Percutaneous autologous impaction bone graft for advanced femoral head osteonecrosis: a retrospective observational study of unsatisfactory short-term outcomes.

BACKGROUND: Half of osteonecrosis of the femoral head (ONFH) patients suffer femoral head collapse at initial diagnosis, and more than half are bilaterally affected. This study developed a percutaneous autologous impaction bone graft (IBG) technique as a modification of core decompression (CD). We also summarized the short-term results and treatment efficacy of percutaneous autologous IBG in advanced ONFH. METHODS: Twenty patients (12 males, 8 females) with nontraumatic, postcollapse ONFH except one case underwent CD (10-mm core diameter) and reverse IBG. Radiological changes of the ONFH stage and type were analyzed. Survival analysis using Kaplan-Meier estimates was performed with conversion to total hip arthroplasty (THA) as the endpoint. In addition, the Harris hip score (HHS) and University of California, Los Angeles (UCLA) activity rating scale were evaluated. RESULTS: Percutaneous autologous IBG was performed successfully, with an average operation time of < 1 h and small blood loss, and 7 patients (35%) needed conversion to THA at an average of 17 months postoperatively. We observed radiological progressive change in 60% of the patients during a mean observation period of 3 years. The mean clinical scores, except data recorded, after THA significantly improved (before vs. after 3 years: UCLA activity score, 3.7 vs. 5.2 [P = 0.014]; HHS, 57.6 vs. 76.5 points [P = 0.005]). In addition, 6 patients showed radiological progression but no clinical deterioration. CONCLUSIONS: Percutaneous autologous IBG was technically simple and minimally invasive, but short-term results were unsatisfactory for advanced ONFH. Indications for this procedure should be carefully examined to improve it in order to enable bone formation.

Distal Metatarsal Segmental Shortening for the Treatment of Chronic Metatarsophalangeal Dislocation of Lesser Toes.

BACKGROUND: This retrospective study aimed to describe the techniques and results of distal metatarsal segmental shortening (DMSS) for the treatment of chronic irreducible metatarsophalangeal (MTP) dislocation of lesser toes. METHODS: We retrospectively reviewed patients who underwent DMSS for chronic dislocation of MTP joints of lesser toes between January 2010 and December 2017 with follow-up of at least 24 months. Demographic data, radiographic measurements, functional outcomes, and complications were analyzed. Furthermore, the results of patients with short segment of shortening (group I, <10 mm) were compared to those with long segment of shortening (group II, ≥10 mm). A total of 43 MTP joints of 30 patients with an average age of 70.4 years were included. RESULTS: Union was observed in 42 metatarsals (97.7%). Mean American Orthopaedic Foot & Ankle Society scale scores improved significantly from 42.2 (range, 15-65) preoperatively to 79.1 (range, 52-90) (P < .001). Mean visual analog scale pain score improved significantly from 5.0 (range, 1-9) preoperatively to 1.8 (range, 0-6) (P < .001). Complications included 1 nonunion, 1 osteonecrosis, 3 metatarsal angulation, 4 recurrent instability, 4 symptomatic osteoarthritis, 3 transfer metatarsalgia, and 1 floating toe. Group I included 23 MTP joints and group II included 20 MTP joints. There was no significant difference in clinical outcomes and complications between the 2 groups. CONCLUSION: DMSS was a reliable procedure for the treatment of chronic irreducible dislocated MTP joint of lesser toes. It provided satisfactory surgical outcomes and a low rate of postoperative complications, regardless of length of metatarsal shortening. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Volar and Dorsal Blood Supply to the Lunate: A Cadaveric Study.

