Effects of age and gender on the movement workspace of the trapeziometacarpal joint.

While researchers have suggested that joint mobility would probably be affected by age and gender, research findings often present discrepancies. Little research has been performed on the factors which effect mobility of the trapeziometacarpal (TMC) joint. The purpose of this study was to address the effects of age and gender on the ranges of motion of the normal TMC joint. Eighty normal subjects divided into four age groups participated in this study. The TMC joint motions were recorded using an electromagnetic tracking system. In order to achieve a maximal range of TMC joint motion which was defined as the maximal workspace, each subject was asked to perform actively maximal circumduction, flexion-extension, and abduction-adduction of the TMC joint. Numerical and statistical methods were used to compute the TMC workspace and to detect significant differences. A workspace-to-length ratio was determined as an index to examine the effects of the age and gender on the joint mobility. The results demonstrated that age and gender had significant influences on the TMC workspace among the groups studied. The understanding of TMC joint mobility under different age and gender conditions is achieved through this study. The findings can be used to report clinical measures in the determination of the extent of impairment of osteoarthritis as well as the outcomes between pre- and post-surgical (or non-surgical) interventions.

Total joint arthroplasty. Introduction to the upper extremity.

Total joint replacement in the upper extremity has developed in step with that of the lower extremity. The indications for treatment, the place of total joint arthroplasty in contrast to other forms of arthroplasty, and the criteria for patient selection have recently been classified. A number of problem areas are under biomechanical and clinical study, and most investigators are proceeding cautiously. In properly selected patients, however, prosthetic replacement offers great improvement in both relief of pain and joint function, and improvement should continue. The patient and physician should recognize the limitations that are inherent in any "artificial joint" replacement. Realistic expectations would be for improvement that approaches, but rarely achieves, normal function.

Skeletal reconstruction by vascularized bone transfer: indications and results.

The indications for and the results of 60 consecutive microvascular bone transfers performed at our institution during a 50-month period are reviewed. All 60 patients were followed up for at least 1 year. The overall primary union rate was 67%, and the eventual union rate was 77%. The most frequent indication for the procedure was long-bone reconstruction after limb-salvage wide local resection of a malignant tumor. We achieved the best results with limb reconstruction after resection of a malignant tumor and with recipient sites that involved the forearm or mandible. In contrast, our results were least favorable with reconstruction after resection for chronic osteomyelitis and with reconstruction of defects of the shoulder girdle. Overall, vascularized bone transfer seems to be a valuable reconstructive technique for management of clinical problems that involve massive skeletal defects.

Total joint arthroplasty. The role of biomechanics.

The role of biomechanics is intricately involved in total joint replacement from its inception to its clinical use. By integrating knowledge of joint function and material properties, the artificial joint is designed and tested. After clinical use, the joint function is again studied and failure modes are defined. Biomechanics is the single most important discipline that can be employed to study the cause of failure in order to improve design and technique. This will increase the reliability of, and decrease the incidence of failure associated with, total joint replacement.

Melorheostosis in a patient with familial osteopoikilosis.

We report on a 40-year-old woman with melorheostosis who also had radiographic findings of generalized osteopoikilosis. Three of her sibs have osteopoikilosis, but none of them have melorheostosis. Several cases of "mixed sclerosing bone dysplasia" have been described previously, and all have been sporadic. Isolated melorheostosis without osteopoikilosis is also generally a sporadic condition, but osteopoikilosis has been described as an autosomal-dominant trait. The finding of mixed sclerosing bone dysplasia in a family with osteopoikilosis suggests that the melorheostotic component of this disorder may be due to a second mutation at the same locus that causes isolated familial osteopoikilosis.

Kinematics of the trapeziometacarpal joint after sectioning of ligaments.

This study was designed to examine the roles of ligaments in the maintenance of the articular kinematics of the trapeziometacarpal joint. Circumduction of the trapeziometacarpal joint was studied in 12 hands from fresh human cadavera. With use of a magnetic tracking system, changes in the motion of the base of the first metacarpal after ligament sectioning were analyzed and compared with those of the normal joint. Two sets of ligaments were sectioned: (a) the anterior oblique and ulnar collateral ligaments and (b) the first intermetacarpal ligament and the ulnar joint capsule. Sectioning of the anterior oblique and ulnar collateral ligaments resulted in a significant dorsal-ulnar shift in the path of the base of the first metacarpal. However, sectioning of the first intermetacarpal ligament did not affect the movement pattern of the center of the base. The anterior oblique and ulnar collateral ligaments provided constraint of the trapeziometacarpal joint during circumduction of the thumb.

