Hemi-hamate arthroplasty for pilon fractures of finger

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.

Extension block pinning for chronic volar base fractures of the middle phalanges

Due to the simplicity, low cost and benefit of avoiding long-term joint immobilization, extension block pinning could be a suitable option for treating the volar base fractures of the middle phalanges. The aim of the present study was to evaluate the outcomes of using extension block pinning in chronic volar base fractures of the middle phalanges. In total, 26 patients with chronic closed volar base fractures of the middle phalanges were included our study. The mean age was 37 years (SD 11.59), and the mean follow-up time was 35 months (SD 19.41). The mean active range of motion (ROM) after surgery was 93° (SD 12.9). There was a negative correlation between the age and the ROM of the injured proximal interphalangeal joint after surgery. ROM did not correlate with the articular surface involvement or the interval between injury and surgery. We obtained a satisfactory result from extension block pinning for volar base fractures of the proximal interphalangeal joint in patients with chronic injuries.Level of evidence: IV.

Extension-Block Pinning for Unstable Dorsal Proximal Interphalangeal Joint Fracture-Dislocations: A Simple, Percutaneous Technique With Reproducible Outcomes

BACKGROUND

Proximal interphalangeal (PIP) joint fracture-dislocations can be technically challenging injuries to treat, and no technique has proven to be superior nor lead to predictably good outcomes. We describe our experience of treating unstable dorsal fracture-dislocations of the PIP joint with extension-block pinning (EBP) at our institution over a 22-year period.

METHODS

In all, 23 patients with 24 unstable dorsal fracture-dislocations of the PIP joint treated with EBP between January 1998 and October 2020 were identified. All patients underwent closed reduction of the PIP joint and insertion of a Kirschner wire into the proximal phalanx, creating a mechanical block. Range of motion and joint congruity were assessed at final clinic follow-up. Long-term function was assessed via completion of a Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire. Spearman's correlation coefficient was utilized to assess if any association existed between treatment delay, pin-in-body days, or amount of articular surface involved and QuickDASH score.

RESULTS

Mean range of motion at final follow-up was 83.3° and 22 of 24 PIP joints demonstrated a congruent reduction. In all, 15 of the 23 patients completed the QuickDASH questionnaire at a median long-term follow-up of 57.5 months (range: 3-157 months). Average QuickDASH score was 18.8, indicating minimal long-term disability. No statistically significant associations were found between treatment delay, pin-in-body days, or amount of articular surface involved and QuickDASH score.

CONCLUSIONS

EBP offers a simple and innovative method to treat a complex injury of the PIP joint. It is technically straightforward and cheap, and produces excellent functional outcomes with minimal long-term disability.

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.

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.

Hemihamate arthroplasties in pilon fractures: a modified approach and experience in 30 patients

Hemihamate arthroplasty is an established method of managing difficult Pilon fractures of the proximal interphalangeal (PIP) joint. We present our experience in 30 patients, whose injuries were further complicated by severe comminution and late presentations. Several modifications were utilized, including preoperative distraction, use of smaller size grafts and functional release of collaterals. The average follow-up period was 28 months (range 18 to 28). Postoperatively, the average range of flexion at the PIP joint improved from 30° (range 20° to 45°) preoperatively to 104° (90° to 110°) at the final follow-up. The average extension lag was 6° (0° to 20°). Five patients required secondary procedures and no patient had a recurrent dorsal dislocation. We propose these modifications in the use of hemihamate arthroplasty for the management of difficult PIP joint fractures.Level of evidence: IV.

