Proximal Junctional Degeneration and Failure Modes: A Novel Classification and Clinical Implications.

STUDY DESIGN: Case-control study. OBJECTIVE: To introduce a classification system that will include the major types of degenerative changes and failures related to the proximal junction, and to determine the clinical course and characteristics for the different types of proximal junctional degeneration (PJD). SUMMARY OF BACKGROUND DATA: Proximal junctional kyphosis (PJK) and failures are well recognized after adult spinal fusion, however, a standardized classification is lacking. METHODS: The proposed system identified four different patterns of PJD: Type 1 (multi-level symmetrical collapse), Type 2 (Single adjacent level collapse), Type 3 (fracture) and Type 4 (spondylolisthesis). A single center database was reviewed from 2018 to 2021. Patients ≥18 years of age, who underwent posterior spinal fusion of ≥3 levels with an upper instrumented vertebral level between T8-L2, and a follow-up of ≥2 years were included. Radiographic measurements, revision surgery and time to revision were the primary outcomes. RESULTS: 150 patients were included with a mean age of 65.1 (±9.8) years and a mean follow-up of 3.2 (±1) years. 69 patients (46%) developed significant degenerative changes in the proximal junction, and were classified accordingly. 20 (13%) were Type 1, 17 (11%) were Type 2, 22 (15%) were Type 3 and 10 (7%) were Type 4. Type 3 had a significantly shorter time to revision with a mean of 0.9 (±0.9) years. Types 3 and 4 had greater preoperative sagittal vertical axis, and Types 1 and 3 had greater final follow-up lumbar lordosis. Bone density measured by Hounsfield units showed lower measurements for Type 3. Types 1 and 4 had lower rates of developing PJK. Type 1 had the lowest revision rate with 40% (types 2, 3 and 4 were 77%, 73% and 80%, respectively, P=0.045). CONCLUSION: This novel classification system defines different modes of degeneration and failures at the proximal junction, and future studies with larger sample sizes are needed for validation. LEVEL OF EVIDENCE: 3.

Immediate Postoperative Change in the Upper Instrumented Screw-Vertebra Angle Is a Predictor for Proximal Junctional Kyphosis and Failure.

STUDY DESIGN: Retrospective review. OBJECTIVES: To determine if change in position of upper instrumented vertebral (UIV) screw between intraoperative prone and immediate postoperative standing radiographs is a predictor for proximal junctional kyphosis or failure (PJK/PJF). SUMMARY OF BACKGROUND DATA: Cranially directed UIV screws on post-operative radiographs have been found to be associated with PJK. Change in the screw position between intraoperative and immediate postoperative radiographs has not been studied. METHODS: Patients with posterior fusion ≥3 levels and UIV at or distal to T8, and minimum 2-year follow-up were identified from a single center database. Primary outcomes were radiographic PJK/PJF or revision for PJK/PJF. Demographic, surgical and radiographic variables, including intraoperative screw-vertebra (S-V) angle, change in S-V angle, direction of UIV screw (cranial-neutral-caudal) and rod-vertebra (R-V) angle were collected. RESULTS: 143 cases from 110 patients were included with a mean age of 62.9 years and a follow-up of 3.5 years. 54 (38%) cases developed PJK/PJF, of whom 30 required a revision. Mean S-V angle was -0.9°±5.5° intraoperative and -2.8°±5.5° postoperative. The group with PJK/PJF had a mean S-V angle change of -2.5°±2.4 while the rest had a change of -1.0°±1.6 (P=0.010). When the change in S-V angle was <5°, 33% developed PJK, this increased to 80% when it was ≥5° (P=0.001). Revision for PJK/PJF increased from 16% to 60% when S-V angle changed ≥5° (P=0.001). Regression analysis showed S-V angle change as a significant risk factor for PJK/PJF (P=0.047, OR=1.58) and for revision due to PJK/PJF (P=0.009, OR=2.21). CONCLUSIONS: Change in the S-V angle from intraop prone to immediate postop standing radiograph is a strong predictor for PJK/PJF and for revision. For each degree of S-V angle change, odds of revision for PJK/PJF increases by 2.2x. A change of 5° should alert the surgeon to the likely development of PJK/PJF requiring revision.

Safety and efficacy of growth-friendly instrumentation for early-onset scoliosis in patients with spinal muscular atrophy type 1 in the disease-modifying treatment era.

