Summary Adult Limb Deformity is a lower extremity condition that can result from childhood growth impairment, metabolic bone disorders, severe osteoarthritis, trauma, or fracture malunion/nonunion. Diagnosis is made with a combination of clinical examination and plain full limb length radiographs. Treatment is usually osteotomy of the femur and/or tibia, although arthroplasty may also correct deformity in appropriate patients. Epidemiology Incidence varies depending on the underlying cause of the deformity Demographics no gender predilection age younger patients login to view 1 more bullet Location upper extremity - rare deformity is commonly seen at elbow and wrist secondary to fracture malreduction lower extremity (focus of this topic) femur vs. tibia or both login to view 1 more bullet proximal vs. distal Risk factors family history trauma Etiology Pathophysiology mechanism of injury related to associated injury or orthopedic condition that contributes to bony limb deformity pathoanatomy in most cases, the anatomic axis of bone is altered for some reason (malunion/nonunion, metabolic bone disease, etc) to the point where there is significant mechanical axis deviation (MAD), leading to altered joint contact pressures and ligamentous stability, which further contributes to joint degeneration and worsening of mechanical alignment over time Associated conditions orthopaedic conditions malunion nonunion previous osteotomies genu valgum/genu varum advanced arthritis with deformity bony tumors childhood abnormalities blount's disease focal fibrocartilaginous dysplasia proximal tibial physeal injury cozen's phenomenon skeletal dysplasia login to view 2 more bullets femoral anteversion limb length discrepancy (LLD) medical conditions metabolic bone disorders login to view 5 more bullets neuromuscular disorders login to view 1 more bullet neurofibromatosis Anatomy Osteology femur normal proximal femur neck shaft-angle 130 +/- 7º normal proximal femur anteversion 10 +/- 7º tip of greater trochanter should be at the level of the center of femoral head and is used as the start point for measuring the anatomic axis of the femur (AAF) difference between anatomic and mechanical femoral axes is normally 5-7º tibia shaft is triangular in cross-section tibial tubercle sits anterolaterally and attaches to patellar tendon anatomic and mechanical tibial axes should be equal if no deformity exists Ligaments knee medial collateral ligament (MCL) - superficial MCL (sMCL) and deep MCL (dMCL) login to view 2 more bullets lateral collateral ligament (LCL) login to view 1 more bullet both LCL and MCL contribute to coronal plate stability and can complicate deformity login to view 1 more bullet Classification Descriptive based on bone(s) affected, position (varus/valgus, procurvatum/recurvatum, etc.) and degree of deformity Presentation History prior trauma or childhood deformity/bone disease with/without progression Symptoms common symptoms pain with location based on deformity login to view 2 more bullets subtle to obvious deformity complaints of abnormal gait or loss of function Physical exam inspection note coronal/sagittal plane deformity note any rotational deformity login to view 2 more bullets limb-length discrepancy motion range of motion (ROM) at the hip, knee and ankle should be evaluated ligamentous laxity should be evaluated Imaging Radiographs recommended views weight-bearing AP & lateral full-length lower extremity views login to view 2 more bullets weight-bearing AP & lateral views of each affected limb segment findings anatomic axis - measured on each anatomic segment login to view 7 more bullets mechanical axis login to view 7 more bullets joint line axes login to view 4 more bullets measurements coronal plane login to view 25 more bullets sagittal plane measurements login to view 2 more bullets leg length discrepancy (LLD) login to view 2 more bullets deformity calculation login to view 4 more bullets criteria dictating treatment abnormal values help determine the site of deformity and site/degree of correction needed login to view 4 more bullets CT indications rotational malalignment views axial, sagittal, coronal sequences findings axial cuts particularly helpful for establishing femoral version and axial malalignment Treatment Overview angulation, translation, length, and rotation should be evaluated and corrected in that order Nonoperative bracing/orthoses indications login to view 3 more bullets modalities dependent on etiology of deformity login to view 2 more bullets outcomes bracing is often not well tolerated minimal data exists to demonstrate risk of deformity progression with nonoperative management Operative osteotomy derotational femoral osteotomy login to view 13 more bullets valgus-producing tibial osteotomy login to view 11 more bullets valgus-producing femoral osteotomy login to view 7 more bullets varus-producing femoral osteotomy login to view 12 more bullets gradual limb lengthening (LLD) indications login to view 1 more bullet techniques login to view 2 more bullets outcomes login to view 2 more bullets total knee arthroplasty (TKA) indications login to view 1 more bullet techniques login to view 4 more bullets outcomes login to view 4 more bullets Techniques Bracing/orthoses (KAFO) technique consists of an AFO with metal uprights, a mechanical knee joint and two thigh bands Derotational femoral osteotomy approach lateral approach to femur or medial femur subvastus approach depending on technique used technique proximal osteotomy login to view 3 more bullets diaphyseal osteotomy w/ intramedullary fixation login to view 5 more bullets distal supracondylar osteotomy login to view 3 more bullets complications under correction over correction causing retroversion and out-toeing login to view 1 more bullet Valgus producing tibial osteotomy approach lateral closing wedge osteotomy login to view 1 more bullet medial opening wedge osteotomy login to view 1 more bullet technique lateral closing wedge osteotomy login to view 4 more bullets medial opening wedge osteotomy login to view 4 more bullets complications nonunion patellar tendon injury patella baja alterations in tibial slope login to view 2 more bullets Valgus producing femoral osteotomy approach lateral subvastus approach to distal femur technique lateral closing wedge femoral osteotomy login to view 5 more bullets complications nonunion medial hinge fracture Varus producing femoral osteotomy approach lateral opening wedge femoral osteotomy login to view 1 more bullet medial closing wedge femoral osteotomy login to view 1 more bullet technique lateral opening wedge femoral osteotomy login to view 3 more bullets medial closing wedge femoral osteotomy login to view 2 more bullets complications quadriceps tendon injury intercondylar femur fracture login to view 1 more bullet lateral hinge fracture login to view 1 more bullet Gradual limb lengthening approach lateral hip approach for intramedullary nailing vs. external fixation technique distraction osteogenesis login to view 7 more bullets complications external fixator login to view 3 more bullets intramedullary lengthening login to view 3 more bullets TKA approach standard medial parapatellar technique goal is to restore neutral mechanical alignment with bone cuts of distal femur and proximal tibia login to view 3 more bullets with extra-articular malalignment, same rules of normal limb deformity assessment apply login to view 7 more bullets complications periprosthetic infection ligamentous contractures/laxity patellar tendon injury Complications Deformity undercorrection/overcorrection unfavorable loading on one compartment preoperative planning important to avoid this opening wedge osteotomy may be at higher risk because it can lose some correction over time Nonunion reported rates around 5% risk factors smoking older age > 60 obesity far cortex hinge fracture Ligamentous/tendon damage quadriceps tendon more at risk in femoral osteotomies patellar tendon at risk in tibial osteotomies Patella baja caused by proximal tibia osteotomies supra-tubercle osteotomy increases risk compared to infra-tubercle may cause increased knee pain and difficulty with future TKA Infection 1-4% incidence increases risk of nonunion risk factors smoking admission to hospital vs. outpatient surgery center Prognosis Within first 5 years, radiographic and clinical outcomes remain excellent in >90% of patients. After >10 years, this drops to around 50-70% 15-25% end up requiring TKA within 10 years risk factors for poorer outcomes prior failed arthroscopic treatment obesity age > 60 insufficient correction