The abducted little finger in low ulnar nerve palsy.

In 12 dissections the extensor digiti minimi tendons inserted into the abductor tubercle of the proximal phalanx. In eight of the 12, the tendons passed to the ulnar side of the abductor-adductor axis of the metacarpophalangeal joint. A separate tendon from the extensor digitorum communis to the little finger was found in only one dissection, with all others showing a connecting band which varies in its obliquity and thus in its adducting effect. To correct an abducted little finger, the ulnar portion of the extensor digiti minimi was transferred to the radial side of the little finger. Two methods were used: (1) the tendon was passed to the volar side of the metacarpophalangeal joint, if the joint could be hyperextended; if not, (2) a simple transfer to the radial collateral ligament was performed.     

Abductor digiti minimi opponensplasty in hypoplastic thumb

Ten cases of hypoplastic thumbs were treated by abductor digiti minimi opponensplasty in order to restore opposition of the thumb and reform the wasted thenar eminence. In eight of these ten cases operations were combined with multiple Z-plasty or rotation flap to correct the narrowing of the first web space. Adductor plasty using extensor indicis proprius was performed in six cases to restore the stability of the metacarpophalangeal joint of the thumb and ligament reconstruction of the carpometacarpal joint in one hand. In all cases, the transferred abductor digiti minimi was strong enough to abduct the thumb and provide good functional and cosmetic results. We modified Littler's procedure by transferring the origins of abductor digiti minimi muscle from the flexor carpi ulnaris to the palmaris longus tendon. Our modified method gave a better cosmetic appearance than that provided by Littler's method.     

The biomechanical properties of the finger metacarpophalangeal joints to varus and valgus stress

PURPOSE: The purpose of this study was to determine the normal biomechanical properties of the passive capsuloligamentous structures about the finger metacarpophalangeal (MCP) joints subjected to dynamic varus/valgus loading and to equate these findings to the clinical situation. METHODS: The finger MCP joints from 9 fresh-frozen cadaver hands were tested in a custom-designed testing apparatus that applied a varus/valgus force in each direction. Testing was performed at 0 degrees, 30 degrees, 60 degrees, and 90 degrees of MCP joint flexion. Load-displacement curves were generated for each specimen. A nonlinear hysteresis curve was apparent on loading and unloading. A region of collateral ligament laxity was identified whereby minimal torque (< 0.5 Nm) caused progressive joint angulation. Subsequently incremental load was required to produce further joint angulation. The slope of this region was used to calculate early and late collateral ligament stiffness. RESULTS: The index and long fingers showed a significant decrease in the region of collateral ligament laxity between 0 degrees and 90 degrees. The long finger collateral ligament laxity also diminished significantly between 30 degrees and 90 degrees. The collateral ligament laxity did not significantly change in the ring and small digits throughout MCP joint flexion. The early or late phase of collateral ligament stiffness was not affected by the amount of MCP joint flexion across any of the digits, except in late radial collateral ligament stiffness of the long finger between 0 degrees and 60 degrees. CONCLUSIONS: The additional stability and clinical observation of tightening of the MCP in flexion appears related to the decreased laxity of the collateral ligaments and not to alterations in the biomechanical properties of the collateral ligaments.     

Morphometric Evaluation of Collateral Ligaments of the First Metacarpophalangeal Joint

Introduction The collateral ligaments of the first metacarpophalangeal (MCP) joint provide stability to the thumb. Injury to these collateral ligaments occurs more commonly in sports accidents leading to joint instability, weakness in pinch and grip strength. Normal morphometric measurements of collateral ligaments are essential for primary repair or reconstruction of the injured ligament. Hence, the objective of the study is to give the detailed morphometric profile of the proper collateral ligaments of the MCP joint of the thumb. Materials and Methods A total of 55 adult cadaveric hands were included in the study taken from 18 male (36 hands) and 10 female (19 hands) cadavers. Out of 55 hands, 28 belonged to the left side, while 27 were of the left side. The MCP joints were dissected to expose the collateral ligament complex. The length and width of the proper ligaments were measured. Results Both the proper collateral ligament attachments and the direction of the fibers were defined. Overall length and the width of both the proper collateral ligaments showed no statistically significant difference of mean between the left and the right sides. However, the length of both the proper collateral ligaments is significantly less in females compared with the males. Conclusion The morphometric details of the proper collateral ligaments obtained from this study would be useful for hand surgeons during surgical correction of the injured collateral ligaments either by primary repair or reconstruction with a tendon graft.     

