An Eastern Europe and Middle East multinational expert Delphi consensus study on the prevention, diagnosis, and treatment of developmental dysplasia of the hip before walking age.

PURPOSE: The incidence of developmental dysplasia of the hip (DDH) is higher in Eastern Europeans and Middle Easterners. This study aimed to establish consensus among experts in this geographical area on the management of DDH before walking age. METHODS: Fourteen experienced orthopedic surgeons agreed to participate in a four-round online consensus panel by the Delphi method. The questionnaire included 31 statements concerning the prevention, diagnosis, and treatment of DDH before walking age. RESULTS: Consensus was established for 26 (84%) of 31 statements. Hip ultrasonography is the proper diagnostic tool under six months in DDH; universal newborn hip screening between three and six weeks is necessary; positive family history, breech presentation, female gender, and postnatal swaddling are the most important risk factors; Ortolani, Barlow tests, and limitation of abduction are the most important clinical findings; Pavlik harness is the first bracing preference; some Graf type IIa hips and all Graf type IIb and worse hips need abduction bracing treatment; the uppermost age limit for closed and open reductions is 12 months and 12-24 months, respectively; anatomic reduction is essential in closed and open reductions, postoperative MRI or CT is not always indicated; anterior approach open reduction is better than medial approach open reduction; forceful reduction and extreme positioning of the hips (> 60° hip abduction) are the two significant risk factors for osteonecrosis of the femoral head. CONCLUSION: The findings of the present study may be useful for clinicians because a practical reference, based on the opinions of the multinational expert panel, but may not be applicable to all settings is provided.

Developmental Dysplasia of the Hip (DDH): Etiology, Diagnosis, and Management.

Developmental dysplasia of the hip (DDH) is a complex disorder that refers to different hip problems, ranging from neonatal instability to acetabular or femoral dysplasia, hip subluxation, and hip dislocation. It may result in structural modifications, which may lead to early coxarthrosis. Despite identifying the risk factors, the exact aetiology and pathophysiology are still unclear. Neonatal screening, along with physical examination and ultrasound, is critical for the early diagnosis of DDH to prevent the occurrence of early coxarthrosis. This review summarizes the currently practised strategies for the detection and treatment of DDH, focusing particularly on current practices for managing residual acetabular dysplasia (AD). AD may persist even after a successful hip reduction. Pelvic osteotomy is required in cases of persistent AD. It could also be undertaken simultaneously with an open hip reduction. Evaluation of the residual dysplasia (RD) of the hip and its management is still a highly active area of discussion. Recent research has opened the door to discussion on this issue and suggested treatment options for AD. But there is still room for more research to assist in managing AD.

Satisfactory outcomes of post-operative subtalar extra-articular arthroereisis in juvenile flexible flat foot.

OBJECTIVES: To analyze the surgical outcomes of subtalar extra-articular arthroereisis and the patient/parent satisfaction regarding the foot's shape, foot pain, ability to walk, ability to jump, and shoe wear. METHODS: Our retrospective cross-sectional study was carried out through an online-based questionnaire to assess patient satisfaction postoperatively at 3 hospitals (King Khalid University Hospital, Sultan bin Abdulaziz Humanitarian City, and Dallah Hospital, Riyadh, Saudi Arabia) between the years 2014-2021. RESULTS: A total of 65 patients participated in our study. Approximately 86.1% of them had the operation bilaterally. The most important aspects where patients noticed the most improvement were the foot's shape (90.8%), pain (81.5%), and ability to walk (76.9%). CONCLUSION: Several studies have been carried out highlighting the surgical technique and complications of the procedure. However, a limited number of studies have been carried out to assess patient satisfaction with the procedure, especially in Saudi Arabia, as the procedure is considered relatively new in the region with insufficient data regarding it. Therefore, this study is considered one of the few articles regarding subtalar extra-articular arthroereisis in the region.

Open Reduction at 15 Months of Left Hip Dislocation in a Male Infant Diagnosed with Arthrogryposis.

