Popliteal pseudoaneurysm in a young patient with multiple hereditary exostosis.

Multiple hereditary exostosis is an osteogenic disorder that causes outgrowths of cartilaginous bone tumors that are associated with adjacent neurovascular compressive injuries. We present the case of an adolescent male with multiple hereditary exostosis complicated by popliteal pseudoaneurysm formation who underwent excision of the osteochondroma and vein patch angioplasty repair of the artery. We highlight the rare association between this genetic disease and subsequent vascular complications and review the available literature of arterial complications of this disease.

Conservative and Surgical Treatment of Osteochondromas in Children, Particularly with or without Surgical Lengthening of the Ulna.

Prevention of rotatory impairment and radial head dislocation in the forearm is an important aspect when treating children with osteochondromas. Various studies tried to determine the best treatment, describing different surgical techniques. No consensus has been reached yet. This retrospective study compares the treatment outcome of patients with osteochondroma of the radius and ulna after surgical or conservative treatment. Seventeen forearms treated over a period of 20 years were analysed. Outcome parameters were the prospectively collected clinical data and the radiological findings: "relative shortening" of ulna/radius, the "radial articular angle" (RAA) and the "carpal slip" (CS). Our study shows an improvement of the range of motion and cosmetic appearance of the forearm after an operative procedure, with or without bone lengthening. We observed an increase in wrist and elbow mobility with a decrease in pain scores and a confirmed high cosmetic satisfaction in almost 70% of the patients after bone lengthening and up to 85% after simple excision. For patients suffering from functional impairment or pain, an operative approach is beneficial. Multiple and repetitive osteochondroma excisions are recommended during growth to prevent deformity and rotatory motion restriction. Lengthening procedures require a careful indication.

Forearm deformity in multiple hereditary exostosis. Radiologic predictors of radial head dislocation.

INTRODUCTION: Radial head dislocation in patients with multiple hereditary exostosis (MHE) can lead to functional deficit. We investigated whether the location of the exostosis and certain radiological criteria predict risk of radial head dislocation/subluxation. HYPOTHESIS: We hypothesized that the radiological criteria differentiate between patients who need closer follow-up of the forearm and others for whom multiple radiographs are superfluous. PATIENTS AND METHODS: We retrospectively reviewed the demographics of patients with MHE in our hospital, and radiographic measurements were made on forearm radiographs: radial length, ulnar length, ulnar variance, radial articular angle, and radial bowing. RESULTS: Forty-nine forearms were analyzed in 30 patients. Mean age was 9.5 years at first evaluation and 11.8 years at last evaluation. Radial head dislocation or subluxation was found in 6 forearms (12%). Risk factors comprised isolated exostosis in the distal portion of the ulna or exostosis in the distal part of both the ulna and radius, radial or ulnar shortening>4.6cm, radial bowing>8.1%, radial articular angle>35°, and≥3 exostoses in the forearm. DISCUSSION: In patients with MHE with risk factors for radial head dislocation, close follow- up with regular radiography is indicated and early surgery should be performed before the radial head dislocates. LEVEL OF EVIDENCE: IV; retrospective study.

Functional Impairment of Hip Joint and Activities of Daily Living Failure in Patients with Multiple Hereditary Exostoses.

Objective: In this study, we focused on the hip joints and examined pain and functional impairment, and their relationship with anatomical characteristics in MHE patients. Methods: Patients with MHE followed up in our hospital from January 2020 to December 2020 were enrolled. Clinical hip functional outcomes were evaluated using the Japanese Orthopedic Association (JOA) hip score and hip range of motion (ROM). Proximal femur geometric measurements were evaluated using radiography. Results: A total of 39 patients (78 hips) with a median age of 25.6 years and average JOA score of 94.0 ± 10.5 were included. Eight patients felt pain in their hip joints. The average ROM score was 18.2 ± 2.5, and 47.4% of the patients with MHE had ROM limitation. The average score of ability to walk was 19.6 ± 1.8, and three patients had some problems with walking. The average ADL score was 18.2 ± 2.5, and 51.3% of patients with MHE had some failures in ADL. The hip flexion and internal rotation were markedly restricted compared with the normal values. When patients were grouped according to their ADL scores, we found that the ADL failure group had a significantly lower ROM score than the no ADL failure group (p < 0.0001), and there were significant differences between the groups in terms of femoral neck widening (p = 0.0001). Conclusions: We found that half of MHE patients had some failures in their ADL due to hip functional impairment. The study results also suggest that femoral neck widening affected ADL failure and ROM limitation.