Ligamentous structures of the metacarpophalangeal joint: a quantitative anatomic study.

The ligamentous structure of the metacarpophalangeal (MCP) joint of the index finger in human cadavers was studied by gross examination and quantitative measurement. Anatomically, the collateral ligament is separable into two layers, with the precise origin arising from the metacarpal head and inserting on the proximal phalanx. Quantitatively, the change in length of the collateral ligament was studied with biplanar radiographic techniques. The distance between the origin and insertion of the collateral ligament changed in different portions of the ligament when the joint was moved from a position of hyperextension to that of flexion. When the MCP joint was flexed from 0 degree to 80 degrees, the dorsal portions of both the radial and ulnar collateral ligaments were lengthened (3-4 mm). The middle portions of both ligaments were slightly elongated (0.4-1.0 mm), and the volar portions of the ligaments were shortened (1-2 mm). When the MCP joint extended into hyperextension, the dorsal portions of the ligaments shortened 2-3 mm, the middle thirds of the ligaments shortened slightly, and the volar thirds of the ligaments lengthened. The results of this study suggest that the dorsal and volar portions of the collateral ligament provide MCP joint constraint at the flexed and extended positions, respectively.

Quantification of regional blood flow to canine flexor tendons.

Although the blood supply and the microcirculation of flexor tendons have been studied and defined extensively using qualitative methods, the quantitative assessment of blood flow has been lacking because of the limitations of the available experimental techniques. We studied the regional blood supply to the flexor tendons of dogs by the technique of radionuclide-labeled microspheres. Seven adult mongrel dogs were used. Microsphere injection and tissue-counting techniques previously used for other tissues were applied. Samples of proximal, isthmus, and distal portions of the profundus and superficialis flexor tendons were harvested from each digital unit of available limbs from each dog. Mean (+/- SE) flows (ml/100 g dry tissue/min) were proximal profundus 1.78 +/- 0.60 and superficialis 7.10 +/- 1.50. The differences were significant (p less than 0.01). The study suggests that regional variation in blood flow to canine digital flexor tendons exists, so that a single value for blood flow to these tendons is not relevant. Furthermore, the study supports the concept of dual (vascular and synovial) nutrition to the digital flexor tendons in dogs. These observations may have implications regarding tendon repair techniques.

Blood flow and bone uptake of 99mTc-labeled methylene diphosphonate.

In mature dogs with comparable levels of bone remodeling, we produced either increased (with adenosine triphosphate) or decreased (with epinephrine) blood flow to one hindlimb. In 13 dogs (five control, four with increased flow, and four with decreased flow), we compared uptake, at 3 h after injection of radiolabeled diphosphonate in the mid-tibia, with blood flow as determined by microspheres. Blood flow was determined with 85Sr-labeled microspheres, and determination of uptake of 99mTc methylene diphosphonate (99mTc-MDP) was by a gamma detector. There was a linear relationship between changes in diphosphonate uptake and changes in blood flow at decreased and normal flows; however, at high flows the relationship was nonproportional, indicating a disproportionately slower increase in 99mTc-MDP uptake with increasing blood flow. In six dogs an initial 1-h uptake curve of 99mTc-MDP was determined in both control and experimental limbs under states of increased and decreased blood flow. The 30-min uptake value, 60-min uptake value, area under the curve, and the slope of the curve were related to flow as determined by microspheres. The data are consistent with the hypothesis that deposition of bone-concentrating isotopes such as 99mTc-MDP is partly controlled by blood flow; at supranormal and normal flows tracer uptake is closely related to blood flow, but at supranormal flow rates it is not and appears to be diffusion limited.

Forces in the normal and abnormal hand.

