Outcomes of the Hemi-Hamatum Arthroplasty

: Background: Multi-fragmental intra-articular middle phalanx base fractures mostly occur in young adults during sports or work-related activities. If left untreated properly proximal interphalangeal joint (PIPJ) instability and pain persists, thus impairing the hand's function and the patient's quality of life. Joint surface reconstruction with hamate osteochondral graft can be used for multi-fragmental middle phalanx base reconstruction. Methods: A retrospective study was conducted. The technique was used for 17 patients. Follow-up was performed at least 6 months after the surgery. Patients were asked to fulfil multiple surveys: Disabilities of the Arm, Shoulder and Hand (DASH), Patient-Rated Wrist Evaluation (PRWE) and Modern Activity Subjective Survey 2007 (MASS07). Objective measurements included strength of the power and pinch grip, range of motions (ROM) in both proximal interphalangeal and distal interphalangeal (DIPJ) joints. All measurements were taken on both hands, on operated and contralateral fingers. Results: Out of 17 patients 5 were females and 12 males, mean age 40 (ranged 22-65 years) Eleven patients agreed to participate in the follow-up. All patients were right-handed, 8 patients had injured their right hand. The injuries' aetiologies were sports (n = 3), fighting (n = 2) and work-related (n = 4). Six patients were treated with immobilisation before the surgery, which was performed on average 45 days after the injury (ranged 1-184 days). Two patients developed arthrosis post-operatively and received synthetic joints. Mean DASH score was 6.9, PRWE score was 5.2 and mean MASS07 score was 6.8. Patients achieved on average 90% of power grip and 100% of pinch grip with their injured hand compared to their healthy hand. Average ROM in PIPJ was 82.2° and in DIPJ 68.9°. No patients experienced joint instability or chronic pain. Conclusions: Hemi-hamate arthroplasty provides satisfactory results in patients with both acute and chronic dislocated intra-articular middle phalanx base fractures.