Avascular Necrosis of the Metacarpal Head: A Review of 4 Cases.

PURPOSE: To report on 4 cases of avascular necrosis of the metacarpal head. METHODS: We retrospectively reviewed 4 patients who received a diagnosis of avascular necrosis of the metacarpal head and were treated from 2000 to 2016. RESULTS: All patients were males with involvement of the dominant hand. Three patients had a history of trauma and/or fractures in another finger and one had a history of fracture in the same finger. The diagnosis was confirmed on regular x-rays and magnetic resonance imaging. Nonsurgical management was offered to all patients (rest, placement of an orthosis, and nonsteroidal anti-inflammatory drugs) for 3 to 6 months. Two patients responded well to nonsurgical management and improved in their symptoms. One patient refused surgical intervention and continued to have persistent pain. The other patient was treated with curettage and bone graft and had total resolution of pain symptoms with full active range of motion. CONCLUSIONS: A high index of suspicion is required to diagnose and treat avascular necrosis of the metacarpal head correctly. Treatment options are numerous and require further studies to investigate their effectiveness in the treatment of this rare disease. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Open reduction and internal fixation for intraarticular fracture of metacarpal head.

Intraarticular fracture of the metacarpophalangeal (MP) joint presents complex problems related to the sophisticated functional aspects of the hand. Injury to the metacarpal head may have a severe effect on hand function but few studies have investigated the management of this condition. In this study, we applied open reduction and internal fixation for the displaced fracture of the metacarpal head and report the clinical and radiographic outcomes of our experience. Thirteen patients (12 men, 1 woman; mean age 21 years) were included in this study, and medical records and radiographs were reviewed retrospectively. The average follow-up period was 12.5 months. Range of motion (ROM) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were analyzed, and functional results and serial radiographs were investigated for the maintenance of articular congruity and fracture union. The injured fingers were 5 long, 4 small, 2 ring, and 2 index. Five cases were fixed with K­wires, 5 cases with headless screws, and 3 cases with screw and K­wire. The average range of injured MP joint motion was 89°, total active range of motion (TAM) was 265°, and the average DASH score was 3.8 at the last follow-up. All patients showed fracture union on the radiographs and no patient showed significant articular surface incongruence or degenerative change. Open reduction and internal fixation of the metacarpal head fracture had favorable outcomes in our study. The authors suggest accurate reduction and stable fixation for better functional results in metacarpal head fractures.

CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING, MAGNETIC RESONANCE ARTHROGRAPHY, AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT.

Osteoarthritis of the metacarpophalangeal joint is common cause of lameness in equine athletes, and is hallmarked by articular cartilage damage. An accurate, noninvasive method for measuring cartilage thickness would be beneficial to screen for cartilage injury and allow for prompt initiation of interventional therapy. The objective of this methods comparison study was to compare computed tomographic arthrography (CTA), magnetic resonance imaging (MRI), and magnetic resonance arthrography (MRA) measurements of articular cartilage thickness with gross measurements in the metacarpophalangeal joint of Thoroughbred horses. Fourteen cadaveric, equine thoracic limbs were included. Limbs were excluded from the study if pathology of the metacarpophalangeal articular cartilage was observed with any imaging modality. Articular cartilage thickness was measured in nine regions of the third metacarpal bone and proximal phalanx on sagittal plane MRI sequences. After intra-articular contrast administration, the measurements were repeated on sagittal plane MRA and sagittal CTA reformations. In an effort to increase cartilage conspicuity, the volume of intra-articular contrast was increased from 14.5 ml, to maximal distention for the second set of seven limbs. Mean and standard deviation values were calculated, and linear regression analysis was used to determine correlations between gross and imaging measurements of cartilage thickness. This study failed to identify one imaging test that consistently yielded measurements correlating with gross cartilage thickness. Even with the use of intra-articular contrast, cartilage surfaces were difficult to differentiate in regions where the cartilage surfaces of the proximal phalanx and third metacarpal bone were in close contact with each other.

Ultrasonographic findings in 38 horses with septic arthritis/tenosynovitis.