BACKGROUND Arthrogryposis is a congenital condition of multiple contractures of joints associated with hip dislocation. The outcome of open reduction of hip dislocation in arthrogryposis patients is debatable. Open reduction of arthrogryposis is challenging for shallow acetabulum and extensive adhesions and fibrosis. For this reason, a careful extensive release must be carried out to achieve the open reduction of the hip in arthrogryposis patients. The literature lacks surgical recommendations for open reduction of the hip in arthrogryposis patients and how to deal with cases of the extruded bone segment during open reduction. CASE REPORT The patient presented in the first few weeks of life with bilateral clubfoot and left hip dislocation. Clinical diagnosis of arthrogryposis was made after referral to a genetics specialist. The hip was clinically irreducible. The patient underwent open reduction and femoral shortening using the Smith Peterson approach at the age of 15 months, with accidental extrusion of the proximal femur, which was retained immediately. The clinical outcome showed a painless, good range of motion. Radiographically, features of avascular necrosis and healed osteotomy site were evident. CONCLUSIONS A difficult hip reduction was expected in this arthrogryposis patient, which required careful dissection of surrounding fibrosis and appropriate femoral shortening. Careful dissection should be carried out during open reduction to avoid jeopardization of femoral head vascularity or even complete devitalization of the proximal femur.

Targeted Minimally Invasive Percutaneous Posteromedial Release of Residual Clubfoot in Myelomeningocele Patients: A Report of Two Cases.

Congenital talipes equinovarus (CTEV) is commonly associated with myelomeningocele (MMC). It is thought to be a mixture of intrauterine development and a result of an imbalance in muscular innervation. Conservative management has been explored for those cases, but most resulted in recurrence. In this study, we report two cases where targeted minimally invasive percutaneous posteromedial release of residual clubfoot was done using an 18-gauge needle and a small incision for the cuboid osteotomy. In both cases, we achieved plantigrade shoeable/braceable feet. Both cases are still followed in our clinic. They require further follow-up to assess their long-term outcomes.

The Effect of Delayed Closed Reduction of Supracondylar Fracture on Perioperative Complications.

Background Supracondylar fracture is one of the most frequent pediatric traumas and surgically managed fractures. Multiple factors can contribute to delaying surgical management of supracondylar fracture, which is thought to lead to difficult reduction and more complications. Surgical treatment during the nighttime shift (from 20:00-8:00) might increase the complication rate including vascular injury, nerve injury, and the need to convert closed reduction to open due to multiple reasons including nontrained staff, exhausted on-call team, and other reasons. Objectives We are looking into the effect of delaying surgical intervention 24 hours from the trauma to the surgical intervention and the impact of daytime or night-time surgeries on perioperative complications. Methods A retrospective cohort study was conducted on all patients who presented with supracondylar fracture Gartland type 2 or 3 who required surgical intervention (63 patients) from 2018-2021 in an academic institute. All patients presented with unilateral injury. Patients were divided into an early surgical group where the surgery was done within the first 24 hours from the trauma and a delayed surgical group if performed after 24 hours. Additionally, patients were classified based on the time of the day surgery was performed into daytime or nighttime surgeries. The complication rate was compared between the groups. Results Most of the patients were male, and the mean age was 4.52 ± 2.28 years. No significant difference was found between the early and delayed groups in the complication rate. Nerve and vascular injury were statistically higher for cases operated at nighttime. Conclusion Delayed surgical treatment of supracondylar fracture doesn't affect the complication rate, whereas closed reduction of supracondylar fractures that were performed during nighttime duty was shown to lead to a higher rate of vascular and nerve injuries.

A Novel Modification of Woodward Procedure for Correction of Sprengel Deformity by Application of Anchoring Sutures.

PURPOSE: To report the functional and cosmetic results of cases with Sprengel deformity (SD) who underwent a novel technical modification in Woodward procedure for severe SD comprising of lowering of the scapula followed by stabilization of scapula with application of anchoring sutures. MATERIALS AND METHODS: Twenty-three children were operated at a mean age of 6.6 ± 2.5 years (range 3.4-11 years) and followed up for a mean period of 5.51 ± 1.98 years. RESULTS: The mean Cavendish score of the patients before procedure of 3.2 ± 0.45 was reduced to 1.7 ± 0.56 (p < 0.001) after the surgery. All patients improved in global shoulder abduction. The mean preoperative abduction of 97° ± 15.2° increased to a mean of 149° ± 14.1° post-operatively (p < 0.001). Significant improvement was also observed in mean Rigault grades after surgical intervention using anchoring suture modification of Woodward procedure. The mean Rigault grade of 2.7 ± 0.47 prior to surgery was reduced to 1.3 ± 0.47 (p < 0.001) at final evaluation. Age of the patients negatively correlated with the functional outcome (r = - 0.48; p < 0.02). The presence of an omovertebral bar or associated congenital anomalies did not affect the functional outcome. CONCLUSION: The modification of Woodward procedure for correction of SD by application of anchoring sutures was a reliable method for correction of SD particularly at younger age. The procedure was associated with significant improvement in shoulder abduction, cosmetic appearance and radiological grades over 5 year follow-up.