An analytic model for human hand force analysis was developed through anatomical study and measurement of multiple cadaveric specimens. A method of solution was developed to determine muscle and joint force distributions under various isometric hand functions. Applications of this model to abnormal conditions include studying the effects of tendon laceration, neuromuscular weakness, and surgical restoration by tendon transfer. Limitations and further applications of the model are discussed in detail.

Effects of a scaphoid waist osteotomy on carpal kinematics.

The effects of a scaphoid osteotomy on the kinematics of the carpal bones were determined in five cadaveric wrist specimens. Minute radiographic markers were inserted into the distal radius and selected carpal bones through limited arthrotomies between the intercarpal ligaments. Simultaneous biplanar radiographs were obtained in neutral and the extreme wrist positions of extension, flexion, radial deviation, and ulnar deviation, both before and after a scaphoid waist osteotomy. The positions of each of the carpal markers and their corresponding carpal bones were digitized for each wrist position , and a computer-assisted motion analysis was performed for each specimen before and after transverse scaphoid waist osteotomy. Following the osteotomy, there was a tendency for the scaphoid osteotomy to collapse into a dorsally angulated or "humpback collapse" deformity during each extreme wrist position. There was also multiplanar osteotomy site motion as well as complex collapse deformities of the midcarpal joint associated with loss of the mechanical tie-rod function of the scaphoid. These findings reveal the importance of the scaphoid in maintaining normal kinematics and the inherent instability of these fractures with loss of scaphoid integrity.

Transverse stability of the carpus. An analytical study.

The stabilizing structures of the transverse carpal arch were studied utilizing an analytical model based on a rigid body spring model theory. This method was used to calculate the relative motion between carpal bones, the distribution of compressive forces in the intercarpal joints, and the tensions in the ligaments under simulated dorsopalmar compression. The contribution of each ligament against the effect of compression was determined by removing ligaments from the model. A multivariate analysis of variance disclosed that sectioning the flexor retinaculum alone does not significantly modify the distribution of forces in ligaments and joints (p = 0.33), and decreases dorsopalmar carpal stiffness by only 7.8%. In contrast, isolated removal of the palmar hamate-capitate ligament causes a pronounced weakening of the carpal structure, from an average of 232 to 131 N/mm (p less than 0.01). If the flexor retinaculum is removed in addition to releasing one palmar intercarpal ligament, a gross instability of the carpal arch is created.

Kinematics of the normal trapeziometacarpal joint.

Motion of the trapeziometacarpal joint was studied in 12 hands from fresh human cadavera. By use of a magnetic tracking system, a full range of motion of the first metacarpal was analyzed with respect to a defined trapezial coordinate system. The traces of the reference points on the head and base of the first metacarpal were monitored, and the instantaneous centers of rotation were calculated. During circumduction, the reference points on the head and base followed elliptical paths but in opposite directions. The average instantaneous center of circumduction was at approximately the center of the trapezial joint surface. In flexion-extension, the axis of rotation was located within the trapezium, and the path of the head was identical to the path of the base. In abduction-adduction, the axis of rotation was located distal to the trapezium within the base of the first metacarpal, and the base and head moved in opposite directions. There was no single center of rotation; rather, instantaneous motion occurred reciprocally between these centers of rotation within the trapezium and metacarpal base in the normal thumb. This changing instantaneous center of rotation results in a unique pattern of motion which is related to congruent, tightly constrained joint surfaces of two reciprocal saddle joints and to precisely positioned extraarticular ligaments.

A multidisciplinary study of the 'yips' phenomenon in golf: An exploratory analysis.