Elbow joint stability following experimental osteoligamentous injury and reconstruction

Elbow joint dislocation was simulated in cadaveric specimens to quantify laxity induced by radial head and coronoid process lesions, either alone or in combination with collateral ligament insufficiency. The effects of lateral ligament reconstruction and radial head prosthesis replacement were also considered. Absence of the radial head and the coronoid process induced rotatory laxity of 145% and 128% (both P <.01), respectively, compared with the intact joint. When both were absent, the joints subluxated regardless of collateral ligament status. Isolated radial head prosthesis implantation prevented this subluxation, and laxity almost normalized. Lateral collateral ligament reconstruction prevented major laxity even in the absence of the radial head. Lateral collateral ligament reconstruction and radial head prosthetic replacement yielded restraint against gross instability in the maximal unstable situation (terrible triad). The lateral collateral ligament is the prime stabilizer to external rotation, and reconstruction of this alone, even with an absent radial head, is beneficial.     

Congenital hypoplasia of the thumb with absence of the extrinsic extensors, abductor pollicis longus, and thenar muscles.

An unusual congenital anomaly of the thumb has been seen in 10 hands of eight patients. It consists of skeletal hypoplasia, instability of the metacarpophalangeal joint, absence of the extrinsic extensors and abductor, and adduction contracture of the first web space. Surgical reconstruction consisted of transfer of the extensor indicis proprius, the palmaris longus, and the abductor digiti minimi, as well as ankylosis of the metacarpophalangeal joint and release of the web space contracture. Useful grasp and pinch were provided for all patients. The patients were followed from 2 to 5 years.     

Experimental investigation of finger dynamics before and after metacarpophalangeal joint arthroplasty

PURPOSE: The purpose of this study was to quantify the changes in the arc of digital flexion before and after metacarpophalangeal (MCP) silicone arthroplasty with a 30 degrees preflexed design. METHODS: Index, middle, and ring fingers of 4 fresh-frozen cadaver hands were used. Each hand was attached (palmar side up) to a custom test apparatus. The tendon was drawn by a small winch-type servomotor. Micropotentiometers that were attached to the centers of rotation of the MCP, distal interphalangeal, and proximal interphalangeal joints measured angular displacement before and after MCP arthroplasty as a function of tendon excursion. The data were analyzed comparing the angle of flexion initiation and the angular displacement as a function of tendon excursion before and after joint arthroplasty. RESULTS: There were no statistical differences in the angles of the MCP joints at rest, the order of initiation of joint flexion, and the overall degree of flexion between the unoperated fingers and the fingers that had surgery. There was, however, a trend toward delay in flexion initiation, an increase in the MCP angle at rest, and a decrease in torque after implant arthroplasty. CONCLUSIONS: The decrease in initiation of flexion of the MCP joint, although not statistically significant, probably was related to the 30 degrees of preflexion built into the implant. We also noted a trend of decreased flexion at the MCP joint and increased flexion at the proximal interphalangeal and distal interphalangeal joints. This trend may be advantageous in the reconstruction of hands that initially have an MCP joint flexion deformity. TYPE OF STUDY/LEVEL OF EVIDENCE: to come.     

Electromyographic assessment of neuromuscular block at the gastrocnemius muscle

We have assessed neuromuscular block electromyographically at the gastrocnemius muscle and compared it with that at the abductor digiti minimi muscle in 60 adult patients undergoing cervical spine surgery under general anaesthesia. All patients were in the prone position. After vecuronium 0.2 mg kg-1, times to onset of neuromuscular block at the gastrocnemius and abductor digiti minimi muscles were mean 147 (SD 24) and 145 (14) s, respectively (ns). Times to return of the first response of the post-tetanic count (PTC1) at the gastrocnemius and abductor digiti minimi muscles were 27.7 (5.6) and 37.0 (5.9) min, respectively (P = 0.0001). Times to return of the first response of the train-of-four (TOF) at the gastrocnemius and abductor digiti minimi muscles were 41.0 (9.1) and 49.9 (8.7) min, respectively (P = 0.01). Recovery of PTC, T1/T0 and TOF ratio at the gastrocnemius muscle were significantly faster than at the abductor digiti minimi muscle.      