Purpose: To evaluate the safety of growth-friendly instrumentation for early-onset scoliosis (EOS) in patients with spinal muscular atrophy (SMA) type 1 who received disease-modifying treatment (DMT) and analyze short-term efficacy. Methods: Retrospective search was conducted between 2017 and 2023. Patients with genetically confirmed SMA type 1 who were surgically treated for spinal deformity and receiving DMTs (nusinersen, risdiplam, or onasemnogene abeparvovec) were included. SMA types 2 and 3 and patients who do not receive DMTs were excluded. Clinical and radiographic data were collected at preoperative, postoperative, and latest follow-up visits. Results: Twenty-eight patients (mean follow-up: 16 months (range 2-41)) were included. The mean age at surgery was 60 months (range 29-96). Fifteen were treated with dual magnetically controlled growing rods (MCGR), four with unilateral MCGR and a contralateral guided growth system, three with Vertical Expandable Prosthetic Titanium Rib (VEPTR®) implants, five with self-distracting systems, and one with traditional dual growing rods. The mean amount of correction was 57% (44°± 17) for scoliosis and 83% (13°± 11) for pelvic obliquity. The mean T1-12 height gain during surgery was 31 mm (±16 mm), while the mean T1 S1 height gain was 51 mm (±24 mm), and instrumented growth was observed during follow-up. Five patients (18%) developed six serious adverse events: three surgical site infections, two anchor failures, and one rod fracture, and all required unplanned reoperations. No neurologic complication, difficulty during nusinersen injections, or respiratory decline was recorded. Conclusion: We report that spinal deformity in this population can be safely treated with growth-friendly instrumentation, with similar complication rates when compared with SMA type 2.

Management of low back pain accompanying sagittal plane pathologies in children: Spondylolysis/spondylolisthesis and Scheuermann's disease.

Background: Low back pain in childhood was underappreciated for a long time, but recent studies report higher prevalences, up to 70%. Two of the common causes are spondylolyis/spondylolisthesis and Scheuermann's disease. These disorders are relevant in a way they both cause significant back pain, and may disrupt the sagittal spinal balance. Purpose: To present the current evidence on the diagnosis, natural history and treatment of these disorders with a special focus on sagittal spinal alignment. Methods: This study is conducted as a literature review. Results and Conclusions: Spondylolysis and low-grade spondylolisthesis have a benign course and are typically treated conservatively. When pars repair is indicated, pedicle screw-based techniques achieve more than 90% fusion with acceptable complication rates. High-grade spondylolisthesis, however, is frequently progressive. Surgical treatment involves fusion, which can be done in situ or after reduction. Reduction is useful for "unbalanced" patients to acquire sagittal spinopelvic balance, and it is important to distinguish these patients. Despite lowering the risk for pseudoarthrosis, reduction brings a risk for neurologic complications. With re-operation rates as high as 40%, these patients definitely require careful preoperative planning. Scheuermann's disease generally causes back pain in addition to cosmetic discomfort during adolescence. If the kyphosis is lower than 60°, symptoms typically resolve into adulthood with conservative measures only. However, it must be kept in mind that these patients may experience problems with physical performance and have a lower quality of life even when the problem seems to have "resolved". Severe kyphosis and intractable back pain are the most frequently referred surgical indications, and surgery typically involves fusion. Proper utilization of osteotomies and proper selection of the upper and lower fusion levels are of utmost importance to prevent complications in these patients.

Predictive value of different glycemic control markers in total hip or knee arthroplasty: A prospective study.

OBJECTIVE: The optimal glycemic control marker before total hip or knee arthroplasty remains inconclusive. Hemoglobin A1c (HbA1c) is widely used, while fructosamine may be valuable for predicting periprosthetic joint infection (PJI). Fructosamine levels can be affected by serum albumin levels; albumin-corrected fructosamine (AlbF) can be calculated to overcome this issue. The objective of this study was to evaluate the predictive value of different markers for complications after primary total hip or knee arthroplasty. METHODS: This prospective cohort study included 304 patients (mean age: 65 years [range, 16-85), mean follow-up: 32 months (range, 12-49)] who underwent primary total hip or knee arthroplasty between 2018 and 2021. Of them, 156 patients had diabetes. Mean HbA1c was 6.5% (range, 4.8%-13%), fructosamine 244 µmol/L (range, 98-566 µmol/L), and AlbF 632 (range, 238-2308). Patients who did and did not have diabetes were matched 1 : 1. Hemoglobin A1c 7% and fructosamine 292 µmol/L were used as cutoff. Complications were documented. Glycemic markers were compared using logistic regression analyses, with a special focus on PJI. RESULTS: In the logistic regression analyses, HbA1c was strongly associated with total complications [adjusted odds ratio (OR): 3.61; 95% CI, 1.65-7.91, P = .001], while fructosamine was associated with PJI (adjusted OR: 13.68; 95% CI, 1.39-134.89, P = .025). Albumin-corrected fructosamine did not show any additional benefits. CONCLUSION: Preoperative assessment before total hip or knee arthroplasty must not focus on a single marker; HbA1c is a good predictor of total complications, while fructosamine is a better predictor of PJI. To the best of our knowledge, in its first orthopedic study, AlbF did not show any advantages. LEVEL OF EVIDENCE: Level II, Prognostic Study.