A novel technique for proximal interphalangeal joint fracture-dislocations: the second toe middle phalanx osteochondral graft

Many different surgical techniques have been used to treat unstable dorsal proximal interphalangeal joint fracture-dislocations. The authors have used the base of the middle phalanx of the second toe base as an alternative autograft to treat this type of injury. This retrospective study assessed the clinical outcomes of this procedure in 11 patients. Range of motion, grip strength, Disability of the Arm, Shoulder and Hand score and donor site morbidity were assessed at regular intervals postoperatively. Nine patients had acute injuries and two had chronic injuries. The mean range of motion in the proximal interphalangeal joint at final review was 65° for patients with acute injuries and 41° for patients with chronic injuries. Other outcomes were satisfactory and there were no complications.Level of evidence: IV.

Treatment for Acute Proximal Interphalangeal Joint Fractures and Fracture-Dislocations: A Systematic Review of the Literature

Proximal interphalangeal joint (PIPJ) fractures and fracture-dislocations are common hand injuries and recognition of this injury pattern is essential in the management of these fractures. Although a variety of treatment options have been reported in the literature, the optimal treatment remains controversial. MEDLINE, EMBASE, and The Cochrane Library Database were screened for treatment strategies of PIPJ fracture and fracture-dislocation. Demographic data and outcome data were collected and recorded. A total of 37 studies including 471 patients and 480 fingers were reviewed. PIPJ range of motion (ROM) was greatest postoperatively in patients who underwent volar plate arthroplasty at 90.6 degrees. Dynamic external fixation resulted in the lowest PIP joint ROM with an average of 79.7 degrees. Recurrent pain and osteoarthritis were most often reported in extension block pinning at 38.5 and 46.2%, respectively. Open reduction and internal fixation had the highest rate of revision at 19.7%. Overall, the outcomes of PIP fractures and fracture-dislocations are based on the severity of injury, and the necessary treatment required. Closed reduction with percutaneous pinning and volar plate arthroplasty had good clinical and functional outcomes, with the lowest complication rates. Hemi-hamate arthroplasty and dynamic external fixation were utilized in more complex injuries and resulted in the lowest PIPJ ROM. This is a therapeutic, Level III study.

An Analysis of Hamate Morphology Relevant to Hemi-Hamate Arthroplasty

PURPOSE

Dorsal fracture-dislocations of the proximal interphalangeal (PIP) joint can lead to joint incongruity from loss of the buttress function of the middle phalanx volar base. Hemi-hamate arthroplasty can reconstruct the volar articular surface of the middle phalangeal base where repair is not possible. We compared the anatomy of the hamate graft with the middle phalanx base.

METHODS

Forty unique skeletal specimens (40 hamates, 160 middle phalanges) were sampled. Anatomical features relevant to hemi-hamate reconstruction were measured, including the articular surface areas, the axial ridge angles, and the sagittal inclination angles of the hamate and the middle phalanx base specimens. Facets of the articular surfaces were classified as concave, convex, or flat. Calibrated measurements were made using digital photographs of the cadaveric specimens. Descriptive and univariate statistics were performed.

RESULTS

There was greater variability in the distal hamate than in the middle phalanx base. The ring finger facet of the distal hamate was concave in 39 of 40 specimens, whereas the little finger facet was convex in 31 of 40 specimens. The hamate axial ridge angle (66.0° ± 3.7°) was significantly different from the middle phalanx base (90.4° ± 0.4°). The hamate articular sagittal inclination (3.2° ± 4.1°) was significantly different from the middle phalanx base (51.2° ± 1.3°). The hamate articular surface area (1.96 cm²) was significantly greater than the middle phalanx base (mean index/middle/ring finger = 0.85 cm² and mean little finger = 0.59 cm²).

CONCLUSIONS

The distal articular surface of the hamate is not anatomically identical to the middle phalanx base. The differences may still preclude anatomical reconstruction in the setting of a dorsal PIP fracture-dislocation, thereby affecting short- and long-term outcomes.

CLINICAL RELEVANCE

Knowledge of the anatomical differences between the distal hamate and the middle phalanx base may improve graft harvest and inset during reconstruction.

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.

