Fracture of the radial sesamoid bone of the thumb: an unusual fracture

The hand consists of five sesamoids. Two of them are present at the metacarpophalangeal (MCP)joint of the thumb. Fracture of the sesamoid bones of the thumb is a rare injury and the literature on the radial side is seldom reported. We reported a case of a patient with a fracture of the radial sesamoid at the MCP joint of the thumb in order to increase attention regarding this type of injuries. A 44-year-old male, high level gymnastic trainer, was helping one of his athletes during an exercise while he reported a hyperextension trauma to the MCP joint of the right thumb.One week after trauma, he presented to the hand surgeon complaining of a painful thumb at the MCP joint level on its palmar aspect. Standard A-P and lateral X-rays revealed a fracture of the radial sesamoid and the fracture was treated with a splint for 3 weeks. He was able to resumed his entire work 6 weeks after the injury. The sesamoid fractures is an indicator of the magnitude of the hyperextension injury and sometimes associated with tears of the volar plate ligament of the MCP joint. And a failure to recognize the ligament injury may lead to a long-term hyperextension instability on pinching.     

Locked thumb metacarpophalangeal joint caused by sesamoid entrapment.

We report an unusual case of locked thumb in a 24-year-old man, caused by entrapment of the radial sesamoid in the metacarpophalangeal joint. Tomography clearly revealed sesamoid entrapment in the joint. Surgical exploration and cadaver dissection demonstrated that avulsion of the proximal portion of the palmar plate and some dissociation of the sesamoid from the palmar plate with intraarticular displacement were necessary for the sesamoid to be trapped in the joint.     

The sesamoid bones of the hand and their pathology

Three cases of sesamoid bone pathology are presented, including two cases of sesamoid fracture and a case of sesamoid periostitis. The literature is reviewed.Sesamoid bones probably function in the body as pulleys. Most people have five sesamoid bones in each hand. Two at the thumb metacarpophalangeal joint, one at the interphalangeal joint of the thumb, one at the metacarpophalangeal joint of the index finger on the radial side, and one at the metacarpophalangeal joint of the little finger on the ulnar side.Sesamoid bones have been seen with periostitis in Reiter's syndrome. The medial sesamoid bone of the thumb metacarpophalangeal is frequently enlarged in acromegaly. The sesamoid bones of the thumb have been fractured or trapped inside the joint during injury to the thumb metacarpophalangeal joint.The treatment of disabling rain in a sesamoid bone is enucleation of the bone.     

拇指籽骨翻转脱位致掌指关节绞锁的诊治

目的:探讨拇指籽骨翻转脱位致掌指关节绞锁的诊断和治疗.方法:对5例掌指关节绞锁患者(男4例,女1例;年龄18～47岁,平均35岁)行闭合手法复位,成功3例,另2例闭合复位失败后行手术切开复位.术中见拇指籽骨翻转脱位,与掌板、拇短屈肌腱一起卡入掌指关节间隙的掌侧,形成绞锁.籽骨复位后,绞锁即得到纠正.结果:5例均获得随访,时间3～34个月,平均15个月.治疗后所有患者局部疼痛症状消失,无红肿,手指感觉正常,掌指关节屈曲35°～60°,平均45°,不影响正常生活及正常工作,治疗后绞锁无复发.结论:拇指籽骨翻转脱位是导致掌指关节绞锁的重要原因之一.     

Distal avulsion of the palmar plate of the interphalangeal joint of the thumb

A 63-year-old woman was unable to actively flex the interphalangeal joint of her right thumb after a hyperextension injury. Surgical exploration revealed an avulsion of the distal insertion of the palmar plate, allowing the bulk of the plate to block the joint during attempted active flexion. Resection of the palmar plate restored active flexion and caused no joint instability. We do not believe this lesion, which resulted in this disability, has been previously described.     