BACKGROUND: The 'yips' is a psychoneuromuscular impediment affecting execution of the putting stroke in golf. Yips symptoms of jerks, tremors and freezing often occur during tournament golf and may cause performance problems. Yips-affected golfers add approximately 4.7 strokes to their scores for 18 holes of golf, and have more forearm electromyogram activity and higher competitive anxiety than nonaffected golfers in both high and low anxiety putting conditions. The aetiology of the yips is not clear. OBJECTIVE: To determine whether the yips is a neurological problem exacerbated by anxiety, or whether the behaviour is initiated by anxiety and results in a permanent neuromuscular impediment. METHODS: In phase I, golf professionals assisted investigators in developing a yips questionnaire that was sent to tournament players (<12 handicap) to establish the prevalence and characteristics of the yips. Phase II measured putting behaviour in scenarios that contribute to the yips response. Four self-reported yips and 3 nonaffected golfers putted 3 scenarios using an uncorrected grip and a standard length putter. Heart rate was superimposed on the videotape and the putter grip was instrumented with strain gauges to measure grip force. Electromyograms and relative putting performance were also measured. RESULTS: The questionnaire was sent to 2,630 tournament players, of whom 1,031 (39%) responded (986 men and 45 women). Of these, 541 (52%) perceived they experienced the yips compared with 490 (48%) who did not. Yips-affected golfers reported that the most troublesome putts were 3, 4 and 2 feet (0.9, 1.2 and 0.6 metres) from the hole. Fast, downhill, left-to-right breaking putts and tournament play also elicited the yips response. Golfers affected by the yips had a faster mean heart rate, increased electromyogram activity patterns and exerted more grip force than nonrffected golfers and had a poorer putting performance. CONCLUSIONS: For <10 handicap male golfers and <12 handicap female golfers, the prevalence of the yips is between 32.5% and 47.7%, a high proportion of serious golfers. This high prevalence suggests that medical practitioners need to understand the aetiology of the yips phenomenon so that interventions can be identified and tested for effectiveness in alleviating symptoms. Although previous investigators concluded that the yips is a neuromuscular impediment aggravated but not caused by anxiety, we believe the yips represents a continuum on which 'choking' (anxiety-related) and dystonia symptoms anchor the extremes. The aetiology may well be an interaction of psychoneuromuscular influences. Future research to test the effect of medications such as beta-blockers should assist in better identifying the contributions these factors make to the yips phenomenon.

Biomechanical analysis of static forces in the thumb during hand function.

Using a three-dimensional analysis, the internal forces in the joints and soft tissues of the thumb during pinch and grasp were calculated. To do this, mechanical equivalents were ascribed to the anatomical system, the joint orientation and tendon locations were determined from biplanar roentgenograms of five marked normal cadaver specimens, and the magnitudes of forces in the tendons, intrinsic muscles, joint contact surfaces, and constraining ligaments were calculated based on assumed loads applied to the tip of the thumb in various types of pinch and grasp. These results are the direct extension of a two-dimensional analysis that proved inadequate for the determination of static tendon and joint forces. Extrinsic and intrinsic tendons of the thumb were found to sustain forces of up to 10.0 and thirty kilograms during pinch, producing five kilograms of force at the thumb tip and forces of as much as fifty kilograms during grasp. The joint compression (contact) forces averaged three kilograms of force at the interphalangeal joint, 5.4 kilograms at the metacarpophalangeal joint, and 12.0 kilograms at the carpometacarpal joint during simple pinch (one kilogram of applied force). Compression forces of as much as 120 kilograms may occur at the carpometacarpal joint during strong grasp.

External pin fixation for unstable Colles' fractures.

During a five-year period, a double-pin Roger Anderson apparatus, with pins perpendicularly placed in the second and third metacarpals and in the distal part of the radius, was applied in 130 patients with an unstable Colles fracture. Sixty of the 130 were followed for two years. Shortening was limited to a median of two millimeters and dorsal angulation, to a median of 3 degrees. Wrist dorsiflexion averaged 58 degrees, and volar flexion averaged 50 degrees. Pronation and supination had an average loss of 5 degrees when compared with the uninjured side. Repeat reduction was required in only three patients. Patient assessment revealed that 85 per cent of the patients had good results; 12 per cent, fair; and 3 per cent, unsatisfactory. Objective analysis (McBride system) revealed that 90 per cent had good to excellent results; 8 per cent, fair; and 2 per cent, poor. Ninety-two per cent had no pain, 89 per cent had no deformity, and the mean grip strength was twenty kilograms. Sixteen patients had complications; seven of the sixteen had pin loosening, which occurred most frequently late during the course of treatment and without adverse sequelae.

Open reduction and internal fixation of displaced, comminuted intra-articular fractures of the distal end of the radius.

