Does a plastic drape reduce incidence of heterotopic ossification after hip resurfacing?

Basic study on improvement of plastic drape adhesion for surgery: effect of adhesive layer thickness on drape detachment from wound edge

BACKGROUND

Plastic drapes are used in surgery for a wide range of purposes, but currently marketed drapes often become detached from the wound edge during surgery. The purpose of this study was to determine the appropriate adhesive layer thickness for optimal peel and shear strength and the smallest peeled area to improve surgical drape wound adhesion.

METHODS

Thirty-two rats were randomly assigned to four groups of different adhesive layer thickness (50, 100, 300 and 800-1000 μm). The rats were anaesthetized, and drapes were applied to the dorsal chest. After incision, the peeled area was visualized by dropping ink in the wound site to measure the peeled area over time.

RESULTS

All drapes peeled off from the wound edge, and the peeled area increased over time. The peeled area decreased in the order of 50 μm > 100 μm > 800-1000 μm > 300 μm.

CONCLUSIONS

It is possible to control the peeling of plastic drapes during surgery by limiting the peeled area at the time of cutting. Three-hundred micrometres is the suitable adhesive layer thickness to minimize the peeled area at cutting.

Risk factors for heterotopic ossification and spur formation after total knee arthroplasty

INTRODUCTION

The present study investigated the incidence and risk factors of heterotopic ossification (HO) after implantation of knee prosthesis.

MATERIALS AND METHODS

We undertook a retrospective cohort study in 434 cases (363 patients) treated with a total knee replant using a Press-Fit-Condylar (P.F.C.(®)Sigma(®)) prosthesis. The occurrence of HO in radiograph after a follow-up period of 11.2 ± 2.4 months was correlated in a regression model with a variety of influencing factors.

RESULTS

21 patients (4.8 %) developed heterotopic ossifications, all located in the area of the distal femur. The only risk factor found concerning the development of HO was osteoarthritis when compared to rheumatoid arthritis (OR = 4.07, 95 % CI 1.18-14.05; p = 0.0201) and postoperative wound healing problems (OR = 11.32, 95 % CI 3.26-39.33; p = 0.0001). Notching (OR = 2.22, 95 % CI 0.92-5.36; p = 0.0765) and osteophyte forming (hypertrophic) arthrosis (OR = 2.40, 95 % CI 0.97-5.95; p = 0.0596), however, were associated with the development of a bony spur in the contact area of the femoral component of the prosthesis.

CONCLUSIONS

Our study has revealed that patients with rheumatoid arthritis are at lower risk of HO than patients with osteoarthritis. An impairment of wound healing would appear to promote the development of a HO. Notching and hypertrophic arthrosis are highly likely to be associated with the development of a bony spur in the ventral contact area of the prosthesis.

Incidence of heterotopic ossification after surface and conventional total hip arthroplasty: a comparative study using anterolateral approach and indomethacin prophylaxis

The incidence and severity of heterotopic ossification (HO) in two homogeneous groups of patients that received surface replacement arthroplasty (SRA) and conventional total hip arthroplasty (THA) were evaluated retrospectively. Thirty-nine patients undergoing 42 hip resurfacing procedures and 41 primary cementless THAs through an anterolateral approach received a 10-day course of 150 mg/die of indomethacin postoperatively. The median surgical time was 190 minutes and 156 minutes, respectively (P < 0.003). At a minimum 1-year followup, the development of HO was assessed on standard X-ray using Brooker grading. Ectopic bone formation was detected in five cases (11.9%, two Brooker grade I and three grade II) in the SRA group and in 14 hips (34.1%, 12 grade I and two grade II) treated with conventional THA, but the difference was not significant (P < 0.11). No clinically relevant periprosthetic ossification (Brooker III or IV) occurred in both groups. Although the difference was not statistically significant, the incidence of HO after SRA was lower than conventional THA. More extensive soft tissue trauma, bone debris, and longer operative time in hip resurfacing are not likely to be absolute risk factors for HO. Further investigations including larger patient populations are needed to confirm these findings.