Sesamoid arthritis mimicking trigger thumb

This article presents a case of undiagnosed sesamoid arthritis with coexisting trigger thumb. A 25-year-old woman presented with a 2-year history of metacarpophalangeal joint pain and triggering of the thumb. She was a right-handed bank employee and recalled a trivial thumb sprain. The pain improved slightly while on medication, but the triggering recurred 1 month after the steroid injection. Six months after the first visit, she underwent A1 pulley release surgery for the triggering without a more detailed evaluation such as radiographs or sonographs. Intraoperatively, no definite abnormalities in the fibrous flexor sheath or flexor tendon were observed. The triggering resolved, but the pain persisted. One month postoperatively, a repeat physical examination was performed, and the painful region was localized to the radial sesamoid area. Radiography was then performed, which showed joint space narrowing of the sesamoid metacarpal head and sclerotic changes and spur formation on the metacarpal head. An additional diagnosis of sesamoid arthritis of the thumb was made and the pain finally resolved as a result of the sesamoidectomy. Orthopedic surgeons often overlook pathologies around the metacarpophalangeal joint, especially those related to triggering. A high index of suspicion and clinical findings consistent with intermittent mechanical obstruction and tenderness in the palmar aspect of the metacarpophalangeal joint warrant inclusion of sesamoid arthritis as a differential diagnosis for metacarpophalangeal joint pathology. Detailed physical examinations should be performed and proper radiographs taken in all patients with tenderness in the metacarpophalangeal joint even if triggering of the thumb is present.     

Posttraumatic sesamoid arthritis of the metacarpophalangeal joint of the thumb

The articular interface between the radial sesamoid and the radial condyle of the metacarpal head, which is the radial subsesamoid joint, is the most frequently involved area of abnormality in the metacarpophalangeal joint complex. More than 85% of all adult cadavers demonstrate degenerative arthritis of the radial subsesamoid joint. Confusing this condition with degenerative arthritis of the metacarpophalangeal joint may lead to unnecessary joint fusions. The predisposition of the radial subsesamoid to degenerative arthritis is related to the asymmetry of the palmar condyles of the metacarpal. The ulnar sesamoid has a flatter and broader condyle compared with the radial sesamoid, which rides on a high, narrow ridge. Thirty-six patients with symptomatic sesamoiditis have been treated by sesamoidectomy since 1978. Twenty-one of these patients were available for follow-up examination between 1 and 5 years after surgery, and 19 had relief of proximal thumb pain after sesamoidectomy.     

Chronic finger joint instability reconstructed with bone-ligament-bone graft from the iliac crest

Five patients with chronic instability of digital joints presented with instability and functional disability. Two patients had ulnar collateral ligament damage of the thumb metacarpophalangeal joint and another had chronic multidirectional instability due to radial collateral ligament, dorsal capsule and palmar plate laxity of the metacarpophalangeal joint of the thumb. The fourth patient had a lax radial collateral ligament and palmar plate of the proximal interphalangeal joint of the little finger and the fifth had chronic laxity of the ulnar collateral ligament of the interphalangeal joint of the thumb. All were reconstructed with bone-ligament-bone graft harvested from the iliac crest. The graft was fixed with screws and joint stability was achieved intra-operatively in all patients. All patients achieved a stable joint with improved functional performance at final follow-up.     

Compression neuropathy of the radial palmar thumb nerve

Compression neuropathy of a single digital nerve is a rare entity. We report the case of a patient with numbness in the distribution of the radial digital nerve of the thumb caused by the use of a walking stick. The nerve was compressed between the handle of the stick, the loop and the radial sesamoid bone of the first metacarpophalangeal joint. The site of the lesion was confirmed by electrophysiologic examination. Orthodromic recording of the sensory response from the radial palmar digital nerve of the thumb documented a complete absence of nerve action potential whereas the ulnar digital thumb nerve showed a normal response. Sensory function was restored when a padded ski glove was used to protect the area of the metacarpophalangeal joint whilst using the stick.     

Complete dorsal dislocation of the metacarpophalangeal joint of the thumb

In the pathology of simple complete dislocation involving the metacarpophalangeal joint of the thumb, whether or not the palmar plate is interposed within the joint is controversial. Nine cases of complete dorsal dislocation of the joint were reviewed, and cadaver dissection was performed to study the pathology of this injury. Eight of the nine patients were seen within 4 days of injury and treated successfully by closed manipulation. One patient treated 7 days after the injury required open reduction. We were able to reproduce the pathological anatomy of the dislocation, wedging of the palmar plate in the joint of the cadaver. In this cadaver and in all clinical cases, radiographs showed a complete dislocation with an increased distance between the palmar edge of the base of the proximal phalanx and the metacarpal head, indicating an interposition of the palmar plate. Our study suggests that in simple complete dislocations of this joint, the palmar plate is interposed between the displaced bones. Received: 16 December 1997     

Tension wire fixation of avulsion fractures at the thumb metacarpophalangeal joint