Modified Hemihamate Arthroplasty With Oblique Osteotomy of the Middle Phalanx Base to Reconstruct Proper Contour of the Articular Surface

Treatments of unstable dorsal fracture dislocations of the proximal interphalangeal (PIP) joint are very challenging. The authors performed modified hemihamate arthroplasty for these injuries in 13 patients (13 fingers). Our surgical technique was unique in the point that we put volarly oblique osteotomy in the coronal plane at the recipient site to create an adequate reconstruction of the volar lip of the articular surface of the middle phalanx. Affected fingers are index in 2, middle in 4, ring in 3, and little in 3, and the mean duration of follow-up was 14 months. Hemihamate arthroplasty was indicated if >30% to 50% of the volar articular surface of the middle phalangeal base showed comminuted fracture which was not large enough to allow open reduction and internal fixation. The average range of motion of the PIP joint was 17.7 degrees preoperatively, which was improved significantly to 71.3 degrees at final follow-up. Radiographically, all grafts were united but 1 showed mild graft absorption. Ten patients demonstrated normal joint space and other 3 showed mild degenerative change of PIP joints. Eleven patients showed good congruency of the PIP joint and other 2 demonstrated slight dorsal subluxation. Four patients complained of mild pain in flexion, but other 9 had no pain at all. The modified hemihamate arthroplasty is a reliable technique to treat comminuted dorsal fracture dislocations of the PIP joint.

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.

Evaluation of Articular Surface Similarity of Hemi-Hamate Grafts and Proximal Middle Phalanx Morphology: A 3D Geometric Morphometric Approach

PURPOSE

Hemi-hamate arthroplasty has been described as a viable treatment option for unstable proximal interphalangeal joint fracture-dislocations. The procedure uses a dorsal distal hamate osteochondral graft to recreate the injured volar middle phalanx (MP) proximal base. The purpose of this study was to evaluate the similarity in shape of these articular surfaces using quantitative 3-dimensional methods.

METHODS

Three-dimensional virtual renderings were created from laser scans of the articular surfaces of the dorsal distal hamate and the volar MP bases of the index, middle, ring, and little fingers from cadaveric hands of 25 individuals. Three-dimensional landmarks were obtained from the articular surfaces of each bone and subjected to established geometric morphometric analytical approaches to quantify shape. For each individual, bone shapes were evaluated for covariation using 2-block partial least-squares and principal component analyses.

RESULTS

No statistically significant covariation was found between the dorsal distal hamate and volar MP bases of the middle, ring, or little digits. Whereas the volar MP bases demonstrated relative morphologic uniformity among the 4 digits both within and between individuals, the dorsal distal hamates exhibited notable variation in articular surface morphology.

CONCLUSIONS

Despite the early to midterm clinical success of hemi-hamate arthroplasty, there is no statistically significant, uniform similarity in shape between the articular surfaces of the dorsal distal hamate and the volar MP base. In addition, there is wide variation in the articular morphology of the hamate among individuals.

CLINICAL RELEVANCE

The lack of uniform similarity in shape between the dorsal distal hamate and the volar MP base may result in unpredictable outcomes in HHA. It is recommended that the variation in hamate morphology be considered while reconstructing the injured volar MP base in the procedure.

[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.

A simple pre-operative imaging method to assess donor and recipient anatomy in hemi-hamate arthroplasty for proximal interphalangeal joint reconstruction

PURPOSE

Post-traumatic arthritis is common in long-term follow-up of patients undergoing hemi-hamate arthroplasty (HHA). We hypothesize that anatomic mismatch could play a role in the development of arthritis. The purpose of this study is to establish a novel, computed tomography (CT)-based imaging technique for pre-operative assessment in HHA. With this technique, our group aims to identify digits with a high likelihood for anatomical mismatch between the donor graft and recipient interphalangeal joint. Using this technique to eliminate cases with high-likelihood of incongruent anatomy, we hypothesize the rates of arthritis could be reduced.

