This randomized clinical trial (RCT) aims to compare clinical and radiographic outcomes of different partial wrist fusion techniques in participants with post-traumatic wrist arthritis. Participants with stage II or III scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC) who meet the eligibility criteria will be randomly assigned to one of two parallel groups: Group A (partial wrist arthrodesis without triquetral excision i.e. four-corner arthrodesis), or Group B (partial wrist arthrodesis with triquetral excision i.e. three-corner or capitolunate arthrodesis with triquetral excision). The results of this study will provide evidence to guide surgeons in determining the ideal wrist fusion technique in the management of patients with post-traumatic wrist arthritis requiring surgery.

This study has been designed as a multi-center double-blind prospective randomized clinical trial. Eligible participants will be adults presenting with SNAC or SLAC wrist arthritis who have been deemed an operative candidate and qualify for one of the following salvage techniques: four-corner arthrodesis (without triquetral excision) or three-corner/capitolunate arthrodeses with triquetral excision.

Once eligibility is confirmed, participants will be randomly assigned to one of two treatment arms. Participants in Group A will undergo four-corner arthrodesis; the scaphoid will be excised and the lunate, capitate, triquetrum, and hamate will be prepared and fused. Participants in Group B will undergo partial wrist arthrodesis with triquetral excision; the scaphoid and triquetrum will be excised. In the three-corner arthrodesis procedure, the articular surfaces between the lunate, capitate, and hamate will be prepared and fused. In the capitolunate arthrodesis procedure, only the articular surface between the lunate and capitate will be prepared and fused.

Eligible and consented participants will undergo a pre-operative study assessment and follow-up assessments at 6-weeks, 3-, 6-, and 12-months post-operative. Assessments will be conducted by an assessor blinded to participant treatment allocation. At each assessment, grip strength, wrist range of motion (ROM), Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaire, Patient-Rated Wrist Evaluation (PRWE) questionnaire, and Visual Analog Scale (VAS) for pain will be completed. The work and sports/performing arts modules of the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), and the WOrk-Related Questionnaire for UPper extremity disorders (WORQ-UP), will be completed at baseline (pre-surgery) and at 12-months. Standard posteroanterior and lateral radiographs will be completed at all visits. Complications will be documented at each visit.

The primary outcome, grip strength, will be measured with a handheld dynamometer. Absolute values and percentage of their contralateral side will be compared between the two groups.

Statistical analysis will use the intention-to-treat approach with all outcomes attributed to the assigned group. Descriptive statistics will be used for group comparisons with independent t-tests for continuous and Pearson Chi-square or Fisher's Exact tests for categorical variables at baseline and for possible complications/adverse events. Linear Mixed Modeling (LMM), adjusted for age and sex, will compare outcomes between groups over the 12-month evaluation period. The level of significance will be set at α=0.05.

This study hypothesizes that partial wrist fusion with triquetral excision will lead to improved grip strength and ROM compared to four-corner arthrodesis. Considering the importance of ROM and grip strength in many activities of daily living and manual work, it is hypothesized that the group with triquetral excision (Group B) will have better patient-reported outcomes. We hypothesize no significant difference between the groups with regards to radiographic outcomes and complications.

Inclusion Criteria:

• Participant has a stage II or III scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC) wrist and is a surgical candidate for the included surgical interventions

Exclusion Criteria:

• Participant has been diagnosed with other forms of wrist arthritis other than SLAC or SNAC
• Participant has significant arthritis of the ipsilateral hand/finger joint(s), major joint trauma, previous major wrist surgery, infection or neuromuscular pathology affecting the function of the ipsilateral upper extremity or ability to make a fist
• Participant has a physical or mental health condition preventing completion of consent or questionnaires
• Participant does not speak/read/understand English
• Participant has no fixed address or means of contact
• Participant is unwilling to complete necessary follow-ups
• Surgeon concludes that eligible salvage techniques are not appropriate at the time of surgery (based on injury characteristics or concomitant wrist pathology)