15-year Comparison of Cementless Total Hip Arthroplasty With Anatomical or High Cup Placement for Crowe I to III Hip Dysplasia

Abstract

This study compared radiological and clinical results of Mallory-Head (Biomet, Warsaw, Indiana) cementless total hip arthroplasty (THA) by anatomical (AP group) or high cup placement (HP group) for Crowe I to III developmental dysplasia of the hip. Of the 68 hips studied, 43 hips were available for 15.3-year follow-up. Ten cups were placed at anatomical center with bulk bone grafting, and 33 cups were at high hip center without bulk bone grafting. No acetabular or femoral components showed loosening in either group. One standard polyethylene liner in a highly placed cup was revised due to excessive wear after 11 years. The average rate of polyethylene wear was 0.128 mm/year in the AP group and 0.148 mm/year in the HP group (except for the revision case). The extent of grafted bone coverage was 34.6% in the AP group. Hip center height was 24.5 mm from the inter-teardrop line in the HP group. The center of the hip horizontal location in the AP group (24.5 mm) and HP group (26.4 mm) was significantly shorter than in normal hips (35.6 mm). Postoperative center-edge angle was 11° (except grafted bone) in the AP group and 25° in the HP group. Mean Harris Hip Score in the AP group improved from 38 points preoperatively to 82 points postoperatively and in the HP group improved from 40 points preoperatively to 88 points postoperatively. Survivorship was 100% in the AP group and 97% in the HP group. Our results indicate that moderate high cup placement without bulk bone grafting at a horizontal locus more medial than that of a normal hip is an alternative durable solution.
 

Clavicle Nonunion in a 10-year-old Boy

Abstract

Posttraumatic clavicle nonunion is rare, particularly in children. Four cases of clavicle fracture nonunion in patients aged 10 years and younger have been reported. A variety of techniques have been used to treat pediatric clavicle nonunions. A 10-year-old boy presented to our institution after a fall, sustaining a right closed midshaft clavicle fracture. No other injuries occurred, and neurovascular examination of the right upper extremity was normal. The fracture was initially treated with a sling for >4 months, and the fracture progressed to a hypertrophic nonunion. Serial radiographs failed to demonstrate progression to union. The patient continued to have pain with activity 4 months after his injury. Clavicle pseudarthrosis was considered; however, radiographs did not have the characteristic appearance of this condition. This fracture nonunion was treated with internal fixation and united with no complication. The patient was back to full activities of daily living 6 months postoperatively. He reported no tenderness at the fracture site or along the hardware. The treating surgeon (A.M.S.) prefers to remove hardware in young children, but the family declined removal. Pediatric posttraumatic nonunion of the clavicle is rare but can be safely treated with plate fixation, with excellent results.
 

Dash™ — Computer Assisted Joint Replacement with the iPod touch (Brainlab)

Biomet releases surgical guide system for partial knee replacement

 Biomet Orthopedics announced the launch of the Signature Personalized Patient Care System for use with the Oxford Partial Knee System. The system enables surgeons to preoperatively plan a knee replacement surgery and precisely place implants by using Signature custom positioning guides, according to a company press release.

 Biomet’s Oxford Partial Knee System is designed to help surgeons preserve and restore normal knee function and movement by replacing only the medial, diseased compartment of the knee. During this process, surgeons use the Signature system to create custom femoral and tibial surgical positioning guides that help achieve optimal joint implant positioning.

“With Signature and the Oxford Partial Knee, surgeons now have state-of-the-art technology for patients undergoing partial knee replacement surgery,” Michael Berend, MD, from Center for Hip & Knee Surgery at St. Francis Health Hospital, stated in the release.

DePuy Receives PMA for TRUMATCH

What with their focus on precision, the engineers at DePuy Orthopaedics, Inc. must be especially thrilled…the company’s TRUMATCH Personalized Solutions with DePuy’s SIGMA RP Knee System has received Premarket (PMA) Supplement Approval from the FDA. Already in use in 17 countries, TRUMATCH Solutions for use with DePuy’s SIGMA Fixed Bearing Knee System was previously cleared in August 2011. And this made DePuy the only orthopedic company to have personalized instrumentation for use with both rotating platform and fixed bearing knees.

“We’re very excited about the opportunity to offer patients the world’s leading mobile bearing knee system, the SIGMA RP Knee, with TRUMATCH Personalized Solutions,” said Andrew Ekdahl, President, DePuy Orthopaedics, in the February 15, 2012 news release. “This approval means patients can now benefit from precise implant positioning, enabled by TRUMATCH Solutions, and the proven performance of both the SIGMA RP and Fixed Bearing Knee Systems, while increasing efficiency in the operating room.”

As indicated by the company, the TRUMATCH is the first system to utilize CT scans and computer software to guide the development and production of femoral and tibial cutting blocks that are individually prepared to match the actual bone surfaces of each patient. Also, TRUMATCH Solutions uses CT scans, rather than MRIs, for improved bone imaging, less scanning time and lower costs. DePuy states that procedures done with TRUMATCH Solutions also require less instrumentation and eliminate up to nine surgical steps compared to total knee replacement performed without TRUMATCH Solutions.

Surgeons call for end to metal hip replacements

Expert surgeons in the UK say patients should no longer be given all-metal hip replacements, despite assurances from regulators amid safety concerns.

Large head metal-on-metal implants can cause serious side effects with wear.

The BBC's Newsnight and the British Medical Journal recently discovered the problems were known about for decades.

The Medicines and Healthcare products Regulatory Agency (MHRA) insists the implants can still be used but the British Hip Society disagrees.
 

Laser-Sintering for Orthopedics

Geometry in the OR…EOS is thrilled that it had a chance to showcase its EOSINT M 280 direct metal laser-sintering (DMLS) system at the recent American Academy of Orthpaedic Surgeons (AAOS) annual meeting. According to the company, there is no shortage of orthopedic applications for this technology.

“An entire new world of orthopedic treatment and procedures has opened up,” said Martin Bullemer, EOS manager for medical business development, in the February 3, 2012 news release. “Because our laser-sintering systems can cost-effectively manufacture any imaginable geometry, and any variation on it, they are changing the way we think about medical products.”