Anatomy of the joints of the thumb.

The three joints of the thumb differ markedly with respect to anatomy and function. Each contributes its own anatomic personality, and when functioning together, they allow the thumb to move with remarkable versatility and grace yet with the stability necessary to perform a wide variety of tasks. The carpometacarpal and interphalangeal joints allow for thumb mobility while the metacarpophalangeal joint provides stability. Thumb rotation primarily takes place at the CMC joint, although the MP and IP joints each contribute a small amount of pronation with flexion. Although much is known about the static structural anatomy of the thumb, its dynamic anatomy requires further investigation. The fluid, elegant and powerful movements of the thumb are complex, and defining the contributions of the various individual structures is difficult. Hopefully, future investigators using newer techniques will unravel the complexities of the functional anatomy of this remarkable digit.     

Thumb reconstruction

Thumb reconstruction aims to restore the cardinal thumb traits and actions including mobility, stability, sensibility, length, and appearance. The level of thumb loss is divided into thirds: distal (tip to interphalangeal [IP] joint), middle (IP joint to metacarpal neck), and proximal (metacarpal neck to carpometacarpal joint). Distal third reconstruction usually requires only soft tissue restoration. Many options exist for middle third reconstruction, including increasing thumb ray length (metacarpal lengthening, osteoplastic reconstruction, toe transfer) and increasing relative length (phalangization). Proximal third reconstruction is best accomplished with toe transfer, pollicization, or on-top plasty (pollicization of a damaged index finger).     

Extensor pollicis brevis tendon can hyperextend thumb interphalangeal joint in absence of extensor pollicis longus:Case report and review of the literature

We are reporting a case of extensor pollicis longus tendon rupture which did not require tendon transfer owing to the ability of the intact extensor pollicis brevis(EPB) to fully hyperextend the thumb interphalangeal joint. The thumb metacarpophalangeal joint was also able to be fully actively extended by the EPB. Previous anatomical studies have demonstrated that the insertional anatomy of the EPB tendon is highly variable and sometimes inserts onto the extensor hood and distal phalanx, which is likely the mechanism by which our patient was able to fully extend the thumb interphalangeal joint. Despite the potential for the EPB to extend the IP joint of the thumb, virtually all previously reported cases of extensor pollicis longus(EPL) tendon rupture had deficits of thumb IP extension requiring tendon transfer. This case highlights the potential ability of the EPB tendon to completely substitute for the function of the EPL tendon in providing thumb IP joint extension.     

A systematic review of outcomes of revision amputation treatment for fingertip amputations

Purpose

The purpose of this study was to conduct a systematic review of outcomes of fingertip revision amputation for fingertip amputation injuries in the English-language literature to provide best evidence of functional outcomes.

Methods

A MEDLINE literature search was performed to identify studies that met the following criteria: (1) reported primary data; (2) included at least five cases of primary revision amputation treatment following digit amputation injury; (3) reported finger or thumb amputation at or distal to the distal interphalangeal (DIP) joint or interphalangeal (IP) joint, respectively; (4) presented at least one of the following outcomes: static two-point discrimination (2PD), cold intolerance, arc of motion (AOM) of metacarpophalangeal (MCP) joints, proximal interphalangeal joints (PIP), DIP joints, or return-to-work time.

Results

Thirty-eight studies met the inclusion criteria. Twenty-seven studies reported 2PD, 20 studies reported cold intolerance, eight studies reported AOM, and 18 studies reported return-to-work time after revision amputation of fingertip injuries. The mean 2PD was 5.6 mm. On average, 24 % of patients experienced cold intolerance. AOM at the PIP joint was reported in four studies and averaged 94°. DIP joint AOM was presented in four studies and averaged 66°. Thumb MCP and IP joint AOM was presented in three and four studies, respectively. Mean thumb MCP joint AOM was 54° and that of the IP joint was 71°. The mean return-to-work time was 47 days.

Conclusions

On average, fingertip revision amputation can achieve almost normal sensibility and satisfactory motion and patients can expect to return to work on average approximately 7 weeks after surgery.     

半关节移植治疗重复拇指畸形伴指间关节严重发育不良

目的 通过半关节移植修复缺如的指间关节近端关节面及侧副韧带，重建重复拇指畸形患者严重偏斜的指间关节。方法 1994年3月—2002年11月间，对7例患者利用赘生拇指近节指骨的近端关节面及部分关节囊，行一期或二期半关节移植，重建保留拇指的指间关节近端发育不良或缺如的关节面。术后随访3年，观察骨关节生长及功能恢复情况。结果 移植的半关节大部存活，85％患者的骨外形良好、功能恢复较满意。结论 半关节移植是治疗重复拇指畸形伴指间关节严重发育不良的一种可行的手术方法。     

Split distal flexor pollicis longus tenodesis: long-term results.