Although various studies have proposed vascular and mechanical factors, the etiology of Kienböck disease is unknown. Kienböck theorized that lunatomalacia resulted from traumatic disruption of blood supply and bony nutrition to the lunate. Extraosseous supply to the lunate, as far as volar or dorsal vessels are concerned, is still controversial. This study evaluated the extraosseous nutrient foramina from the dorsal and volar aspects of lunate specimens. A total of 913 specimens from the Hamann-Todd Osteological Collection in Cleveland, Ohio, were examined. The nutrient artery foramina on left and right lunate specimens were examined from dorsal and volar aspects. The number of nutrient artery foramen was tabulated. Age, sex, and race data were collected. Specimens were divided into groups according to the number of nutrient artery foramina, and the dorsal and volar foramina were compared. The average number of foramina on the dorsal aspect of the lunate (1.71) was greater than the volar aspect (1.64), except in specimens younger than 35 years. A greater number of specimens had 3 or more foramina on the dorsal side compared with the volar aspect. Based on this study, there was significant contribution of dorsal arterial vessels to the blood supply of lunate specimens older than 35 years, which contrasts with findings in earlier studies. The disruption of dorsal intercarpal and radiocarpal ligaments leading to the disruption of the dorsal arterial arches may contribute to vascular insufficiency of the lunate and should be evaluated further in the etiopathogenesis of Kienböck disease. [Orthopedics. 2021;44(2):e243-e247.].

Early Outcomes of 3D Printed Total Talus Arthroplasty.

BACKGROUND: Patients with talar avascular necrosis (AVN) have limited treatment options to manage their symptoms. Historically, surgical options have been limited and can leave patients with little ankle motion and have high failure rates. The use of custom 3D printed total talar replacements (TTRs) has arisen as a treatment option for these patients, possibly allowing better preservation of hindfoot motion. We hypothesized that patients undergoing TTR will demonstrate a statistically significant improvement in Foot and Ankle Outcome Score (FAOS) at 1 year after surgery. METHODS: We retrospectively reviewed 15 patients who underwent a TTR over a 2-year period. Patient outcomes were reviewed, including age, sex, comorbidities, etiology of talar pathology, number and type of prior surgeries, radiographic alignment, FAOS and Visual Analog Scale (VAS) score, and range of motion. Data analysis was performed with Student t-tests and multivariate regression. RESULTS: FAOSs and VAS scores showed statistically significant improvements postoperatively as compared with preoperative scores. There was a statistically significant decrease in VAS pain scores from 7.0 preoperatively to 3.6 (P < .001). Average follow-up was 12.8 months. With the number of patients available, there was no statistically significant change in radiographic alignment parameters postoperatively as compared with preoperatively (P values ranged from .225 to .617). CONCLUSION: Our hypothesis that these patients show statistically significant improvements in FAOSs at 1 year was confirmed. TTR represents an exciting treatment option for patients with talar AVN, though longer-term follow-up is needed.Level of Evidence: Level IV: Case series.

Clinical observation of two bone cement distribution modes of percutaneous vertebroplasty in the treatment of thoracolumbar Kümmell's disease.

BACKGROUND: In recent years, percutaneous vertebroplasty (PVP) has provided a new option for the treatment of Kümmell's disease (KD). This retrospective study aimed to investigate the differences in clinical characteristics, clinical efficacy, and related complications between two types of bone cement distribution patterns in the PVP treatment of KD. METHODS: A total of 63 patients with KD from January 2016 to February 2018 who received PVP treatment were examined at least 24 months. According to X-ray distribution modes of bone cement after PVP treatment, they were divided into 2 groups: blocky group (30 cases) and spongy group (33 cases). Clinical features and disease severity preoperatively, and clinical efficacy and related complications postoperatively were statistically compared between the two groups. RESULTS: The two groups were followed for at least 24 months. The duration of disease, age, Cobb angle, and vertebral compression rate preoperatively were significantly higher in the blocky group than in the spongy group (P < 0.05, respectively). The height of vertebral anterior margin and BMD were significantly lower in the blocky group than in the spongy group (P < 0.05, respectively). The amount of bone cement injected was significantly greater in the blocky group than in the spongy group (P = 0.000). VAS and ODI of the two groups were significantly reduced at the first day, the first year, and the last follow-up postoperatively (all P = 0.000) and were maintained at the last follow-up. VAS and ODI postoperatively decreased significantly in the spongy group compared with the blocky group (P = 0.000). The correction degrees of kyphosis and vertebral compression postoperatively in the two groups were significantly corrected, but gradually decreased over time (P < 0.05), and these correction degrees were significantly higher in the blocky group than in the spongy group, and the postoperative losses were also more serious. CONCLUSIONS: The disease was more serious in the blocky group than in the spongy group. The amount of bone cement, correction degrees of postoperative kyphosis and vertebral compression were significantly higher in the blocky group than in the spongy group, but its postoperative losses of the correction degrees of kyphosis and vertebral compression were also more serious. However, for pain relief and functional recovery, the spongy group was superior to the blocky group. Therefore, the spongy distribution pattern should be formed during the injection of bone cement to obtain better therapeutic effect.