METHODS

We conducted a retrospective review of upper extremity CT scans from 2007 to 2014 at our institution. Those studies meeting our inclusion criteria were exported to a clinical radiology software suite. Subsequently, angular and linear measurements of the hamate and potential recipient proximal interphalangeal joints were collected. Angular and linear comparisons were then made between the donor hamate graft and the individual recipient sites. Using pre-established cutoff values, matches were deemed to be inconsistent or consistent.

RESULTS

The study included 31 CT scans. The rate of anatomical consistency was low; the small finger was most often consistent (38.7 %) and the index finger was least often consistent (12.9 %). Linear inconsistency was common in all joints besides the small finger; angular inconsistency was most prevalent in the index and long fingers.

CONCLUSIONS

This novel use of CT scans as a tool for pre-operative HHA planning is a crucial first step in trying to reduce the observed rates of arthritis after HHA.

Current concepts in treatment of fracture-dislocations of the proximal interphalangeal joint

BACKGROUND

Proximal interphalangeal joint fracture-dislocations are common injuries that require expedient and attentive treatment for the best outcomes. Management can range from protective splinting and early mobilization to complex surgery. In this review, the current concepts surrounding the management of these injuries are reviewed.

METHODS

A literature review was performed of all recent articles pertaining to proximal interphalangeal joint fracture-dislocation, with specific focus on middle phalangeal base fractures. Where appropriate, older articles or articles on closely related injury types were included for completeness. The methodology and outcomes of each study were analyzed.

RESULTS

When small avulsion fractures are present, good results are routinely obtained with reduction and early mobilization of stable injuries. Strategies for management of the unstable dorsal fracture-dislocation have evolved over time. To provide early stability, a variety of techniques have evolved, including closed, percutaneous, external, and internal fixation methods. Although each of these techniques can be successful in skilled hands, none has been subjected to rigorous, prospective, comparative trials. Volar dislocations fare less well, with significant loss of motion in many studies. Pilon fractures represent the most complicated injuries, and return of normal motion is not expected.

CONCLUSIONS

The best outcomes can be achieved by (1) establishing enough stability to allow early motion, (2) restoring gliding joint motion rather than noncongruent motion, and (3) restoring the articular surface congruity when possible. Although the majority of literature on this topic consists of expert opinion and retrospective case series, the consensus appears to favor less invasive techniques whenever possible.

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.

Management of difficult intra-articular fractures or fracture dislocations of the proximal interphalangeal joint

Intra-articular fractures or fracture dislocations of the proximal interphalangeal joint are difficult clinically because the bone and soft tissue structures are small and intricate. Suboptimal treatment of intra-articular fractures typically leads to functional impairment of the hand. This article reviews the current methods of treatment, together with the senior author's experience in treating difficult proximal interphalangeal joint fractures and dislocations. Besides conservative treatments, surgical treatments include open or closed reduction with traditional Osteosynthesis, such as K-wires, screws or plates. Among recent developments are the percutaneous application of thin cannulated compression screws and novel dynamic external fixators. After a preferred minimally invasive treatment with stable reconstruction of the articular surface, sufficient aftercare is necessary to improve surgical outcomes.

Possibility of the hamatum carpometacarpal joint as a new joint donor site for interphalangeal joint restoration

OBJECTIVE

This research investigates the anatomic basis for the repair and reconstruction of hand joints using transposition of the carpometacarpal (CMC) joint of the hamatum.

METHODS

The morphology and structure of the CMC joints of the hamatum and the base joints of the middle phalanx were observed on 22 freshly frozen wrist specimens at Shanghai 6th People's Hospital Research Institute of Microsurgery. The volar dorsal dia, radioulnar dia, depth of concave, and area of the joints were measured. Data were obtained through statistical analysis, and the resemblance of joints was compared in terms of morphology, structure, area, length, and diameter.

