The purpose of this study was to quantify tibial tunnel enlargement at 3-, 6- and 12-months post-anterior cruciate ligament reconstruction (ACLR), and evaluate the magnitude of tunnel widening with use of a Poly (L-lactic Acid) interference screw (PLLA (Bioscrew XtraLok, Conmed, New York)) compared to a Poly (L-lactic Acid) + tricalcium phosphate interference screw (PLLA+TCP (GENESYS Matryx screw comprised of microTCP and 96L/4D PLA, Conmed, New York)).

This was a prospective randomized controlled trial with two parallel groups. Eighty unilateral ACL-deficient participants awaiting ACLR surgery were recruited between 2013 and 2017 from the clinic of a sole fellowship trained orthopaedic surgeon. Patients had to be skeletally mature and less than 45 years old, with no concomitant knee ligament injuries requiring surgery, chondromalacia, or previous history of ipsilateral knee joint pathology, surgery or trauma to the knee.

Participants were randomized intra-operatively into either the PLLA or PLLA+TCP tibial interference screw fixation group. Study time points were pre-, 3-, 6-, and 12-months post ACLR. Participants underwent x-rays with a 25 mm calibration ball, IKDC knee assessment, and completed the ACL-Quality of Life score (ACL-QOL) at each visit.

Measurement (mm) of the most proximal and distal extents as well as the widest point of the tibial tunnel were taken using efilm (IBM Watson Health) and were standardized relative to the calibration ball. A contrast inverter was used to determine clear borders based on contrast between normal and drilled bone. In addition, a subjective evaluation of the tunnel was conducted looking for bowing of the borders of the tunnel or change in tunnel shape, categorizing the tunnel as widened or not widened.

Differences between groups at each time point were evaluated using independent t-tests corrected for multiple comparisons. Tunnel width was also compared as a percentage of actual screw size at 12-months post-operative. Categorical data were compared using Fisher's Exact Test. Forty participants were randomized to each group with mean age (SD) of 29.7 (7.6) and 29.8 (9.1), for PLLA and PLLA+TCP, respectively. There were no differences between groups in age, gender or ACL-QOL.

There were no differences found between groups at any time point in either tunnel width measurements or tunnel width as a percentage of actual screw size. The greatest difference between groups was noted in the measurement of the widest point on lateral x-ray view with a mean difference of 11%. Based on subjective evaluation of tunnel shape, three participants had visible widening in the PLLA group, and two in the PLLA+TCP group (p=NS).

No differences in tunnel widening were identified between ACL reconstruction patients using a PLLA interference screw compared to a PLLA+TCP screw for tibial fixation up to 12-months post-operative.

It is estimated that a quarter to half of all hospital waste is produced in the operating room. Recycling of surgical waste in the perioperative setting is largely underutilized, despite the fact that many of the materials being discarded can be potentially recycled safely and easily. Given this mounting waste production, recycling programs have become increasingly popular. Therefore, the primary objective of this study is assess the effect of these recent eco-friendly polices by determining the amount of waste and recycling produced in the pre-operative and operative time period for several orthopaedic subspecialties.

Surgical cases were prospectively chosen and assigned to an orthopaedic subspecialty category, which included trauma, arthroplasty, sports, foot and ankle, upper extremity, and paediatrics. The preoperative phase began with the opening of the surgical case carts and concluded with the end of skin preparation. The intraoperative period began after skin preparation was complete, and concluded after the operating room was cleaned. At the end of the preoperative period all surgical waste was weighed and divided into recyclables and non-recyclables. Following the intraoperative period, surgical waste was divided into recyclables, non-recyclables, linens, and biohazardous waste streams. All bags were weighed in a standardized fashion using a portable hand held scale. The primary outcome of interest was the amount of recyclable waste produced per case. Secondary outcomes included the amount of nonrecyclable, biohazardous and total waste produced during the same time intervals. Statistical analysis was then completed using (ANOVA) to detect differences between specialties.

This study included 55 procedures collected over a 1-month period at two hospitals from October 2017 to November 2017. A total of 341 kg of waste was collected with a mean mass of 6.2 kg per case. In terms of primary outcomes, arthroplasty surgery produced a significantly greater amount of recyclable waste per case in the preoperative (2327.9 g)and intraoperative (938.6 g)period. It also produced the greatest amount of total recyclable waste per case, resulting in a significantly greater ratio of waste recycling per case then nearly all other specialties in the preoperative (86.2%) and intraoperative period (14.5%). In terms of secondary outcomes, arthroplasty surgery similarly produced a significantly greater amount of nonrecyclable waste per case then all other specialties (5823.6 g), the majority of which was produced during the intraoperative period (5512.9 g). Arthroplasty surgery also produced a significantly greater amount of biohazardous waste then all other specialties (409.3 g). The majority of surgical waste was produced in the intraoperative period compared to the preoperative period. In the preoperative period an average of 74.4% of waste was recyclable, compared to 7.6% of waste produced during the intraoperative period. In total, the average amount of waste recycled per case was 25.6%. Biohazardous waste only constituted 1.8% of the total waste mass.

Orthopaedic surgery is a significant source of waste production in our hospital system. Among orthopaedic subspecialties, arthroplasty is one of the largest waste producers, but also has the highest potential for recycling of materials. Effective OR recycling programs can significantly reduce our ecological footprint by diverting waste from landfills. In particular, the preoperative period has significant potential for landfill diversion as our study showed that nearly three quarters of all waste in this period can be effectively recycled.