Irreducible palmar metacarpophalangeal joint dislocation due to junctura tendinum interposition: a case report and review of the literature

Three different anatomic structures have been reported to prevent reduction of a palmar dislocation of metacarpophalangeal joint: dorsal capsule, palmar plate, and a ruptured collateral ligament. In our case, extensor digitorum communis of the fifth finger and extensor digiti minimi subluxated on the ulnar side of the fifth metacarpal neck. Extensor digitorum communis of the fourth finger remained in its anatomic location. The junctura tendinum connecting the fourth and fifth extensor digitorum communis tendons slipped distal and then palmar to the metacarpal head, where it was trapped between the metacarpal neck and the base of the proximal phalanx. It was easily pulled out and the joint promptly reduced. Residual subluxation persisted due to rupture of the radial collateral ligament and the dorsal capsule. Repair restored joint reduction and stability. (J Hand Surg 2000; 25A:166-172.     

Problems with the metacarpophalangeal joint in the surgical treatment of osteoarthritis by inserting an ARPE type joint prosthesis

Progressive ankylosis of the trapeziometacarpal joint in flexion-adduction with closure of the first web in advanced trapeziometacarpal osteoarthritis gradually leads to compensatory dislocation of the metacarpophalangeal joint with hyperextension in the sagittal plane and abduction in the frontal plane. This deformity of the MP joint, initially reducible, but subsequently irreducible, results in the classical 'Z' deformity of the thumb in the sagittal plane. A less well known 'Z' deformity can also occur in the frontal plane due to distension of the medial collateral ligament. Surgical treatment of trapeziometacarpal osteoarthritis by arthroplasty must correct this secondary deformity of the MP joint to obtain an optimal result. The classical sagittal 'Z' deformity of the thumb can be easily corrected while this deformity is still reductible by releasing the fist metacarpal by tightening the abductor pollicis longus. When it is irreducible, this deformity can only be treated by MP arthrodesis, which contraindicates insertion of the ARPE trapeziometacarpal implant. Correction of the frontal 'Z' deformity of the thumb requires repair of the medial collateral ligament of the MP joint by ligamentorraphy (retightening) or ligamentoplasty.     

Reconstructive hand surgery for scleroderma joint contractures

Systemic scleroderma can cause significant hand deformity and functional impairment. Surgery is often avoided due to the perceived risks of wound healing. The most common surgical procedures have been digital sympathectomy, arthrodesis or arthroplasty of the proximal interphalangeal (PIP) or both, and metacarpophalangeal (MCP) joints. We describe herein successful soft tissue hand surgery in 2 patients for treatment of scleroderma claw deformities without the use of arthrodesis or arthroplasty. At the MCP joint, the tight capsules were excised, and the collateral ligaments and volar plates were released. At the PIP joints, the volar plates were released and the tight palmar skin was released, resulting in marked improvement of joint position. Intensive hand therapy was used to maximize function. In these 2 patients with claw deformity, we found that tight volar skin was the main contributor to flexion contracture at the PIP level. In contrast, joint capsule contracture was the main contributor to hyperextension deformity at the MCP level.     

