The vascular basis of the hemi-hamate osteochondral free flap. Part 1: vascular anatomy and clinical correlation

Vascularized hemi-hamate graft: Anatomic description of a novel pedicled osteo-chondro-ligamentous flap for proximal scaphoid reconstruction

Scaphoid proximal pole destruction remains a surgical challenge owing to its high propensity for nonunion and osteonecrosis. The hemi-hamate graft has shown promising results in addressing this issue. However, long-term results of non-vascularized composite grafts remain uncertain. The purpose of this study was to investigate the feasibility of a vascularized hemi-hamate osteo-chondro-ligamentous pedicled flap for the reconstruction of the proximal pole of the scaphoid. Thirty fresh cadaveric wrists were used to harvest the hamate proximal pole on the dorsal intercarpal arch. A loss of substance of the scaphoid proximal pole was simulated and the hamate flap was transferred. In 15 wrists, a canulated screw osteosynthesis was performed to assess donor site morbidity and carpus stability on post-osteosynthesis dynamic radiographs. This study suggests that the proximal hamate can be harvested pedicled on the dorsal intercarpal arch. The pedicle (average pedicle diameter 0.9 mm, mean length 31.5 mm) allowed tension-free graft placement in all dissections, except for one. The morphology of the graft was very similar to that of the scaphoid proximal pole and the palmar capito-hamate ligament allowed scapholunate ligament reconstruction in all dissections. This is the first study that describes the use of a pedicled flap to fully reconstruct the complex osteo-chondro-ligamentous anatomy of the scaphoid proximal pole. This vascularized hemi-hamate flap could facilitate better long-term preservation of cartilage biomechanical properties compared to non-vascularized grafts. Donor site morbidity requires further investigation before recommending clinical use.

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.

Hemi-hamate Arthroplasty for Base of Middle Phalanx Fracture: A Systematic Review

Intra-articular fracture dislocations of the base of the middle phalanx are complex and debilitating injuries that present a management conundrum when nonreconstructable. Hemi-hamate arthroplasty (HHA) is a treatment modality of particular use in the setting of highly comminuted fractures. This systematic review aims to summarize the reported outcomes of HHA in this context. A literature search was conducted using MEDLINE, Embase, and PubMed, yielding 22 studies with 235 patients for inclusion. The weighted mean postoperative range of movement at the proximal interphalangeal joint was 74.3° (range, 62.0°-96.0°) and at the distal interphalangeal joint was 57.0° (range, 14.0°-80.4°). The weighted mean postoperative pain Visual Analog Scale was 1.0 (range, 0.0-2.0). The weighted mean postoperative grip strength was 87.1% (range, 74.5%-95.0%) of the strength on the contralateral side. Posttraumatic arthritis was reported in 18% of cases, graft collapse in 4.2%, and donor site morbidity in 3.0%, with a mean follow-up period of 28.4 months (range, 1-87 months). Hemi-hamate arthroplasty is a reliable and effective technique for the reconstruction of intra-articular base of middle phalangeal fracture dislocations, affording symptomatic relief and functional restoration. Further research is required to assess the true incidence of long-term complications.

Modeling the Articular Surface of the Hamate with the Fourth and Fifth Metacarpal Bases with Three-dimensional Laser Scanning

Introduction

Our purpose is to highlight the articulating surfaces between the hamate and fourth and fifth metacarpal (MC) bases of the hand using three- dimensional (3D) laser scanning. This joint surface is used for osteochondral grafting of small joints such as the proximal interphalangeal joint using the hamate articular surface. It is an important joint for hand function and can develop osteoarthritis. 

Methods

NextEngine (NextEngine, Santa Monica, CA) 3D laser scanner (accurate to ±100 µm) was used to capture the articular surfaces of the hamate with the fourth and fifth MC bases of 10 embalmed cadaver right hands. Articular surfaces were defined and modeled using Amira (Visage Imaging, Andover, MA) and MatLab7 (MathWorks, Natick, MA). Articular surfaces were evaluated in terms of size, shape, the radius of curvature (ROC) by three points and sphere-fit (SF) and inter-facet angles.

Results

In the fourth carpometacarpal (CMC) joint, the hamate articular surface with the 4th MC was single, concave, and well approximated by SF ROC (mean: 11.18 mm). The fourth MC base was convex; SF ROC mean was 9.94 mm. Six of the 10 articulations flattened from volar to dorsal.