Avulsion fractures of the thumb metacarpophalangeal joint require adequate treatment to prevent instability or articular incongruity. Open reduction and internal fixation may be difficult because of the small fracture fragment size. Nine patients underwent acute open reduction and tension wire fixation of displaced or rotated avulsion fractures. Follow-up examination was at approximately 26 months. All fractures healed in anatomic alignment without instability or articular incongruity. Pain, stiffness, and loss of pinch, were subjectively rated as none in six patients and mild in three. The injured thumb demonstrated firm stability in extension and 30° flexion in all patients. Metacarpophalangeal and interphalangeal motion averaged 77% and 97% of the opposite hand respectively. Planar and palmar abduction averaged 96%. Pinch strength in apposition averaged 97% and in opposition 99% of the uninvolved hand. Grip strength was 96% of the contralateral extremity.     

桡骨远端C型骨折掌侧锁定钢板与外固定架的疗效比较

目的比较掌侧锁定钢板与外固定架治疗桡骨远端C型骨折的疗效。方法采用随机对照法,纳入2014年10月到2017年10月收治的桡骨远端C型骨折患者,随机分为两组,分别采用外固定架或者掌侧锁定钢板治疗。比较两组患者手术时间、术中出血量、骨折愈合时间、术后并发症发生率;比较末次随访时患者腕关节活动度、桡骨掌倾角、尺偏角;比较健、患侧握力比值和患侧腕关节Gartland-Werley评分。结果共纳入30例患者,其中外固定架组14例,掌侧锁定钢板组16例。两组患者术后均随访1年。结果显示,掌侧锁定钢板组手术时间长于外固定架组,术中出血量多于外固定架组,但末次随访时桡骨掌倾角、尺偏角恢复水平优于外固定架组(P<0.05);两组骨折愈合时间,末次随访时腕关节屈伸、旋转活动度,健、患侧握力比,患侧腕关节Gartland-Werley评分等,均未见明显统计学差异(P>0.05);两组患者均未发生术后并发症。结论对于桡骨远端C型骨折,外固定架治疗的手术风险小于掌侧锁定钢板,但会造成术后一定程度的复位丢失,然而这种复位丢失并不影响患者的腕关节功能恢复。     

Fracture of the ulnar sesamoid of the metacarpophalangeal joint of the thumb —An arthrographic study

We report a case of fracture of the ulnar sesamoid of the metacarpophalangeal joint of the thumb. The role of arthrography and stress X-rays in delineating the pathological anatomy of this injury is discussed.     

Influence of metacarpophalangeal joint position on basal joint-loading in the thumb

BACKGROUND: Conventional wisdom holds that hyperextension of the metacarpophalangeal joint of the thumb is secondary to degenerative subluxation of the trapeziometacarpal joint as occurs in osteoarthritis. We propose that a hypermobile metacarpophalangeal joint may have a causative role in the development of primary osteoarthritis at the base of the thumb by concentrating forces on the palmar aspect of the trapeziometacarpal joint. METHODS: Twenty fresh-frozen cadaveric forearm specimens were obtained post mortem from donors with no history of connective-tissue disease. Each specimen was categorized by its passive range of metacarpophalangeal joint motion. Testing was conducted with Fuji ultra-low-pressure-sensitive film while the hand was in the lateral-pinch mode with the metacarpophalangeal joint in each of the following positions: unrestrained, pinned in neutral, pinned in 30 degrees of flexion, and pinned in maximal hyperextension. Quantitative analysis of the trapezial contact surface at each of the metacarpophalangeal joint positions was performed, and the center of pressure was determined. Each specimen was then classified according to the extent of arthritic disease (nonarthritic, moderately arthritic, or affected by end-stage arthritis). RESULTS: In specimens affected by end-stage osteoarthritis, the center of pressure on the trapeziometacarpal joint moved dorsally by 56.8% of the length of the trapezial surface with metacarpophalangeal joint flexions of 30 degrees (p < 0.01), whereas the corresponding values were 28.2% and 40.9% in the hyperextended and neutral metacarpophalangeal joint positions, respectively. In specimens with moderate osteoarthritis, 30 degrees of metacarpophalangeal joint flexion also produced the most dorsal trapeziometacarpal center of pressure (44.8%); however, this center of pressure was not significantly different from the centers of pressure at the other metacarpophalangeal joint positions. In nonarthritic specimens, the center of pressure was again significantly more dorsal with metacarpophalangeal joint flexion of 30 degrees than it was at the other positions (p < 0.01). CONCLUSION: Metacarpophalangeal joint flexion effectively unloaded the most palmar surfaces of the trapeziometacarpal joint regardless of the presence or severity of arthritic disease in this joint.     