Determining the correlation between Cobb angle severity and bone mineral density in women with adolescent idiopathic scoliosis.

OBJECTIVES: To determine the correlation between Cobb angle severity and varying bone mineral density (BMD) and measure the prevalence of low BMD in women with adolescent idiopathic scoliosis (AIS) in KSA. METHODS: The sample included 54 women with AIS between 10 and 20 years of age. Data regarding Cobb angles and femoral and lumbar Z-scores according to dual-energy X-ray absorptiometry (DXA) scans performed between 2008 and 2018 were reviewed. RESULTS: Of the 54 patients recruited, 41 exhibited Cobb angles of 40-70° and 13 had Cobb angles >70°. The mean lumbar bone, right femur, and left femur BMDs were markedly higher in those with Cobb angles ≤70° compared with BMDs in those with Cobb angles >70°. Of the group with Cobb angles ≤70°, six (14.6%) and nine (22.0%) exhibited low BMD according to their lumbar and femoral Z-scores, respectively. Of the group with Cobb angles >70°, eight (61.5%) and nine (69.2%) exhibited low BMD according to their lumbar and femoral Z-scores, respectively. CONCLUSIONS: Female AIS patients with greater higher Cobb angles exhibited a significantly higher frequency of low BMDs.

Assessment of serum vitamin D levels in surgical adolescent idiopathic scoliosis patients.

BACKGROUND: The mechanism behind idiopathic scoliosis and its progression is not fully understood. Vitamin D insufficiency is known to play a role in the progression and/or occurrence of a variety of bone diseases. In this study, we aimed to estimate the prevalence of vitamin D insufficiency among patients with adolescent idiopathic scoliosis. Additionally, we aimed to calculate the differences in serum vitamin D levels, Cobb angles, spinal bone mass densities, and serum alkaline phosphatase levels between the sexes in the sample and to assess the possibility of a correlation between any of these factors. METHODS: Demographic details, vitamin D levels, Cobb angle, spinal bone mass density, and alkaline phosphatase were collected from the records of 67 patients who were eligible for corrective surgery. These values were compared to normal levels and between the sexes within the study. RESULTS: Of the 67 patients, 54 (80.6%) were female. The mean serum vitamin D level was 37.86 ± 26 nmol/L, and levels below normal were found in 92.5% of the patients. Statistical analysis showed significant differences (p = 0.002) in serum alkaline phosphatase levels between the sexes. No correlation was found between vitamin D levels and the Cobb angles, spinal and bilateral femoral neck bone mass densities, and serum alkaline phosphatase levels. CONCLUSIONS: Most adolescent idiopathic scoliosis patients had insufficient serum vitamin D levels and also suffered from low bone mineral density at an early age.

Simultaneous bilateral single-stage combined open reduction and pelvic osteotomy for the treatment of developmental dysplasia of the hip.

Children older than 18 months with developmental dysplasia of the hip (DDH) for the first time or who do not respond to closed treatment require open reduction with/without acetabuloplasty. We determined whether open reduction and pelvic acetabuloplasty using the Pemberton or Dega technique for both hips simultaneously was well tolerated and offered better outcomes. A total of 140 hips of 70 patients with bilateral DDH were identified. All patients were diagnosed after they started walking. Patients were treated with bilateral single-stage open reduction with acetabuloplasty using the Pemberton or Dega procedure. All patients were prospectively followed up between 2007 and 2018. Results were considered satisfactory if the acetabular index was <24°. Hemoglobin levels were evaluated in all patients. At the final follow-up, the results were evaluated radiologically and clinically based on the modified Severin's classification and modified McKay criteria, respectively. The mean age at surgery was 20.3 months (range, 16-24). The mean operative time was 228 minutes. The mean postoperative hemoglobin level was 90.5 g/L (range, 61-122; SD, ±13.4). The mean differences between the preoperative and postoperative acetabular index values for both hips were 22.36° (SD, ±6.69°) and 22.64° (SD, ±6.69°) for the right and left hips, respectively. Open reduction with pelvic acetabuloplasty using the Pemberton or Dega technique simultaneously in both hips was well tolerated, cost-effective, had excellent outcomes, and posed no additional risk to patients with DDH younger than 24 months.