Intraoperative medial wall disruption in Dega pelvic osteotomy: Does it effect the radiographic outcome at medium-term?

OBJECTIVES: To compare the radiographic outcomes of our patients who encountered medial wall disruption, with those who did not while undergoing Dega osteotomy. METHODS: We retrospectively reviewed the records of 95 hips with developmental dysplasia of the hip who were treated with Dega pelvic osteotomy. Hips were divided into 2 groups according to medial wall disruption: group A included the hips with medial wall disruption, while group B included the hips without disruption. Preoperative, immediate postoperative, 12 weeks and last follow-up anteroposterior radiographs of the pelvis were reviewed for changes in the acetabular index (AI) between groups. RESULTS: There were 22 hips in group A and 73 hips in the group B. Preoperative (34.6 versus [vs] 37.2, p=0.231), postoperative (17.9 vs 18.4, p=0.682), 12th week (18 vs 18, p=0.504) and last follow-up (13.3 vs 15.1, p=0.097). The acetabular index measurements were comparable between the groups. Corrections achieved during surgery, and during the follow-up period were also comparable between the two groups, indicating no loss of radiographic correction caused by medial wall disruption. Ninety one percent of the patients in group A and 90% of group B achieved good or excellent results according to the Severin classification (p=0.944). CONCLUSION: Our study shows that disruption of the medial wall did not have a significant detrimental effect on radiographic correction when performing Dega osteotomy.

Closed versus medial open reduction in the treatment of developmental dysplasia of the hip under age 1: A retrospective comparative study.

OBJECTIVE: This study aimed to compare the mid-term results of closed reduction (CR) versus medial open reduction (MOR) in the treatment of children with developmental dysplasia of the hip (DDH) under age 1. METHODS: Thirty-four patients with DDH (41 hips) were included in this retrospective study with a mean follow-up of 4.2 years (range: 2-6.9 years). All hips were then divided into 2 groups based on the treatment type: the CR group (20 hips) and the MOR group (21 hips). All hips from both groups were assessed with post-spica magnetic resonance imaging (MRI) in the first 24 hours, and reinterventions were recorded. Medial dye pool width was also measured. RESULTS: Age at the time of reduction was similar between the CR and MOR groups (6.6 ± 1.3 months vs. 6.7 ± 1.6 months). There was no significant difference between groups regarding avascular necrosis rate and further corrective surgery (FCS) requirement (P=.454, .697). The appropriate reduction was seen at 38/41 hips. Three hips in the CR group had revealed dislocation in post-spica MRIs and required re-intervention, and none of the hips in the MOR group required re-intervention (P=.107). Medial dye pool width in 3 planes showed no significant difference between MOR and CR. CONCLUSION: There is no difference in the avascular necrosis rate and FCS requirements between CR and MOR under age 1. Post-spica MRI is a favorable tool for evaluating reduction after CR, but its efficacy after MOR is questionable.

Evaluation of the Effects of Transforming Growth Factor-Beta 3 (TGF-ß3) Loaded Nanoparticles on Healing in a Rat Achilles Tendon Injury Model.

