okoj, Volume 1, No. 12

Removal of Cementless Acetabular Components

Cementless acetabular components were introduced in the United States in the early 1980s. Their popularity has steadily grown, such that cementless designs are currently the most popular devices used for acetabular reconstruction in both primary and revision total hip arthroplasty. With more widespread use and increasing length of follow-up, the need to remove such components has also increased. This OKO module includes video of the removal of cementless acetabular components.

    • Keywords:
    • hip implant

    • hip prosthesis

    • implant removal

    • prosthesis removal

    • acetabular wear debris

    • osteolysis

    • prosthetic loosening

    • cementless implant

    • cementless fixation

    • revision total hip arthroplasty

    • revision total hip replacement

    • Subspecialty:
    • Adult Reconstruction


Flatfoot is the term used to describe a weight-bearing foot shape in which the hindfoot is in valgus alignment, the midfoot sags in a plantar direction with reversal of the longitudinal arch, and the forefoot is supinated in relation to the hindfoot. There is no agreement on strict clinical or radiographic criteria for defining a flatfoot. Therefore, the point beyond which a foot with a low normal arch becomes defined as a flatfoot is unknown. Nonsurgical treatment options include education, orthotics, and achilles tendon stretching programs.

This article reviews the pathophysiology and clinical presentation of flatfoot and reviews considerations in mangement. The specfic surgical technique of calcaneal lengthening osteotomy is discussed in detail in this article.

    • Keywords:
    • flexible flatfoot

    • rigid flatfoot

    • orthotics

    • calcaneal lengthening osteotomy

    • Subspecialty:
    • Pediatric Orthopaedics

Spinal Osteoporosis

Osteoporosis is a metabolic disorder of the bone with decreased bone mass that leads to fragility fractures. The true incidence of osteoporosis is difficult, if not impossible, to measure. It is estimated that 30% of Caucasian women in the United States have osteoporosis. Osteoporosis is the most prevalent metabolic bone disorder in the United States. TThe National Osteoporosis Foundation has estimated that 700,000 vertebral compression fractures (VCFs) occur each year; 260,000 are persistently painful after nonoperative care (about one third). Nonoperative modalities consist of pain medication, bracing, anti-osteoporotic pharmaceuticals, and rehabilitative therapy. In cases of osteoporotic compression fractures resistant to nonoperative care, percutaneous vertebral augmentation, in the form of kyphoplasty or vertebroplasty, can be performed. This article reviews two surgical techniques in detail: kyphoplasty and vertebroplasty. Video is available.

    • Keywords:
    • low bone mass

    • porous bone

    • brittle bones

    • metabolic bone disorder

    • metabolic bone disease

    • primary osteoporosis

    • senile osteoporosis

    • postmenopausal osteoporosis

    • osteopenia

    • osteoporotic vertebral fractures

    • vertebral compression fractures

    • burst fractures

    • bone densitometry

    • DEXA

    • anterior corpectomy and decompression

    • posterior fusion with instrumentation

    • percutaneous vertebral augmentation

    • kyphoplasty

    • vertebroplasty

    • Subspecialty:
    • Spine

Hindfoot Arthrodesis

Hindfoot arthrodesis is indicated to relieve pain from joint degeneration or from major hindfoot deformity. Although loss of motion from a fusion is concerning in any joint, in most cases the underlying disease has already resulted in significant restriction of motion. The goal of hindfoot arthrodesis is to convert a painful, possibly stiff and deformed extremity into a straight, stiff, and more comfortable one. The indications and considerations for hindfoot arthrodesis are reviewed in detail in this article, and the specific technique of arthrodesis is reviewed specifically.

    • Keywords:
    • ankle fusion

    • ankle joint fusion

    • subtalar joint

    • talonavicular joint

    • calcaneocuboid joint

    • osteoarthritis

    • arthritis

    • foot deformity

    • bone grafting

    • Subspecialty:
    • Foot and Ankle

Patellar Instability

Patellar instability is defined as abnormal, clinically symptomatic, lateral or, in rare cases, medial translation of the patella out of the trochlear groove. Instability includes dislocations as well as subluxations, both of which can be either traumatic or atraumatic. One of the considerations in the management of patellar instability is whether the instability is due to an acute patellar dislocation or chronic/recurrent instability. The article reviews the pathophysiology and clinical presentation of patellar instability and reviews the management options for acute and for chronic/recurrent instability. Two surgical techniques are reviewed in detail: anteromedialization and MPFL reconstruction. Video is available.

    • Keywords:
    • patellofemoral dysfunction

    • patellofemoral dislocation

    • patella subluxation

    • patellofemoral joint dysfunction

    • patellofemoral pain

    • patellofemoral pain syndrome

    • dislocated kneecap

    • patellofemoral joint anatomy

    • patellofemoral joint biomechanics

    • trochlear dysplasia

    • proximal realignment

    • distal realignment

    • combined realignment

    • anteromedialization (AMZ) of tibial tubercle

    • medial patellofemoral ligament reconstruction

    • semitendinosus graft

    • Subspecialty:
    • Sports Medicine