Hamate Research Articles

Progression of Hamate Hook Stress Reactions in Elite Baseball Players.

Background:Hamate hook fractures can occur as a result of repetitive contact with the knob of the bat used in the sport of baseball. Hamate hook excision has resulted in excellent outcomes and return to sport (RTS) in elite baseball players. The ideal treatment for hamate stress response before the development of a fracture line is unknown.Purpose:To report the outcomes of elite baseball players with hamate bone edema.Study Design:Case series; Level of evidence, 4.Methods:We reviewed the medical records of all elite baseball players with hamate bone edema consistent with a stress response at 2 institutions. Players were eligible for inclusion if they played collegiate or professional baseball at the time of initial injury, had magnetic resonance imaging (MRI) showing hamate bone edema, and had no radiographic evidence of acute fracture lines at initial presentation.Results:A total of 4 players with a mean age of 22.8 years were included. All injuries occurred in the nondominant hand. All athletes had normal initial wrist radiographs and MRI showing hamate edema but no fracture line. Patients returned to play as tolerated and developed an acute injury at an average of 25.8 days (range, 10-56 days) from the initial presentation. Repeat radiographs demonstrated acute hamate hook fractures in all 4 (100%) athletes. All 4 athletes underwent hamate hook excision. There were no postoperative complications. All athletes returned to sport at their previous level of competition at a mean of 5.3 weeks (range, 3.6-7.3 weeks).Conclusion:There is a high rate of hamate bone edema progression to acute hamate hook fracture in elite baseball players, with 100% RTS at preinjury level after hamate hook excision. We therefore recommend against prolonged rest. Continuation of play with hamate bone edema followed by hamate hook excision for acute fracture limits the time missed and obtains a faster RTS in elite baseball players.

Guyon’s Canal Syndrome with Ganglion Cyst Compression from Baby-Holding Overuse

A 45-year-old man was frequently bothered by a weakness of the right hand, and it was difficult for him to do adduction of the thumb for half a year. According to his presentation, the patient held his child by the right upper limb with wrist flexion habitually for a year. Besides, there was an obvious atrophy of the hypothenar eminence. In MRI image, there were two lobulated cyst lesions in the Guyon’s canal between the right hook of the hamate bone and the abductor digiti minimi muscle. During the surgery, the two lobulated cysts were in the Guyon’s canal, and the ulnar nerve was compressed. Three weeks after the tumor excision, the weakness of the right hand improved dramatically, and the patient could perform adduction of the right thumb to pinch paper easily without flexion of the interphalangeal joint.

Acute Median Nerve Compression by a Fragment of Hamate Bone

Acute Median Nerve Compression by a Fragment of Hamate Bone

CT Image Measurement and Analysis of the Influence of Different Motion Modes on the Geometrical Morphology of Carpal Bone

The purpose of this study is to explore the influence of different movement modes on the geometrical morphology of carpal bones. In this study, Computed Tomography (CT) imaging is used for measurement and analysis. The results show that the changes of wrist bone volume of athletes are not significant compared with that of non-athletes, and the changes of bone density of the wrist bone are more obvious under the motion stress stimulation. According to results of CT imaging measurement and calculation, the average CT values of triangular bone, trapezoid bone, capitate bone and pisiform bone in the left hand and hamate bone in the right hand of the athlete are greater than that of the non-athlete, and the difference is statistically significant. Therefore, CT imaging technology can help to reconstruct the three-dimensional image of the carpal bone and deeply understand the geometric shape of the carpal bone of athletes.

Sonoanatomy of the deep branch of the ulnar nerve.

This study evaluated the sonoanatomy of the deep motor branch of the ulnar nerve (DBUN) using high-resolution ultrasonography (HRUS). In 60 wrists of 30 healthy adults, the gross course, cross-sectional area (CSA), and diameter of the DBUN were observed by HRUS (frequency band 3-16 MHz). Its course was assessed by using the distance from anatomical landmarks and depth from the skin. The DBUN was found in all subjects with HRUS, and it branched off from the ulnar nerve before reaching the hamate bone. At the hook-of-hamate level, the mean DBUN CSA was 1.5 ± 0.2 mm2 , and the mean diameter was 1.5 ± 0.2 mm. The mean distance from the hamate hook to the DBUN was 5.4 ± 1.0 mm, and the mean depth from the skin was 8.6 ± 1.6 mm. Sonoanatomy of the DBUN obtained from HRUS may be useful in detecting or preventing DBUN lesions.

