Hereditary Multiple Exostoses Research Articles

Hereditary human diseases with skeletal pathology – molecular pathogenesis and clinical characteristics

Differential diagnosis of hereditary diseases is challenging due to similar clinical manifestations, diversity of nosologies, wide clinical variability and genetic heterogeneity, severity, rare frequency and complex molecular etiology. In some of them, connective tissue as a whole is involved in the pathological process, affecting almost all organs and systems of the human body, and in particular bone tissue, disrupting its remodeling and microarchitecture. The defect can occur at any of the stages of remodeling: during the initiation process, during bone resorption, osteoblast differentiation, osteoid mineralization, etc. Violation of the microarchitecture of bone tissue is accompanied by the development of low-traumatic fractures and deformities, early osteoarthritis, the formation of contractures and chronic pain syndrome. Genetic studies of patients have expanded knowledge about the molecular signaling pathways that coordinate bone development and metabolism, the nature of disease inheritance, clinical features, and specific bone biomarkers. This article provides an overview of key cellular mechanisms, features of diagnosis and treatment of hereditary human diseases that affect the condition of bone tissue and skeleton: osteogenesis imperfecta, EhlersDanlos syndrome, Marfan syndrome, juvenile osteoporosis, hypophosphatasia, osteopetrosis, progressive diaphyseal dysplasia, mucopolysaccharidoses, achondroplasia, multiple hereditary exostoses. Doctors of different specialties can encounter these diseases, and making a correct diagnosis will make it possible to determine the correct algorithm for patient management and begin timely treatment, the ability to prevent the development of severe complications, improve the quality of life of patients, restore maximum working capacity and reduce the percentage of disability.

Peroneal Nerve Decompression in Patients with Multiple Hereditary Exostoses: Indications, Complications, and Recurrence.

To our knowledge, there have been no studies examining peroneal nerve decompression and proximal fibular osteochondroma excision exclusively in patients with multiple hereditary exostoses (MHE). The purpose of this study was to evaluate the indications, complications, and recurrence associated with nerve decompression and proximal fibular osteochondroma excision in patients with MHE. The records on patients with MHE undergoing peroneal nerve decompression from 2009 to 2023 were retrospectively reviewed. Indications, clinical status, surgical technique, recurrence, and complications were recorded and were analyzed using the Fisher exact test, logistic regression, and the Kaplan-Meier method. There were 126 limbs identified in patients with MHE who underwent peroneal nerve decompression. The most common indications were pain over the proximal fibula, tibialis anterior and/or extensor hallucis longus weakness, and dysesthesias and/or neuropathic pain. Seven cases experienced postoperative foot drop as a complication of the decompression and osteochondroma excision. Logistic regression found significant relationships between complications and excision of anterior osteochondromas (odds ratio [OR], 5.21; p = 0.0062), proximal fibular excision (OR, 14.73; p = 0.0051), and previous decompression (OR, 5.77; p = 0.0124). The recurrence rate was 13.8%, and all recurrences occurred in patients who were skeletally immature at the index procedure. The probability of skeletally immature patients not experiencing recurrence was 88% at 3 years postoperatively and 73% at 6 years postoperatively. Indications for peroneal nerve decompression included neurologic symptoms and pain. The odds of a complication increased with excision of anterior osteochondromas and previous decompression. Recurrence of symptoms following decompression and osteochondroma excision was found exclusively in skeletally immature patients. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Research

The April 2024 Research Roundup360 looks at: Prevalence and characteristics of benign cartilaginous tumours of the shoulder joint; Is total-body MRI useful as a screening tool to rule out malignant progression in patients with multiple osteochondromas?; Effects of vancomycin and tobramycin on compressive and tensile strengths of antibiotic bone cement: a biomechanical study; Biomarkers for early detection of Charcot arthropathy; Strong association between growth hormone therapy and proximal tibial physeal avulsion fractures in children and adolescents; UK pregnancy in orthopaedics (UK-POP): a cross-sectional study of UK female trauma and orthopaedic surgeons and their experiences of pregnancy; Does preoperative weight loss change the risk of adverse outcomes in total knee arthroplasty by initial BMI classification?.