Bone cement spacer: a novel technique for treating a complicated case of developmental dysplasia of the hip with an injured acetabulum: Case report with 7-year follow-up.

RATIONALE: Developmental dysplasia of the hip (DDH) has an incidence of 5 per 1000 newborns and its management depends on various factors. We present a rare case of DDH with soft tissue obliteration and a bony prominence in the center of the acetabulum after failed open reduction and acetabuloplasty. PATIENT CONCERNS: A 20-month-old girl presented to our clinic with right hip stiffness after undergoing open reduction and acetabuloplasty at another hospital. DIAGNOSES: The diagnosis of DDH was made using a computed tomography scan that revealed a right hip dislocation with soft tissue obliteration and a bony prominence in the center of the acetabulum. INTERVENTIONS: We used a novel technique for treating the rare presentation of complicated DDH with massive soft tissue obliteration and bony prominence in the center of the acetabulum after failed open reduction and acetabuloplasty. The right hip was surgically explored. The acetabulum was deepened and resurfaced. Bone cement was applied over the acetabulum to prevent future ankylosis. OUTCOMES: At the follow-up 7 years after the last surgery, the patient had regained full range of motion and a properly reduced right hip with optimal acetabular coverage on radiographs. LESSONS: Care must be taken in any patient with DDH who presents with hip redislocation after open reduction. If deepening and resurfacing of the acetabulum are required, bone cement could be used as a temporary spacer for 8 weeks; this was key in treating our patient.

Assessing public awareness of clubfoot and knowledge about the importance of early childhood treatment: a cross-sectional survey.

BACKGROUND: Clubfoot is a treatable abnormality that can be managed with early intervention. However, there is a lack of public knowledge regarding clubfoot, which can delay treatment. This study aimed to assess the public awareness of clubfoot and knowledge regarding the importance of treatment in early childhood. METHODS: This cross-sectional survey spanned 6 months, from June through November 2018, and involved persons living in Saudi Arabia. To collect data on public awareness of clubfoot risk factors, treatment, and prognosis, a questionnaire was developed by orthopedic experts and disseminated online. The target population included people of both genders and all age groups from the general population, regardless of their knowledge of someone with clubfoot. RESULTS: By the end of the study period, 746 participants completed the online survey. In total, 520 of the respondents (69.7%) had never heard about clubfoot syndrome. Among the participants, 5.4% had a child with clubfoot syndrome and 4.6% were aware of clubfoot because they had an affected child. The top resource accessed by respondents for obtaining knowledge about clubfoot was social media channels (38.4%), followed by obtaining knowledge from relatives and friends (19.9%). The most reported perceived cause of clubfoot was hereditary and genetic disorders (58.4%), followed by neurological disorders (39.9%). CONCLUSIONS: Results show that there is low public knowledge of clubfoot which may be attributed to a lack of awareness campaigns. We recommend increasing awareness regarding clubfoot through social media platforms and public campaigns in key locations, such as malls, as this may encourage people to seek early treatment. This is important because early management of clubfoot is less invasive and with regular follow-up, leads to better patient outcomes.

Assessment of perceptions, knowledge, and attitudes of parents regarding children's schoolbags and related musculoskeletal health.

BACKGROUND: Heavy schoolbags and their adverse musculoskeletal effects are a cause of great concern. Parents' awareness and knowledge about this are crucial to prevent such health problems. Thus, this study aimed to assess parents' perceptions, knowledge, and attitudes regarding children's schoolbags and related musculoskeletal health. METHODS: A cross-sectional study was conducted targeting parents with children of school age. In January 2015, a self-administered, validated questionnaire was distributed to all participants, consisting of questions about their awareness, knowledge, and attitude regarding the negative effects of carrying inappropriate schoolbags on children's musculoskeletal health. RESULT: A total of 616 parents (284 fathers and 332 mothers) completed the questionnaire (response rate of 100%). A total of 247 (87.3%) fathers and 301 (90.9%) mothers knew that carrying heavy schoolbags produces back problems. However, only 105 (36.9%) fathers and 107 (37.6%) mothers knew that incorrect schoolbag weight and inadequate way to carry it may impede the normal alignment and growth of the spine. Only 107 (37.6%) fathers and 96 (28.9%) mothers knew the ideal weight of the schoolbag, while 49.6% of fathers and 42.8% of mothers did not check their children's schoolbags for unnecessary contents. CONCLUSION: Awareness of parents about the consequences of heavy schoolbags and correct use is still limited and suboptimal. Educational sessions for parents and awareness campaigns may help to reduce the prevalence of musculoskeletal health problems among children.