A Study on the Hamate Bone Learning Effect Using DICOM Images and 3D Printing

Background/Objectives: This study compared the characteristics and the anatomical learning effects of a hamate bone model printed from DICOM images on a 3D printer.Method/Statistical Analysis: After printing a hamate bone model from DICOM images obtained from a wrist joint examination using a 3D printer, this study examined the anatomical understanding of 102 university students in public health departments.Findings: The intuitive awareness and the morphological awareness of the students on the protrusion, front and back of the hamate bone, and 5-way joint contact surfaces which were difficult to identify in conventional 2D and 3D medical images were improved by 60.7% and 58%, respectively.Improvements/Applications: The experiment showed that instrumenting of shape through 3D printing as a knowledge transfer method for students learning anatomy can improve the learning effect.

Application of dorsal supporting plate for treatment of the fourth and fifth carpometacarpal joint fractures and dislocations

Objective To report the clinical efficacy of dorsal lateral supporting plate in the treatment of the fourth and fifth carpometacarpal joint fractures and dislocations. Methods From June 2010 to May 2017, 7 patients with the fourth and fifth carpometacarpal joint fractures and dislocations were treated by dorsal lateral supporting plate and Kirschner wire fixation. The fractures of the hamate bone were all Cain type Ⅱunstable fractures, including 1 case of type ⅡA, 4 cases of type Ⅱ B, and 2 cases of type Ⅱ C. Among them, 2 cases had the base of the fourth and fifth metacarpal bone fractures, and 2 cases had only the base of the fourth metacarpal bone fracture. Results All the wounds achieved primary healing. The fracture healing time ranged from 8 to 12 weeks. The internal fixation was taken out depending on the healing of the fracture. All the patients were follow-up from 5 to 12 months with an average of 7 months. The flexion and extension function of all the hand joints recovered well. According to the upper extremity function evaluation criteria issued by the Hand Surgery Society of the Chinese Medical Association, the results were rated as excellent in 4 cases and good in 3 cases. Conclusion The treatment of fractures and dislocations of the fourth and fifth carpometacarpal joints with dorsal supporting plate and Kirschner wire fixation can provide stable fixation in multiple planes and directions, which is helpful for early functional exercise. Key words: Hamate bone; Carpometacarpal joints; Fractures,bone; Dislocations

Pressure algometry and palpation of the upper limb peripheral nervous system in subjects with hand osteoarthritis are repeatable and suggest central changes

Study DesignCase-control study. IntroductionA subset of patients with hand osteoarthritis (OA) shows evidence of central pain phenotypes. Purpose of the StudyTo examine whether differences exist in experimental pain responses in the affected and nonaffected sides of patients with unilateral hand OA. To investigate the test-retest reliability of pressure algometry and manual digital palpation in patients with unilateral hand OA. MethodsThe hand OA group consisted of 20 patients, and the control group consisted of 20 healthy subjects. Pressure pain threshold (PPT) measurements were made 2 times, consisting of 3 repeat trials, each using computerized algometry and manual digital palpation. Grip and key strength (dynamometer), pain (visual analog scale), and function (Disabilities of the Arm, Shoulder and Hand [short version]) were also measured. The 2-way analysis of variance was conducted to determine the differences between sides and groups. Intraclass correlation coefficient (ICC) and standard error of measurement were calculated. ResultsPatients with hand OA had decreased PPTs over the thumb carpometacarpal joint as well as radial and median nerves compared with controls (all P < .01). No significant group effect by side interaction was detected for any measure. The minimal detectable change values needed to detect change in subjects with hand OA were C5-C6 joint (0.3-0.5 kg/cm2), carpometacarpal joint (0.3-0.5 kg/cm2), hamate bone (0.2-0.4 kg/cm2), radial nerve (0.2-0.8 kg/cm2), median nerve (0.3-0.6 kg/cm2), and ulnar nerve (0.2-0.4 kg/cm2) for PPT. Test-retest reliability was calculated for both hands of participants with OA (ICC, 0.98-0.99) and healthy participants (ICC, 0.74-0.99). DiscussionAlthough pressure algometry and manual digital palpation are techniques already used in previous studies and have been shown to be reproducible and moderately reliable for joint palpation, this current study suggests that pressure algometry and manual digital palpation could also be reliable methods of determining nerve sensitivity of the radial, ulnar and median nerves in subjects with hand OA. ConclusionsHyperalgesia in patients with hand OA might be associated with clinical measures, and bilateral signs in unilateral OA could suggest central changes.

