An Analysis of Hamate Morphology Relevant to Hemi-Hamate Arthroplasty

Comparison of hamate versus second or third toe osteochondral graft using magnetic resonance imaging for reconstruction of proximal interphalangeal fracture-dislocations

Hemi-hamate arthroplasty is a method used to reconstruct complex fracture-dislocations of the proximal interphalangeal joint of the fingers. Other graft sites, including the toe second and third phalanges, have been proposed as alternatives to hemi-hamate arthroplasty due to variable clinical outcomes and anatomy. Through a prospective magnetic resonance imaging (MRI)-based study in asymptomatic individuals, we aimed to characterize the anatomy of the proximal interphalangeal joint and compare this with the hamate, second and third toes to determine the closest anatomical match using pre-determined measurements. Our results show that the second and third toes have greater anatomical similarity to the proximal interphalangeal joint of the fingers compared to the hamate. High-resolution MRI is a reliable method of characterizing the anatomy of these structures and could be a useful clinical tool in determining reconstructive options in the management of this challenging injury.Level of evidence: II.

Free hemi-hamate arthroplasty: A review of donor site outcomes

Introduction

The use of the dorsal hamate as a free osteochondral bone graft or vascularized bone flap has become the mainstay for large, comminuted middle phalanx volar lip fractures. To date, few studies have been conducted in the assessment of donor site morbidity for the hemi-hamate graft or flap, and none have discussed modes of repair or reconstruction of this donor site.

Methods

A retrospective analysis of 14 hemi-hamate arthroplasty (HHA) procedures, including 6 vascularized and 8 non-vascularized grafts, from two surgeons was performed. Four hamate defect reconstruction techniques were utilized: no formal reconstruction, autologous bone grafting, gel foam, or synthetic bone substitute. The dorsal capsule was repaired with either extensor retinaculum grafting or by direct closure. Wrist range of motion, pain scores, and radiographic alignment were assessed.

Results

At 6 months follow-up, all patients achieved full, pain-free wrist motion compared to the uninjured side, with visual analog scale pain scores of 0. Serial radiographs showed maintained carpal alignment without instability or subluxation. No differences based on the hamate defect reconstruction method or capsular repair technique was demonstrated.

Conclusion

Safe return to pain free, unrestricted wrist function is achievable after HHA, regardless of hamate donor site management. Adequate dorsal capsular repair appears critical to prevent instability. Further study is needed to compare techniques, but choice may be guided by surgeon preference in the absence of clear evidence.

Hemihamate Arthroplasty Revisited: A Retrospective Review of 11 Cases

PURPOSE

Proximal interphalangeal joint (PIPJ) fracture dislocations are complex injuries that can result in persistent pain, stiffness, and angulation. Hemihamate arthroplasty (HHA) can be used to reconstruct the base of the middle phalanx in cases of unstable PIPJ fracture dislocations. Despite previous case series describing good outcomes with HHA, it has not gained widespread use. The purpose of this study is to describe our straightforward, reproducible technique and to demonstrate the benefit in motion after the procedure in chronic unstable PIPJ fracture dislocations.

METHODS

All patients with chronic, unstable PIPJ fracture dislocations requiring joint resurfacing of greater than 40% of the base of the middle phalanx treated with HHA were retrospectively reviewed. Patient demographics, injury features, surgical technique, preoperative and postoperative PIPJ range of motion and arc of motion, time to surgery, and complications were reviewed. Any fracture amenable to fixation or cases with radiographic evidence of arthritis or injury to the head of the proximal phalanx were excluded.

RESULTS

Eleven cases were reviewed. The mean patient age was 35 years. The mean time from injury to surgery was 6 months. The mean joint surface involved was 64%. The mean PIPJ arc of motion was 17 degrees preoperatively and 63 degrees postoperatively. The mean bone block size required was 8 × 8 × 8 mm. The mean follow-up was 26 months. Postoperative pain at the PIPJ on the visual analog scale was 0.4 (scale of 0 to 10). Complications included 2 patients requiring tenolysis.

CONCLUSIONS

Despite the lack of a perfect geometric recreation of the base of the middle phalanx with the hamate, patients recover acceptable PIPJ motion and have minimal pain. Hemihamate arthroplasty is a good option for any patient with minimal motion of their PIPJ and a chronic, unstable fracture dislocation.

Hamate vs. capitate grafting for proximal interphalangeal joint fracture-dislocation: an MRI-based study of 35 hands

We examined the MRI scans of 35 adult hands to assess the feasibility of the hamate and the capitate as potential donor grafts in the management of comminuted intra-articular fractures at the base of the middle phalanges. Essentially neither the hamate nor the capitate were perfect anatomic matches in most digits, but the capitate had the advantage of having more uniform facets, and the capitate facet shapes were similar to those of the little finger. The measurement of angles in the coronal and sagittal plane showed that in some respects the differences between the potential graft and the base of the middle phalanges were smaller for the capitate than for the hamate. Moreover, the sagittal morphology of the capitate made it less prone to joint overstuffing than the hamate. We conclude that the capitate may be considered as a graft donor in selected cases, especially for the little finger.