Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Product sales, net	$ 237,224	$ 197,516	$ 163,698
Other revenue	0	0	667
Total revenue	237,224	197,516	164,365
Change in estimates related to prior periods
Disaggregation of Revenue [Line Items]
Product sales, net	2,529	2,157	2,034
Total MACI implants, kits, and instruments
Disaggregation of Revenue [Line Items]
Product sales, net	197,309	164,800	131,967
Through Intermediary | MACI implants, kits, and instruments | Contract rate
Disaggregation of Revenue [Line Items]
Product sales, net	141,806	105,948	81,388
Through Intermediary | MACI implants, kits, and instruments | Time-and-materials contract
Disaggregation of Revenue [Line Items]
Product sales, net	15,058	22,203	18,695
Time-and-materials contract | MACI implants, kits, and instruments | Time-and-materials contract
Disaggregation of Revenue [Line Items]
Product sales, net	4,603	4,921	3,499
Provider or Facility | MACI implants, kits, and instruments | Contract rate
Disaggregation of Revenue [Line Items]
Product sales, net	31,217	27,484	24,261
Provider or Facility | NexoBrid
Disaggregation of Revenue [Line Items]
Other revenue	3,292	1,142	667
Directly to consumer | Biopsy kits and instruments - direct bill
Disaggregation of Revenue [Line Items]
Product sales, net	2,096	2,087	2,090
Directly to consumer | Epicel
Disaggregation of Revenue [Line Items]
Product sales, net	$ 36,623	$ 31,574	$ 31,731