Lunate loads following different osteotomies used to treat Kienböck's disease: A 3D finite element analysis.

BACKGROUND: One of most accepted principles for treating Kienböck's disease before wrist degeneration settles in is to decompress the lunate by an osteotomy. Several osteotomies have been proposed since 1935. However, they are based on biomechanical hypotheses that are sometimes conflicting: This study compares the decompression effect of radius transverse shortening, radius lateral closing and medial closing wedge osteotomies, capitate shortening - with and without hamate shortening - and a Camembert-type radius wedge osteotomy with and without ulnar head shortening according to Sennwald. METHODS: We built a 3D wrist model using finite elements that included the metacarpal, carpal and forearm bones. All wrist ligaments and Triangular Fibrocartilage Complex were incorporated in the simulation. Load was applied on the metacarpals with the forearm bones fixed. We then applied the different osteotomies to the model. FINDINGS: When load was applied to the wrist, the osteotomies that best unloaded the lunate were the capitate shortening osteotomy combined with hamate shortening and the Camembert osteotomy combined with ulna shortening; the latter was the only osteotomy that completely unloaded the lunate. INTERPRETATION: We think the association of the radius Camembert osteotomy and ulna Sennwald's shortening osteotomy is the most effective procedure to propose in Kienböck's disease.

Sickle cell disease as a vascular disorder.

INTRODUCTION: In sickle cell disease (SCD), hemoglobin S (HbS) red blood cells (RBCs) are characteristically deformed and inflexible. Often breaking down in the circulation, they exhibit increased adhesive properties with the endothelium and activated neutrophils and platelets, increasing the risk of occlusion of the microcirculation. SCD is categorized into two sub-phenotypes: hyperhemolytic, associated with priapism, leg ulcers, pulmonary hypertension, and stroke, and high hemoglobin/viscosity, which may promote vaso-occlusion-associated pain, acute chest syndrome, and osteonecrosis. AREAS COVERED: The sub-phenotypes are not completely distinct. Hemolysis may trigger vaso-occlusion, contributing to vascular complications. Targeting P-selectin, a key mediator of cross-talk between hyperhemolysis and vaso-occlusion, may be beneficial for vascular and vaso-occlusion-associated complications. English-language articles from PubMed on the topic of SCD and vaso-occlusive crises (VOCs) were reviewed from 1 January 2000 to 1 January 2019 using the search terms 'sickle cell disease,' 'vaso-occlusive crises,' and 'selectin.' EXPERT OPINION: Besides targeting P-selectin, other strategies to counter VOCs and RBC sickling are being pursued. These include platelet inhibition to counter aggregation, intercellular adhesion, and thrombosis during VOCs; gene therapy to correct the homozygous missense mutation in the ß-globin gene, causing polymerization of HbS; L-glutamine, possibly reducing oxidative stress in sickled RBCs; and fetal hemoglobin inducers.

Valgus Correctability and Meniscal Extrusion Were Associated With Alignment After Unicompartmental Knee Arthroplasty.

