The Prevalence of Focal Carpal Chondromalacia Concurrent With Chronic Dynamic Scapholunate Instability

There is a paucity of information regarding the prevalence of focal chondromalacia with chronic dynamic scapholunate instability (CDSI), and current treatment algorithms do not account for its presence. We aimed to determine the prevalence and distribution of chondromalacia in CDSI.

We conducted a retrospective, longitudinal, cohort study of all wrist arthroscopies performed from January 2008 to December 2020. We included wrists with an arthroscopically confirmed primary diagnosis of CDSI. Patients were grouped based on the presence (CDSI+C) or absence (CDSI-C) of focal carpal chondromalacia. All ligament tears were debrided, and focal chondral lesions were treated with chondral shaving to partial carpectomy. We followed the Debride-First-Then-Wait protocol, which incorporates a waiting period for patients to assess if arthroscopic intervention alone is sufficient to return to normal daily activities. The surgeon considers the patient's perceived wellness when determining the need for a subsequent Dynadesis (tendon-to-tendon transfer through the distal scaphoid) or partial fusion.

Of 255 wrist arthroscopies, 164 wrists (155 patients) met the inclusion criteria. Focal chondromalacia was arthroscopically identified in 48% of wrists, with a notably higher occurrence in older patients and those with lunotriquetral ligament or triangular fibrocartilage tears. The most frequent sites of chondromalacia were the radial styloid (27%) and the scaphoid body (15%). Dynadeis was performed in 29% of wrists in the CDSI+C cohort and 47% in the CDSI-C cohort. Four percent of CDSI+C wrists necessitated partial wrist fusion.

Focal chondromalacia is common in patients with CDSI. The presence of focal lesions alone did not notably decrease the efficacy of arthroscopic treatment as <50% of patients needed a secondary procedure (7.4-year follow-up). The distribution of focal chondromalacia suggests injuries to other wrist ligaments. We recommend using the Debride-First-Then-Wait protocol to aid in selecting a personalized and lower-risk treatment for CDSI.

Therapeutic IIb.