder implant was higher than has been reported by others for other proximal humerus prostheses. The highly constrained design that helps prevent instability might also transmit increased stresses to the humeral component-bone interface, therefore making it susceptible to loosening. We believe that any other implant with a similar degree of constraint will have the same problem, and changing the indications for patient selection may not solve this issue. These theories need to be tested biomechanically, but our desire is to warn surgeons that while trying to prevent instability, one might trade one complication (instability) for another: aseptic loosening. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Denosumab treatment in aneurysmal bone cyst: Evaluation of nine cases.

BACKGROUND: Aneurysmal bone cyst (ABC) is a benign bone tumor. Curettage and bone grafting is the common treatment. Here, we retrospectively evaluate nine patients treated with denosumab. PROCEDURE: Nine patients with ABC, mostly pelvic and vertebral, treated with denosumab were analyzed retrospectively. A 70 mg/m2 denosumab dose was used weekly in the first month, and then monthly. Clinical and radiological responses to treatment were evaluated. RESULTS: In all patients, clinical symptoms including pain and limping regressed completely within 3 months. Radiological evaluation revealed changes in lesion size and content. In six patients, overall volume reduction in the range of 18-82% was detected. Decreases in the size and number of cysts were detected in eight patients. In five patients, fat signal appeared on follow-up imaging. No major side effects were observed during treatment. Median follow-up time after treatment was 15 months. At 5 months, severe hypercalcemia was observed in two patients due to rebound increase in osteoclastic activity. Subsequent to denosumab treatment, three patients underwent surgery for clinical or radiological recurrence. CONCLUSIONS: Our results showed that denosumab provided a meaningful clinical and radiological improvement in ABC. It may be a treatment option, especially in spinal and pelvic tumors with potentially high surgical morbidity. However, late rebound hypercalcemia may restrict its use. Studies with more cases are required for routine use of denosumab in ABC.

Pull-out of Upper Thoracic Pedicle Screws Can Cause Spinal Canal Encroachment in Growing Rod Treatment.

BACKGROUND: Proximal foundation failure is a common complication of growing rod (GR) treatment for early-onset scoliosis. Spinal canal encroachment due to pull-out of pedicle screw used as proximal foundation has been anecdotally reported in GR patients. The aim of this study is to report the prevalence of spinal canal encroachment of pedicle screws in GR treatment and determine risk factors using a single-center cohort. METHODS: Inclusion criteria were: (1) GR for early-onset scoliosis and (2) pull-out of at least 1 proximal anchor pedicle screw. Patients were divided into 2 groups according to the presence of medial screw migration. Medial migration of the screw was confirmed by computed tomography. The extracted data included demographic, clinical, and radiographic information. RESULTS: A total of 21 patients (of 96) met inclusion criteria (21.8%). None of the screws appeared malpositioned on early postoperative x-ray. Average follow-up until screw failure was 50.4 months (64 to 85 mo) and average number of lengthenings 8.1 (4 to 13). Computed tomography revealed canal encroachment in 11 patients (group 1), and no encroachment in 10 (group 2). There was no significant difference between groups for age, follow-up or number of lengthenings. At the time of screw pull-out, coronal plane deformity was increased compared with early postoperative x-ray in all; however, this increase was significantly higher in group 1 (45.7 vs. 35 degrees, P=0.002). Proximal junctional angle (PJA) was increased in both groups at the time of pull-out. While not statistically significant, PJA increased linearly in group 1 but spiked in group 2 at the time of pull-out. There was no neurological event preoperatively, intraoperatively or postoperatively. Failed screws were safely revised in either planned/unplanned surgeries. CONCLUSIONS: In patients with proximal anchor failure of GR, especially if there is increase of coronal deformity and/or PJA, possible spinal encroachment should be kept in mind. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Convex Instrumented Hemiepiphysiodesis With Concave Distraction: A Treatment Option for Long Sweeping Congenital Curves.

