Sesamoid bone transfer for metacarpophalangeal hyperextension instability of the thumb: A CT-osteoabsorptiometry study

First metacarpal extension-abduction osteotomy effect on joint remodeling and articular cartilage repair in thumb carpometacarpal osteoarthritis

BACKGROUND

The first metacarpal osteotomy is a joint-preserving surgery for thumb carpometacarpal (CMC) osteoarthritis that improves pain and function. However, its effects on joint remodeling and articular cartilage repair under physiological conditions remain unclear. This study aimed to clarify these aspects using computed tomography (CT)-based subchondral bone density analysis and arthroscopic evaluation.

METHODS

Fifteen hands of 14 patients who underwent a first metacarpal extension-abduction osteotomy for thumb CMC osteoarthritis were included. CT scans were performed preoperatively and one year postoperatively to assess changes in subchondral bone density (measured in Hounsfield units [HU]) across nine regions of the first metacarpal and trapezium articular surfaces. Arthroscopic evaluation of the articular cartilage was performed at the time of osteotomy and at implant removal one year postoperatively using the International Cartilage Repair Society (ICRS) grading scale.

RESULTS

Preoperatively, higher HU values (median [interquartile range]) were observed in the palmar regions of the first metacarpal (758 [643-803] HU) and the central regions of the trapezium (898 [867-960] HU). One year after osteotomy, these values decreased significantly in these initially high-stress regions (first metacarpal palmar regions: 433 [307-475] HU, p <.001; trapezium central regions: 571 [508-649] HU, p <.001; Wilcoxon matched-pairs signed rank test), indicating a more uniform stress distribution. Arthroscopic evaluation revealed improvements in ICRS grade in five out of nine cases on the metacarpal side and four out of nine cases on the trapezium side.

CONCLUSIONS

The first metacarpal extension-abduction osteotomy alters the abnormal stress distribution patterns in thumb CMC osteoarthritis, leading to a more uniform stress distribution across the joint. Arthroscopic findings suggest that articular cartilage repair may occur following osteotomy. These results provide new insights into the mechanisms underlying the clinical benefits of this procedure and support its use as a joint-preserving surgery for thumb CMC osteoarthritis.

Basal thumb arthritis surgery: complications and its management

The management of complications after surgery for basal thumb arthritis is sometimes challenging, and there are no clear recommendations on how to evaluate and manage patients with residual symptoms. The aim of the present article was to review the most common complications after surgery for basal thumb arthritis, with an emphasis on resection arthroplasty, joint replacement and joint fusion. In addition, possible management strategies for the different types of complications will be highlighted.

Does intra-articular load distribution change after lateral malleolar fractures? An in vivo study comparing operative and non-operative treatment

PURPOSE

The impact of isolated malleolar fractures on the intra-articular load distribution within the ankle joint has been studied in several biomechanical cadaver studies during the last decades. Recently, computed tomography osteoabsorptiometry (CT-OAM) has been proposed as a valuable tool to assess intra-articular joint load distribution in vivo. The purpose of this retrospective matched pair analysis was to apply CT-OAM to evaluate in vivo changes of talar load distribution after lateral malleolar fractures in patients treated with open anatomic reduction and internal fixation (ORIF) compared to patients treated non-operatively.

METHODS

Ten matched pairs of patients with isolated lateral malleolar fractures with a maximum fracture dislocation of 3mm and a median follow-up of 42 month were included into the study. Patients were matched for age, gender, and fracture dislocation. Range of ankle motion (ROM), the AOFAS hindfoot score and the Short Form 36 (SF-36) were evaluated. CT-OAM analysis of the injured and the uninjured contralateral ankles were performed.

RESULTS

Patients treated with ORIF showed a significant lower ROM compared to the uninjured contralateral ankle. No differences were found regarding clinical scores between patients treated by ORIF and those treated non-operatively. CT-OAM analysis showed symmetrical distribution of subchondral bone mineralization in comparison to the uninjured contralateral ankles for both groups of patients.

CONCLUSIONS

The data of this study suggest that isolated lateral malleolar fractures with fracture gaps up to 3mm are not associated with a change of the tibio-talar joint load distribution in vivo. Therefore, patients with isolated minimally displaced lateral malleolar fractures may achieve good clinical long-term outcome following non-operative treatment.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.