Health-related quality of life and associated risk factors in patients with Multiple Osteochondromas: a cross-sectional study

PurposeTo evaluate the health-related quality of life and associated risk factors for Multiple Osteochondromas patients.MethodsA cross-sectional, observational study was conducted from May to December 2022 during the routine visit to the referral center for rare skeletal disorders. All patients with Multiple Osteochondromas aged ≥ 3 years were included. EuroQol 5-dimension questionnaires, and demographic, clinical, and surgical history data were collected. Descriptive statistics, Fisher’s exact test, One-sample t-test, Spearman’s correlation, and multiple linear and logistic regression were performed to analyze the data. Results are reported following STROBE guidelines.ResultsA total of 128 patients were included in the study, with a mean age of 14 [SD, 10] years. The mean EQ-5D Index Value was 0.863 [SD, 0.200] and the EQ-VAS was 84 [SD, 19] with a positive correlation between two scores [r = 0.541, p < 0.001]. Patients frequently referred problems in pain/discomfort [78.8%], anxiety/depression [50%], and usual activities [38.8%] dimensions. Increasing age was the common risk factor for health-related quality of life [p < 0.000], as well as Index Value and VAS scores were significantly lower in surgical patients [p = 0.001 and p < 0.001, respectively].ConclusionIncreasing age and surgical procedures were found highly associated with reduced health-related quality of life in Multiple Osteochondromas patients. Our findings provide relevant information to support the establishment of patient-centered healthcare pathways and pave the way for further research into medical and non-medical therapeutic strategies for these patients.

Hemiepiphysiodesis for Genu Valgum in Patients With Multiple Hereditary Exostoses.

Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population. All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum. A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up. Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction. Level III.

Secondary peripheral chondrosarcoma in multiple osteochondromas: a retrospective single-institution case series

BackgroundMultiple osteochondromas is genetic disorder characterized by the formation of multiple benign cartilage-capped bone tumors, named osteochondromas, during skeletal development. The most feared complication is the secondary peripheral chondrosarcoma, a malignant cartilaginous neoplasm that arises from the chondroid cap of pre-existent osteochondromas. We conducted a retrospective cohort study on patients diagnosed and followed up from 1960 to 2019 to describe the clinical and pathological features of individuals affected by peripheral chondrosarcoma in multiple osteochondromas, to evaluate follow up information and individual outcome and to compare the results with literature. Data, including age, gender, site, histological grade, cartilage cap thickness, surgical treatments, surgical margins, genotype mutational status as well as treatment details were captured from the hospital electronic health records and from Registry of Multiple Osteochondromas. In addition, a complete histological review of all hematoxylin and eosin (H&E)-stained sections has been performed by expert pathologists.ResultsOne hundred five of the screened cases were included in the present study. The age at diagnosis of SPC ranges from 13 to 63, with median age at diagnosis of 34 years. The site most frequently affected by malignant degeneration was the pelvis (46 patients, 44%) with higher incidence in male patients (32 males vs.14 females). The second one was lower limbs (including femur, fibula, or tibia), identified in 35 patients. Histological information - available for 103 patients – showed: 59 patients with grade 1; 40 patients had a grade 2 and 4 patients had a grade 3. The most common surgical treatment was the complete resection, followed by debulking, amputation and partial resection. Most of cases did not have recurrence of the disease. Outcome in disease-free survival highlights that a worse course of the disease was associated with histological grade 2 or 3, and partial resection surgery. In most of analyzed cases (94%) a pathogenic variant was identified.ConclusionsIn conclusion, the present study gives an overview of the secondary peripheral chondrosarcomas, confirming that this disease represents an impacting complication for multiple osteochondromas patients and suggests that malignant transformation can occur also in younger patient, in a not irrelevant number of cases.