BACKGROUND: Convex hemiepiphysiodesis has been reported to have mixed results in the treatment of congenital spine deformities. Multiple modifications of the original technique were suggested to improve the results. The purpose of this study is to report the results and complications of an instrumented convex growth arrest procedure modified with concave distraction. METHODS: The records of 11 patients with long sweeping congenital curves (involving multiple anomalous vertebrae) who underwent convex instrumented hemiepiphysiodesis with concave distraction were evaluated. Mean age at index operation was 58 months (range, 29 to 101 mo). Lengthening of the concave distraction rod was done every 6 months. The magnitude of coronal/sagittal deformity and T1-T12 height were measured on the preoperative, postoperative, and latest follow-up radiographs. Average follow-up was 44.9 months (range, 24 to 89 mo). RESULTS: In the coronal plane, the convex hemiepiphysiodesis segment was corrected from an average of 60.5 to 40.4 degrees postoperatively and further improved to 35.5 degrees at the latest follow-up. The distracted segment was corrected from 33.4 to 15.2 degrees postoperatively and to 12.7 degrees at the latest follow-up. Sagittal plane alignment was minimally affected. The average T1-T12 height was 157.1 mm in the early postoperative period and 181.1 mm at last follow-up. During follow-up, we identified partial pull-out of screws on the distraction side in 5 of the 11 patients and rod breakages in 3 patients. These were revised during planned lengthenings. There were no unplanned surgeries, deep wound infections, nor neurological complications. CONCLUSIONS: Convex instrumented hemiepiphysiodesis with concave distraction resulted in good curve correction while maintaining the growth of thorax. The correction of the anomalous segment improved over time, proving the effectiveness of the hemiepiphysiodesis. Addition of a concave distraction construct appears to enhance spinal growth, thereby augmenting the hemiepiphysiodesis effect.

Evaluation of vacuum-assisted closure in patients with wound complications following tumour surgery.

Covering the reconstructed area with a healthy soft-tissue envelope is a major challenge after limb-sparing surgery in patients with malignant bone and soft-tissue tumours. Negative pressure wound therapy (NPWT) of open wounds hastens healing and minimises the requirement for complex reconstructive soft-tissue surgery. The aim of this study was to investigate the effectiveness and safety of NPWT in bone and soft-tissue malignant tumour patients with postoperative wound complications. Between January 2006 and November 2009, at a single institution, 13 patients with malignant bone and soft-tissue tumours who had undergone wide resection were retrospectively analysed. NPWT was performed in all patients to temporarily close the soft-tissue defects. After obtaining the culture negativity and normal infection markers, definitive soft-tissue reconstruction was performed to close the wound with primary suturisation in two patients, split thickness grafts in four patients, full thickness grafts in two patients, rotational flaps in three patients and free flaps in two patients. Mean duration of hospitalisation was 20 (range 8-48) days and mean follow-up period was 57·3 (range 50-74) months. There was no tumour recurrence or skip metastasis in the follow-up period. In addition, there was no periprosthetic infection or complication associated with NPWT. In conclusion, NPWT therapy seems to be a safe and effective option in the management of local wound problems and secondary surgical site infections after musculoskeletal tumour surgery.

Serial derotational casting in congenital scoliosis as a time-buying strategy.

BACKGROUND: Serial casting is an effective treatment modality in early-onset idiopathic scoliosis; however, the role of this method in congenital scoliosis is not well studied. METHODS: A total of 11 patients with progressive congenital scoliosis were treated with serial cast application. Age at initial cast application, magnitudes of the congenital, compensatory and sagittal deformities, coronal balance, T1 to T12 height, number of casts and time-in cast per patient, subsequent surgical interventions, and complications were evaluated. RESULTS: Mean age at the first cast application was 40 months, and the average number of cast changes was 6.2 per patient. There were no major complications. The average precasting curve magnitude was 70.7 degrees (range, 44 to 88 degrees) and was significantly reduced to 55.1 degrees (range, 16 to 78 degrees) at the latest follow-up (P=0.005). The average precasting compensatory curve was 55.8 degrees (range, 38 to 72 degrees) and was significantly reduced to 39.8 degrees (range, 23 to 62 degrees) at the latest follow-up (P=0.017). Average T1 to 12 height increased from 12.8 cm at post-first cast to a 14.6 cm at the latest follow-up (P=0.04). Average time in cast was 26.3 months (range, 13 to 49 mo). During the treatment period, none of the patients required surgery for curve progression. CONCLUSIONS: Serial derotational casting is a safe and effective time-buying strategy to delay the surgical interventions in congenital deformities in the short-term follow-up. LEVEL OF EVIDENCE: Level IV, case series.

