Chemical eluates from ultra-high molecular weight polyethylene and fibroblast proliferation

Is proximal tibial tubercle osteotomy superior to distal tibial tubercle osteotomy for medial compartmental osteoarthritis? A meta-analysis

BACKGROUND

Open-wedge high tibial osteotomy (OWHTO) is commonly performed for the treatment of medial compartment knee osteoarthritis (KOA), and is classified into proximal tibial tubercle osteotomy (PTO) and distal tibial tubercle osteotomy (DTO). The PTO osteotomy point is generally located about 3-4 cm below the joint of the proximal tibia, and the osteotomy line points to the upper part of the proximal tibiofibular joint. The DTO osteotomy point is generally located about 0.5-1.0 cm below the tibial tubercle, and the osteotomy line points to the contralateral cortex. However, there is currently no consensus on which surgical technique is superior. The purpose of our study was to investigate which among the two is superior for medial KOA, with respect to knee joint parameters, clinical function, and complications.

METHODS

This study was conducted as per the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The Cochrane Central Library, MEDLINE, Embase, PubMed, CNKI, and WanFang databases were systematically searched for trials comparing PTO and DTO in patients with medial compartment KOA, from inception until March 2022. The meta-analysis was conducted using RevMan 5.2 software. The Cochrane risk-of-bias tool was used to assess methodological quality. Statistical analysis was performed with Stata 12.0. Outcomes of interest included the Insall-Salvati index (ISI), Caton-Deschamps index (CDI), Blackburne-Peel index (BPI), posterior tibial slope (PTS), and the Hospital for Special Surgery (HSS) knee-rating scale.

RESULTS

A total of 15 retrospective studies (910 knees) were included. There were no significant differences in the age or sex of included patients. There was a significant difference in the ISI, CDI, BPI, and PTS between the two groups (all p ≤ 0.05). Further, DTO was associated with a significantly greater number of postoperative complications (p < 0.05) compared to PTO. However, there was no significant difference in the femorotibial angle (FTA), mechanical medial proximal tibial angle (mMPTA), and HSS knee score (all p > 0.05).

CONCLUSIONS

Compared with DTO, PTO is associated with a greater incidence of postoperative patella baja and increased PTS, whereas DTO is associated with more postoperative complications. Nevertheless, both can significantly correct knee varus deformity and improve knee function; their early knee function scores are also similar.

TRIAL REGISTRATION

Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42021284443.

Effects of sterilization on implant mechanical property and biocompatibility

This article concisely reviews the effects of sterilization on the mechanical properties and surface chemistries of implantable biomaterials. This article also summarizes the biological effects of the sterilization-related changes in the implant. Because there are so many different types of implant materials currently in use (including metals, polymers, and diverse biological materials), the response of tissue to these different materials varies dramatically. This review further discusses the effects of sterilization on in vivo and in vitro tissue response specifically to implantable metals and polyethylene, with the possibility of future biocompatibility testing of the implants sterilized with supercritical phase carbon dioxide sterilization.

Does pelvic osteolysis occur with a nonmodular uncemented acetabular component?

We present a radiographic follow-up of an uncemented, nonmodular, pure titanium-backed acetabular component at 6 to 12 years postimplantation. Between 1990 and 1992, 130 primary total hip arthroplasties were carried out by 1 surgeon using this implant, in association with both cemented and uncemented femoral components. There were 19 deaths, 5 revisions, and 19 hips lost to follow-up, leaving 87 hips available for review at a mean of 9.6 years. Two revisions were for infection, whereas 3 well-fixed cups were changed at the time of revision of a loose femoral component to allow downsizing to a 28-mm head. No cup has been revised for aseptic loosening. There was no radiographic evidence of periacetabular osteolysis or loosening of any of the cups, even in a subgroup of 31 patients who were 60 years or younger at the time of implantation.