The Influence of a Single Intra-Articular Lidocaine Injection on the Viability of Articular Cartilage in the Knee.

OBJECTIVE: To evaluate the in vivo effect of a single intra-articular injection of local anesthetic (LA) lidocaine on the viability of articular cartilage in the intact or osteoarthritic (OA) human knees, and to measure the synovial postinjection concentration of lidocaine in the knee. DESIGN: This study includes 3 interconnected experiments: (A) Synovial LA concentration measurement after a 2% lidocaine injection before knee arthroscopy in 10 patients by liquid chromatography-tandem mass spectrometry (LC-MS/MS). (B) Human osteochondral explants (N = 27) from intact knees procured at autopsies were incubated for different time intervals (30 minutes, 2 hours, 24 hours) with 2% lidocaine, 0.04% lidocaine (measured), or culture medium (control), and later evaluated for cell viability by LIVE/DEAD staining. (C) Ten out of 19 matched patients scheduled for knee replacement received a single intra-articular injection of 2% lidocaine approximately 30 minutes prior to the procedure; 9 patients served as control. Osteochondral samples with OA changes were harvested during surgery and analyzed for chondrocyte viability by LIVE/DEAD staining. RESULTS: (A) The synovial LA concentration was significantly lower than the primary concentration injected: average 0.23 mg/mL (0.02%), highest measured 0.37 mg/mL (0.04%). (B) In vitro exposure to a reduced LA concentration had no significant influence on chondrocyte viability in intact cartilage explants (24-hour averages: control, 93%; 0.04% lidocaine, 92%; 2% lidocaine, 79%). (C) Viability of chondrocytes in OA knees was similar between 2% lidocaine injection (85%) and control (80%). CONCLUSIONS: A single intra-articular knee injection of 2% lidocaine did not influence the chondrocyte viability neither in healthy nor in OA cartilage. A fast postinjection reduction of synovial LA concentration (more than 40 times) is the most likely protective mechanism.

Effect of intra-articular local anesthesia on articular cartilage in the knee.

PURPOSE: To evaluate the hypothetical toxic effect of local anesthetics on the articular cartilage using patient data from autologous chondrocyte cultivation with different anesthesia types used for arthroscopic cartilage biopsy specimen procurement. METHODS: A retrospective analysis of patient data from the national autologous chondrocyte implantation registry and the corresponding hospital records was approved by the National Medical Ethics Committee. Articular cartilage biopsy specimens from the knees of 49 consecutive patients assigned for autologous chondrocyte implantation (aged 14 to 44 years) were procured from the non-weight-bearing articular surface during arthroscopy under general anesthesia (12 patients), spinal anesthesia (18 patients), or local anesthesia (intra-articular injection of 15 to 20 mL of 2% lidocaine hydrochloride) (19 patients). All the biopsy specimens were further manipulated following the same chondrocyte cultivation protocol. General patient data and surgery-related parameters, together with chondrocyte viability, population doublings, and chondrocyte morphology in biopsy specimens and primary cell cultures, were analyzed and compared across different types of anesthesia. RESULTS: Patients in the general, spinal, and local anesthesia groups showed no statistical differences in age (27 years, 29 years, and 32 years, respectively), duration of surgery (36 minutes, 37 minutes, and 39 minutes, respectively), weight of biopsy specimens (110 mg, 178 mg, and 130 mg, respectively), cell viability in cartilage biopsy specimens (67%, 69%, and 78%, respectively) or primary cultures (95%, 95%, and 95%, respectively), and population doublings (5.2, 5.2, and 5.2, respectively). Similar chondrocyte morphology in primary cell cultures was observed among the 3 groups. CONCLUSIONS: This retrospective study showed that a single intra-articular injection of lidocaine hydrochloride used for knee arthroscopy did not influence the viability, morphology, and cultivation potential of chondrocytes in articular cartilage biopsy specimens assigned for autologous chondrocyte implantation. LEVEL OF EVIDENCE: Level IV, retrospective comparative study.