Forearm Hereditary Multiple Exostosis: A Retrospective Case Series Study.

Background Hereditary multiple exostosis (HME) is a significantly rare genetic condition with benign chondrogenic lesions affecting long bones. Forearm involvement is relatively common, with varied treatment modalities reported. Here we describe our experience with HME. The study is the first of its kind to be conducted in the Middle East and Saudi Arabia. Methods A retrospective medical record-based case review was carried out on patients with forearm HME operated from 2006 to 2022 at our institution. Patient demographics, clinical presentation, management, outcome, Masada scale, and radiological outcomes were analysed.  Results Ten patients (12 affected forearms) with HME were included. The average age of those undergoing surgery was 12.7 ± 5.13 years, and the average length of follow-up was 62.25 months. Most patients (n = 5, 50%) had Masada type 1 (Type I indicates radial head not displaced, primary exostosis from the distal region of the ulna, ulna relatively short, radius bending). Five (50%) underwent radial head resection. The majority of the patients (n = 8, 80%) had no complications or recurrence. Two patients developed recurrence; the first one developed recurrent radial bone deformity and dislocation of the radial head and the second, who underwent excision with an iliac crest bone graft application, developed osteolysis of the bone graft with recurrent deformity. Conclusion HME is typically managed primarily by excision of the lesion at skeletal maturity and annual check-up and radiological follow-up. If a secondary procedure is needed in future, simple excision of the dislocated radial head would be the most feasible approach. Due to the rarity of the illness and limited literature, further studies are still required to optimize the outcome in children with HME.

Rapidly acquired valgus deformity of the knee after osteochondroma resection in multiple hereditary exostoses pediatric patients: A report of two cases.

Patients with multiple hereditary exostoses (MHE) often develop leg length discrepancies and limb alignment deformity around the knee as part of the natural course of the disease. Limb alignment deformity occurring post-resection of an osteochondroma has been described in one case report and only pertaining to the proximal medial tibia location. Here we describe the case of 2 patients with MHE, a 7-year-old female who underwent resection of distal femur and proximal tibia osteochondromas and a 9-year-old female who had a distal femur osteochondroma resected. Both patients developed rapidly progressive valgus knee deformity requiring surgical intervention. Excision of osteochondromas near the physis of a skeletally immature patient can cause overgrowth from the involved side of the growth plate resulting in a rapidly progressing unilateral coronal plane deformity. Surgeons should be aware of this potential complication and closely follow growing patients with serial alignment radiographs and counsel the family regarding the potential of acquired limb deformity and subsequent surgeries.

Diagnosis, Management, and Treatment Options: A Cervical Spine Osteochondroma Meta-Analysis.

Osteochondroma is described as a capped benign bony neoplasm that forms on the outer surface of bone. These tumors affect nearly 6 million people per year. Although osteochondromas most often involve the appendicular skeleton, many involve the spine, with many cases located in the cervical spine. When osteochondromas involve the spine, they can present with a variety of symptoms, including pain, radiculopathy, and myelopathy, which may necessitate surgical treatment. Spinal osteochondromas can be classified into 2 types: multiple osteochondromas in the context of patients with multiple hereditary exostosis (MHE) and solitary osteochondroma or solitary exostosis (SE). Previous reviews have captured only some of the available literature on cervical osteochondromas and have generally focused on either SE or those associated with MHE. The purpose of our review was to provide an extensive review of all previously reported cervical osteochondromas and to compare osteochondroma characteristics, clinical presentation, and outcomes in the context of MHE and SE.

Brachymetacarpia and Brachymetatarsia in Patients with Multiple Hereditary Exostosis.