Intralesional curettage and cementation for low-grade chondrosarcoma of long bones: retrospective study and literature review.

BACKGROUND: Various treatment strategies for low-grade chondrosarcomas with variable outcomes have been reported in the literature. The aim of this study was to assess the oncological and functional outcomes associated with intralesional curettage followed by adjuvant therapy comprising high-speed burring, thermal cauterization, and bone cementation with polymethylmethacrylate. METHODS: We performed a retrospective review of 21 consecutive patients with intramedullary low-grade chondrosarcoma of long bones treated by intralesional curettage and adjuvant therapy comprising high-speed burring, thermal cauterization, and cementation at our institution from 2007 to 2012. RESULTS: The average age of the patients was 48.7 (range, 18-71) years. There were 7 male and 14 female patients. The mean follow-up period was 58.4 (range, 26-85) months after surgery. The treated lesions were located in the proximal humerus (n=10), proximal tibia (n=6), and distal femur (n=5). At the average follow-up time point of 58.4 (range, 26-85) months, no patient had developed local recurrence and no distant metastases were observed. The average Musculoskeletal Tumor Society score among all 21 patients was 95% (84-100). CONCLUSIONS: The combination of intralesional curettage, application of high-speed burring, thermal cauterization, and cementation is an effective treatment strategy for low-grade intramedullary chondrosarcoma of long bones. Excellent oncological and functional results can be obtained.

Effects of the fusionless instrumentation on the disks and facet joints of the unfused segments: a pig model.

BACKGROUND: Growing rod (GR) is a state-of-the-art procedure favored when curvatures of the spine cannot be managed nonoperatively in early-onset scoliosis. Although some postulate that multiple distractions and/or relative immobilization of the unfused segments affect the health of disk and facet joint (FJ) and cause degeneration and/or spontaneous fusion, this has not thoroughly been investigated. In this study, changes in the unfused segment after a spine-based fusionless instrumentation (SBFI) are investigated and compared with the control (CG) and instrumented fusion (IF) groups. METHODS: A total of 13 piglets, 10 to 14 weeks of age, were used. SBFI and IF were performed on 7 and 3 piglets, respectively, and 3 formed the CG. In SBFI, lengthening procedures of 5 mm were applied once monthly for 3 months, and, after 4 months, all piglets were euthanized. Histologic sections of the unfused disks and FJ were analyzed, and morphometric histologic analysis was performed. RESULTS: On the basis of the Gries criteria, unfused disk median grades were 1, 2, and 4 for control, SBFI, and IF, respectively, that revealed a statistical difference (P<0.001). Unfused FJ median grades were 1 and 2 for control and SBFI, respectively, that revealed a statistical difference (P<0.001). The mean hypertrophic zone (HZ) heights were 69.78, 84.20, and 66.14 µm; HZ chondrocyte cell widths were 19.03, 18.76, and 17.36 µm; and HZ chondrocyte cell heights were 15.01, 15.04, and 12.42 µm in the CG, SBFI, and IF groups, respectively. Statistically, for HZ heights, SBFI was different compared with CG and IF (P<0.001), and, for HZ chondrocyte cell widths and heights, IF was different compared with CG and SBFI (P<0.001). CONCLUSIONS: Morphometric analysis in this study supports the findings that SBFI preserves the growth potential of the spine. Furthermore, changes in the HZ heights show that distractive forces stimulate the apophyseal growth of the axial skeleton describing how the growth rate of the spine in GR might surpass the normal growth rate. Overall, although some degenerative changes are observed, SBFI and repeated distractions alone are not solely responsible for FJ arthrosis and disk degeneration, given that they are structurally preserved. CLINICAL RELEVANCE: GR and regular lengthening procedures do not impair disk health and preserve the growth potential of the spine if it is applied with a meticulous technique.