The Missing Piece of the Puzzle: Unveiling the Role of PTPN11 Gene in Multiple Osteochondromas in a Large Cohort Study

This study is aimed at investigating the clinical and genetic characteristics of 244 unrelated probands diagnosed with multiple osteochondromas (MO). The diagnosis of MO typically involves identifying multiple benign bone tumors known as osteochondromas (OCs) through imaging studies and physical examinations. However, cases with both OCs and enchondromas (ECs) may indicate the more rare condition metachondromatosis (MC), which is assumed to be distinct disease. Previous cohort studies of MO found heterozygous loss-of-function (LoF) variants only in the EXT1 or EXT2 genes, with DNA diagnostic yield ranging from 78 to 95%. The PTPN11 gene, which is causative for MC, was not previously investigated as a gene candidate for MO. In this study, we detected a total of 177 unique single nucleotide and copy number variants in three genes across 220 probands, consisting of 80 previously reported and 97 novel variants. Specifically, we identified five cases with OCs and no ECs as well as four cases with MC carrying LoF variants in the PTPN11 gene and two additional cases with ECs harboring variants in the EXT1/2 genes. These findings suggest a potential overlap between the MO and MC both phenotypically and genetically. These findings highlight the importance of expanding genetic testing beyond the EXT1 and EXT2 genes in MO cases, as other genes such as PTPN11 may also be causative. This can improve the accuracy of diagnosis and treatment for individuals with MO and MC. It is essential to determine whether MO and MC represent distinct diseases or if they encompass a broader clinical spectrum.

Growth modulation in Genu Valgum secondary to Multiple Hereditary Exostosis

Objective: Hereditary Multiple Exostoses (HME) is a rare disease with a prevalence of 1:50,000, which can manifest in various ways. This cartilaginous tumor can appear in a spectrum, ranging from mobility restriction to chronic pain and alignment disorders. Literature often describes forearm deformities such as excessive radial bowing, ulnar shortening, and radial head dislocation. Factors resulting in genu valgus and specific treatment strategies are not frequently studied. Considerations specific to the disease, such as the morphology of the lesion, time taken for deformity correction, and timing of exostosis excision, should be taken into account when treating genu valgum in patients with MHE. Case: Our case report highlights a teenager with underlying MHE who presented to us with "knock knees" since childhood. Clinically, it was observed that the patient had bilateral genu valgum and multiple bony swellings overlying the proximal tibia and distal femur. The deformity was subsequently addressed with bilateral proximal tibia hemi-epiphysiodesis, exostoses excision of bilateral proximal tibia, and left distal tibia. The radiographs and surgical technique are detailed in the case report. Our literature review indicates that distal femur exostoses play a significant role in causing genu valgus in these patients. The morphology of the exostoses also affects the development of genu valgus, with sessile lesions contributing more bony deformity compared to pedunculated lesions. Hemi-epiphysiodesis, as performed in our patient, often achieves outcomes similar to idiopathic genu valgum. However, the correction would take about 6 months longer, so in cases of MHE, correction should start earlier. Another dilemma in cases of pathological genu valgus is whether to remove exostosis during corrective surgery. Literature advocates delaying the excision of proximal tibia exostoses as long as possible to reduce the risk of accelerating deformity worsening. Conclusion: In conclusion, factors influencing genu valgus progression include the morphology of the lesion (sessile), presence of metaphyseal flaring, and a history of prior exostosis excision. Early detection of the pathology would yield better outcomes, as the rate of deformity correction in children with MHE is slower due to abnormal physis. Meticulous surgical technique to prevent injury to the physis and knee immobilization post-excision of exostosis are important factors in preventing the development of genu valgus in children with MHE.