Septic arthritis/tenosynovitis in the horse can have life-threatening consequences. The purpose of this cross-sectional retrospective study was to describe ultrasound characteristics of septic arthritis/tenosynovitis in a group of horses. Diagnosis of septic arthritis/tenosynovitis was based on historical and clinical findings as well as the results of the synovial fluid analysis and/or positive synovial culture. Ultrasonographic findings recorded were degree of joint/sheath effusion, degree of synovial membrane thickening, echogenicity of the synovial fluid, and presence of hyperechogenic spots and fibrinous loculations. Ultrasonographic findings were tested for dependence on the cause of sepsis, time between admission and beginning of clinical signs, and the white blood cell counts in the synovial fluid. Thirty-eight horses with confirmed septic arthritis/tenosynovitis of 43 joints/sheaths were included. Degree of effusion was marked in 81.4% of cases, mild in 16.3%, and absent in 2.3%. Synovial thickening was mild in 30.9% of cases and moderate/severe in 69.1%. Synovial fluid was anechogenic in 45.2% of cases and echogenic in 54.8%. Hyperechogenic spots were identified in 32.5% of structures and fibrinous loculations in 64.3%. Relationships between the degree of synovial effusion, degree of the synovial thickening, presence of fibrinous loculations, and the time between admission and beginning of clinical signs were identified, as well as between the presence of fibrinous loculations and the cause of sepsis (P ≤ 0.05). Findings indicated that ultrasonographic findings of septic arthritis/tenosynovitis may vary in horses, and may be influenced by time between admission and beginning of clinical signs.

Interobserver variability in the treatment of little finger metacarpal neck fractures.

PURPOSE: To address the null hypothesis that surgeons shown radiographs of little finger metacarpal neck fractures with measured fracture angulation would recommend surgery as often as surgeons shown unmarked radiographs. METHODS: Members of the Science of Variation Group, an international collaboration of fully trained orthopedic and trauma surgeons, were asked to review 20 little finger metacarpal neck fracture cases, which included a vignette and 3 high-quality radiographs. Members were then randomized to review radiographs with or without measured fracture angulation on the lateral view and select operative or nonoperative management. RESULTS: Surgeons shown radiographs with measured angulation were more likely to recommend surgery, and there was less variability among these surgeons, particularly for fractures with less angular deformity. CONCLUSIONS: Measured fracture angulation has a small but significant influence on treatment recommendations for little finger metacarpal neck fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Elastographic characteristics of the metacarpal tendons in horses without clinical evidence of tendon injury.

Tendon and ligament injuries are common causes of impaired performance in equine athletes. Gray-scale ultrasonography is the current standard method for diagnosing and monitoring these injuries, however this modality only provides morphologic information. Elastography is an ultrasound technique that allows detection and measurement of tissue strain, and may provide valuable mechanical information about equine tendon and ligament injuries. The purpose of this study was to determine the feasibility, reproducibility, and repeatability of elastography; and to describe elastographic characteristics of metacarpal tendons in sound horses. Nineteen legs for 17 clinically sound horses without evidence of musculoskeletal pathology were included. Elastographic images of the superficial and deep digital flexor tendons and the branches of the suspensory ligament (tendon of the interosseous muscle) were described quantitatively and qualitatively. There was no statistically significant difference between operators (P = 0.86) nor within operators (P = 0.93). For qualitative assessments, reproducibility (0.46) was moderate and repeatability (0.78) was good. Similar to human Achilles tendons, equine tendons were classified as predominantly hard using elastography. There was no statistically significant difference in stiffness of the flexor tendons (P = 0.96). No significant difference in stiffness was found with altered leg position during standing (P = 0.84) and while nonweight bearing (P = 0.61). The flexor tendons were softer when imaged in longitudinal versus transverse planes (P < 0.01) however, the suspensory branches were not (P = 0.67). Findings supported future clinical application of elastography as a noninvasive "stall-side" imaging modality for evaluation of the tendons and ligaments of the distal forelimb in horses.

Singleton-Merten syndrome: an autosomal dominant disorder with variable expression.

In 1973, Singleton and Merten described two females with abnormal dentition, unique radiographic changes especially of the hands, and severe calcification and intimal weakening of the aortic arch and valve. Since then three additional cases with similar features have been reported and the diagnosis was suggested in another three individuals. We present an update of one case and the detailed clinical phenotype of six other cases with Singleton-Merten syndrome. The occurrence of the disorder in six members of two families and vertical male-to-male transmission indicate an autosomal dominant pattern of inheritance. Variability in phenotype, also within a single family, is significant. Core manifestations are marked aortic calcification, dental anomalies (delayed eruption and immature root formation of primarily the anterior permanent teeth, and early loss of permanent teeth due to short roots, acute root resorption, high caries, and aggressive alveolar bone loss), osteopenia and acro-osteolysis, and to a lesser extend also glaucoma, psoriasis, muscle weakness, and joint laxity. Additional clinical characteristics described here include particular facial characteristics (high anterior hairline, broad forehead, smooth philtrum, thin upper vermillion) and abnormal joint and muscle ligaments. The cause and pathogenesis of this syndrome remain unknown. © 2013 Wiley Periodicals, Inc.