A Study on the Hamate Bone Learning Effect Using DICOM Images and 3D Printing

Background/Objectives: This study compared the characteristics and the anatomical learning effects of a hamate bone model printed from DICOM images on a 3D printer.Method/Statistical Analysis: After printing a hamate bone model from DICOM images obtained from a wrist joint examination using a 3D printer, this study examined the anatomical understanding of 102 university students in public health departments.Findings: The intuitive awareness and the morphological awareness of the students on the protrusion, front and back of the hamate bone, and 5-way joint contact surfaces which were difficult to identify in conventional 2D and 3D medical images were improved by 60.7% and 58%, respectively.Improvements/Applications: The experiment showed that instrumenting of shape through 3D printing as a knowledge transfer method for students learning anatomy can improve the learning effect.

Optimal parameters and location for diffusion tensor imaging in the diagnosis of carpal tunnel syndrome: a meta-analysis

To assess the diagnostic value of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of diffusion tensor imaging (DTI) at several anatomical locations in patients with carpal tunnel syndrome (CTS) to explore the optimal parameters and measurement location. A search was conducted using the PubMed, EBSCO, Ovid, Web of Science, and Cochrane databases to identify articles relevant to this study published before September 2017. Studies were selected and included according to strict eligibility criteria. Mean differences (MD) and 95% confidence intervals (CIs) were used to compare FA and ADC values between CTS patients and healthy subjects. Potential publication bias was investigated. Eleven studies involving 349 CTS wrists and 278 controls were selected for the meta-analysis. A notable MD: was found for lowered FA at the level of the pisiform bone for CTS versus controls (MD: -0.11, 95% confidence interval [CI]: -1.14 to -0.07, z=5.83, p<0.001). A higher ADC was found at the pisiform bone and hamate bone levels for CTS versus controls (P: MD: 0.15, 95% CI: 0.10 to 0.20, z=5.98, p<0.001, H: MD: 0.15; 95% CI: 0.09 to 0.21, z=4.67, p<0.001). The meta-analysis demonstrated a significant FA reduction and ADC increase in CTS patients. This result supports the use of DTI parameters in differentiating CTS patients from health subjects. The anatomical site for FA at the pisiform and ADC at the pisiform and hamate levels were more accessible than other sites for the diagnosis of CTS patients.

Variations in Hook of Hamate Morphology: A Cadaveric Analysis

The hook of the hamate is an anatomical structure that separates the ulnar border of the carpal tunnel from Guyon's canal and serves as a landmark for surgeons. The hook of the hamate is also subject to fracture from injury. We hypothesize that there are variations in the hook of the hamate in the general population. One thousand pairs of hamates (2,000 hamates) from the Hamann-Todd Collection at the Cleveland Natural History Museum were analyzed. The height of the hook of the hamate and the total height of the hamate bone were measured using digital calipers. The hook height ratio was defined as the hook height divided by the total height of the hamate. Statistical analysis was performed using unpaired Student's t test to determine differences in sex and race. The mean hook height was 9.8 ± 1.4 mm (range, 2.5-15.9 mm), whereas the mean hook height ratio was 0.42 ± 0.04 (range, 0.15-0.56). There was a 3.1% (62/2,000) incidence of abnormally small hooks, which we classified as hypoplastic and aplastic. Of the hypoplastic hooks, 55% (24/44) were bilateral, whereas 44% (8/18) of the aplastic hooks were bilateral. The incidence of variation in size in the hook of the hamate was highest in white females (9.3%) and lowest in black males (1.4%). Abnormalities in hook of hamate anatomy are common in the general population, especially in white females. Knowledge of anatomic variation in the hook of the hamate may provide additional insight into surgeons' palpation of bony anatomy, interpretation of imaging studies, and use of the hook as a landmark during surgery.