Higher femoral head–to–femoral neck ratio are associated with limited range of motion of hip joints in hereditary multiple exostosis patients

Hip involvement is one of the most common skeletal manifestations of hereditary multiple exostoses (HME) in 30-90% of the patients. The anatomical changes in the proximal femur in patients with HME, may lead to deformities and related functional deficits. Its effect on the range of motion (ROM) of the hip joint is not well described. The aim of this study was to evaluate the role of hip deformity of HME disease in the ROM of the hip joint. It was hypothesized that certain morphological parameters affect the ROM of the hip joint. Conclusively, 44 patients including 27 men and 17 women (88 hips) were evaluated. Hips are divided in Group 1 (no ROM limitation group) and Group 2 (ROM limitation group). The head-neck ratio (HNR), center edge angle (CE), Sharp’s acetabular angle (SAA), alpha angle (AA), neck shaft angle (NSA) and ROM parameters were measured. The correlations between radiological parameters (SAA, CE, NSA, AA and HNR), and the ROM data (F, E, Abd, Add, IR and ER) were statistically evaluated. All evaluated parameters (SAA, CE, NSA, AA) except the HNR do not show significant differences between study group 1 (no ROM limitation group) and group 2 (ROM limitation group). The means of the HNR in group 1 were significantly higher than those in group 2 (HNR: 1.23 vs. 0.92, p&lt;0.001). In group 2 HNR showed a strong positive correlation with Abd (PC 0.72, p&lt;0.001), E (PC 0.7, p&lt;0.001), ER (PC 0.67, p&lt;0.001), IR (PC 0.67, p&lt;0.001) and F (PC 0.66, p&lt;0.001). HME patients with hip involvement have better ROM of the hip joint, if they have the higher HNR. Additionally, a positive correlation between HNR and ROM capacity was determined.

Osteochondromas Gone Pelvic: A Case Report of Concurrent Tibial Osteoblastoma and incidental detection of multiple pelvic Osteochondromas on bone scan.

In a unique clinical presentation, a 20-year-old female with a known left distal Tibial Osteoblastoma (previously treated via curettage) developed pain and weight-bearing difficulties in her left lower limb six months later. Subsequently bone scan revealed a unprecedented clinical presentation: residual activity in the treated Osteoblastoma alongside additional foci of increased tracer uptake on skeletal scintigraphy, localized to the bilateral anterior superior and inferior iliac spines. Subsequent radiographs confirmed sessile bony outgrowths in these locations, consistent with multiple pelvic Osteochondromas (an uncommon variant). Notably, these Osteochondromas lacked associated radiolucencies or cortical destruction. Further MRI confirmed the Osteochondroma diagnosis. Interestingly, the patient declined surgical intervention for the asymptomatic Osteochondromas, prioritizing ongoing treatment for the primary Osteoblastoma. This case highlights the rare co-occurrence of these distinct tumor types in an uncommon usual pelvic location, emphasizing the importance of patient centered treatment approach based on patient preferences and clinical context.

Rare coexistence of multiple osteochondromas and solitary osteoid osteoma: A case report

Rare coexistence of multiple osteochondromas and solitary osteoid osteoma: A case report

Defining priorities in the transition from paediatric to adult healthcare for rare bone disease patients: a dialogic approach

The Italian patient association for Multiple Osteochondromas, Ollier Disease, and Maffucci Syndrome, Associazione Conto Alla Rovescia-ACAR Aps, conducted a mixed-methods study at its 2023 annual conference. The study included the Open Dialogue Approach and a feedback survey to identify the main priorities in the transitioning process from paediatric to adult healthcare for patients with Multiple Osteochondromas, Ollier Disease, and Maffucci Syndrome.The common needs identified by patients, families, caregivers, and healthcare professionals were coordination and continuity of care, patient empowerment and communication, social and practical support, and transition planning and support.This experience fostered a sense of collaboration and cooperation among stakeholders, helping to build trust and create a shared vision for improving the quality of care for these patients. Furthermore, it could be considered a starting point for other patient associations interested in using different approaches to identify the needs of their members and actively involve all stakeholders.