Conservative management of Dieterich disease: case report.

Dieterich disease is characterized by avascular necrosis of the metacarpal head. The recent literature has described surgical management of this condition relatively soon after its presentation. We present a case treated conservatively with a satisfactory outcome at 28 months.

Osteochondral mosaicplasty as a treatment method for bilateral avascular necrosis of the long finger metacarpal: case report.

Avascular necrosis of the metacarpal head is a rare condition known to occur in conjunction with repetitive trauma, systemic lupus erythematosus, and the use of steroids. This clinical case reports a 31-year-old man with bilateral long finger metacarpal head avascular necrosis, treated with osteochondral mosaicplasty.

Correction of a severe torsional malunion of the metacarpus in a calf by transverse osteotomy, transfixation pinning and casting.

A four-month-old Holstein heifer was presented for evaluation of an angular limb deviation. Upon initial presentation, the heifer was not clinically lame. An external rotation of 90 degrees of the fetlock was observed in the left forelimb. Radiographs identified a healing closed spiral fracture of the third and fourth metacarpal bones, with a 90 degrees external torsion. A mid-metacarpal bone transverse osteotomy was performed after insertion of transcortical pins in the distal and proximal part of the third and fourth metacarpal bones and in the distal radius. The reduction was performed in order to align both fetlock and carpal joints and a fiberglass cast was applied to complete the external fixation. A satisfactory outcome was associated with the treatment.

Osteochondroses of the bilateral metacarpal heads: Dieterich disease. A case report with review of the literature.

Osteochondroses is a well-known entity and typically affecting immature skeleton with few common locations involved are femoral head epiphysis, tibial tubercle apophysis, calcaneal apophysis, humeral capitellum and anterior vertebral end plates. We report a rare case of osteochondroses showing avascular necrosis involving metacarpal heads known as Dieterich disease, involving the head of the third metacarpal and probably the first case with a history of rock climbing as an etiology. Chronic repetitive microtrauma plays a significant role in the disease, as is seen in our patient. Imaging plays a crucial role in diagnosing, as well as monitoring progress, with MRI being a critical modality. The fact that this entity is rare does not necessarily make it difficult to detect. It may be clinical underdiagnosed due to lack of familiarity with this entity and radiographic findings may be subtle or inapparent. Bone scan is likely sensitive but not specific. MRI also likely has a role for early detection. This article is written with educational intent for the reader for the benefit of the patients with this rare disease.

Use of computed tomography to diagnose new bone formation associated with desmitis of the proximal aspect of the suspensory ligament in third metacarpal or third metatarsal bones of three horses.

CASE DESCRIPTION: 3 horses with lameness localized to the proximal aspect of the metacarpus or metatarsus. CLINICAL FINDINGS: All horses had evidence of problems that originated from the proximal aspect of the suspensory ligament (PASL), including signs of pain on palpation, positive results of diagnostic nerve blocks, ultrasonographic detection of enlargement and diffuse areas of reduced echogenicity in the proximal region of insertion of the ligament, and radiographic detection of increased mineral opacity in the proximal aspect of the metacarpus or metatarsus. Desmitis of the PASL was diagnosed in each horse; however, conservative treatment failed to improve the lameness. The horses were taken to surgery for splitting of the PASL and osteostixis of the proximal aspect of the third metacarpal or metatarsal bone. At that time, the proximal aspect of the metacarpus or metatarsus was evaluated via computed tomography (CT), which identified new bone formation at the proximal aspect of the third metacarpal or metatarsal bone that had not already been identified. TREATMENT AND OUTCOME: In all horses, the newly formed bone was removed surgically under radiographic and CT guidance, and the splitting and osteostixis that had been planned were performed. After rehabilitation, all horses returned to full training at 6 months after surgery. All horses responded well to the surgical treatment and were sound 8 months afterward. CLINICAL RELEVANCE: Use of CT imaging should be considered in lame horses with pain associated with the proximal aspect of the third metacarpal or metatarsal bones that does not improve with conservative treatment.

