The Physiological Effects, Including Risks and Potential Benefits, of Cannabis for Patients Undergoing Elective Orthopedic Procedures.

Given the evolving regulations regarding and availability of cannabis in the United States, physicians should understand the risks and benefits associated with its use. Patients are interested in learning about the use of cannabis for the management of orthopedic pain and any potential risks associated with it when undergoing elective surgery. Edible and topical cannabis products appear to have fewer side effects than inhaled cannabis products. A review of the literature was performed regarding different modes of administration and their related risks and potential benefits specifically regarding perioperative concerns for elective orthopedic procedures. Larger studies are necessary to further determine the efficacy, safety, and side effect profile of cannabis. [Orthopedics. 2021;44(3):e314-e319.].

Quantifying the Relationship Between the Transverse Acetabular Ligament and the Radiographic Teardrop.

BACKGROUND: The transverse acetabular ligament (TAL) has been described as an anatomic landmark to guide in the positioning of the acetabular component during total hip arthroplasty. On plain films, the radiographic teardrop (RT) has similarly been used as a measure of appropriate cup positioning. The goal of this study is to quantify the distance and location between the anatomic TAL and RT landmarks to aid in the positioning of acetabular component. METHODS: Sixteen randomly selected cadaveric pelvises (eight males, eight females) underwent dissection. Radiographic markers were placed bilaterally at the anteromedial insertions of the TAL, and true anteroposterior pelvic radiographs of the cadavers were obtained. Distances between the markers and the lateral borders of the RT were measured. RESULTS: The mean distance between the anteromedial insertion of the TAL and the lateral border of the RT in the male specimens was 11.8 (99% confidence interval, 11.4-12.2) mm. In the female specimens, the TAL to RT distance was shorter, with a mean of 8.4 (99% CI, 7.2-9.6) mm. There was a statistically significant difference between male and female cadavers (P < .01). CONCLUSION: The distance between the RT and TAL differs between males and females. Understanding the distance between these anatomic and radiographic landmarks should aid surgeons in obtaining a more accurate degree of acetabular component medialization and can serve as a guide to minimize overmedialization in order to achieve more accurate and reproducible placement of acetabular components during a total hip arthroplasty.

Cruciate-retaining vs posterior-substituting inserts in total knee arthroplasty: functional outcome comparison.

Despite clinical success, it is unclear which one, posterior-substituting (PS) or cruciate-retaining (CR) insert, has superior functional outcomes or longevity. We compared the collected results from 2 institutional review board-approved, multicenter, prospective observational studies following CR (412) and PS inserts (328). Participants were evaluated preoperatively, at 6 weeks, at 3 months, and at 1 and 2 years regarding pain, motion, function (Knee Society Score, Krackow Activity Score, Short Form-36), and procedure variables such as anesthesia and preoperative/perioperative/postoperative complications. Implant longevity was recorded at the 2-year follow-up. Improvement was observed within each group; however, there was no difference between groups in terms of pain, motion, or function at any end point. Two-year survival rate was higher than 95%. A higher incidence of wound hematoma was observed in the PS group. Both inserts can be used expecting satisfactory outcomes and high survival rates at 2 years.

Use of tibialis anterior tendon as distal landmark for extramedullary tibial alignment in total knee arthroplasty: an anatomical study.

We studied the accuracy of using the tibialis anterior tendon (TAT) as a distal landmark for extramedullary alignment in total knee arthroplasty. Forty-five consecutive ankle magnetic resonance imaging scans were reviewed. On the computerized images, a digital ruler was used to measure the distance from the midpoint of the distal tibia (point M) to the TAT. Mean distance was 1.89 mm; range was 0 to 4.5 mm (95% confidence interval, 1.45-2.33). For 7 (15.6%) of the 45 scans, the distance was 0 mm. On 38 scans (84.4%), the TAT was within 2 mm of point M. The TAT is an easily palpable fixed anatomical structure that corresponds very closely to the midpoint of the distal tibia.

