A Comparison of the Outcomes of Excision of the Fractured Hook of Hamate via a Carpal Tunnel Approach versus a Lateral Approach.

Background: The excision of the hook of the hamate is an accepted modality for the treatment of hook of hamate fractures. Three surgical approaches to the hook of hamate have been described in literature. This includes two palmar approaches namely the Guyon canal approach and the carpal tunnel approach, and the lateral approach. The aim of this article is to compare the outcomes of the carpal tunnel approach and the lateral approach. Methods: Twenty-four patients with hook of hamate fractures were treated by excision of the hook of hamate. The hook of hamate was approached via the carpal tunnel in 15 patients and via the lateral approach in 9 patients. The outcomes with regard to duration of the surgery, complications such as pain, sensory disturbance and scar problems and time to return to sports were measured and analysed. Results: There were no significant differences in outcomes between the carpal tunnel and the lateral approach for excision of hook of hamate fractures. Conclusions: The outcomes of excision of the hook of hamate via the carpal tunnel approach and the lateral approach are similar. The decision to choose an approach should be based on the surgeon's familiarity with the approach. Future studies should include a comparison with the Guyon canal approach preferably in a homogenous group of patients. Level of Evidence: Level IV (Therapeutic).

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.

Arthroscopic Excision of Hamate Osteoid Osteoma.

Osteoid osteoma is considered the most common benign bone forming tumor accounting for 12% of all benign bone tumors. The carpus is a rare site for this tumor but quite a few cases were reported before. The lesion can be subperiosteal, cortical or medullary. Computed tomography scan is the gold standard diagnostic study, whereas magnetic resonance imaging can result in delaying the diagnosis as reported in the literature. Open excision with or without grafting was the technique of choice in most reviewed cases in the literature. In this paper we will illustrate a minimally invasive technique using wrist arthroscopy for an osteoid osteoma of hamate proximal pole. This minimally invasive arthroscopic technique provides a rapid recovery for patients with lesions that are accessible to wrist arthroscopy.

First reported case of a coronal hamate fracture associated with intrusion of the fifth metacarpal base, together with a fracture of the fourth metacarpal base.

We present a case reporting a rare combination of base of fourth metacarpal fracture and coronal body of hamate fracture, treated conservatively with excellent results. High index of suspicion for undetected bony injuries drove the execution of a CT scan, which allowed us to make a full correct diagnosis and plan treatment. Moreover, this case becomes the first reported case in the literature of such injury causing the intrusion of the base of the fifth metacarpal within the hamate bone, thus causing the coronal pattern of the hamate fracture. Differently from the common surgical management of this type of injury, we successfully treated this patient with close reduction and immobilisation, with full recovery after 3 months.

Unsuccessful Intervention of CT-Assisted Osteosynthesis for Stress Fractures of the Hook of the Hamate: A Report of 3 Cases.

CASE: We performed computed tomography (CT)-assisted dorsal approach osteosynthesis for stress fractures of the hook of the hamate using the dorsal approach in 3 high school baseball players in the hybrid operating room. Bony union was observed in all patients on CT. All patients were able to play baseball without pain for at least 6 months after surgery. However, refractures were observed in all patients at a mean 9.7 months after surgery. CONCLUSION: The indications of osteosynthesis for stress fractures of the hook of the hamate in baseball players should be carefully considered.

Triquetrum osteotomy to approach an otherwise inaccessible coronal malunion of the hamate.

Fractures of the hamate are rare, and a clear treatment algorithm does not exist. Nonetheless, surgical treatment is generally recommended for displaced fractures using a dorsal approach. There is also a lack of data on hamate malunion. We present a case of a 28-year-old female with a coronal malunion of the hamate and hamate hook fracture. Because the triquetrum prevented direct access to the fracture, we planned and undertook a transtriquetral coronal osteotomy based on three-dimensional computed tomography imaging data. After removing the bone callus, reduction was possible with subsequent fixation. We recommend performing a transtriquetral osteotomy to treat an otherwise inaccessible fracture or malunion of select hamate fractures.

Coronal Hamate Fractures with Carpometacarpal Dislocation Treated Effectively Using Headless Compression Screws with Percutaneous Pinning Fixation by Using the 2-Directional Approach: A Report of 2 Cases.

CASE: Coronal shear fractures of the hamate are relatively rare injuries. Surgical intervention is recommended for displaced fractures. However, there is no established surgical procedure for the displaced coronal shear fractures of the hamate. Therefore, we present 2 cases of the displaced coronal hamate fracture with metacarpal dislocations, which were successfully managed with open reduction and internal fixation, using the headless compression screw by the 2-directional approach. CONCLUSION: Our procedure ensured that the screw's distal end captured the hamate hook, and the displaced bone fragments were reduced considerably in both cases.

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.

Value of cross-sectional area of median nerve by MRI in carpal tunnel syndrome.