Effectiveness analysis of maintaining the stability between the fourth and the fifth metacarple base during the treatment in the hamate-metacarpal joint injury

To explore the effectiveness of maintaining the stability between the fourth and the fifth metacarple base during the treatment in the hamate-metacarpal joint injury. Between September 2015 and June 2017, 13 cases of hamate-metacarpal joint injury were treated, including 12 males and 1 female, aged from 17 to 55 years (mean, 30.8 years). The injury causes included heavy boxing in 10 cases and falling in 3 cases. There were 2 cases of simple fourth metacarpal basal fracture, 1 basal fracture of the fourth metacarpal bone combined with intermetacarpal ligament fracture, 7 fractures of the fourth and fifth metacarpal base, 2 fourth metacarpal basal fractures combined with the fifth metacarpal basal fracture dislocation, and 1 base fracture of fourth and fifth metacarpal bone combined with hamate bone fracture. The time from injury to operation was 5-11 days (mean, 7.2 days). According to different damage degree and stability change between the fourth and the fifth metacarple base, a preliminary classification was made for different degrees of injury: 2 cases of type Ⅰ, 1 case of type Ⅱ, 7 cases of type Ⅲ, 2 cases of type Ⅳ, and 1 case of type Ⅴ. The patients were treated with corresponding internal fixation methods under the principle of stability recovery between the fourth and fifth metacarple base. All the incisions healed by first intention without infection or skin necrosis. All the 13 patients were followed up 6-18 months with an average of 9.4 months. All fractures healed clinically, and the healing time was 5.5-8.0 weeks with an average of 6.3 weeks. No complication such as plate breakage, fracture dislocation, fracture malunion, and bone nonunion occurred. Hand function was evaluated according to the total active motion (TAM) functional evaluation standard of hand surgery at 6 months after operation, and the results was excellent in 9 cases, good in 3 cases, and fair in 1 case, with an excellent and good rate of 92.3%. Stability between the fourth and fifth metacarple base is of great significance to the classification and the treatment of the hamate-metacarpal joint injury.

Diffusion tensor imaging findings of the median nerve before and after carpal tunnel corticosteroid injection in patients with carpal tunnel syndrome: a preliminary study.

Corticosteroid injections are a popular technique for carpal tunnel syndrome (CTS) treatment and are believed to provide rapid symptom relief. To use magnetic resonance diffusion tensor imaging (MR-DTI) to determine the association between diffusion values of the median nerve (MN) at several anatomic locations and symptom relief in patients with CTS following corticosteroid injection. MR-DTI was performed on 15 wrists of 12 patients with CTS before and two weeks after ultrasound-guided corticosteroid injections. We recorded the patients' clinical data including sex, age, side of injection, satisfaction, and symptom relief. Satisfaction and symptom relief were rated using a Likert scale and the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scale. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the MN at the levels of the distal radioulnar joint (DRUJ), pisiform bone, and hamate bone were determined. All patients had ≥50% satisfaction on the injection side. In comparison with baseline values, post-injection ADC was significantly lower ( P = 0.001) but FA was not significantly higher ( P = 0.11) at the pisiform bone level on the injected wrists. At the DRUJ and hamate bone levels, no obvious inter-scan change in FA and ADC ( P > 0.05) was observed. The decrease in ADC at the pisiform bone level strongly correlated with the decrease in BCTQ scores (r = 0.628; P = 0.012). Symptom relief in patients with CTS receiving corticosteroid injection is related to the change in ADC of the median nerve at the level of the pisiform bone, as determined using MR-DTI.

Carpal tunnel syndrome treatment: The effect of scaphoid and hamate mobilization

The aim of this study was to assess the effects of scaphoid and hamate bones mobilization on patients with carpal tunnel syndrome. In this randomized clinical trial, 40 patients with mild and moderate carpal tunnel syndrome were randomly assigned in two groups. Intervention group received splinting with hamate and scaphoid mobilization, control group received splinting only. Outcome variables included pain (based on visual analogue scale), symptom severity and functional status (based on Boston questionnaire) and nerve conduction study measured before and 10 weeks after the treatments. At the end of study, both groups showed an improvement in pain and symptom severity, functional status as well as median nerve conduction study. Although there was no statistically significant difference between the groups regarding changes in median nerve sensory and motor distal latencies; the improvement was significantly higher in pain ( P < 0.05) and symptom severity as well as functional status in mobilization group ( P < 0.05). Hamate and scaphoid mobilization can be used as an effective option in women with mild and moderate carpal tunnel syndrome. Further investigation is required for determining long-term effects and cost-effectiveness of this modality.