In the fifth CMC joint, we noted a bicondylar construct. The two hamate surfaces were concave while MC bases were convex. The joint surface was best approximated with two overlapping spheres. Ulnar sphere averaged 30.21% of the surface of the hamate and 29% of the MC base. Ulnar hamate SF ROC mean was 11.63 mm, and ulnar fifth MC SF ROC mean was 8.07 mm. Radial SF hamate mean was 7.92 mm, and the radial fifth MC SF mean was 7.47 mm. The mean of the angle of divergence between the condylar spheres represented on the hamate surface was 21.4°, while that of the fifth MC base angle of divergence was 10.99°.

The mean of the angle formed between the fourth and fifth CMC joints at the hamate was 31.69°. A single articular facet between the fourth and fifth MC bases was concave on fourth and convex on the fifth MC base.

Conclusions and clinical relevance

Laser scanning of cadaver fourth and fifth CMC joints clarified the normal anatomy of the osteochondral joint surface. The topography of the joints was well-approximated by SF with curved surfaces in both the anteroposterior and radial-ulnar planes with the fifth CMC having two unique surfaces for articulation. We noted the distinct radial and ulnar articulating surfaces of the fifth CMC joint, which would permit flexion and limited supination.

Hemi-hamate osteochondral autograft for acute dorsal proximal interphalangeal fracture-dislocations

PURPOSE

Our aim was to investigate the clinical and radiological results of a hemi-hamate autograft arthroplasty method in patients with acute trauma who had a fragmented fracture of the proximal palmar joint surface of the middle phalanx and dorsal PIP subluxation.

METHODS

A total of 13 fingers from 13 patients who met the criteria were included in the study (11 men and 2 women) and prospectively reviewed. The mean age of the patients was 39.5 years. The mean interval between the injury and surgery was 6.3 days. The active movement of the DIP, PIP, MP and wrist joints was started on postoperative day. Follow-ups were performed at 6 weeks, 3, 6 and 12 months postoperatively. Range of motion for the DIP, PIP and MP joints, DASH and VAS scores, grip strength, two-point discrimination, finger pulp and palmar curve distance were evaluated.

RESULTS

All PIP joints were stable against coronal and sagittal stress at the 1st postoperative year and there was no limitation in wrist movements. Two-point discrimination was < 5 mm in all fingers. Union was achieved in all grafts except one. The mean active total PIP range of motion was 82.3°, DIP range of motion was 61.1°, MP joint motion was 87°. The mean DASH score was 7.6, and the mean VAS score was 1.5. The mean grip strength was 33.7 kg, which was 93% of the healthy side. The mean finger pulp and palmar curve distance was 8.6 mm.

CONCLUSIONS

We believe that HHA is an appropriate alternative in cases of acute dorsal PIP fracture-dislocations with an intact middle phalanx dorsal cortex that is not suitable for primary fixation, with the advantages of obtaining stable joint and satisfactory functional results.

The Use of the Proximal Hamate as an Autograft for Proximal Pole Scaphoid Fractures: Clinical Outcomes and Biomechanical Implications

Scaphoid proximal pole fractures remain a surgical challenge because of high propensity for nonunion, osteonecrosis, and ultimately carpal collapse. Options for management of nonsalvageable proximal pole fractures include non-vascularized bone grafts, vascularized pedicled bone grafts, free vascularized bone flaps, and rib cartilage grafts. The proximal pole of the hamate can also serve as a replacement arthroplasty in the setting of proximal pole scaphoid nonunions with collapse, bone loss, and/or osteonecrosis. This novel graft addresses shortcomings of other graft choices by providing a local structural autograft solution with minimal donor site morbidity, correcting carpal collapse, reconstructing the scapholunate ligament, and mitigating the need for microvascular anastomosis.

Injuries Around the Proximal Interphalangeal Joint

Proximal interphalangeal joint (PIPJ) injuries are common and challenging to treat, involving a spectrum of conditions ranging from isolated ligamentous injuries to severe fracture dislocations. The main goal of treatment is to achieve a congruent, stable joint, which is key to achieving early range of motion and a favorable outcome. Injuries that do not compromise the stability of the joint may be treated nonsurgically, whereas those that render the joint unstable may be managed with one of many surgical strategies available. This article focuses on the current practices of treatment of injuries around the PIPJ.