Multislice computed tomography angiography of the fourth dorsal interosseous space in cadavers.

PURPOSE: To study computed tomography angiography (CTA) findings and compare anatomic correlation of the 4th dorsal metacarpal spaces and to determine the role of this technique for anatomic studies and flap design. METHODS: Hands from 17 cadavers were injected with a radiopaque mixture. The specimens were imaged using 16-detector-row computed tomography. Each image was analyzed by a radiologist, a plastic surgeon, and an anatomist. The following data were recorded: the presence of the 4th dorsal metacarpal artery, proximal and distal communicating branches and distal recurrent branch, and the number of cutaneous perforators. Afterwards, a meticulous dissection was carried out. A correlation between the radiologic findings and the gross anatomy was established. RESULTS: In all specimens, the 4th dorsal metacarpal artery and distal recurrent branch were identified. In 15 cases, at least 1 perforator was identified within the 4th space. In 2 cases, no perforator was identified. In all cases, the radiologic findings correlated with the anatomic findings in the dissection. CONCLUSIONS: Multislice CTA provides good-quality information about the vascular anatomy of the dorsal aspect of the hand, including perforator vessels less than 0.5 mm in diameter. Multislice CTA allows for observation of the axis, trajectory, and branching pattern of the blood vessels and, most importantly, demonstrates the anatomic relationships among blood vessels, bones, and soft tissue.

Idiopathic osteonecrosis of the third metacarpal head.

Osteonecrosis of the metacarpal head is a rare disease entity and there are only a few isolated case reports in the literature. No single modality of treatment can be recommended as ideal. In this report, we describe a patient who presented with changes resembling avascular necrosis at the third metacarpal head of the right hand. It presented as a 2-week history of sudden onset of pain in the region of the right third metacarpophalangeal joint with limitation of flexion. We treated the 51-year-old male patient by curettage, debridement and multiple drilling. At 1-year follow-up, the patient was symptom-free and showed improved range of motion of the metacarpophalangeal joint (0 to 80 degrees). He returned to his original work 2 weeks after the operation without limitation of daily activities. This report presents a new operative treatment that improved the functional outcome of osteonecrosis of the metacarpal head.

Magnetic resonance imaging findings of the proximal metacarpus in Quarter Horses used for cutting: Retrospective analysis of 32 horses 2009-2012.

BACKGROUND: Injury to the proximal suspensory ligament is a common cause of lameness in cutting horses. Radiographic and ultrasonographic imaging of lesions responsible for lameness can provide ambiguous results. MRI provides the most comprehensive diagnostic imaging evaluation of lesions specifically affecting cutting horses. OBJECTIVES: To describe the distribution and severity of bone and soft tissue lesions present in the proximal metacarpus of Quarter Horse cutting horses and to assess the impact of these lesions on return to competition. STUDY DESIGN: Retrospective case series. METHODS: Retrospective analysis of 32 cutting horses referred for MRI of the proximal metacarpus between 2009 and 2012 with a 2-year follow-up period. MRI studies were evaluated by a board-certified veterinary radiologist; the severity of lesions was graded from 0 (absent) to 3 (severe). RESULTS: A total of 20 right and 24 left forelimbs (12 bilateral studies) of 32 horses were evaluated. The most common findings were: third metacarpal (McIII) sclerosis at the proximal suspensory ligament (PSL) origin (42/44), McIII resorption at the PSL origin (32/44), PSL dorsal margin fibre irregularity (30/44) and McIII bone contusion (22/39). Of the 30 horses, 22 horses successfully returned to competition, irrespective of severity of injury. Strong correlation exists between the degree of resorption in the palmar cortex of proximal McIII, degree of McIII sclerosis and severity of dorsal margin fibre irregularity. MAIN LIMITATIONS: Statistical significance was limited by small study population. Further analysis of prognosis was limited by availability of comprehensive medical records. CONCLUSIONS: Cutting horses with proximal metacarpal pain have significant pathological change within the proximal suspensory ligament and its enthesis on the palmar cortex of McIII. Severity of lesions and degree of lameness at the time of diagnosis does not influence return to performance. Accurate diagnosis of proximal metacarpal lesions based on MRI offers clinicians the capacity to select treatment protocols targeted to each disease process.

Pyrolytic Carbon Hemiarthroplasty for Avascular Necrosis of the Metacarpal Head: A Case Report.