Safety and efficacy of instrumented convex growth arrest in treatment of congenital scoliosis.

BACKGROUND: Anterior and posterior convex hemiepiphysiodesis is a widely used surgical alternative in the treatment of congenital scoliosis. This procedure has the disadvantage of the need for both anterior and posterior approaches. Furthermore, outcomes may be unpredictable. Posterior convex growth arrest (CGA) with pedicle screws at each segment on the convex side may obviate the need for anterior surgery and provides more predictable outcomes. This study retrospectively evaluates the safety and efficacy of instrumented posterior CGA in congenital scoliosis. METHODS: Patients who had posterior CGA with convex pedicle screw instrumentation for congenital scoliosis were evaluated retrospectively. Thirteen patients (6 male, 7 female) were included in the study. Preoperative, early postoperative, and last follow-up standing posteroanterior and lateral x-rays were evaluated. Cobb angles were recorded for the instrumented segment (main curve). Global thoracic kyphosis was measured between T2 and T12 on sagittal plane. These values were compared preoperatively, postoperatively, and at last follow-up. The T1-S1 vertical height and the height between the concave side pedicles of the upper and lower end vertebra of the main curve was also determined and recorded as the concave height. RESULTS: The average follow-up was 56.1±10 months (range, 36 to 74 mo) and the average age of the patients at the time of operation was 64.5±30.1 months (range, 15 to 108 mo). All patients were Risser zero at the time of surgery. The average curve magnitude was 49±10.9 degrees (range, 34 to 68 degrees) preoperatively, 38.3±9.7 degrees (range, 28 to 58 degrees) early postoperatively, and 33.5±12.4 degrees (16 to 52 degrees) at last follow-up. There was a significant difference between the preoperative and early postoperative main curve Cobb angle measurements (P=0.001). The average concave height was 94.2±20.2 mm in the early postoperative period and 104.7±21.7 mm at last follow-up (P=0.003). The average T1-S1 height was 292.1±67.1 mm in the early postoperative period and 363.9±94.5 mm at last follow-up (P=0.005). There was at least ≥5 degrees improvement in 9 of the 12 patients in the follow-up period after the index procedure. In 3 patients, the curve did not change and the correction was maintained. Curve progression was observed in 1 patient due to a technical error. There were no wound infections or instrumentation failures during follow-up. CONCLUSIONS: Instrumented CGA can safely be used in long sweeping curves of immature spines. Using this technique; thoracotomy, anterior procedure, and 2-stage surgery can be avoided. Moreover, it guarantees some degree of correction in all patients because of the instrumentation effect, eliminating the unpredictable nature of classic CGA. LEVEL OF EVIDENCE: Therapeutic level IV study.

Long-term results of reconstruction with pelvic allografts after wide resection of pelvic sarcomas.

Reconstruction after the resection of a pelvic tumor is a challenging procedure in orthopedic oncology. The main advantage of allograft reconstruction is restoration of the bony architecture of the complex pelvic region. However, high complication rates such as infection and allograft resorption had been reported in the literature. In this study, we aimed to retrospectively review nine patients treated with pelvic resection and structural pelvic allograft reconstruction. Functional results, complications, and survival of the patients and the allografts were evaluated. At a mean follow-up of 79 months, three patients were dead. Major complications were detected in eight of the nine patients. Infection (four of the nine patients) and allograft resorption (three of the nine patients) were the most common causes of failure. The cumulative survival of the patients was 66.7 percent at 70 months. However, allograft survival was only 26.7 percent at 60 months. Mean MSTS score was 69. In conclusion, we suggest that other reconstruction options should be preferred after pelvic resections because of the high complication rates associated with massive allograft reconstruction.

Primary Cutaneous Adenoid Cystic Carcinoma in a Rare Location With an Immune Response to a BNT162b2 Vaccine: A Case Report.