Fracture of the Body's Hamate Bone: Open Reduction Internal Fixation by Double Approach—A Case Report

AbstractHamate fractures are rare. Their treatment depends on the displacement and type of fracture. We present the case and surgical technique of a 33-year-old male patient, who is a manual worker, with a displaced fracture of the body of the hamate bone associated with dislocation of the fourth and fifth metacarpal (MC) bones. The patient was operated on with a double palmar and dorsal approach directly over the hamate and the body hook, respectively, which was performed to improve the control reduction and avoid damaging the neighboring vascular and nerve structures. The open reduction internal fixation (ORIF) was performed by inserting mini-screws in a dorsal to palmar direction. Later, the dislocations were reduced and fixed with Kirschner wires between the fourth and fifth MC bases, and between the fourth MC base and the capitate bone. The patient was discharged 2.5 months after the fracture. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire outcome measure was 5 points at 6 months postsurgery.

F133. Safe-zone data of the deep branch of the ulnar nerve

Introduction Deep branch of the ulnar nerve (DBUN) study using ultrasound has just begun with the development of high-resolution ultrasound (HRUS) technology. In this study, we would like to present the safe-zone data that can be used to accurately locate the DBUN using HRUS. So it could be used as reference for various procedures such as acupuncture and botox injection. Methods We performed HRUS with high-frequency probes (5–12 MHz). In both hands of 10 healthy volunteers (n = 20), the cross-sectional area (CSA) was measured at medial side of the hook of the hamate bone. Depth from the skin and distance from the tip of the hook of the hamate were also measured. Same data were measured from 1 patient who was diagnosed as DBUN neuropathy which was confirmed by electromyography study. Results DBUN was clearly observed in the medial wall of the hook of the hamate bone in all subjects. The mean CSA value of healthy volunteers was 1.4 ± 0.2 mm 2 , the depth from the skin was 7.4 ± 1.1 mm, and the distance from the tip of the hook of the hamate bone was 6.0 ± 0.8 mm. The depth from the skin of DBUN neuropathy patient was 9.6 mm and the distance from the hook of the hamate was 7.1 mm, which was not significantly different from healthy volunteers, but CSA was significantly increased to 2.9 mm 2 . Conclusion This study provides data that can predict the location of the DBUN, which will help avoid complications when performing various injection procedures on the hand. In addition, HRUS could be helpful for diagnosis of DBUN neuropathy.

Finite element analysis for transverse carpal ligament tensile strain and carpal arch area

Mechanics of carpal tunnel soft tissue, such as fat, muscle and transverse carpal ligament (TCL), around the median nerve may render the median nerve vulnerable to compression neuropathy. The purpose of this study was to understand the roles of carpal tunnel soft tissue mechanical properties and intratunnel pressure on the TCL tensile strain and carpal arch area (CAA) using finite element analysis (FEA). Manual segmentation of the thenar muscles, skin, fat, TCL, hamate bone, and trapezium bone in the transverse plane at distal carpal tunnel were obtained from B-mode ultrasound images of one cadaveric hand. Sensitivity analyses were conducted to examine the dependence of TCL tensile strain and CAA on TCL elastic modulus (0.125–10 MPa volar-dorsally; 1.375–110 MPa transversely), skin-fat and thenar muscle initial shear modulus (1.6–160 kPa for skin-fat; 0.425–42.5 kPa for muscle), and intratunnel pressure (60–480 mmHg). Predictions of TCL tensile strain under different intratunnel pressures were validated with the experimental data obtained on the same cadaveric hand. Results showed that skin, fat and muscles had little effect on the TCL tensile strain and CAA changes. However, TCL tensile strain and CAA increased with decreased elastic modulus of TCL and increased intratunnel pressure. The TCL tensile strain and CAA increased linearly with increased pressure while increased exponentially with decreased elastic modulus of TCL. Softening the TCL by decreasing the elastic modulus may be an alternative clinical approach to carpal tunnel expansion to accommodate elevated intratunnel pressure and alleviate median nerve compression neuropathy.