A thumb lacking intrinsic muscle function but having extrinsic flexion will hyperflex in the interphalangeal joint giving a positive Froment's sign. This can effectively be prevented with split flexor pollicis longus tenodesis. The mean postoperative range of motion in the IP joint of 39 hands was 28 (18) degrees and 23 (20) degrees six and 12 months postoperatively. The procedure makes arthrodesis (temporary or permanent) superfluous. This procedure can be recommended strongly.     

示指拇化治疗重度拇指发育不全

目的 介绍示指拇化治疗先天性重度拇指发育不全(ⅢB～V型)的手术方法.方法 对Ⅳ型(漂浮拇)2例、ⅢB型(腕掌关节缺如)2例采用示指拇化,将示指自掌骨部位转位重建拇指.结果 4例移位指全部存活.术后随访2～3年,虎口开大70°～90°,接近健侧.拇指掌指关节屈曲后可与所有手指对指,近指间关节活动度从0°至100～120°,远指间关节活动度从0°至90°.指端两点分辨觉同健侧,外观和功能满意.结论 采用示指转位治疗重度发育不全的拇指,外形和功能满意,克服了以往采用皮瓣和骨瓣移植的缺点,是一种实用而可取的方法,值得推广.     

Long-term results of cemented Steffee arthroplasty of the thumb metacarpophalangeal joint

A retrospective evaluation of the Steffee metacarpophalangeal (MCP) thumb joint prostheses was performed to determine the long-term outcome and survivorship of the prosthesis. Fifty-four primary thumb arthroplasties (49 patients) were performed for pain, weakness, or instability involving the thumb MCP joint secondary to arthritis. Underlying etiology included rheumatoid (49 thumbs), psoriatic (1 thumb), scleroderma (2 thumbs), and degenerative (2 thumbs) arthritis. Thirty-one thumbs had concomitant interphalangeal joint instability and underwent interphalangeal joint fusions. At an average follow-up period of 57 months, the average motion of the MCP joint was 21 degrees (range, 0 degrees to 40 degrees ), with a significant improvement in position and stability. Thumb axis length was maintained or increased in 98%. Although there was not a consistent long-term improvement in grip or pinch strength, 87% of the patients reported subjective improvement in strength and function as a result of surgery. Pain was relieved in all thumbs with preoperative pain. Complications included a periprosthetic fracture, 2 late infections, and 1 gross loosening of the implant. The survivorship of the implant was 93% survivorship at 5 years and 89% survivorship at 10 years, with only 4 failures in 54 thumbs. The Steffee thumb MCP arthroplasty resulted in excellent long-term survivorship, patient satisfaction, and functional outcome.     

Split distal flexor pollicis longus tenodesis: long-term results

A thumb lacking intrinsic muscle function but having extrinsic flexion will hyperflex in the interphalangeal joint giving a positive Froment's sign. This can effectively be prevented with split flexor pollicis longus tenodesis. The mean postoperative range of motion in the IP joint of 39 hands was 28 (18)° and 23 (20)° six and 12 months postoperatively. The procedure makes arthrodesis (temporary or permanent) superfluous. This procedure can be recommended strongly.     

The non-opposable triphalangeal thumb: a new technique of management

Fifteen non-opposable triphalangeal thumbs (eight patients) were treated with a new two-staged surgical technique. The first stage included excision of the proximal interphalangeal joint and osteotomy of the thumb metacarpal, and aimed to restore a correct thumb length, position and alignment and to create a wide thumb web space. The second stage consisted of an opponensplasty with refining of any of the first stage components, as necessary. The mean age at surgery was 3.2 years (range, 2.5-6 years). After a mean follow-up period of 42 months (range, 26 months to 7 years), the targets of treatment had been accomplished without loss of growth potential, joint stability or thumb motion. All children had improved function and cosmesis of the hand.     

Modified Bilhaut-Cloquet procedure for Wassel type-II and III polydactyly of the thumb

BACKGROUND: The Bilhaut-Cloquet operation is a combined surgical procedure for the treatment of a symmetric bifid thumb. Although this procedure can obtain a normal-sized thumb with a stable interphalangeal joint, it has limitations, such as the technical difficulty of combining all segments of a duplicated thumb, possible later physeal growth arrest, joint stiffness, and nail-plate deformity. We reviewed the results of our modification of this procedure for the treatment of Wassel type-II and III polydactyly of the thumb. METHODS: Seven patients, two with type-II and five with type-III polydactyly of the thumb, underwent the modified Bilhaut-Cloquet procedure and were followed for an average of fifty-two months. Cosmetic and functional assessments were made. RESULTS: All patients and their parents were satisfied with the cosmetic and functional results. Compared with the preoperative motion, the postoperative range of motion of the interphalangeal joint was preserved in thumbs with type-III deformity and was increased in those with type-II deformity. No nail deformity or growth arrest occurred, and remodeling and hypertrophy of the distal phalanx occurred with time. CONCLUSIONS: Our modification of the Bilhaut-Cloquet procedure for the treatment of type-II and III thumb polydactyly is effective in preserving interphalangeal joint motion, minimizing nail deformity, and preventing growth arrest.     