BACKGROUND: Appropriate postoperative lower limb alignment is one important element of a successful unicompartmental knee arthroplasty (UKA). To predict postoperative alignment, it is important to investigate the association between preoperative imaging evaluations and lower limb alignment after medial UKA. QUESTIONS/PURPOSES: (1) Do preoperative valgus stress radiographic and MRI measurements (% mechanical axis, hip-knee-ankle angle, medial meniscal extrusion distance, and osteophyte area at the medial femur and tibia) correlate with postoperative lower limb alignment after UKA; and (2) Can useful cutoffs be calculated in advance of surgery for those findings that were associated with coronal-plane overcorrection? METHODS: We retrospectively analyzed 125 patients with medial knee pain who underwent UKA from January 2012 to October 2018. Valgus stress radiography and MRI were performed routinely to assess the knee. Valgus stress radiography was obtained with the patient supine with the knee in full extension and a firm manual valgus force applied to the knee. Full-length weightbearing radiography was performed 3 months after surgery. There were 12% (15) of patients who did not undergo MRI, and 4% (five) of patients who did not receive the postoperative full-length weightbearing radiograph and they were excluded, leaving 84% (105) of patients available for analysis. There were 27 men and 78 women with a mean (range) age of 77 years ± 6 years (60 to 87). The preoperative diagnosis was medial osteoarthritis in 99 patients and osteonecrosis of the medial femoral condyle in six. To investigate the associations, we routinely measured % mechanical axis using radiography, and also measured the medial meniscal extrusion distance and osteophyte area at the medial femur and tibia using MRI after surgery. Medial meniscus extrusion distance was defined as the distance from the outermost edge of the medial meniscus to a line connecting the femoral and tibial cortices. From these parameters, postoperative alignment was estimated using regression and receiver operating characteristic curve analyses. Variables with p < 0.05 were included. RESULTS: The % mechanical axis on the valgus stress radiograph and medial meniscal extrusion distance were correlated with postoperative lower limb alignment after UKA (adjusted correlation coefficient 0.72; p < 0.001, adjusted correlation coefficient 0.2; p = 0.003, respectively). The estimated % mechanical axis on the postoperative weightbearing radiograph was equal to -0.27 + 0.86% (% mechanical axis on valgus stress radiograph) + 1.14 mm (medial meniscal extrusion distance). Using a cutoff point of 36%, the % mechanical axis on valgus stress radiograph was associated with overcorrection after UKA (area under the curve: 0.89; odds ratio 14 [95% CI 0.75 to 0.95]; p < 0.001, sensitivity 77.8%, specificity 80.9%). CONCLUSIONS: The overcorrection of a varus knee on a valgus stress radiograph before UKA and the increased extrusion of the medial meniscus on preoperative MRI was associated with a greater likelihood of overcorrected alignment after UKA. Future studies should conduct long-term follow-up of malalignment patients to assess the possible complications. LEVEL OF EVIDENCE: Level III, diagnostic study.

The effect of the necrotic area on the biomechanics of the femoral head - a finite element study.

BACKGROUND: Femoral head collapse is the key to the progress of osteonecrosis of the femoral head (ONFH), but the causes of collapse are not completely clear. The better understanding of the progress of femoral head collapse will guide the treatment strategy for ONFH patients. The purpose of this study was to evaluate the biomechanical influence of necrosis area on the collapse of the femoral head by finite element analysis. METHODS: CT and MRI data from the hip joint of a healthy volunteer were collected to establish a finite element (FE) model of a normal hip. Subsequently, five categories of osteonecrosis FE models were established by using the normal model and computer software according to China-Japan Friendship Hospital (CJFH) classification for ONFH. The CJFH system includes five types based on the size and location of necrosis lesions in the femoral head (type M, C, L1, L2, and L3) and the stage of ONFH. The collapse indices of each model were analyzed by FE method, including the displacement, peak von Mises stress and stress index of the simulated necrotic area as well as the lateral pillar contact area of the femoral head to acetabular. RESULTS: (1) The displacement increments in the simulated necrotic areas of type M, C, L1, L2, and L3 models were 3.75 µm, 8.24 µm, 8.47 µm, 18.42 µm, and 20.44 µm respectively; the peak von Mises stress decrements were 1.50 MPa, 3.74 MPa, 3.73 MPa, 4.91 MPa, and 4.92 MPa respectively; and the stress indices were 0.04, 0.08, 0.08, 0.27, and 0.27 respectively. (2) The displacement increments in the lateral pillar contact areas of five type models were significantly different (P < 0.001) and increased in sequence as follows: 1.93 ± 0.15 µm, 5.74 ± 0.92 µm, 5.84 ± 1.42 µm, 14.50 ± 3.00 µm, and 16.43 ± 3.05 µm. The peak von Mises stress decrements were also significantly different (P < 0.001) and increased in sequence as follows: 0.52 ± 0.30 MPa, 0.55 ± 0.12 MPa, 0.67 ± 0.33 MPa, 4.17 ± 0.59 MPa, and 4.19 ± 0.60 MPa. (3) The collapse indices including the displacement increments and peak von Mises stress decrements of type L2 and L3 models were markedly higher than those of type M, C, and L1 models (P < 0.001). CONCLUSIONS: The collapse indices of the femoral heads of type L2 and L3 FE models were significantly higher than those of type M, C, and L1. Different areas of necrosis result in varied impact on the femoral head collapse.