Long-term outcome of total hip arthroplasty in patients with multiple hereditary exostosis.

Multiple hereditary exostosis (MHE) is a rare autosomal dominant disorder characterized by multiple osteochondromas. There is a paucity of literature concerning total hip arthroplasty (THA) in patients with MHE. The aim of this study is to report long-term outcomes of THA in patients with MHE. Fourteen patients undergoing 15 THA's for the treatment of osteoarthritis in the presence of osteochondromas and proximal femoral deformity secondary to MHE were reviewed. Mean age at the time of surgery and follow-up was 56 and 12years. Seven (47%) had uncemented femoral components. Eleven hips had coxa valga on preoperative imaging. Clinical outcomes were assessed with both Harris hip scores (HHS) and Musculoskeletal Tumor Society Scores (MSTS). Following surgery, there was an improvement in the HHS (48-82, p < 0.01) and MSTS scores (41-70%, p < 0.01). Complications occurred in 5 patients leading to reoperation in 3 patients, of which 2 patients underwent a revision procedure at 19 and 20-years postoperative. The 10-year revision free survival was 100%. THA in the setting of MHE reliably improves patient function. One in three patients will have a postoperative complication; however, the long-term incidence of revision is low.

Research

The October 2023 Research Roundup360 looks at: Gut microbiota in high-risk individuals for rheumatoid arthritis associated with disturbed metabolome and initiates arthritis by triggering mucosal immunity imbalance; International Consensus on Anaemia Management in Surgical Patients (ICCAMS); Sleep disturbance trends in the short-term postoperative period for patients undergoing total joint replacement; Achilles tendon tissue turnover before and immediately after an acute rupture; Quadriceps or hip exercises for patellofemoral pain? A randomized controlled equivalence trial; Total-body MRI for screening in patients with multiple osteochondromas.

One-Bone Forearm Procedure for Severe Recalcitrant Forearm Deformities in Masada IIb Hereditary Multiple Exostoses.

Hereditary multiple exostoses (HME) Masada IIB has traditionally been treated by gradual ulnar lengthening with questionable efficacy in reducing the dislocated head. One-bone forearm (OBF) has been used as a reconstructive procedure in forearm deformities with very scarce literature for HME. The study aims to report short-term results of OBF as a definitive procedure for severe forearm deformities in Masada IIB patients with respect to clinical and radiological parameters. Four patients with HME Masada IIb were included in this retrospective study. All patients complained of forearm and wrist deformity with an abnormal bony protrusion restricting elbow motion. Indications for OBF were ulnar shortening > 3cm, dysplastic proximal radius with convex radial head and restricted prono-supination. All patients were examined pre-operatively and post-operatively clinically and radiographically using the Peterson's outcome score. The average age was 13 years (12-14years). Pre-operative ulnar shortening, carpal slip percentage, and radial articular angle was 3.4 cm, 79.5%, and 47.5°, respectively. All radial heads were dislocated with convex articular surface restricting elbow extension and forearm prono-supination. At the latest follow-up, the mean elbow flexion was 110° with forearm in 10° supination. The mean carpal slip percentage, radial articular angle, and Peterson functional grade was 15%, 22.5°, and 8 points, respectively. The mean follow-up period was 30.25 months with no recurrence. We recommend one bone forearm as a definitive procedure in HME Masada IIB patients with severe forearm deformities with ulnar shortening > 3cm and dysplastic proximal radius with a dislocated radial head, for faster return to function.