Effects of the adductor pollicis and abductor pollicis brevis on thumb metacarpophalangeal joint laxity before and after ulnar collateral ligament reconstruction

PURPOSE: The intrinsic muscles and ulnar capsuloligamentous structures (UCLS), which consist of the ulnar collateral ligament (UCL), accessory UCL, dorsal capsule, and volar plate of the thumb metacarpophalangeal (MCP) joint are important for controlling the motion and stability of the MCP joint during pinch. The purpose of this cadaveric study was to determine the effects of the adductor pollicis (AdP) and abductor pollicis brevis (APB) on the 3-dimensional MCP joint laxity before transection of the UCLS and after reconstruction of the UCL and repair of the dorsal capsule. METHODS: Loads were applied to the flexor pollicis longus (FPL) alone, to the AdP and FPL in combination, and to the APB and FPL in combination in 11 cadavers. This was done in the intact joint after the UCLS were transected and after the UCL was reconstructed for flexion angles of 0 degrees, 15 degrees, 30 degrees, and 45 degrees. The spatial positions of the proximal phalanx and the metacarpal of the MCP joint were measured with a 6-degrees-of-freedom digitizing system. RESULTS: In the intact joint combined loading of the AdP and FPL did not affect the position of the proximal phalanx. Combined loading of the APB and FPL changed the position of the phalanx from an ulnar to a radial shift and from an ulnar to a radial deviation and it increased pronation. After transection of the UCLS combined loading of the FPL and AdP increased supination of the MCP joint and combined loading of the FPL and APB increased radial shift, radial deviation, and pronation of the joint. Reconstruction of the UCL restored normal laxity to the MCP joint. CONCLUSIONS: The AdP failed to affect MCP joint motion. The ABP produced a radial shift and radial deviation of the MCP joint and increased pronation of the thumb. Transection of the UCLS increased joint laxity for each of the combined loadings and reconstruction of the UCL restored normal laxity to the MCP joint.     

Radiologic evaluation of the rheumatoid hand after synovectomy and extensor carpi radialis longus transfer to extensor carpi ulnaris

PURPOSE: In this study we radiologically evaluated the effects of extensor carpi radialis longus (ECRL) tendon transfer on the stability and deformity of joints of rheumatoid hands in cases with a postoperative period of more than 5 years. METHODS: Synovectomy concomitant with tendon transfer of the ECRL to the extensor carpi ulnaris (Clayton's procedure) was performed in 28 wrists of 23 patients with rheumatoid arthritis. The follow-up period was 8.8 +/- 2.8 years. Pre- and postoperative x-rays were reviewed and measured. Follow-up evaluation included Steinbrocker's classification of the radiocarpal joints, Larsen's grade of the third metacarpophalangeal (MCP) joint, radial angulation of the wrist, ulnar translocation of the carpus, and ulnar drift of the fingers. RESULTS: Nineteen of 28 wrists (68%) were ankylosed (radius-proximal carpal row fusion or radiolunate limited fusion). Radial angulation of the wrist was reduced from 131 degrees +/- 8.8 degrees before surgery to 121 degrees +/- 7.9 degrees after surgery. Dislocation and ulnar translocation of the carpus (UTC) were prevented by surgery (UTC: 1.05 +/- 0.10 before and 1.07 +/- 0.09 after surgery). The mean ulnar drift of the fingers was maintained at the preoperative level (UDF: 14 degrees +/- 5.7 degrees before and 14 degrees +/- 12.9 degrees after surgery). The incidence of alteration (increase and decrease) of UDF of more than 5 degrees between pre- and postoperative evaluation was significantly higher in the group with worsening of Larsen grade of MCP joints than in the group without worsening (with worsening: 7 of 8 MCP joints, without worsening: 8 of 20 MCP joints). CONCLUSIONS: ECRL tendon transfer (Clayton's procedure) provided effective stabilization at more than 5 years (mean, 8.8 y) after surgery. In addition, this method may help to prevent ulnar drift of the fingers if combined with correction of local factors at the MCP joints.     

Modified abductor digiti minimi opponensplasty in congenital hypoplastic thumb with laxity of metacarpophalangeal joint

The abductor digiti minimi (ADM) opponensplasty is used widely as a standard technique of opponensplasty for congenital hypoplastic thumb. Functional results, however, are not always satisfactory in cases of marked laxity of the thumb metacarpophalangeal (MP) joint. The authors have developed a modified procedure of ADM opponensplasty to stabilize the thumb MP joint and to obtain appropriate opponens function. The first step of their modification is to retain the maximum length of transferred ADM muscle. The origin of the ADM is shifted radially and is reattached to the transverse carpal ligament. In our modification the ADM tendon is passed underneath the extensor pollicis longus tendon and is sutured to the adductor pollicis tendon at the ulnar side of the thumb MP joint. By this modified anchoring point the transferred ADM tendon runs across the ulnar side of the thumb MP joint and is expected to act as if it were an ulnar collateral ligament.     