Reconstruction of the rheumatoid thumb

Thumb deformities are common manifestations of rheumatoid arthritis and represent a significant source of disability. A clear understanding of the pathophysiology of the disease is essential in directing treatment. Differential diagnosis for flexible deformities includes soft-tissue imbalances as well as tendon ruptures. In its early stages, thumb involvement can be treated nonsurgically or with soft-tissue reconstruction. With more advanced disease, arthrodesis and arthroplasty often are required. Isolated interphalangeal involvement is best addressed with arthrodesis. Metacarpophalangeal involvement can be treated with arthroplasty in low-demand patients or with arthrodesis in more active patients. Trapezium resection arthroplasty provides excellent relief for patients with carpometacarpal joint destruction.     

Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament: Early Outcomes of Suture Anchor Repair with Suture Tape Augmentation

Introduction The purpose of this study was to evaluate the early outcomes of thumb metacarpophalangeal (MCP) joint ulnar collateral ligament (UCL) repair using suture anchors with suture tape augmentation. Materials and Methods Six patients underwent thumb UCL repair or reconstruction with suture tape augmentation and six patients underwent thumb UCL repair with intraosseous suture anchors between January 2013 and January 2018. The main outcome measures were range of motion, strength, Disabilities of the Arm, Shoulder, and Hand (DASH) score, and complications. Results At final follow-up for patients who had suture tape augmentation, the average thumb MCP joint and interphalangeal (IP) joint flexion were 65 and 73 degrees, respectively. The average DASH score was 4.3. At final follow-up for patients who had intraosseous suture anchor repair, the average thumb MCP joint and IP joint flexion were 50 and 60 degrees, respectively. The average DASH score was 38. There were no complications or secondary procedures in either group. Conclusion The use of suture anchor repair with suture tape augmentation for thumb UCL injuries is a treatment option that allows for early range of motion with satisfactory early outcomes that are comparable to intraosseous suture anchor repair. Level of Evidence  This is a level IV, case series article.     

The effect of thumb interphalangeal joint position on strength of key pinch

Thirty normal male and female subjects participated in a study to determine if the interphalangeal (IP) joint position of the thumb affects the outcome of lateral pinch strength tests. The subjects performed strong lateral pinch for three trials with both the thumb IP joint flexed and extended. The results showed that when flexion of the thumb IP joint was used, female subjects showed an increased strength of 30% for the right side and 28% for the left side compared to when they used extension of the thumb IP joint during lateral pinch. The male subjects showed increased strength of 36% for the right side and 38% for the left side when flexion versus extension of the thumb IP joint was used. IP joint position of the thumb was found to significantly affect the results of lateral pinch strength tests.     

Joint lesions of the first column of thumb

Lesions involving the thumb from the interphalangeal joint to the trapezo-metacarpal (TM) joint are very frequently the result of sports injuries. The authors discuss the most frequent lesions: 1) Dislocations of the metacarpo-phalangeal (MP) joint of the thumb which can be reduced in almost every case by means of well conducted orthopaedic manoeuvres. 2) Sprains of the MP joint of the thumb, very common lesions the severity of which must not be underestimated and which always require surgical treatment in the serious lesions, regardless of the compartment involved (radial or ulnar). 3) Bennett's fractures or fracture-dislocations of the TM joint; when neglected inadequately treated, these lesions lead to disabling post-traumatic arthritis of the TM joint. A poor result of treatment for any one of these three lesions always compromises opposition of the thumb and/or the strength of pollico-digital grip.     

Review of thumb carpometacarpal arthritis classification, treatment and outcomes

Thumb carpometacarpal osteoarthritis (CMC OA) is a common disease, affecting up to 11% and 33% of men and women in their 50s and 60s, respectively, which leads to pain, laxity and weakness of the CMC joint. Based on the staging of the CMC OA, different forms of treatment can be used, including both conservative and surgical measures. Surgical options include osteotomy, trapezial excision, ligament reconstruction with or without tendon interposition, and various prosthetic interpositional implants with or without trapezial excision. The present article reviews the staging of CMC OA, the evaluation of hand function using patient-reported questionnaires, and outcomes of both conservative and surgical treatments. The present review also introduces a commercially available interpositional spacer surgical technique for CMC OA and the early evidence that the literature has shown for improving hand function, strength and stability of the thumb CMC joint postoperatively.     