Jawbone remodeling: a conceptual study based on Synchrotron High-resolution Tomography.

One of the most important aspects of bone remodeling is the constant turnover mainly driven by the mechanical loading stimulus. The remodeling process produces changes not only in the bone microarchitecture but also in the density distribution of the mineralized matrix - i.e. in calcium concentrations- and in the osteocyte lacunar network. Synchrotron radiation-based X-ray microtomography (microCT) has proven to be an efficient technique, capable to achieve the analysis of 3D bone architecture and of local mineralization at different hierarchical length scales, including the imaging of the lacuno-canalicular network. In the present study, we used microCT within a conceptual study of jawbone remodeling, demonstratively focusing the investigation in two critical contexts, namely in the peri-dental and the peri-implant tissues. The microCT analysis showed that a relevant inhomogeneity was clearly present in both peri-dental and peri-implant biopsies, not only in terms of microarchitecture and mineralization degree, but also considering the lacunar network, i.e. size and numerical density of the osteocyte lacunae. The correlated histological results obtained on the same samples confirmed these observations, also adding information related to non-mineralized tissues. Despite its demonstrative nature, it was concluded that the proposed method was powerful in studying jawbone remodeling because it revealed a direct correlation of its rate with the lacunar density, as achieved by the analysis of the osteocyte lacunar network, and an inverse correlation with the local bone mineral density, as revealed with the Roschger approach.

Long-Term Functional Outcomes Among Childhood Survivors of Cancer Who Have a History of Osteonecrosis.

BACKGROUND: Glucocorticoids used to treat childhood leukemia and lymphoma can result in osteonecrosis, leading to physical dysfunction and pain. Improving survival rates warrants research into long-term outcomes among this population. OBJECTIVE: The objective of this study was to compare the physical function and quality of life (QOL) of survivors of childhood cancer who had an osteonecrosis history with that of survivors who had no osteonecrosis history and with that of people who were healthy (controls). DESIGN: This was a cross-sectional study. METHODS: This study included St Jude Lifetime Cohort Study participants who were ≥ 10 years from the diagnosis of childhood leukemia or lymphoma and ≥ 18 years old; 135 had osteonecrosis (52.5% men; mean age = 27.7 [SD = 6.08] years) and 1560 had no osteonecrosis history (52.4% men; mean age = 33.3 [SD = 8.54] years). This study also included 272 people who were from the community and who were healthy (community controls) (47.7% men; mean age = 35.1 [SD = 10.46] years). The participants completed functional assessments and questionnaires about QOL. RESULTS: Survivors with osteonecrosis scored lower than other survivors and controls for dorsiflexion strength (mean score = 16.50 [SD = 7.91] vs 24.17 [SD = 8.61] N·m/kg) and scored lower than controls for flexibility with the sit-and-reach test (20.61 [SD = 9.70] vs 23.96 [SD = 10.73] cm), function on the Physical Performance Test (mean score = 22.73 [SD = 2.05] vs 23.58 [SD = 0.88]), and mobility on the Timed "Up & Go" Test (5.66 [SD = 2.25] vs 5.12 [SD = 1.28] seconds). Survivors with hip osteonecrosis requiring surgery scored lower than survivors without osteonecrosis for dorsiflexion strength (13.75 [SD = 8.82] vs 18.48 [SD = 9.04] N·m/kg), flexibility (15.79 [SD = 8.93] vs 20.37 [SD = 10.14] cm), and endurance on the 6-minute walk test (523.50 [SD = 103.00] vs 572.10 [SD = 102.40] m). LIMITATIONS: Because some eligible survivors declined to participate, possible selection bias was a limitation of this study. CONCLUSIONS: Survivors of childhood leukemia and lymphoma with and without osteonecrosis demonstrated impaired physical performance and reported reduced QOL compared with controls, with those requiring surgery for osteonecrosis most at risk for impairments. It may be beneficial to provide strengthening, flexibility, and endurance interventions for patients who have pediatric cancer and osteonecrosis for long-term function.