BACKGROUND: Carpal tunnel syndrome is diagnosed based on history, physical examination, and nerve conduction testing; however, there are no clear criteria for the diagnosis of carpal tunnel syndrome. Recently, studies have aimed to diagnose carpal tunnel syndrome through ultrasound or MRI. The purpose of this study was to compare and analyze the cross-sectional area of the median nerve between patients with carpal tunnel syndrome and a control group. METHODS: From July 2015 to August 2017, we retrospectively analyzed fishery and white-collar workers (164 people, 37 men, 127 women). Carpal tunnel syndrome was diagnosed on the basis of both physical examination and nerve conduction testing. A negative result in either test led to exclusion from the study. RESULTS: In total, 164 wrist MRI were retrieved, with 67 patients diagnosed with carpal tunnel syndrome and 97 patients allocated to the control group. The mean value of cross-sectional area at the pisiform was 18.8 mm2 in the MRI of the carpal tunnel syndrome patients and 12.1 mm2 (p-value <0.05) in the control group. The mean value of cross-sectional area at the hook of hamate was 11.70 mm2 and that at the control group was 11.67 mm2 (p-value 0.055). CONCLUSION: Cross-sectional area at pisiform in MRI is a valuable factor in the diagnosis of carpal tunnel syndrome and in predicting the duration of pain.

Topographical Analysis of the Hamate for Proximal Pole Scaphoid Nonunion Reconstruction.

PURPOSE: To quantify the similarity of the surface topography of the proximal hamate and proximal pole of the scaphoid for nonunion reconstruction. METHODS: Using previously acquired computed tomographic scans of the wrist of 10 patients, the 2 bones were segmented and subsequently aligned using both a manual and automated technique. Surface error between corresponding articular surfaces was computed to determine the similarity of the shape of the 2 bones. RESULTS: The median distance between the 2 articulating surfaces for each patient was 1 mm or less for all cases. Maximum distance varied from 2.7 to 9.7 mm. The automated method improved alignment such that the maximum distance was 4.1 mm. Visual review of the alignment revealed that the maximum error occurred on or around the margin of the articulating surfaces. CONCLUSIONS: In most cases, the proximal hamate appears to be a suitable donor match to reconstruct proximal pole scaphoid nonunions. CLINICAL RELEVANCE: This study serves as a guide to practitioners when considering the suitability of the proximal hamate autograft for unsalvageable proximal pole scaphoid nonunions.

A Modified Surgical Approach Through Guyon's Canal and the Proximal Ulnar Border of the Carpal Tunnel Allows for Safe Excision of the Hook of the Hamate.

Hook of the hamate fractures can be treated by various methods including cast immobilization, open reduction, and internal fixation and excision. Usually, those individuals who elect for excision have acute fractures and need to return to sporting activity or work quickly or have nonunions with persistent symptoms. There is a paucity of descriptions in the literature and textbooks of a technique to safely excise the hook of the hamate. The authors present a method of safely exposing and removing the hook of the hamate by visualizing the potential structures at risk: the motor branch of the ulnar nerve, the ulnar digital nerve to the little finger, and the flexor tendons to the ring and little fingers by an approach through Guyon's canal and the proximal ulnar border of the carpal tunnel.

Diagnosis of a hamate hook fracture with 3D reconstruction of computed tomography images: A case report and review of literature.

We report the case of a 19-year old man who presented to our institution with a history of pain of one week in the ulnar side of the left wrist and continuous pressing sensation in the palm. According to patient, there was no history of acute hand trauma. The conventional roentgenograms did not show the fracture and computerized tomographic (CT) scanning demonstrated a complete fracture of the hook of the hamate. The patient was given a surgical intervention and the hamate bone was reduced through a palmar skin incision. After surgery, the operated hand was immobilized in a wrist brace and the patient was put on a rehabilitation protocol. At the last follow-up, the patient was able to return to normal living activities without any symptoms. We reviewed the latest articles of the past 18 years and compared the research studies related to the diagnosis and treatment of the hamate hook fracture. Our conclusion is that CT scan is the most effective diagnostic tool for detecting the hamate hook fracture. Three-dimensionally (3D) reconstructed images based of CT could provide more accurate and insight illustration for better evaluation in surgical planning.

Fracture of an Os Hamulus Proprium: A Case Report.

CASE: We report the case of a 39-year-old man who sustained an acute fracture of an os hamulus proprium, which was treated with open surgical excision after nonoperative treatment was unsuccessful. At the most recent follow-up, at 6 years after surgery, the patient was asymptomatic and maintained full function of the hand and the wrist. CONCLUSION: An os hamulus proprium is often confused with a fracture of the hook of the hamate, and little information exists in the literature regarding these accessory ossicles. To our knowledge, an os hamulus proprium fracture has not previously been described in the literature.

Sliding Position of the Flexor Tendons Relative to the Hook of Hamate in CT Scans.

BACKGROUND: The aim of this study was to assess the height of nonunion formation injuring the ulnar-side finger flexor tendon, the positional relationship between the hook of the hamate and little finger flexor tendon was evaluated on CT scans. METHODS: The subjects were 20 healthy patients (40 hands) (14 males and 6 females, mean age: 28 years old). Their hands were imaged in extension and flexion of the fingers on CT. The position of the little finger flexor tendon was determined regarding the height of the hook of the hamate as 100%. RESULTS: The heights of the flexor digitorum profundus tendons were 46 ± 6% in extension and 44 ± 9% in flexion, and those of the flexor digitorum superficialis tendons were 87 ± 8% in extension and 91 ± 9% in flexion. CONCLUSIONS: Our study suggested that 40% of the base of the hook of the hamate does not contact with the flexor tendon, suggesting that flexor tendon injury is unlikely to occur in that region.