[Reconstruction of the middle phalangeal base of the finger using an osteocartilaginous autograft from the hamate]

OBJECTIVE

Restoration of proximal interphalangeal joint stability with preservation of mobility by reconstruction of the middle phalanx base using an osteochondral graft from the carpometacarpal joint surface of the hamate.

INDICATIONS

Acute and older isolated destruction of the palmar middle phalanx base >25%.

CONTRAINDICATIONS

Destruction of the head of the proximal phalanx, advanced chondropathia of the head of the proximal phalanx, extensive soft tissue injury with loss of skin coverage at the proximal interphalangeal joint.

SURGICAL TECHNIQUE

The fractured middle phalangeal base is debrided and the defect is replaced by a size-matched autograft from the dorsal carpometacarpal hamate osteoarticular surface that is secured in place with miniscrews.

POSTOPERATIVE MANAGEMENT

Immobilization for 2 weeks in a below-elbow cast in intrinsic plus position. Subsequent immobilization by a splint including the distal and proximal interphalangeal joint.

RESULTS

Healing was achieved in 100% with restoration of joint congruity in 12 of 13 cases and slight subluxation in 1 case. Follow up was possible in 9 cases after 22 ± 16 (5-51) months. The average range of motion in the reconstructed joint achieved 0/9/73°, grip strength 82% of the unaffected side. Of the 9 patients, 5 developed a mild flexion contracture of the proximal interphalangeal joint. The DASH score achieved 4 ± 3 (0-8) points, pain at rest was 1 ± 2 (0-5), pain at exercise 2 ± 2 (0-5) on a visual analogue scale (0-10). All patients were satisfied and willing to undergo the procedure again. According to the literature, reconstruction of the base of the middle phalanx by using an osteochondral graft from the hamate is a reliable procedure to restore stability and mobility of the joint.

Vascularized versus Nonvascularized Bone Grafts: What Is the Evidence?

BACKGROUND

There is a general perception in practice that a vascular supply should be used when large pieces of bone graft are used, particularly those greater than 6 cm in length for long-bone and large-joint reconstructions. However, the scientific source of this recommendation is not clear.

QUESTIONS/PURPOSES

We wished to perform a systematic review to (1) investigate the origin of evidence for this 6-cm rule, and (2) to identify whether there is strong evidence to support the importance of vascularization for longer grafts and/or the lack of vascularization for shorter grafts.

METHODS

Two systematic reviews were performed using SCOPUS and Medline, one for each research question. For the first research purpose, a review of studies from 1975 to 1983 matching article title ("bone" and "graft") revealed 725 articles, none of which compared graft length. To address the second purpose, a review of articles before 2014 that matched "bone graft" AND ("vascularised" OR "vascularized") AND ("non-vascularised" OR "non-vascularized") revealed 633 articles, four met prespecified inclusion criteria and were evaluated qualitatively. MINORS ratings ranged from 16 to 18 of 24, and National Health and Medical Research Council [NHMRC] Evidence Hierarchy ratings ranged from III-2 (comparative studies without concurrent controls) to III-3 (comparative studies with concurrent controls).

RESULTS

No evidence was found that clarified grafts longer than 6 cm should be vascularized. The first reference to the 6-cm rule cites articles that do not provide strong evidence for the rule. Of the four articles found in the second systematic review, none examined osseous union of vascularized and nonvascularized grafts with respect to length. One study (III-3, MINORS 18 of 24) of fibular grafts to various limb defects found that vascularization made no difference to union rate or time to union. Vascularized grafts were more likely to require surgical revision for wound breakdown, nonunion, graft fracture, or mechanical problems (hazard ratio [HR], 5.97, p = 0.008) and grafts smaller than 10 cm had fewer complications requiring revision (HR, 0.88; p = 0.03). Three studies (III-2 to III-3, MINORS 16 to 18 of 24) that examined fibular grafts to the femoral head found that vascularized grafts had superior Harris hip and pain scores. Two of the three articles showed that vascularization was associated with superior radiologic measures of collapse progression.