Nonsyndromic Massive Tarsal and Tarsometatarsal Coalitions in a Young Female.

Tarsal coalition is an abnormal connection between 2 or more tarsal bones, with the most common sites being between the talus and the calcaneus and between the navicular and the calcaneus. The occurrence of multiple and massive tarsal coalitions is rare. We describe a rare case of nonsyndromic bilateral tarsal coalition involving most of the tarsal bones and extending to the metatarsal bones in a 4-year-old female. The condition was not painful and did not affect her gait. The main concern was the abnormal shape of her feet. Tarsal coalition can occur as an isolated anomaly or in association with other congenital disorders, usually presenting around the age of 12 years. The coexistence of nonsyndromic bilateral multiple tarsal coalitions is seldom reported. Regardless of the presentation, treatment is not indicated in cases of asymptomatic tarsal coalition. Our patient had a unique presentation of tarsal coalition, involving both the tarsal and tarsometatarsal bones. To our knowledge, this is the first report of this type of presentation.

Expanding the phenome and variome of skeletal dysplasia.

PURPOSE: To describe our experience with a large cohort (411 patients from 288 families) of various forms of skeletal dysplasia who were molecularly characterized. METHODS: Detailed phenotyping and next-generation sequencing (panel and exome). RESULTS: Our analysis revealed 224 pathogenic/likely pathogenic variants (54 (24%) of which are novel) in 123 genes with established or tentative links to skeletal dysplasia. In addition, we propose 5 genes as candidate disease genes with suggestive biological links (WNT3A, SUCO, RIN1, DIP2C, and PAN2). Phenotypically, we note that our cohort spans 36 established phenotypic categories by the International Skeletal Dysplasia Nosology, as well as 18 novel skeletal dysplasia phenotypes that could not be classified under these categories, e.g., the novel C3orf17-related skeletal dysplasia. We also describe novel phenotypic aspects of well-known disease genes, e.g., PGAP3-related Toriello-Carey syndrome-like phenotype. We note a strong founder effect for many genes in our cohort, which allowed us to calculate a minimum disease burden for the autosomal recessive forms of skeletal dysplasia in our population (7.16E-04), which is much higher than the global average. CONCLUSION: By expanding the phenotypic, allelic, and locus heterogeneity of skeletal dysplasia in humans, we hope our study will improve the diagnostic rate of patients with these conditions.

Occupational injuries among pediatric orthopedic surgeons: How serious is the problem?

In this cross-sectional study, we surveyed all pediatric orthopedic surgeons in Saudi Arabia using an anonymous electronic questionnaire composed of 23 items to identify the rate of occupational injuries and obtain other relevant information. Thirty-nine participants completed the questionnaire (response rate: 83%). Participants who sustained occupational injuries throughout their careers represented 82.5%. The most injured areas were the hands, eyes, and back by 54.5%, 24.2%, and 15.2%, respectively. Approximately 11.1% were injured while operating on infected patients. Approximately 30.3% reported their injuries to their institution. We concluded that the rate of occupational injuries among pediatric orthopedic surgeons is very high and underreported.

Expanding the clinical and genetic heterogeneity of hereditary disorders of connective tissue.

Ehlers-Danlos syndrome (EDS) describes a group of clinical entities in which the connective tissue, primarily that of the skin, joint and vessels, is abnormal, although the resulting clinical manifestations can vary widely between the different historical subtypes. Many cases of hereditary disorders of connective tissue that do not seem to fit these historical subtypes exist. The aim of this study is to describe a large series of patients with inherited connective tissue disorders evaluated by our clinical genetics service and for whom a likely causal variant was identified. In addition to clinical phenotyping, patients underwent various genetic tests including molecular karyotyping, candidate gene analysis, autozygome analysis, and whole-exome and whole-genome sequencing as appropriate. We describe a cohort of 69 individuals representing 40 families, all referred because of suspicion of an inherited connective tissue disorder by their primary physician. Molecular lesions included variants in the previously published disease genes B3GALT6, GORAB, ZNF469, B3GAT3, ALDH18A1, FKBP14, PYCR1, CHST14 and SPARC with interesting variations on the published clinical phenotypes. We also describe the first recessive EDS-like condition to be caused by a recessive COL1A1 variant. In addition, exome capture in a familial case identified a homozygous truncating variant in a novel and compelling candidate gene, AEBP1. Finally, we also describe a distinct novel clinical syndrome of cutis laxa and marked facial features and propose ATP6V1E1 and ATP6V0D2 (two subunits of vacuolar ATPase) as likely candidate genes based on whole-genome and whole-exome sequencing of the two families with this new clinical entity. Our study expands the clinical spectrum of hereditary disorders of connective tissue and adds three novel candidate genes including two that are associated with a highly distinct syndrome.