CASE: In this report, a rare case of primary cutaneous adenoid cystic carcinoma (PCACC) localized in the subcutaneous tissue of the scapular region that grew after BNT162b2 corona virus disease of 2019 (COVID-19) vaccination is presented and may be explained by CD4 and CD8 cell infiltration. The BNT162b2 mRNA vaccine has been associated with a multisystem inflammatory syndrome (MIS-V). A comparable immune reaction could potentially enhance tumor growth rate. CONCLUSION: Primary cutaneous adenoid cystic carcinomas are rare tumors with unique locations. Further studies with case series are required to establish management algorithms for PCACC and investigate the potential effect of vaccination.

Comparison of the Results of Patients Treated With Limb-Sparing Treatment Options in Malignant Bone Tumors: Sharing the Experience of Twelve Bicentric Patients.

OBJECTIVES: Extremity-sparing surgery should be the main objective if a functional extremity is to be obtained in cases of malignant bone tumors. After extensive resection, numerous techniques have been described to reconstruct bone defects. This study aimed to compare the outcomes of patients who underwent external radiation therapy and liquid nitrogen biological reconstruction at two different facilities. METHODS: The study included 12 patients who received biological reconstruction therapy for bone sarcoma and had at least two years of follow-up. Demographic data, pathological diagnosis, presence of systemic metastasis, and recurrence during follow-up were among the information logged. Patients who used liquid nitrogen were placed in group 1, and those who underwent external irradiation were placed in group 2. After being contacted for their final follow-up appointments, the outcomes were compared by recording the Musculoskeletal Tumor Society Score (MSTSS). RESULTS: For participants with a mean age of 10.75±3.6 (5-17), the follow-up period was 30.2±16.3 months in total. In contrast to the patients in group 1, who experienced union on average after 7.5±1.2 months, those in group 2 experienced union after 7.6±1.1 months. Patients in group 1 had an MSTSS of 75.5±11.8%, while those in group 2 had a score of 77±4.4. There was no discernible difference between the two groups' union times (p>0.05). There was no statistically significant difference between the two groups' MSTSS (p>0.05). CONCLUSION: After tumor resection, extracorporeal radiation therapy and the application of liquid nitrogen are still useful treatment options and neither of them is superior to the other.

Lateral Collateral Ligament and Biceps Femoris Tendon Fixation with a Suture Anchor to the Tibial Metaphysis after Proximal Fibula En Bloc Resections Preserve Lateral Knee Stability.

This study aims to analyze the functional outcomes and lateral knee stability of patients who underwent lateral collateral ligament (LCL) and biceps femoris tendon reconstruction with suture anchors after proximal fibula en bloc resection for bone tumors. Patients who underwent proximal fibular en bloc resection between 2007 and 2018 were retrospectively viewed. Patients were invited to visit the clinic, and their functional scores were evaluated using the Musculoskeletal Tumor Society Scoring (MSTS) system. Lateral knee stability was evaluated by varus stress radiographs obtained at 20 degrees of flexion, and the range of motion (ROM) of the bilateral knee was assessed. Side-to-side differences were graded according to the International Knee Documentation Committee (IKDC) criteria and compared between types I and II resections. A total of 17 patients (4 males and 13 females) with a mean age of 31.1 ± 17.1 (range: 13-65) years at the time of surgery were available for radiological and clinical examination at a mean follow-up of 68.6 ± 36.4 (range: 22-124) months after surgery. In terms of ROM measurements, IKDC grades and side-to-side differences in both flexion and extension were not significantly different between the groups. On varus stress radiographs, lateral knee gapping was measured to be 0.93 ± 0.91 mm in type-I resections and 1.83 ± 0.45 mm in type-II resections, and statistically significant differences were detected among the groups (p = 0.039). When the values were graded according to IKDC criteria, none of the knees were classified as abnormal, and no difference was observed between the groups. Mean MSTS score of patients with type-I resections was significantly higher than those of patients with type-II resections (92.7 vs. 84.4%, p = 0.021). In the subscale analysis, a significant difference was observed in the support scores (type I = 94.5%, type II = 70%; p = 0.001). The reattachment of LCL and biceps femoris tendon to the tibial metaphysis with a suture anchor is a simple and effective method to prevent lateral knee instability after proximal fibula resections.