Slipped capital femoral epiphysis (SCFE) is a frequent cause of nontraumatic painful hip of the adolescence. It is the result of the separation of the proximal femoral growth cartilage at the level of the hypertrophic cell zone. The femoral neck metaphysis rotates externally and migrates proximally relative to the femoral head epiphysis, which is stably seated in the acetabulum; early diagnosis and in situ stabilization grants the best long term results. Numerous factors affect treatment outcomes. Not all implants have the same effect on the slipped physis. Application of the traditionally used implants, such as non-threaded pins and cannulated screws, is questioned. Modern implants are available, which stabilize the slip without accelerating physis fusion. This allows femoral head and neck growth and remodeling to limit the post-slip sequellae on hip anatomy and function. Femoroacetabular impingement (FAI) complicates almost all slips. It causes progressive labral and articular cartilage damage and leads to early hip osteoarthritis and total hip replacement, approximately ten years earlier compared to the general population. Avascular necrosis of the femoral head is a dramatic complication, seen almost exclusively in unstable slips. It develops within months after the slip and leads to immediate articular joint degeneration and the need for total hip replacement. Another serious complication of SCFE is chondrolysis, which is a rapid progressive articular cartilage degeneration leading to a narrow joint space and restriction of hip motion. Implant-related complications, such as migration and loosening, may lead to the progression of the slip. Though bilateral disease is quite frequent, there is no consensus about the need for preventive surgery on the healthy contralateral hip. Diagnosis of SCFE is frequently missed or delayed, leading to slips of higher severity. Silent slippage of the capital femoral epiphysis is highly suspected as an underlying cause of cam-type FAI and earlyonset hip osteoarthritis. There is controversy, whether asymptomatic implants should be removed. Novel surgical techniques, such as the modified Dunn procedure and hip arthroscopy, seem to be effective modalities for the prevention of FAI in SCFE.

Prosthetic joint infection (PJI) is a devastating complication of total joint replacement surgery. It affects about 2% of primary total joint replacements. Treatment aims at infection eradication and restoration of patient's mobility. Two-stage revision arthroplasty with an interim application of an antibiotic-loaded cement spacer (ALCS) is the widely accepted treatment for PJI. Spacers are powerful local carriers of antibiotics at the site of infection, effective against biofilm-protected microbes. On the other hand, spacers permit some mobility of the patient and facilitate final prosthesis implantation. ALCS's are either commercially available or prepared intraoperatively on prefabricated or improvised molds. Antibiotic elution from the spacer depends on the amount of the antibiotic used for cement impregnation, at the expense of mechanical stiffness of the spacer. The antibiotic should not exceed 4g per 40g of bone cement to preserve the mechanical properties of the cement. Spacers are frequently accompanied by local or systemic complications. The spacer may break, dislocate and compress vessels or nerves of the limb. Systemic complications are the result of excess elution of antibiotic and include nephrotoxicity, hepatotoxicity, ototoxicity, allergic reactions or neutropenia. Elderly patients with comorbidities are at risk to present such complications. Microbial resistance is a potential risk of long-lasting spacer retention. Persisting infection may require multiple spacer replacements.

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A boy and his father with severe short stature, progressively evolving body asymmetry, and skeletal abnormalities are presented. A next-generation sequencing exome study was performed, and the patient was found heterozygous for the c.1609G>A (p.Gly537Ser) mutation in the <i>COL2A1</i> gene. This mutation is considered a pathogenic variant and has been previously registered in the Human Gene Mutation Database (HGMD) in association with spondyloepiphyseal dysplasia (accession: CM052184). It has been described in a patient as a sporadic case and resulted in a severe phenotype. Segregation studies, in order to determine the inheritance pattern, identified the same mutation in our patient's father. The variant was transmitted in an autosomal dominant pattern. In conclusion, we describe a patient with hereditary spondyloepiphyseal dysplasia congenita, caused by a c.1609G_A (p.Gly537Ser) mutation in the <i>COL2A1</i> gene, which resulted in a milder phenotype.

A case of unilateral genu recurvatum (GR) in a 15-year-old boy with a history of Guillain-Barre syndrome (GBS) and subsequent bilateral drop-foot is presented. Muscle imbalance of the lower limb and repetitive pressure from prolonged usage of an orthosis to deal with drop-foot may be the causative factors for early partial physeal arrest of his right proximal tibia. The result was a right GR and a shorter right lower limb. A below the tibial tuberosity anterior opening-wedge oblique proximal tibial osteotomy was performed. The deformity was gradually corrected using an Ilizarof circular frame. The center of rotation and angulation of the procedure was placed at the posterior tibial cortex. The procedure was completed uneventfully within four months. Excellent clinical and radiological improvement of the deformity was obtained.