Feline osteochondromatosis in a 12-year-old feline leukaemia virus-negative cat

Feline osteochondromatosis is a spontaneous osteocartilaginous exostosis associated with feline leukaemia virus (FeLV) infection or due to a frameshift variant in the exostosin glycosyltransferase 1 (EXT1) gene. Osteochondromatosis was diagnosed in an indoor-only, 12-year-old, neutered female, Russian Blue cat. Radiographs revealed bilateral calcified proliferations in the elbow, costochondral and sternochondral joints, which distorted the normal skeletal structure. Grossly, the proliferated joints presented with consistent, rounded masses, causing complete ankylosis. The main histopathological finding was an osteocartilaginous proliferation composed of multiple irregular islands of well-differentiated hyaline cartilage surrounded and delimited by osteoid tissue. Immunohistochemistry of the osteochondromas, bone marrow and mediastinal lymph nodes, using a primary anti-FeLV gp70 antibody, and FeLV proviral DNA real-time polymerase chain reaction on bone marrow were negative. Sequencing of exon 6 of the EXT1 gene was performed and nucleotide BLAST analysis demonstrated the absence of a frameshift variant. This study reports the only case of spontaneous feline osteochondromatosis in an animal more than 10 years old.

Epidemiology of benign tumors and pseudo tumoral lesions of the femur based on an analysis of patients receiving orthopedic care

Benign tumors and pseudo tumoral lesions of the bones belong to the largest group ofan abnormal growth of tissue in bone, which is characterized by many specific clinical, radiological and histological features. The study of data on the spread of pathology, localization, frequency of recurrence depending on gender and age characteristics helps to determine the category of people who need a more detailed examination. Aim: Determination of the incidence of an abnormal growth of tissue in bone, the most typical localization, as well as the likelihood of recurrence and malignancy in patients with benign abnormal growth of tissue in the femoral bone. Materials and methods: Materials obtained during the analysis of casesur, as well as radiographs of 465 patients operated in the Department of Traumatology and Orthopedics of the Astrakhan State Medical University from 2 years old to 70 years, from 1977 to 2018, using nonparametric analysis methods. Differences were considered significant at r 0.05. Results: Studying various tumors depending on age, it was found that the median age of patients with aneurysmal bone cyst (13.5) was significantly lower than the median age of patients with giant cell tumor (osteoclastoma) (25), respectively. When comparing persons suffering from a metaphyseal fibrous defect (non-ossifying fibroma) and a chondroma (enchondroma), a difference was noted in the average age values, which amounted to 13.5 years and 45 years, respectively. A significant difference was also found between those with a solitary bone cyst and chondroma (enchondroma), where average was 45 years. When analyzing the significance of differences in the incidence of tumors of certain localizations depending on the patients gender, it was found that the differences are not significantly significant in any of the compared groups. A certain dependence of the tumor localization on gender is not determined, which indicates that the localization of the tumor is not related to the sex of the patient. The frequency of recurrence of an abnormal growth of tissue in femoral bone is also not related to gender. Conclusions: The primary incidence of femorals tumor is predominantly characteristic of patients aged 15 years. In the groups of patients with aneurysmal bone cyst, osteochondroma (bone and cartilage exostosis) and solitary bone cyst, the median age of a person is the smallest. In the comparison of patients with giant cell tumor (osteoclastoma), metaphyseal-fibrous defect (non-ossifying fibroma), osteoid osteoma, chondroma (enchondroma), female patients predominated, and in patients with osteochondroma (osteocartilaginous exostosis) and osteoma, male patients predominated. The incidence of recurrence in the compared groups with a diagnosis of aneurysmal bone cyst, giant cell tumor (osteoclastoma), fibrous dysplasia and chondroma (enchondroma) was significantly higher than in other groups.

The Perils of Sleeper Plates in Multiple Hereditary Exostosis: Tibial Deformity Overcorrection Due to Tether at Empty Metaphyseal Hole.