Avascular necrosis of the metacarpal head is a rare entity. Surgical interventions, such as curettage, bone-grafting, and osteotomy, have been reported in symptomatic patients. We present a patient who underwent pyrolytic carbon hemiarthroplasty of the metacarpal head and had satisfactory outcomes at 1-year follow-up.

Subchondral bone microdamage accumulation in distal metacarpus of Thoroughbred racehorses.

BACKGROUND: Microdamage accumulation leads to subchondral bone injury and/or fracture in racehorses. An understanding of this process is essential for developing strategies for injury prevention. OBJECTIVES: To quantify subchondral bone microdamage in the third metacarpal bone of Thoroughbred racehorses at different stages of the training cycle. STUDY DESIGN: Cross-sectional. METHODS: Bone blocks from the palmar aspect of the medial condyles of third metacarpal bones from 46 racing Thoroughbred horses undergoing post-mortem were examined with micro computed tomography (microCT) to detect calcified microcracks, and light microscopy to quantify bulk stained microcracks. Racing and training histories were obtained for comparison with microdamage data using regression modelling. RESULTS: Subchondral bone microcracks were observed in all bones with at least one method. Microdamage grade was greater in older horses, levelling-off for horses 5 years and older (quadratic term P = 0.01), and with lower bone material density in the parasagittal groove (P = 0.02). Microcrack density was higher in older horses (P = 0.004), and with higher bone volume fraction (BV/TV) in the parasagittal groove in horses in training (interaction effect, P = 0.01) and lower in horses resting from training (P = 0.02). MAIN LIMITATIONS: Cross-sectional data only. Incomplete detection of microdamage due to the limits of resolution of microCT and lack of three-dimensional imaging with microscopy. Multicollinearity between variables that indicated career progression (e.g. age, number of career starts, duration of training period) was detected. CONCLUSIONS: Fatigue damage in the distal metacarpal subchondral bone is common in Thoroughbred racehorses undergoing post-mortem and appears to accumulate throughout a racing career. Reduced intensity or duration of training and racing and/or increased duration of rest periods may limit microdamage accumulation. Focal subchondral bone sclerosis indicates the presence of microdamage.

Unusual long bone and metacarpo-carpal abnormalities in a case of pseudo-pseudohypoparathyroidism.

A case of pseudo-pseudohypoparathyroidism (PPH) with shortening of the left femur and tibia and coalition of the base of the fourth metacarpals with capitatum and hamatum in bilateral wrist joints was presented. Involvement of the fourth digits both in hands and feet were more prominent on the left side, with shortening of the left leg.

Preliminary study on the effect of parenteral naloxone, alone and in association with calcium gluconate, on bone healing in an ovine "drill hole" model system.

BACKGROUND: Several diseases affect bone healing and physiology. Many drugs that are commonly used in orthopaedics as "analgesics" or anti-inflammatory agents impair bone healing. Stressful conditions are associated with decreased serum osteocalcin concentration. High endorphin levels alter calcium metabolism, blocking the membrane channels by which calcium normally enters cells. The consequent decrease of intracellular calcium impairs the activities of calcium-related enzymes. Naloxone is a pure opioid antagonist. Morphine-induced osteocalcin inhibition was abolished when osteoblasts were incubated with naloxone. Naloxone restored the altered cellular and tissue physiology by removing beta-endorphins from specific receptors. However, this is only possible if the circulating Ca concentration is adequate. The aim of the present study was to evaluate the efficacy of parenteral naloxone administration in inducing fast mineralization and callus remodelling in a group of sheep with a standardised bone lesion. METHODS: Twenty ewes were randomly assigned to 4 treatment groups. Group A acted as control, group B received a solution of calcium gluconate, group C a solution of naloxone, and group D a solution of calcium gluconate and naloxone. A transverse hole was drilled in the left metacarpus, including both cortices, then parenteral treatment was administered intramuscularly, daily for four weeks. Healing was evaluated by weekly radiographic examination for eight weeks. For quantitative evaluation, the ratio of the radiographic bone density between the drill area and the adjacent cortical bone was calculated. After eight weeks the sheep were slaughtered and a sample of bone was collected for histopathology RESULTS: Group D showed a higher radiographic ratio than the other groups. Sheep not treated with naloxone showed a persistently lower ratio in the lateral than the medial cortex (P < 0.01). Histopathology of bone samples showed more caverns and fewer osteoblasts in group D than in the other groups (P