The effect of thumb metacarpophalangeal ulnar collateral ligament attachment site on joint range of motion: an in vitro study

Although reconstruction of the torn thumb metacarpophalangeal (MCP) joint ulnar collateral ligament (UCL) has been shown to reduce symptoms, final joint motion may be different from that of the uninjured state. It was hypothesized that nonanatomic repositioning of the UCL might affect joint motion; therefore, the effect of UCL attachment site on MCP range of motion was investigated. The UCL and MCP joint capsule were visualized in each of 8 fresh cadaveric hands without otherwise disrupting the joint. The centers of the ligament attachments were marked with pins and each specimen was mounted on a testing frame capable of applying loads through the flexor and extensor tendons. After measuring the flexion, extension, and radial and ulnar deviation ranges of motion of the intact specimen, the origin of the ligament (on the metacarpal) and an attached bone block were elevated and repositioned 2 mm proximal and 2 mm palmar and range of motion was tested. The origin was reattached in its anatomic location and the insertion of the ligament was similarly elevated and displaced 2 mm in distal, dorsal, and palmar directions. Compared with the intact joint, palmar placement of the UCL origin on the metacarpal increased radial deviation (from a mean of 18 degrees to a mean of 27 degrees); proximal placement of the origin decreased it (from 18 degrees to 10 degrees). Similarly, dorsal placement of the UCL insertion on the phalanx increased radial deviation (from 18 degrees to 25 degrees) and distal positioning of the insertion decreased it (from 18 degrees to 11 degrees). Relative to intact joint flexion range of motion (mean, 57 degrees), distal placement of the UCL phalangeal insertion restricted motion (mean, 47 degrees), as did palmar placement (mean, 48 degrees). Extension and ulnar deviation motions were unaffected by ligament attachment position. This study demonstrates that nonanatomic reconstruction of the UCL alters normal MCP joint range of motion.     

Comparison of evoked electromyography in three muscles of the hand during recovery from non-depolarising neuromuscular blockade

The evoked electromyographic responses to supramaximal train of four stimulation of three muscles, all innervated by the ulnar nerve, were compared during recovery from non-depolarising neuromuscular blockade. The abductor digiti minimi was the most resistant to neuromuscular blockade (P <0.001) and the most repeatable (repeatability coefficient 4.4%) when compared with the adductor pollicis (5.9%) and the first dorsal interosseous (5.8%). The abductor digiti minimi had a bias of 0.1 compared to the adductor pollicis and first dorsal interosseous and its limits of agreement were more acceptable (-0.10 to 0.30) at a train of four ratio of 0.9. The electromyography train of four of the adductor pollicis and first dorsal interosseous at 0.8 is equivalent to an electromyography train of four of 0.9 at abductor digiti minimi.     

Investigation of radialization and rerouting of the extensor digiti minimi (EDM) in the abduction deformity of the little finger: a cadaver study

Background  

One of several operations to correct abduction deformity of the little finger, (Wartenberg’s sign) in ulnar nerve palsy, is a combined procedure that radializes the extensor digiti minimi (EDM) at the level of the fifth metacarpophalangeal (MCP) joint and reroutes it from the fifth to fourth extensor compartment. This cadaveric study was designed to investigate the impact of both elements on adduction.     

