Clinical outcomes of proximal row carpectomy by preoperative midcarpal joint morphological classification: Viegas type I versus type II

Carpal bone replacement using personalized 3D printed tantalum prosthesis

Objective: Scaphoid and lunate fractures have a relatively high incidence rate. Traditional carpectomy and carpal arthrodesis in the treatment of carpal osteonecrosis will lead to many complications. Three-dimensional (3D) printed tantalum has good biocompatibility and can be designed to match the patient's personalized anatomical carpal structure. This study aims to investigate carpal function and prosthesis-related conditions after carpal bone replacement using 3D printed tantalum prostheses. Methods: From July 2020 to January 2022 at our center, seven patients with osteonecrosis of the carpus received carpal bone replacement using 3D printed tantalum prosthesis. The Disability of the Arm, Shoulder and Hand (DASH) score and patient satisfaction, as well as the Mayo Wrist Scores (Cooney method, modified Green, and O'Brien wrist score), were used to evaluate the preoperative and postoperative wrist function of patients. The Visual Analog Scale (VAS) pain scores were also recorded before and after surgery. The angles of flexion, dorsiflexion, ulnar deviation, and radial deviation were measured using an arthrometer. The grip strength and pinch strength of the operated hand after carpal bone replacement and the contralateral healthy carpus were measured using a dynamometer. Radiographs were taken to confirm the condition and complications of the tantalum prosthesis. Results: All seven patients were followed for 19.6 ± 2.7 months. At the last follow-up, the grip strength of the operated wrist joint after carpal bone replacement was 33.4 ± 2.3 kg, the pinch strength was 8.9 ± 0.7 kg, the flexion was 54.6° ± 0.8°, the dorsiflexion was 54.7° ± 1.7°, the ulnar deviation was 34.6° ± 1.9°, and the radial deviation was 25.9° ± 0.8°, all of which showed no statistically significant difference with the contralateral healthy carpus (p > 0.05). There were significant differences in the VAS, DASH, and MAYO scores between the preoperative and the last follow-up (p < 0.01). Patients had reduced postoperative pain and improved wrist function and range of motion (ROM), and the tantalum prostheses were stable. Conclusion: The 3D printed tantalum brings us new hope, not only for hip or knee replacement, but also for joint replacement of other complex anatomical structures, and patients with other irregular bone defects such as bone tumors and deformity, which could realize personalized treatment and precise medicine.

Arthroscopic proximal carpal row replacement by semitendinosus and gracilis graft (CArpus Row Plasty Using the Semitendinosus: CARPUS procedure). An anatomical study of 16 cases

INTRODUCTION

Post-traumatic lesions of the carpus (scapholunate rupture, scaphoid non-union) frequently evolve into disabling osteoarthritis (scapholunate advanced collapse or scaphoid non-union advanced collapse: SLAC or SNAC wrist). Proximal row carpectomy (PRC) is a reliable option but with poorer prognosis in case of osteoarthritis of the distal radius or capitate head. In such situations, radiocarpal arthrodesis may be necessary, sacrificing wrist motion. To circumvent this limitation, we propose a new procedure consisting in arthroscopic PRC and replacing the proximal row by tendon graft.

METHODS

This was a study on 16 cadaver specimens. A scapholunate pin was introduced via an approach into the anatomical snuffbox and used as a guide for a cannulated drill bit (9mm) to create a tunnel through the proximal row. The arthroscope and a reamer were introduced into the tunnel via its radial and ulnar ends. PRC was performed under arthroscopic control. The gracilis and semitendinosus tendons were harvested and folded so as to obtain a graft with the same length and diameter as the proximal row. The graft was threaded through the radial approach and fixed to the capsule.

RESULTS

Mean procedure time was 68min. There was no pre- to postoperative difference in joint motion or carpal height. On radiocinematography, the graft was stable between the radius and the second row of the carpus. The radial and ulnar sensory branches, median nerve and radial artery were intact at end of procedure.

DISCUSSION

This technique could be a solution in SLAC or SNAC wrist with osteoarthritis of the capitate head or radial glenoid. It also conserves carpal height. Being arthroscopic, the procedure avoids the major edema observed after a dorsal approach of the carpus, and also ensures graft stability, since the radiocarpal ligaments are conserved. Harvesting from a second anatomical site and the in vivo fate of the transplant are two issues that need to be discussed.

CONCLUSION

This anatomical study paves the way for clinical experimentation.

LEVEL OF EVIDENCE

IV.