BACKGROUND: Multiple hereditary exostosis is a common autosomal dominant inherited musculoskeletal disorder that manifests with multiple osteochondromas. The clinical manifestations and pathological characteristics of osteochondromas found in the long bone and genetic alterations related to multiple hereditary exostosis have been widely reported. In this study, we investigated the characteristics of brachymetacarpia and brachymetatarsia associated with multiple hereditary exostosis. METHODS: Of the 133 patients with a diagnosis of multiple hereditary exostosis who were recruited from 2005 to 2018, 101 patients who underwent plain radiography after 10 years of age were included. There were 55 male (54.5%) and 46 female (45.5%) patients. Brachymetacarpia or brachymetatarsia was diagnosed when disruption of the Lièvre parabola connecting the metacarpal or metatarsal heads was observed on plain radiographs. Three orthopedic surgeons individually reviewed hand and foot plain radiographs. RESULTS: Of the 101 patients, 41 patients (40.6%) had more than 1 brachymetacarpia (88 cases) or brachymetatarsia (81 cases). Among 41 cases, 22 (53.7%) were male and 19 (46.3%) were female. The mean age at the time of radiographic evaluation of the hands and feet was 14.6 years (range, 10-63 years). Shortening was most commonly found in the 3rd and 4th metacarpal or metatarsal bones. CONCLUSIONS: We found a relatively high incidence of brachymetacarpia and brachymetatarsia in our patients. Physicians should suspect the presence of brachymetacarpia and brachymetatarsia when treating patients with multiple hereditary exostosis.

Use of reverse stemless shoulder arthroplasty in a patient with multiple hereditary exostosis.

INTRODUCTION: Multiple hereditary exostosis (MHE) is the formation of benign, cartilage-capped bony outgrowths predominantly extending from the metaphysis of long bones that presents with reduction in growth, deformity, restricted motion, short stature and premature osteoarthritis. AIM: To review the clinical and radiological results of a stemless reverse shoulder arthroplasty in a case of MHE. CASE: 81-year-old, right hand dominant short-statured retired male engineer with long standing shoulder pain and restricted movements on the background of an old proximal humeral fracture managed conservatively.The radiographs revealed osteoarthritis and a mal-united proximal humerus fracture on the background of MHE with 3 plane bone deformity and a lack of medullary canal. RESULTS: The patient underwent a stemless reverse shoulder arthroplasty. At 6 months post operatively the patient had recovered well with a range of movement including: forward flexion 110°, external rotation 20° and abduction of 80°. Internal rotation remained limited to buttocks. Improved ADLIER, Subjective shoulder value and Constant Murley score compared to pre-operative figures. CONCLUSION: The stemless humeral component relies on metaphyseal impaction for stability. When the humeral canal is malformed or in presence of malunited distal fractures, it circumvents the need of navigating a deformed diaphysis with encouraging postoperative results.

Accelerometer-Based, Computer-Navigated Total Knee Arthroplasty to Correct a Complex Deformity in a Patient With Multiple Hereditary Exostoses.

BACKGROUND: Accelerometer-based computer-assisted navigation systems (ABCANSs) have been shown to improve alignment accuracy in total knee arthroplasty (TKA) and are effective in treating complex extra-articular deformity. We present an ABCANS-assisted TKA performed in a 68-year-old male with end-stage arthritis of the right knee, in the setting of a severe valgus deformity secondary to multiple hereditary exostoses. METHODS: The KneeAlign 2 system (OrthAlign, Inc.; Aliso Viejo, CA) was used to perform the TKA in this clinical scenario, given its functionality, which allows angular correction to be tailored to a given deformity, and its reported accuracy in performance of bony resection in TKA. The patient was prospectively followed up for one year postoperatively. Radiographs, PROMs, and patient satisfaction were reported. RESULTS: After the ABCANS-assisted TKA, the patient's alignment was improved from 25° to 4° of valgus. His final range of motion was 0-135° without an instability. In addition, the patient reported excellent scores on multiple joint-specific outcome measures, including the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Forgotten Joint Score, and the Oxford Knee Score. CONCLUSION: This case report illustrates the rationale, technique, and the excellent clinical outcomes achieved in a complex patient with extra-articular deformity using an ABCANS-assisted TKA.

Bone development and remodeling in metabolic disorders.

There are many metabolic disorders that present with bone phenotypes. In some cases, the pathological bone symptoms are the main features of the disease whereas in others they are a secondary characteristic. In general, the generation of the bone problems in these disorders is not well understood and the therapeutic options for them are scarce. Bone development occurs in the early stages of embryonic development where the bone formation, or osteogenesis, takes place. This osteogenesis can be produced through the direct transformation of the pre-existing mesenchymal cells into bone tissue (intramembranous ossification) or by the replacement of the cartilage by bone (endochondral ossification). In contrast, bone remodeling takes place during the bone's growth, after the bone development, and continues throughout the whole life. The remodeling involves the removal of mineralized bone by osteoclasts followed by the formation of bone matrix by the osteoblasts, which subsequently becomes mineralized. In some metabolic diseases, bone pathological features are associated with bone development problems but in others they are associated with bone remodeling. Here, we describe three examples of impaired bone development or remodeling in metabolic diseases, including work by others and the results from our research. In particular, we will focus on hereditary multiple exostosis (or osteochondromatosis), Gaucher disease, and the susceptibility to atypical femoral fracture in patients treated with bisphosphonates for several years.