CONCLUSIONS

No compelling evidence was found to illuminate the origin of the 6-cm rule for vascularized bone grafts, or that such a rule is based on published research. The evidence we found for grafts to long-bone defects suggested that vascularization might increase the risk of complications that require a surgical revision without increasing union rates or time to union. For large joints, vascularization may result in better functional scores and pain scores, while the evidence that they improve radiologic measures of progression is mixed. There were no studies of long-bone or large-joint reconstructions that examined the role of length with respect to osseous union. We suggest that future studies should present data for graft lengths quantitatively and with individual data points rather than categories of length ranges.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Reverse second dorsal metacarpal artery vascularized bone flap for index distal bone loss: A case report

Fingertip trauma with resultant bony loss is optimally reconstructed with an autologous bone substitute, offering a unique opportunity for use of a local vascularized bone graft. The second dorsal metacarpal artery is well-described for use in soft tissue and bony reconstruction, with recent cadaveric studies suggesting a reverse-flow second dorsal metacarpal artery bone flap could reach defects in the distal phalanx. The aim of the current report is to illustrate the use of this technique in reconstructing the distal digit in a traumatized index finger with bony loss of the middle third of the distal phalanx. A 49-year-old man presented with a traumatic circular saw injury to his left index finger, with the unique finding of distal phalanx bony loss to the middle third of this bone, with no associated disruption of palmar or dorsal structures. Reconstructive goals were solely that of bony reconstruction, with no soft tissue coverage required. A reverse SDMA vascularized bone flap was successfully used for reconstruction, with the vascularized bone flap mobilized on its reverse SDMA pedicle and pivoted at the level of the distal anastomoses between the palmar and dorsal metacarpal arteries. There was uncomplicated donor and recipient site closures, and good functional outcomes with the ability to retain full distal interphalangeal joint motion and force on distal pinch grip. This case shows that the reverse second dorsal metacarpal artery vascularized bone flap may be undertaken to reconstruct bony loss in the distal phalanx.

The hemi-hamate autograft arthroplasty in proximal interphalangeal joint reconstruction: a systematic review

Palmar lip injuries of the proximal interphalangeal joint with dorsal fracture-dislocation are difficult to treat and often require major reconstruction. A systematic review was performed and yielded 177 articles. Thirteen articles on hemi-hamate autograft were included in full-text analysis. Results of 71 cases were summarized. Mean follow-up was 36 months and mean proximal interphalangeal joint range of motion was 77°. Overall complication rate was around 35%. Up to 50% of the patients showed radiographic signs of osteoarthritis. However, few of those patients complained about pain or impaired finger motion. Based on this systematic analysis and review, hemi-hamate autograft can be considered reliable for the reconstruction of acute and chronic proximal interphalangeal joint fracture-dislocations with joint involvement >50%, but longer-term follow-up studies are required to evaluate its outcome, especially regarding the rate of osteoarthritis.

The second dorsal metacarpal artery chain-link flap: an anatomical study and a case report

PURPOSE

The purpose of this study was to discuss the distribution characteristics and the anatomical angioarchitecture of cutaneous branches arising from the second dorsal metacarpal artery for the repair of small tissue defects in the hand or fingers using the second dorsal metacarpal artery chain-link flap.

METHODS

Fifteen fresh human cadaveric hands were studied using three methods: latex perfusion for microanatomical analysis, denaturation of material and vinyl chloride mixed packing for cast specimens, and latex perfusion creating pellucid specimens. Cutaneous perforators with a diameter of 0.2 mm or greater were evaluated using statistical analysis. Cluster analysis was conducted to determine the overall distribution of the perforators.

RESULTS

Two main clusters of perforators distributed at a relative distance of 40.8 and 68.6% from the second web space edge to the midpoint of the second metacarpal bone as a unit. The Chi-square analysis revealed no significant differences in either the radial or ulnar side distribution of the cutaneous perforators from the second dorsal metacarpal artery (p = 0.779). Chain-links formed among adjacent perforators were parallel to the axis of the second metacarpal bone on the dorsum of the hand. Based on the anatomic characteristic, we designed the second dorsal metacarpal artery chain-link flap to recover the defect in the index finger. As a result, the patient was satisfied with the appearance and function.

CONCLUSION

This study indicates that there are two main clusters of arterioles in the distal second dorsal metacarpal artery that can be helpful for the second dorsal metacarpal artery pedicle cutaneous chain-link perforator flaps in the repair of defects in the fingers.