RESULTS

The radioulnar dia of the CMC joints of the hamatum (13.54 ± 1.15 mm) did not exhibit any evident differences in the middle phalanx of the forefinger, middle finger, and ring finger, and in the distal phalanx of the thumb. The volar dorsal dia of the CMC joints of the hamatum (10.71 ± 0.93 mm) exhibited an evident difference in the middle phalanx of the ring finger. In all fingers, the depth of the ulnar and radial concave of the CMC joints of the hamatum (1.30 ± 0.08 and 0.95 ± 0.05 mm, respectively) and the area of the CMC joints of the hamatum (139.89 ± 5.44 mm(2)) showed an evident difference.

CONCLUSION

The CMC joint of the hamatum could be considered a new and viable joint donor site that could be used to repair and reconstruct the base joints of the middle phalanx.

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

PURPOSE

The treatment of comminuted fractures of the proximal interphalangeal joint is highly challenging due to the complexities of joint bio-mechanics and stability. The hemi-hamate osteochondral auto-graft has been popularised in this role, able to replace articular loss and restore joint stability. Recent evaluation of their long-term follow-up however has shown the early development of osteoarthritis and potential early cartilage loss, which may be due to the non-vascularised nature of the graft. We offer a new technique that maintains vascularisation of the transferred hamate fragment, and investigate the anatomical vascular basis for the technique.

METHODS

Dissection and angiographic studies of ten cadaveric specimens were undertaken, exploring the vascular anatomy of the dorsal hamate. A clinical case of hemi-hamate osteochondral free flap is presented, including preoperative, intraoperative and postoperative investigation of the relevant vasculature.

RESULTS

Cadaveric studies demonstrated dorsal vascular supply to the hamate from the central of three dorsal carpal arches. The arch was supplied by the dorsal branch of the ulnar artery. Multiple supracapsular veins are present for use in flap venous drainage. This vascular pattern was found to be constant. A clinical case of hemi-hamate osteochondral free flap harvest demonstrated the same vascular anatomy intraoperatively. The digital artery was used as a recipient for microvascular anastomosis. Postoperative computed tomographic angiography and nuclear bone scan confirmed flap perfusion.

CONCLUSIONS

The hemi-hamate osteochondral flap has a reliable anatomical vascular basis, and is clinically feasible as a technique for early vascularisation of the osteochondral fragment to sustain the transferred articular cartilage.

The vascular basis of the hemi-hamate osteochondral free flap. Part 2: surgical anatomy and clinical application

PURPOSE

The free vascularised hemi-hamate flap combines the utility of providing a small osteochondral portion of hamate for reconstruction, while providing a means of vascularisation to preserve articular cartilage after transfer. In Part 1 of this series, we highlighted the vascular approaches to such a technique. The current study investigates the bony architecture of the hamate, with particular emphasis on its utility for a range of osteochondral defects in the hand.

METHODS

A morphometric assessment of the hamate as a potential osteochondral flap donor site for resurfacing digital phalangeal heads (either total or unicondylar) and/or bases was thus undertaken. This anatomic study was undertaken using in vivo imaging performed for a range of clinical indications, with computed tomographic angiography (CTA) and digital subtraction angiography (DSA) of the upper limb included. Bony and vascular measurements and relationships were recorded and assessed both quantitatively and qualitatively. A clinical case is presented, highlighting the application of these measurements.

RESULTS

The mean digital artery diameter was 0.7 mm with a mean distance between digital artery and interphalangeal joint surface (i.e. pedicle length) of 1.18 mm. Mean hamate dimensions comprised a transverse width 16.62 mm, lateral width of 14.29 mm and ridge height of 1.43 mm. Measurements of the phalangeal bases, condyles and total phalangeal heads were recorded, and the optimal hamate harvest approaches demonstrated. Despite perceived differences, in all cases there was statistical similarity demonstrated between the fragments.

CONCLUSION

The hemi-hamate osteochondral flap can be applied to a range of osteochondral defects in the hand and may offer new options to the hand surgeon.