Palovarotene Inhibits Osteochondroma Formation in a Mouse Model of Multiple Hereditary Exostoses.

Multiple hereditary exostoses (MHE), also known as multiple osteochondromas (MO), is an autosomal dominant disorder characterized by the development of multiple cartilage-capped bone tumors (osteochondromas). The large majority of patients with MHE carry loss-of-function mutations in the EXT1 or EXT2 gene, which encodes a glycosyltransferase essential for heparan sulfate (HS) biosynthesis. Increasing evidence suggests that enhanced bone morphogenetic protein (BMP) signaling resulting from loss of HS expression plays a role in osteochondroma formation in MHE. Palovarotene (PVO) is a retinoic acid receptor γ selective agonist, which is being investigated as a potential drug for fibrodysplasia ossificans progressiva (FOP), another genetic bone disorder with features that overlap with those of MHE. Here we show that PVO inhibits osteochondroma formation in the Fsp1Cre ;Ext1flox/flox model of MHE. Four-week daily treatment with PVO starting at postnatal day (P) 14 reduced the number of osteochondromas that develop in these mice by up to 91% in a dose-dependent manner. An inhibition of long bone growth observed in animals treated from P14 was almost entirely abrogated by delaying the initiation of treatment to P21. We also found that PVO attenuates BMP signaling in Fsp1Cre ;Ext1flox/flox mice and that aberrant chondrogenic fate determination of Ext1-deficient perichondrial progenitor cells in these mice is restored by PVO. Together, the present data support further preclinical and clinical investigations of PVO as a potential therapeutic agent for MHE. © 2017 American Society for Bone and Mineral Research.

Multiple hereditary osteochondromatosis with spinal cord compression: case report.

OBJECTIVE: The purpose of the report is to describe a patient with hereditary osteochondromatosis and spinal cord compression at the thoracic level. CLINICAL FEATURES: An 8-year-old patient with hereditary osteochondromatosis inherited from his father presented paraparesis in the left foot, leading to complete paralysis in both legs. INTERVENTION: In a CT scan, a bony tumor rising from the posterior wall of the T3 body narrowing the spinal canal, and the MRI spinal cord compression at the same level and the hydrosyringomyelic cavity extended to the conus medullaris; with an anterior thoracic approach to T2-T4, the fibro-cartilaginous tumor was removed, and the stabilization was completed with bone graft and a plate. Two months after surgery, the patient recovered strength in both legs. CONCLUSIONS: A detailed family history through examination-guided advanced imaging and biopsy provides useful information for diagnosis and appropriate management of occupative lesions in patients affected with multiple hereditary exostosis.

Gradual lengthening of the ulna in patients with multiple hereditary exostoses with a dislocated radial head.

PURPOSE: Multiple hereditary exostoses of the forearm typically form in the distal ulna, causing disturbances in the growth of the ulna and functional disability. Multiple hereditary exostoses inhibit the growth of the ulna, leading to an acquisition of a varus deformity in the radius, which sometimes leads to dislocation of the radial head, the development of limitations in the pronation-supination of the forearm, and cosmetic problems. MATERIALS AND METHODS: We retrospectively reviewed the cases of four patients who had deformities of the forearm with radial head dislocation associated with multiple hereditary exostoses, and evaluated the radiologic and clinical results of excision of the osteochondromas from the distal ulna and gradual ulnar lengthening with an Ilizarov external fixator. RESULTS: Good clinical and radiological results were obtained after a mean follow-up of 25 months. At the most recent follow-up, radial bowing, ulnar shortening, carpal slip, and the pronation/supination arch of the forearm had improved. There was little change in terms of preoperative radial articular angle and the flexion/extension arch of the elbow by the most recent follow-up. CONCLUSION: Treatment of four forearms from four patients by excision of osteochondromas and gradual lengthening of the ulna with an Ilizarov external fixator spontaneously reduced dislocations of the radial heads without the need for any additional operative intervention. All patients were satisfied with the final results.