The results in sixteen patients who had a displaced, comminuted intra-articular fracture of the distal end of the radius and who were treated by open reduction and internal fixation were retrospectively reviewed. At a mean follow-up of 4.8 years, 81 per cent of the patients had a rating of good or excellent by the scoring system of Gartland and Werley, but only 56 per cent had such a rating when the modified scoring system of Green and O'Brien was used. All of the fractures healed at an average of nine weeks. A step-off of two millimeters or more in the distal radial articular surface at the time of healing was important, because the four patients in whom the fracture healed with this amount of incongruity all had post-traumatic arthritis at follow-up, compared with only three of twelve in whom the incongruity was less than two millimeters.

Complications of Colles' fractures.

Patients with Colles' fractures have serious complications more frequently than is generally appreciated. A study of 565 fractures revealed 177 (31 per cent) with such complications as persistent neuropathies of the median, ulnar, or radial nerves (forty-five cases), radiocarpal or radio-ulnar arthrosis (thirty-seven cases), and malposition-malunion (thirty cases). Other complications included tendon ruptures (seven), unrecognized associated injuries (twelve), Volkmann's ischemia (four cases), finger stiffness (nine cases), and shoulder-hand syndrome (twenty cases). In many patients, incomplete restoration of radial length or secondary loss of the reduction position caused the complications.

En bloc resection of tumors of the distal end of the ulna.

The operative treatment of malignant tumors and aggressive benign tumors involving the distal end of the ulna often necessitates en bloc resection. The oncological and functional results for eight patients in whom a neoplasm involving the distal end of the ulna had been treated with en bloc resection without reconstruction of the osseous defect were reviewed retrospectively at a mean of seventy-nine months (range, twenty-three to 271 months). Four patients had a giant-cell tumor; two, a low-grade osteogenic sarcoma; one, a hemangioendothelioma; and one, a soft-tissue epithelioid sarcoma with osseous involvement. The amount of bone that was removed from the distal end of the ulna ranged from 3.1 to 9.0 centimeters. In the four patients who had a malignant tumor, a minimum of 7.5 centimeters was removed in order to achieve an adequate wide margin proximally. In the patients who had a benign tumor, a maximum of 6.6 centimeters was resected. Extraperiosteal resection was performed in three of the patients who had a malignant tumor and in one of the patients who had an aggressive giant-cell tumor. Subperiosteal resection was performed in the three patients who had a benign tumor and in one patient who had a parosteal osteogenic sarcoma. None of the patients had local or systemic evidence of recurrence of the tumor. The functional result was excellent for six patients and good for two. Grip strength was reduced by a mean of 15 per cent compared with the strength on the contralateral side, and this reduction did not appear to be related directly to the amount of bone that had been resected. The findings of this study support the concept that routine reconstruction of the osseous defect is not necessary after en bloc resection of a neoplasm of the distal end of the ulna.

The kinesiology of the thumb trapeziometacarpal joint.

To measure the motions of the trapeziometacarpal joint of the thumb quantitatively, a roentgenographic method was developed and tested using T-shaped metal markers, a special cassette-holder, and biplane roentgenograms. Two experiments were performed. In the first one, the metal markers were fixed to the trapezium and third metacarpal in ten cadaver specimens, and a fixed spatial relationship between the trapezium and the third metacarpal was identified roentgenographically. This relationship was that the reference axes of the trapezium were aligned at median angles of 48 degrees of flexion, 38 degrees of abduction, and 80 degrees of pronation with reference to the reference axes of the third metacarpal. In the second experiment, in the dominant hand of nine male and ten female subjects (average age, twenty-six years) T-shaped markers were fixed to the skin overlying the third metacarpal and the metacarpal and phalanges of the thumb. Using the same roentgenographic technique and coordinate systems employed in the first study, the average total motions of the trapeziometacarpal joint (determined as motions of the first metacarpal with reference to the third metacarpal) were 53 degrees of flexion-extension, 42 degrees of abduction-adduction, and 17 degrees of axial rotation (pronation-supination). In addition, six functional positions of the thumb were studied: rest, flexion, extension, abduction, tip pinch, and grasp. A position of adduction and flexion of the trapeziometacarpal joint was most common during thumb function, and both the trapeziometacarpal and metacarpophalangeal joints contributed to rotation of the thumb.