Irreducible dislocation of the thumb interphalangeal joint due to displaced flexor pollicis longus tendon: case report and new reduction technique

Dislocation of the thumb interphalangeal (IP) joint is uncommon because of the inherent stability of the joint. Cases in which reduction was blocked by the volar plate, the flexor pollicis longus (FPL) tendon, the sesamoid bone, and an osteochondral fragment have been described in the literature. This article reports a case of closed thumb IP joint dislocation caused by the displacement of the FPL tendon. A new percutaneous reduction technique for this injury will also be presented. A 63-year-old woman presented to the emergency room with an obvious thumb deformity. Radiographs confirmed dorsal dislocation of the thumb IP joint without associated fracture. Closed reduction was not successful. Percutaneous reduction was performed under locoregional anesthesia, because the dislocation was due to an FPL tendon that had displaced dorsally and radially to the proximal phalanx. After reduction, Kirschner wire fixation was not needed, but IP joint immobilization with a splint was required for 3 weeks. Postoperatively, there were no complications in soft tissues and the operative scar was almost unrecognizable. This technique enables a mini-invasive reduction by operating percutaneously on the FPL. In addition, unlike with a volar zigzag approach, it is possible to suppress the occurrence of postoperative adhesion of the flexor tendon. This new minimally invasive reduction technique is useful for irreducible dislocation of the thumb IP joint due to a displaced FPL tendon.     

Implant arthroplasty of the metacarpophalangeal joint of the thumb

Thumb metacarpophalangeal arthritis may affect overall hand function more than expected because pain and instability compromise pinch and grip strength. Implant arthroplasty represents one option in the treatment of deformity, destruction, and instability at the metacarpophalangeal joint level. Appropriate use of implant arthroplasty requires careful evaluation of the overall deformity and the status of the interphalangeal joint. If the interphalangeal joint is likely to require fusion--either simultaneous with metacarpophalangeal surgery or subsequently--then implant arthroplasty may be the best treatment option for the metacarpophalangeal joint.     

Abnormal triangular epiphysis causing angular deformity of the thumb

PURPOSE: To present a triangular-shaped abnormal secondary ossification center of the distal phalanx causing angular deformity of the thumb and the surgical outcome of corrective closing-wedge osteotomy for this deformity. METHODS: We treated 6 patients with abnormal triangular epiphysis in the distal phalanx of the thumb, including 3 bilateral cases. The average age was 43 months and there were 2 boys and 4 girls. Of the 9 thumbs intraepiphyseal closing-wedge osteotomy was performed in 5 and proximal phalangeal closing-wedge osteotomy was performed in 4. We measured the deformities in degrees of angulation and the range of motion of the interphalangeal (IP) joint. The average duration of the follow-up period was 27 months after the surgery. RESULTS: Preoperative angular deformity of ulnar deviation averaged 30 degrees , which was reduced to an average of 12 degrees after osteotomy at the last follow-up assessment. All osteotomies healed and there was no evidence of physeal or articular damage. Interphalangeal joint range of motion did not decrease after surgery in all cases. Patients and parents were satisfied with the results of the surgery, although mild deformity persisted in the interphalangeal joint when in the flexed position after proximal phalangeal osteotomy. CONCLUSIONS: Abnormal triangular epiphysis causing angled thumb is different from delta bone and can be treated with either intraepiphyseal or proximal phalangeal closing-wedge osteotomy. The intraepiphyseal procedure, however, could achieve better deformity correction regardless of the interphalangeal joint position. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Distal interphalangeal joint arthrodesis: treatment with Herbert screw

From 1996 to 2000, 20 patients with a mean age of 53 underwent 20 arthrodeses with Herbert screws. There were 16 (80%) distal interphalangeal joint (DIP) and 4 (20%) thumb interphalangeal (IP) joint arthrodeses. Average follow-up was 25 months (range, 6-39 months). The diagnoses included rheumatoid arthritis in 10 patients, degenerative arthritis in 4, and post-traumatic arthritis in 6. Arthrodesis relieved pain and restored stability in all patients. Solid osseous union occurred in 19 patients (95%). The average interval to fusion was 8 weeks for DIP and 12 weeks for IP joint arthrodesis. Solid osseous union occurred in 19 patients (95%). The average interval to fusion was 8 weeks for distal interphalangeal joint arthrodesis and 12 weeks for interphalangeal joint of the thumb. There were three complications: one delayed union, one nonunion because of a short screw, and one dorsal skin necrosis with amputation. It was shown that distal interphalangeal joint arthrodesis with a Herbert screw is a technique with several advantages: good clinical results, high rates of fusion, early mobilization, and the screw does not need to be removed after the fusion heals. Potential complications may be avoided by using the Herbert mini-screw.