Metformin coordinates osteoblast/osteoclast differentiation associated with ischemic osteonecrosis.

In this study, we aimed to identify a candidate drug that can activate endogenous Angiopoietin 1 (Ang1) expression via drug repositioning as a pharmacological treatment for avascular osteonecrosis. After incubation with 821 drugs from the Food and Drug Administration (FDA)-approved drug library, Ang1 expression in U2OS cell culture media was examined by ELISA. Metformin, the first-line medication for treatment of type 2 diabetes, was selected as a candidate for in vitro and in vivo experimental evaluation. Ang1 was induced, and alkaline phosphatase activity was increased by metformin treatment in U2OS and MG63 cells. Wound healing and migration assay showed increased osteoblastic cell mobility by metformin treatment in U2OS and MG63 cells. Metformin upregulated expression of protein markers for osteoblastic differentiation in U2OS and MG63 cells but inhibited osteoclastic differentiation in Raw264.7 cells. Metformin (25 mg/kg) protected against ischemic necrosis in the epiphysis of the rat femoral head by maintaining osteoblast/osteocyte function and vascular density but inhibiting osteoclast activity in the necrotic femoral head. These findings provide novel insight into the specific biomarkers that are targeted and regulated by metformin in osteoblast differentiation and contribute to understanding the effects of these FDA-approved small-molecule drugs as novel therapeutics for ischemic osteonecrosis.

Identification of potential miRNA biomarkers for traumatic osteonecrosis of femoral head.

Traumatic osteonecrosis of femoral head (TONFH) is a common orthopedic disease caused by physical injury in hip. However, the unclear pathogenesis mechanism of TONFH and lacking of simple noninvasive early diagnosis method cause the necessity of hip replacement for most patients with TONFH. In this study, we aimed to identify circulating microRNAs (miRNAs) by integrated bioinformatics analyses as potential biomarker of TONFH. mRNA expression profiles were downloaded from the Gene Expression Omnibus database. Then we combined two miRNA screen methods: Weighted gene co-expression network analysis and fold change based differentially expressed miRNAs analysis. As a result, we identified 14 key miRNAs as potential biomarkers for TONFH. Besides, 302 target genes of these miRNAs were obtained and the miRNA-mRNA interaction network was constructed. Furthermore, the results of Kyoto Encyclopedia of Gene and Genome pathway analysis, Gene Ontology function analysis, protein-protein interaction (PPI) network analysis and PPI network module analysis showed close correlation between these 14 key miRNAs and TONFH. Then we established receiver operating characteristic curves and identified 6-miRNA signature with highly diagnosis value including miR-93-5p (area under the curve [AUC] = 0.93), miR-1324 (AUC = 0.92), miR-4666a-3p (AUC = 0.92), miR-5011-3p (AUC = 0.92), and miR-320a (AUC = 0.89), miR-185-5p (AUC = 0.89). Finally, the results of quantitative real-time polymerase chain reaction confirmed the significantly higher expression of miR-93-5p and miR-320a in the serum of patients with ONFH. These circulating miRNAs could serve as candidate early diagnosis markers and potential treatment targets of TONFH.

Necessary Factors to Achieve Deep Flexion for Asian Populations after Oxford Unicompartmental Knee Arthroplasty.