BACKGROUND: Achilles tendon (AT) midsubstance injuries may heal suboptimally, especially in athletes. Transforming growth factor-beta 3 (TGF-ß3) shows promise because of its recently discovered tendinogenic effects. Using poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles (NPs) may enhance the results by a sustained-release effect. HYPOTHESIS: The application of TGF-ß3 will enhance AT midsubstance healing, and the NP form will achieve better outcomes. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 80 rats underwent unilateral AT transection and were divided into 4 groups: (1) control (C); (2) empty chitosan film (Ch); (3) chitosan film containing free TGF-ß3 (ChT); and (4) chitosan film containing TGF-ß3-loaded NPs (ChN). The animals were sacrificed at 3 and 6 weeks. Tendons were evaluated for morphology (length and cross-sectional area [CSA]), biomechanics (maximum load, stress, stiffness, and elastic modulus), histology, immunohistochemical quantification (types I and III collagen [COL1 and COL3]), and gene expression (COL1A1, COL3A1, scleraxis, and tenomodulin). RESULTS: Morphologically, at 3 weeks, ChT (15 ± 2.7 mm) and ChN (15.6 ± 1.6 mm) were shorter than C (17.6 ± 1.8 mm) (P = .019 and = .004, respectively). At 6 weeks, the mean CSA of ChN (10.4 ± 1.9 mm2) was similar to that of intact tendons (6.4 ± 1.1 mm2) (P = .230), while the other groups were larger. Biomechanically, at 3 weeks, ChT (42.8 ± 4.9 N) had a higher maximum load than C (27 ± 9.1 N; P = .004) and Ch (29.2 ± 5.7 N; P = .005). At 6 weeks, ChN (26.9 ± 3.9 MPa) had similar maximum stress when compared with intact tendons (34.1 ± 7.8 MPa) (P = .121); the other groups were significantly lower. Histologically, at 6 weeks, the mean Movin score of ChN (4.5 ± 1.5) was lower than that of ChT (6.3 ± 1.8). Immunohistochemically, ChN had higher COL3 (1.469 ± 0.514) at 3 weeks and lower COL1 (1.129 ± 0.368) at 6 weeks. COL1A1 gene expression was higher in ChT and ChN at 3 weeks, but COL3A1 gene expression was higher in ChN. CONCLUSION: The application of TGF-ß3 had a positive effect on AT midsubstance healing, and the sustained-release NP form improved the outcomes, more specifically accelerating the remodeling process. CLINICAL RELEVANCE: This study demonstrated the effectiveness of TGF-ß3 on tendon healing on a rat model, which is an important step toward clinical use. The novel method of using PLGA-b-PEG NPs as a drug-delivery system with sustained-release properties had promising results.

Osseous Ilio-Trochanteric Bars as an Etiology of Hip Contracture in a Child with Congenital Contractures: A Case Report.

CASE: A 5-month-old female patient presented with bilateral lower-limb deformities. Hips were fixed at 100° abduction, 15° flexion and 45° external rotation, flexion contracture in the knees, and bilateral teratologic equinovarus deformities. Radiographs revealed ilio-trochanteric osseous bars as the etiology of hip contractures. Staged surgeries were undertaken. At 4 years of age, she could stand upright with orthoses and sit without support. CONCLUSION: This is the first study to report bilateral congenital ilio-trochanteric osseous bars, which were resected without recurrence. Even with a very low potential of walking, release of the contractures allows for better function and possible wheelchair-dependent mobility in the future.

The efficacy of two-hole tension band plates in the treatment of lower extremity limb length discrepancy.

The main purpose of our study was to investigate the efficacy of dual two-hole tension band plates in the treatment of lower extremity limb length discrepancy (LLD). We retrospectively reviewed patients who underwent epiphysiodesis utilizing dual two-hole tension band plates due to lower extremity LLD between January 2012 and June 2018. The efficacy of epiphysiodesis was defined as the inhibited percentage of the expected growth of the physis between two time intervals and was calculated between 0-6 months and 6-18 months as the primary outcome. The relationship of efficacy of epiphysiodesis with time intervals, bone segments, physeal coverage percentage by the screws, age and interscrew angle and physeal health was also assessed. A total of 11 patients' 17 bone segments (9 femurs and 8 tibias) with a mean age of 8.7 ± 2.3 were included. The mean efficacy of the epiphysiodesis in the first 6 months for femurs was 23 ± 20 % (range, 0-53%) and for tibias was 21 ± 19 % (range, 0-53%); between 6 and 18 months it was 27 ± 19 % (range, 0-56%) for femurs and 15 ± 19 % (range, 0-50%) for tibias. In the first 6 months, physeal coverage percentage by the screws (r = 0.503, P = 0.04) and age (r = -0.534, P = 0.027) had a strong correlation with the epiphysiodesis efficacy. Dual two-hole tension band plating has variable efficacy in the treatment of LLD. Age and physeal coverage percentage by the screws could be related to epiphysiodesis efficacy.