Computerized tomographic prediction of flexor tendon injuries complicating hamate hook fractures.

We reviewed computerized axial tomography of 28 patients with hamate hook fractures who had surgical resection of the hook. We analysed the relationship between the fragment height ratio, fragment gap, and intraoperative findings of the tendons. We determined whether parameters in the images can predict complication of tear or disruption of the flexor tendons to the ring or little fingers. Of 28 patients, 16 had fragment height ratios between 50-74; ten among them had worn (eight patients) or ruptured (two patients) flexor tendons. Nine of the ten patients had fragment gaps greater than 2 mm. The remaining 12 patients had fragment height ratios between 75-100 and had intact tendons. We conclude that a fragment height ratio greater than 75 and fragment gap less than 2 mm in computer tomography may rule out tear or disruption of the flexor tendons of the ring and little fingers after hamate hook fractures, and a fragment height ratio between 50-74 with fragment gap greater than 2 mm indicates a high risk of flexor tendon tear or disruption. Level of evidence: IV.

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.

An Anthropometric Assessment of the Proximal Hamate Autograft for Scaphoid Proximal Pole Reconstruction.

PURPOSE: Fragmentation of the scaphoid proximal pole secondary to avascular necrosis presents a difficult reconstructive problem. This anthropometric study assesses the utility of the ipsilateral proximal hamate for complete osteochondral scaphoid proximal pole reconstruction. METHODS: Twenty-nine cadaveric specimens underwent computed tomography scanning and 3-dimensional reconstruction of the carpus and distal radius. Scaphoid height was measured and a third of its height was used to simulate resection of the proximal scaphoid pole and extent of hamate autograft required. The proximal scaphoid and hamate were divided into 6 sections, and compared using an iterative point-to-point distance algorithm. Average distance between the scaphoid and the hamate surfaces was determined. An interbone algorithm was used to assess radioscaphoid joint congruency and articular contact surface of the native scaphoid compared with the scaphoid reconstructed with hamate autograft. RESULTS: The mean height of scaphoid proximal pole excision and proximal hamate autograft height was 9.3 mm. Comparing the morphology of the native scaphoid and hamate autografts, the absolute distances were the largest in the volar radioscaphoid, dorsal radioscaphoid, and dorsal scaphocapitate segments. Without osteotomy, the hamate autograft may cause impaction in the dorsal-radial aspect of the distal radius. The hamate autograft also shifted the articular contact point of the radioscaphoid joint toward the dorsal-radial position. Nine hamate autografts were classified as poor-fitting. Poor-fitting specimens had a greater radial styloid to distal radioulnar joint distance. These specimens also had wider hamates and scaphoids in the radial-ulnar dimension and wider scaphoids in the volar-dorsal dimension. Lunate type did not correspond to anthropometric fit. CONCLUSIONS: The proximal hamate osteochondral graft was poor fitting in 31% of cases (9 of 29 specimens). Wrists with radial-ulnar hamate width less than 10 mm, radial-ulnar scaphoid width less than 10 mm, and volar-dorsal scaphoid width less than 16 mm demonstrate better anthropometric fit. CLINICAL RELEVANCE: This study provides an anthropometric assessment of the recently described proximal hamate autograft, a new bone graft option for proximal scaphoid pole reconstruction.

Does median nerve translate pre- and postoperatively in carpal tunnel syndrome?

OBJECTIVES: This study aims to evaluate the distance between the median nerve and the hook of the hamate pre- and postoperatively in patients with carpal tunnel syndrome and to investigate the efficiency of magnetic resonance imaging in diagnosis and postoperative follow-up. PATIENTS AND METHODS: Median nerve decompression was performed by releasing the carpal tunnel in 15 patients (4 males, 11 females; mean age 51 years; range, 41 to 66 years) with carpal tunnel syndrome. The shortest distance between the median nerve and the hook of the hamate was measured with magnetic resonance imaging preoperatively and at three months after the operation and radial and ulnar translations were assessed. Findings were compared to those of a control group of 15 subjects (5 males, 10 females; mean age 52.2 years; range, 40 to 65 years). RESULTS: Median nerve shifted ulnarwards in patients with carpal tunnel syndrome. An intragroup evaluation of five patients with thenar atrophy revealed that as disease severity increased, the degree of the nerve's medial translation increased. Compared to preoperation, the median nerve significantly shifted to the radial side after decompression. CONCLUSION: In carpal tunnel syndrome patients, we observed significant ulnar translation of the median nerve and lateral translation after releasing the carpal tunnel. Magnetic resonance imaging may be used to establish a diagnosis and to assess operation success in advanced carpal tunnel syndrome patients who may recover slowly postoperatively.