Causes of locking metacarpophalangeal joint of the thumb and its non-operative treatment

The non-operative method of reduction of locking metacarpophalangeal joint of the thumb is described, and illustrated by four case reports. Experimental studies in the hands of a fresh cadaver are also described. Locking of the metacarpophalangeal joint of the thumb can be produced by slight external forces, insufficient to damage strong tissues. Incarceration of the sesamoid bone is anatomically impossible, but incarceration of the proximal portion of the volar plate is believed to be the true cause. This incarceration can be reduced easily by our non-operative method along with intra-articular injection of local anaesthetics.     

Metacarpophalangeal dislocation of the index finger. Apropos of 7 operated cases

Complex dislocation of the metacarpophalangeal joint of the index finger is an uncommon injury. The authors report seven cases, including three neglected dislocations, two with associated osteochondral fractures and one with sesamoid entrapment. Open reduction was necessary in each of the seven cases. In recent dislocations (four cases), both approaches were successful in obtaining reduction and normal finger movements were obtained. The dorsal approach was simple and safe, while the palmar approach was difficult and had many disadvantages. In the case with sesamoid entrapment, the sesamoid had to be removed to achieve reduction. In neglected dislocations (three cases), the dorsal approach was successful in one case (three weeks), two incisions were necessary in one case (seven months), and one case was treated by Swanson prothesis (two years). None of these patients regained normal mobility postoperatively.     

Tendon transfers for thumb opposition: a biomechanical study of pulley location and two insertion sites

PURPOSE:The purpose of this biomechanical study was to test 5 proximal tendon pulley sites or routes of tendon transfer and 2 distal tendon insertion sites that are used commonly for performing a thumb opposition transfer. METHODS: Five fresh-frozen cadaver arms were used to test (1) an around flexor carpi ulnaris (FCU) pulley, (2) an FCU loop pulley, (3) a Guyon's canal pulley, (4) a junction of the distal edge of the transverse carpal ligament and the ulnar border of the palmar aponeurosis (Royle-Thompson pulley), and (5) a palmar thenar subcutaneous transfer (Camitz). Two tendon insertion sites were tested: a palmar radial insertion into the abductor pollicis brevis and a dorsal ulnar insertion into the thumb proximal phalanx. RESULTS: The Guyon's canal and Royle-Thompson pulleys produced the greatest amount of approximation of the thumb pulp to the fifth metacarpal head. The around the FCU pulley, FCU loop pulley, and Camitz transfer produced the greatest palmar abduction. The Guyon's canal and Royle-Thompson pulleys were the most mechanically efficient pulleys, producing the least amount of transmitted force. The palmar radial insertion site produced better thumb opposition, metacarpophalangeal joint abduction, metacarpophalangeal joint flexion, and approximation of the thumb pulp to the fifth metacarpal head. CONCLUSIONS: We conclude that the choice of the proximal pulley used may depend on the needs of the transfer, and a palmar radial thumb insertion is more effective than the dorsal ulnar insertion.     

Complex dorsal subluxation of the metacarpo-phalangeal joint of the thumb requiring open reduction: a case report

The authors present an case of a thumb metacarpophalangeal joint dislocation which was made complicated by the interposition of the sesamoid bone which required open reduction. The intact volar plate prevented closed reduction. The anatomy and surgical management of this unusual case is described.     

Palmar segmental aponeurectomy for Dupuytren's disease with metacarpophalangeal flexion contracture

Eighty palmar segmental aponeurectomies were performed between 1993 and 1999 for well-localized palmar cords with metacarpophalangeal flexion contracture. A retrospective patient review with a minimum follow-up of 1-year demonstrated a 6% rate of recurrent metacarpophalangeal flexion and two minor complications. Segmental aponeurectomy rather than limited fasciectomy is recommended for this type of disease.     

Locking of the metacarpophalangeal joint of the thumb caused by a fracture fragment of the radial condyle of the metacarpal head after dorsal dislocation

We report a case of a locked thumb metacarpophalangeal joint secondary to metacarpal head fracture. As fractures of the radial condyle are not readily seen in routine X-rays, other imaging modalities, including CT, should be considered if the patient complains of limited extension after hyperextension injury of the thumb.