Ultrasound-guided needle release of the transverse carpal ligament with and without corticosteroid injection for the treatment of carpal tunnel syndrome

BackgroundTo compare the clinical effectiveness of ultrasound-guided needle release of the transverse carpal ligament (TCL) with and without corticosteroid injection in carpal tunnel syndrome (CTS).MethodsFrom June 2016 to June 2017, 49 CTS patients (50 wrists) were included in this study. Twenty-five wrists were treated with ultrasound-guided needle release of the TCL plus corticosteroid injection (group A), and 25 wrists were treated with single ultrasound-guided needle release of the TCL (group B). The following parameters were assessed and compared including postprocedure results according to relief of symptoms, ultrasound parameters (cross-sectional area of the median nerve at the levels of pisiform, flattening ratio of median nerve at the levels of the hamate bone, and the thicknesses of TCL on the cross-section at the level of the hamate bone), and electrophysiological parameters (distal motor latency and sensory conduction velocity).ResultsGroup A had higher overall excellent and good rate 3 months after the procedure than group B (84 vs 52%, P < 0.05). There were significant differences regarding the above ultrasonic and electrophysiological parameters between the baseline and postprocedure values in both groups (all P < 0.05). There were significant differences regarding the postprocedure values of above ultrasonic and electrophysiological parameters between the two groups (all P < 0.05). No complications such as infection or tendon rupture were noted. No procedures were converted to the open release.ConclusionsBoth techniques are effective in treating CTS. Ultrasound-guided needle release of the TCL with corticosteroid injection had better treatment benefits than single ultrasound-guided needle release of the TCL in treating CTS.

Role of Diffusion Tensor Imaging of the Median Nerve in Carpal Tunnel Syndrome: A Case Control Comparative Study with Electrophysiological Tests and Clinical Assessment

AbstractBackground: Carpal Tunnel Syndrome (CTS) is the most common peripheral neuropathy of an upper extremity. The diagnosis of CTS is commonly based on findings from the medical history, physical examination, and provocative tests. To confirm the diagnosis, some clinician accepts Electrophys-iological Studies (EPS) as the reference standard. Diffusion-Tensor Imaging (DTI) is a subtype of diffusion-weighted imaging based on measurement of molecular diffusion along multiple directions in space. Directional anisotropy of water diffusibility can be quantified by imaging indices such as Apparent Diffusion Coefficient (ADC) and Fractional Anisot-ropy (FA) used to characterize the degree of diffusion anisot-ropy.Aim of Work: The aim of this study is to study the efficacy of diffusion tensor imaging in the diagnosis of carpal tunnel syndrome.Material and Methods: Twenty-three wrists of 15 healthy subjects and 47 wrists of 31 CTS patients were evaluated with DTI and EPS. FA and ADC of the median nerve were calculated at four locations: Distal radioulnar joint, pisiform bone, hamate bone and hamate hook, and also determined from the whole median nerve. Electrophysiological test, including nerve conduction velocity was also performed for comparison with clinical assessment as a standard of reference.Results: There was a significant difference between healthy individuals and patients with carpal tunnel syndrome (p<0.01 for both FA and ADC). FA value less than 0.54 and ADC value more than 1.19 X 1 0–3mm2/sec might be used in the diagnosis of carpal tunnel syndrome. As regards the DTI results, the sensitivity, specificity, negative predictive value, positive predictive value and accuracy were 97.8%, 95.6%, 95.6%, 97.8% and 97.1% respectively.Conclusion: DTI scan contribute to carpal tunnel syndrome diagnosis on the basis of FA and ADC measurements.

Results of the reconstruction of the middle phalangeal base of the finger through an osteochondral autograft from the hamate bone

The fractured base of the middle phalanx was reconstructed in 13 patients using an osteochondral transplant from the carpometacarpal joint surface of the hamate bone. The goal was to restore joint stability with preservation of mobility. Indications were acute and missed isolated destruction of the palmar middle phalanx base ≥ 30 %. Contraindications were destruction of the head of the proximal phalanx, advanced chondropathy of the head of the proximal phalanx, and extensive soft tissue injury with loss of skin coverage for the proximal interphalangeal joint. In this procedure the fractured middle phalangeal base was debrided and the defect replaced by a size-matched autograft from the dorsal carpometacarpal osteoarticular surface of the hamate bone, which was secured in place with miniscrews. Bone fusion was achieved in 100 % with restoration of joint congruity in 12 of 13 cases and a slight subluxation in one case. Follow-up was possible in 9 cases after 23 (5-51) months. The average range of motion in the reconstructed joint for extension/flexion was 0/9/73°; grip strength was 82 % of the unaffected side. Five out of 9 patients developed a mild flexion contracture in the PIP joint. The DASH score was 6 (0-33) points, pain at rest was 1 (0-5), and pain at exercise 2 (0-6) on a visual analogue scale from 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 an osteochondral graft from the hamate bone is a reliable procedure to restore stability and mobility of the joint.