Five-year comparative study of highly cross-linked (crossfire) and traditional polyethylene.

The purpose of this study was to compare the linear penetration rates of a highly cross-linked ultra-high-molecular-weight polyethylene to traditional polyethylene. Twenty-seven highly cross-linked components were matched to 27 traditional polyethylene components with respect to age, sex, body mass index, and activity level. Each group was followed up for a mean of approximately 6 years. Linear penetration was measured using Martell's computerized technique (J Bone Joint Surg Am 1997;79:1635). The mean total penetration was 0.283 mm (SD, 0.253) for the highly cross-linked group. The mean total penetration for the traditional polyethylene was 0.696 mm (SD, 0.402). This difference was highly significant (P < or = .001). Our experience demonstrates a 59% reduction in total penetration of highly cross-linked polyethylene when compared with traditional polyethylene at a minimum of 5 years.

Ex vivo comparison of mechanical versus thermal chondroplasty: assessment of tissue effect at the surgical endpoint.

PURPOSE: The purpose of this study was to evaluate tissue effect (tissue removal plus underlying cell death) of two chondroplasty techniques: mechanical debridement (MD) using a rotary shaver blade and thermal chondroplasty using radiofrequency energy (RFE). METHODS: Forty-eight human chondromalacic cartilage samples were treated with either MD or RFE. Pre- and post-treatment arthroscopic images of the cartilage surface were recorded. Samples were incubated with cell viability stain and visualized with confocal laser microscopy to determine tissue effect. Smoothing was quantitated by three surgeons using a visual analog scale (VAS) as well as a subjective rating regarding whether smoothing was "arthroscopically acceptable." RESULTS: Tissue effect at the surgical endpoint of arthroscopically acceptable smoothing was 385 microm for MD versus 236 microm for RFE, a significant difference (P < .0001). Mean post-treatment VAS for MD was 2.8 points less smooth than for RFE (P < .0001). Overall, arthroscopically acceptable smoothing was achieved in 90% of RFE samples compared to 49% of MD samples. CONCLUSIONS: Our results shown that chondroplasty using a RFE probe results in greater smoothing of chondromalacic cartilage in fewer treatment passes and with decreased total tissue effect than MD using a rotary shaver blade. CLINICAL RELEVANCE: If safety and efficacy can be shown in vivo, thermal chondroplasty may represent an alternative for treatment of symptomatic chondromalacia.

The tibial sulcus as a reference point for total knee arthroplasty.

Determining the amount of tibial resection is an important aspect of knee arthroplasty. The tibial sulcus is a reference point that should be unaffected by degenerative processes. This study compared the tibial sulcus and plateau height for 50 arthritic knees to 50 normal knees on magnetic resonance imaging. The tibial sulcus measured 17.09 mm in arthritic knees and 17.88 mm in normal knees. Sulcus height differences were not statistically significant. Based on these findings, a tibial cut 12 to 14 mm from the sulcus is recommended as a reference point in arthritic knees. This measuring technique has application in limited incision knee arthroplasty.

Clinical experience using a minimally invasive surgical approach for total knee arthroplasty: early results of a prospective randomized study compared to a standard approach.

There has been recent attention concerning minimally invasive techniques for knee arthroplasty. It is not clear whether these complicated techniques can be reproduced across multiple centers and for all surgeons. This prospective, randomized, multicenter study was carried out to assess safety and efficacy of a minimally invasive total knee arthroplasty. The study consisted of 80 knees. There were no differences in blood loss, operative time for completion of surgery, infection, and ultimate wound healing. There were 4 knees with delayed wound healing in the minimally invasive surgical technique group versus 1 in the standard group, which did not affect outcome. Early clinical and radiographic results were also indistinguishable. At 12 weeks follow-up, there was no difference in mean Knee Society objective and functional scores. In summary, in this study, minimal incision total knee arthroplasty demonstrated no improvement over a standard approach.