There have been many reports on the clinical outcomes of Oxford unicompartmental knee arthroplasty (UKA); however, none have investigated the influence of flexion angle after UKA on clinical outcomes. The objective of this study was to clarify the relationship between outcomes and the postoperative maximum flexion angle and reveal the necessary factors for maximum flexion angle ≥ 140 degrees which is considered necessary for Asian populations. We categorized 212 UKA patients into the following three groups based on the postoperative maximum flexion angle: group 1 had flexion angle ≥ 140 degrees in 80 patients (38%), group 2 had 130 degrees ≤ flexion angle < 140 degrees in 80 patients (38%), and group 3 had flexion angle < 130 degrees in 52 patients (24%). Furthermore, we compared the postoperative clinical outcomes between the three groups and conducted multivariable regression analyses to assess parameters affecting the flexion angle. Postoperative Knee Society function scores for group 1 was significantly higher than for group 3. Group 1 had higher mean knee injury and osteoarthritis outcome scores (KOOS) in all subscales and significantly higher KOOS scores in the sports and quality of life subscales compared with group 2 and in all subscales compared with group 3. Multivariable logistic regression showed that preoperative flexion angle and tibial component posterior slope were associated with maximum flexion angle ≥ 140 degrees. Maximum flexion angle ≥ 140 degrees after Oxford UKA improved the clinical results, particularly for patient-reported outcomes. Furthermore, the tibial posterior slope was an important factor in achieving maximum flexion angle ≥ 140 degrees in UKA patients.

Lunate fracture healing after partial capitate shortening in Kienböck disease.

BACKGROUND: It is unclear whether lunate fracture types in Kienböck disease correlate with the degree of fracture healing. This study aimed to review the clinical results of stage 3 Kienböck disease treated using partial capitate shortening (PCS) and to evaluate the healing rates of lunate fractures based on the fracture types. METHODS: Twenty-three patients were clinically and radiographically followed up for >2 years after PCS. The preoperative location and postoperative healing of the lunate fracture were evaluated using plain radiography, computed tomography, and/or magnetic resonance imaging. Results were evaluated using the Kienböck scoring system by Nakamura. RESULTS: PCS was clinically effective, demonstrating excellent and good results in 11 and 11 patients, respectively. Pain evaluated using the visual analog scale, wrist extension, flexion motion, and grip strength significantly improved postoperatively (p < 0.01). Fractures were preoperatively detected in all 23 cases. Fracture locations were preoperatively classified into five subtypes based on radiographs: volar pole in five patients, dorsal pole in three, coronal in five, transverse in nine, and ulnar in one. The overall union rate of the lunate fracture was 48%, whereas none of the coronal fractures healed. CONCLUSIONS: PCS was effective in treating stage 3 Kienböck disease. Coronal lunate fractures had a poor healing rate relative to those of the other fracture types. STUDY DESIGN: Clinical, retrospective study.

Plate removal without loss of correction after open-wedge high tibial osteotomy is possible when posterior cortex bone union reaches osteotomy gap center even in incompletely filled gaps.

PURPOSE: The study aimed to evaluate the optimal timing for plate removal after open-wedge high tibial osteotomy (OWHTO) without loss of correction and to investigate risk factors for loss of correction after plate removal. The study presents the hypothesis that plate removal without loss of correction was possible when gap filling reached zone 2 (25-50%) on anteroposterior radiographs. METHODS: Ninety-one patients (101 knees) who underwent OWHTO using the TomoFix® plate were enrolled. Plate removal was performed at an average 16.4 ± 5.4 months after OWHTO. Clinical evaluation included plate-related symptoms, the Japanese Orthopedic Association Knee Score (JOA score), and Oxford Knee Score (OKS). Radiological outcomes, including the hip-knee-ankle angle (HKA), weight-bearing line ratio (WBLR), medial proximal tibial angle (MPTA), and posterior tibial slope (PTS), were evaluated preoperatively, at plate removal and at 1 year after plate removal. Computed tomography (CT) was performed at plate removal to evaluate the flange bone union, progression rates of gap filling, and posterior cortex bone union. In addition, the risk factors for loss of correction after plate removal were evaluated. RESULTS: At plate removal, 63 (62.4%) knees had plate-related symptoms (mild, 56 knees; moderate, 7 knees; severe, 0). After plate removal, the JOA score did not change, whereas OKS further improved; six knees developed loss of correction. On CT evaluation at plate removal, the flange bone union was achieved in all cases; the progression rates of gap filling and posterior cortex bone union were 47.0% ± 16.6% and 62.8% ± 16.5%, respectively. A posterior cortex union rate of < 43.3% was the only predictor for loss of correction after plate removal (odds ratio: 1.38, P < 0.01). CONCLUSIONS: Plate removal without loss of correction after OWHTO was possible when bone union of the posterior cortex reached the center of the osteotomy gap even in incompletely filled gaps. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.