Hemi-epiphysiodesis is the mainstay of treatment for angular deformities at the knee in children with multiple hereditary exostosis (MHE). Upon deformity correction, the metaphyseal screw may be removed from the hemi-epiphysiodesis plate, the sleeper plate technique, with anticipated reimplantation of the metaphyseal screw should the original deformity recur. The aim of the present study is to compare the incidence of complications with the sleeper plate technique with complete plate removal in an MHE cohort. Patients under the age of 18 with MHE who underwent hemi-epiphysiodesis of the proximal tibia and/or distal femur between February 1, 2016, and February 6, 2022 with a minimum 2-year follow-up or follow-up to skeletal maturity were identified via ICD-10 codes. Patient charts and radiographic images were reviewed to assess for the bone(s) treated, the use of sleeper plates, and whether any complication occurred, including overcorrection from bony ingrowth at the empty holes or deformity recurrence. In 13 patients, 19 knees underwent hemi-epiphysiodesis at 30 sites; 13 distal femoral and 17 proximal tibial. Of 30 plates, 18 (60%) were removed completely upon deformity correction and 3 (10%) did not require removal due to skeletal maturity. Four of 13 (30.8%) femoral plates and 5 of 17 (29.4%) tibial plates were left as sleeper plates. All 5 tibial sleeper plates developed bony ingrowth into the empty metaphyseal screw hole, which led to unintended progressive deformity overcorrection. In the majority of cases, the deformity was addressed by the removal of the plate and exophytic bone and hemi-epiphysiodesis on the other side of the affected proximal tibia with subsequent resolution of the deformity. All tibial sleeper plates developed bony ingrowth into the screwless metaphyseal hole. The bony ingrowth functioned as a tether, resulting in progressive deformity overcorrection. Sleeper plates should be avoided at the proximal tibia in patients with MHE, and extreme caution should be exercised when considering this technique at the distal femur or other sites. Level III-retrospective comparative study.

Correction of tibial multiplanar deformities using single Taylor external fixator combined with biplanar osteotomy

To investigate the effectiveness of single Taylor external fixator combined with biplanar osteotomy on correction of tibial multiplanar deformities. Between October 2016 and December 2021, 11 patients with tibial multiplanar deformities (20 sides) were treated with single Taylor external fixator and biplanar osteotomy. Of them, 4 were male and 7 were female; the average age ranged from 13 to 33 years (mean, 21.9 years). Diagnosis included rickets severe genu varum deformity (7 cases, 14 sides), rickets severe genu valgum deformity (2 cases, 4 sides), multiple osteochondromatosis calf deformity (1 case, 1 side), neurofibromatosis medial lower leg anterior arch deformity with short of leg (1 case, 1 side). After fibular osteotomy and tibial multiplanar osteotomy, a Taylor external fixator was installed. After operation, the deformities were corrected successively and fixed completely. The osteotomy healed, then the external fixator was removed. Before operation and at 12 months after operation, the full-length X-ray films were taken. The leg-length discrepancy, medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), posterior proximal tibial angle (PPTA), anterior distal tibial angle (ADTA), and tibial rotation angle were measured. The degree of lower limb deformity was scored with reference to a customized tibial mechanical axis scoring table. Osteotomy was successfully completed without neurovascular injury and other complications. The external fixator was adjusted for 28-46 days, with an average of 37 days, and the external fixator was worn for 136-292 days, with an average of 169 days. Mild needle infection during the fixation period occurred in 3 sides, refracture at the distal tibial osteotomy in 1 side after removing the external fixator, and nonunion of the distal fibular osteotomy in 1 side. All patients were followed up 369-397 days (mean, 375 days). At 12 months after operation, the lower limb discrepancy decreased, but there was no significant difference ( P>0.05). MPTA, LDTA, PPTA, ADTA, and tibial rotation angle improved, and the differences in LDTA, ADTA, and tibial rotation angle were significant ( P<0.05). The score of lower limb deformity was significantly higher than that before operation ( P<0.05), and the results were excellent in 9 sides, good in 8 sides, fair in 3 sides, with the excellent and good rate of 85%. Single Taylor external fixator combined with biplanar osteotomy is effective in the correction of tibial multiplanar deformities.

A rare case of co-existence of hereditary multiple exostoses and steroid-sensitive nephrotic syndrome

A rare case of co-existence of hereditary multiple exostoses and steroid-sensitive nephrotic syndrome