Prevalence and Associated Factors of Low Back Pain among Clinicians of A Major Referral Hospital

Objectives: Low back pain (LBP) is one of the most common health problems faced by health care professionals due to their occupational lifestyle. This study aimed to quantify the prevalence of LBP among clinicians, and to identify its associated factors. Methods: A cross sectional study was carried out in King Khalid University Hospital (KKUH) among 460 clinicians from different specialties. A validated questionnaire of 21 items was used to collect data. Chi-square test and odds ratios were used to observe and measure the association between categorical variables. Binary logistic regression by Wald method was used to identify independent factors associated with LBP (yes/no). Results: The prevalence of LBP was found to be 59.4% (244) with 38% of them reported as severe. The distribution of prevalence among consultants, registrars and residents was 110 (45.1%), 91 (37.3%) and 43 (17.6%) respectively. Out of 114 (46.7%) surgeons who suffer from LBP we found, orthopaedic surgeons had 10.2% prevalence of LBP. Male clinician (odds ratio: 1.7; 95% Confidence Interval (CI): 1.1- 2.8), consultant (4.1; 95% CI: 2.1-8.3), registrar (2.2; 95% CI: 1.2-4.2), more than 10 hours/week near bedside (1.8; 95% CI: 1.1-3.0), bending backwards at work (8.3; 95% CI: 5.1-13.4) and pulling objects during work (3.1; 95% CI: 1.7-5.6) were found to be independent statistically significant associated factors of LBP. Conclusion: The high prevalence of LBP among clinicians and its associated factors indicates that clinicians should maintain good posture and avoid sudden movements during working hours in hospital to reduce this occupational health problem.

Wound healing without drains in posterior spinal fusion in idiopathic scoliosis.

OBJECTIVE: To determine the frequency of wound infection and neurological injuries in patients with idiopathic scoliosis who underwent posterior spinal fusion without use of drains. STUDY DESIGN: Case series. PLACE AND DURATION OF STUDY: Department of Orthopaedics, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia, from February 2007 to June 2010. METHODOLOGY: Patients who underwent similar technique of posterior spinal fusion instrumentation for the correction of scoliosis without use of drain were included. Wound Demographics, wound healing, complications and duration of hospital stay were considered and described as frequency and mean values. RESULTS: The average age at the time of surgery was 12.80 ± 1.30 years, duration of surgery was 3.80 ± 0.86 hours, hospital stay was 3.84 ± 0.78 days and patients were followed-up over the last 30 months. There was no incidence of any neurological complication and deep infection. However, only 2 (4.16%) cases with superficial skin infection were treated with dressing and antibiotics with full recovery. CONCLUSION: The wound healing is adequate without using drain for patients with idiopathic scoliosis who underwent posterior spinal fusion and instrumentation when good wash, watertight closure technique and appropriate antibiotics coverage is provided.

Mutations in MEOX1, encoding mesenchyme homeobox 1, cause Klippel-Feil anomaly.

Klippel-Feil syndrome (KFS) is a segmentation malformation of the cervical spine; clinically, it manifests as a short neck with reduced mobility and a low posterior hairline. Several genes have been proposed as candidates for KFS when it is present with other associated anomalies, but the genetics of isolated KFS have been difficult to study because of the syndrome's mostly sporadic occurrence. We describe a multiplex consanguineous family in which isolated KFS maps to a single 17q21.31 locus that harbors a homozygous frameshift deletion in MEOX1; this deletion results in complete instability of the transcript. Direct sequencing of this gene in two siblings from another consanguineous family affected by isolated KFS uncovered another homozygous truncating (nonsense) MEOX1 mutation that also leads to complete degradation of the transcript. This gene encodes a transcription factor with a well-established and nonredundant role in somite development, and homozygous null alleles of Meox1 in mice have a cervical skeletal defect that is remarkably similar to the one we observe in human individuals with MEOX1 mutations. Our data strongly suggest that KFS is the human phenotypic equivalent of the sclerotome polarity defect that results from Meox1 deficiency in mice.