Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Hip 721 articles


Aberrant Femoral Torsion Presenting with Frog-leg Squatting Mimicking Gluteal Muscle Contracture

Chia-Ling Chiang MD, Meng-Yuan Tsai MD, Wei-Ning Chang MD, Clement Kuen-Huang Chen MD

Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture.

Multilevel Surgery Improves Gait in Spastic Hemiplegia But Does Not Resolve Hip Dysplasia

Erich Rutz MD, Elyse Passmore MEng, Richard Baker PhD, H. Kerr Graham MD

Multilevel orthopaedic surgery may improve gait in Type IV hemiplegia, but it is not known if proximal femoral osteotomy combined with adductor release as part of multilevel surgery in patients with hip dysplasia improves hip development.

Polyethylene Wear is Related to Patient-specific Contact Stress in THA

Robert Košak MD, PhD, Veronika Kralj-Iglič PhD, Aleš Iglič PhD, Matej Daniel PhD

General numerical models of polyethylene wear and THA simulators suggest contact stresses influence wear. These models do not account for some patient-specific factors. Whether the relationship between patient-specific contact stress and wear apply in vivo is unclear.

Ceramic Bearings for Total Hip Arthroplasty Have High Survivorship at 10 Years

James A. D’Antonio MD, William N. Capello MD, Marybeth Naughton BS

Ceramic bearings were introduced to reduce wear and increase long-term survivorship of total hip arthroplasty. In a previous study comparing ceramic with metal-on-polyethylene at 5 to 8 years, we found higher survivorship and no osteolysis for the ceramic bearings.

Surgical Technique: A Cup-in-Cup Technique to Restore Offset in Severe Protrusio Acetabular Defects

Thomas J. Blumenfeld MD, William L. Bargar MD

Severe medial and/or superior defects encountered in revision THA are currently managed with jumbo (≥ 66 mm) acetabular components and modular augments, with reconstruction cages, or with the cup-cage technique. Preoperative planning can indicate when these techniques may not restore vertical and horizontal offset. Failure to restore offset can lead to impingement, leg length inequality, abductor weakness, and dislocation.

Low Incidence of Groin Pain and Early Failure with Large Metal Articulation Total Hip Arthroplasty

John B. Meding MD, Lindsey K. Meding, E. Michael Keating MD, Michael E. Berend MD

Large-diameter metal-on-metal articulations reportedly improve stability and wear in THAs. However, some reports suggest some patients have unexplained hip and early failures with these implants. Thus, the potential benefits may be offset by these concerns. However, the incidence of these problems is not clearly established.

A Short Tapered Stem Reduces Intraoperative Complications in Primary Total Hip Arthroplasty

Ryan G. Molli DO, Adolph V. Lombardi MD, FACS, Keith R. Berend MD, Joanne B. Adams BFA, Michael A. Sneller BS

While short-stem design is not a new concept, interest has surged with increasing utilization of less invasive techniques. Short stems are easier to insert through small incisions. Reliable long-term results including functional improvement, pain relief, and implant survival have been reported with standard tapered stems, but will a short taper perform as well?

Stable Fixation of Short-stem Femoral Implants in Patients 70 Years and Older

Ronak M. Patel MD, Matthew C. Smith MD, Chase C. Woodward BA, S. David Stulberg MD

Limitations of conventional uncemented femoral stems persist, including proximal-distal mismatch, nonideal load transfer, loss of bone, and difficulties with minimally invasive surgery. Metaphyseal-engaging short-stem implants have been designed to address these issues in THA. While these devices have been studied in younger patients, it is unclear whether they offer advantages in older patients.

The John Charnley Award: An Accurate and Extremely Sensitive Method to Separate, Display, and Characterize Wear Debris Part 2: Metal and Ceramic Particles

Fabrizio Billi PhD, Paul Benya PhD, Aaron Kavanaugh BS, John Adams MD, PhD, Harry McKellop PhD, Edward Ebramzadeh PhD

Metal-on-metal and ceramic-on-ceramic bearings were introduced as alternatives to conventional polyethylene in hip arthroplasties to reduce wear. Characterization of wear particles has been particularly challenging due to the low amount and small size of wear particles. Current methods of analysis of such particles have shortcomings, including particle loss, clumping, and inaccurate morphologic and chemical characterization.

The John Charnley Award: An Accurate and Sensitive Method to Separate, Display, and Characterize Wear Debris: Part 1: Polyethylene Particles

Fabrizio Billi PhD, Paul Benya PhD, Aaron Kavanaugh BS, John Adams MD, PhD, Edward Ebramzadeh PhD, Harry McKellop PhD

Numerous studies indicate highly crosslinked polyethylenes reduce the wear debris volume generated by hip arthroplasty acetabular liners. This, in turns, requires new methods to isolate and characterize them.