Crossed intrinsic transfer

A retrospective analysis of the long-term results of the crossed intrinsic transfer operation is presented. Twenty-one patients (30 hands) with rheumatoid arthritis and one patient (1 hand) with systemic lupus erythematosus were examined clinically and radiographically. The average follow-up was 12.7 years. The average postoperative ulnar drift for all fingers was 5 degrees. The magnitude of ulnar drift did not increase over time. The average active range of motion for the metacarpophalangeal joints was 47 degrees and for the proximal interphalangeal joints it was 58 degrees. The average radial deviation deformity of the wrist in the resting position was 2 degrees. These variables did deteriorate with time. Extensor carpi radialis longus to extensor carpi ulnaris tendon transfer with crossed intrinsic transfer produced the same result as crossed intrinsic transfer alone. The outcomes for crossed intrinsic transfer attached to the lateral band were similar to outcomes for transfers attached to the collateral ligament of the metacarpophalangeal joint. The crossed intrinsic transfer procedure effectively provides long-term correction of ulnar drift in the rheumatoid hand.     

Radial collateral ligament injury of the thumb with a Stener-like lesion

The original Stener lesion, described in 1962, refers to an ulnar collateral ligament tear of the thumb metacarpophalangeal joint with adductor aponeurosis interposition. The adductor aponeurosis serves as a mechanical block to healing by preventing apposition of the torn ends of the ulnar collateral ligament. This article presents a case of a 27-year-old woman with painful swelling of the thumb metacarpophalangeal joint following a car accident. Complete tear of the radial collateral ligament was diagnosed based on physical and radiographic examinations. Radial collateral ligament injuries are reported to be less common than ulnar collateral ligament injuries, and, in the past, radial collateral ligament tears were thought to be innocuous, requiring little intervention. More recently, the significance of these injuries has been well documented, and there is support for acute surgical management of complete radial collateral ligament tears. During surgical intervention in our case, we found an intrasubstance tear of the radial collateral ligament with the proximal portion of the ligament retracted and lying superficial to the abductor aponeurosis, thereby producing a Stener-like lesion on the radial side of the joint. The incidence of a Stener-like lesion to the radial collateral ligament is unknown, but it has only been reported once in the literature. Although a primary radial collateral ligament tear may heal by soft tissue apposition, we felt that conservative management in our patient would unlikely lead to healing due to interposition of the abductor aponeurosis. This case supports current recommendations for surgical intervention of complete radial collateral ligament injuries due to the possibility of a Stener-like lesion with soft tissue interposition recurring in the future.     

Prognostic factors and clinical features in metacarpophalangeal joint hyperextension after ligament reconstruction with trapeziectomy: A retrospective cohort study

BackgroundManagement of metacarpophalangeal (MCP) hyperextension deformity in thumb carpometacarpal (CMC) joint arthritis is challenging. It remains unclear how the preoperative MCP joint angle affects the outcomes. The present study aimed to clarify the associations between postoperative MCP hyperextension deformity and outcomes, and to determine the preoperative MCP joint angle that can predict poor outcomes.MethodsWe investigated the functional outcomes of patients who underwent surgery for CMC arthritis at two institutions from 2016 to 2020. All patients received a modified Thompson technique, ligament reconstruction suspension arthroplasty, and had no additional treatment for MCP hyperextension. The patients were divided into three groups according to their postoperative MCP joint angles: Group A, <10°; Group B, 10°–20°; Group C, >20°. Evaluations included preoperative and postoperative VAS, Quick DASH, range of motion (ROM), grip power, pinch strength, first web space angle, and postoperative trapezial space ratio (TSR).ResultsOverall, 66 eligible patients (72 thumbs) were identified and received follow-up for a mean of 25.2 months. The 72 thumbs were assigned to Group A (n = 38), Group B (n = 16), and Group C (n = 18). Group C had significantly lower preoperative MCP joint angle and postoperative grip power, pinch strength, and TSR compared with the Group A (P < 0.05). However, there were no significant differences in VAS, Quick DASH, ROM, and first web space angle (P > 0.05). The preoperative risk factor for highly residual MCP hyperextension was preoperative MCP joint angle (OR = 1.078; P = 0.001), with a cut-off value of 21.5° (AUC = 0.79; sensitivity = 0.813; specificity = 0.821).ConclusionsPostoperative MCP hyperextension of >20° after ligament reconstruction with trapeziectomy has adverse effects on functional outcomes. In cases with preoperative MCP joint angle of >21.5°, additional treatment for MCP hyperextension should be considered.