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Biomedical subjects

M M Tomaino

Publications and source records attributed to M M Tomaino.

At least 37 records · Page 2Linked to original sources
PubMed2000

Forearm rotation alters interosseous ligament strain distribution.

Recent interest in reconstruction of the interosseous ligament (IOL) of the forearm has led to questions concerning optimal placement of the reconstructive graft as well as the ideal rotational position of the forearm during graft tensioning. We therefore studied the strain distribution in the IOL to determine which fibers are strained in different positions of forearm rotation. Five cadaveric human forearms were subjected to compressive axial load (simulating power grip) and the strain values across the entire IOL were measured with the forearm in neutral, supination, and pronation. The strain distribution in the IOL changed with forearm rotation. The highest overall strain was found in neutral. In neutral and pronation, higher strain was observed in the proximal region of the IOL. In supination, however, higher average strain was seen in the distal region of the IOL. These results suggest that a reconstructive graft placed in the proximal region of the IOL and tensioned in neutral rotation would provide balanced constraint in different positions of forearm rotation. A graft placed in the distal region and tensioned in forearm neutral, however, may limit forearm rotation.

Adolescent↗
PubMed2000

Treatment of Eaton stage I trapeziometacarpal disease with thumb metacarpal extension osteotomy.

The current benchmark for the treatment of Eaton stage I disease of the trapeziometacarpal (TMC) joint includes palmar oblique ligament reconstruction and reflects its primary role in providing stability during lateral pinch. This study prospectively evaluates the efficacy of an alternative extra-articular approach using a 30 degrees extension osteotomy of the thumb metacarpal to redistribute trapeziometacarpal contact area and load, obviating the need for ligament reconstruction. Preoperative and postoperative subjective and objective data are reported for 12 patients enrolled in the study between 1995 and 1998. Trapeziometacarpal arthrotomy allowed accurate intra-articular assessment and verified palmar oblique ligament incompetence in each case. The average follow-up period was 2.1 years (range, 6-46 months). All osteotomies healed at an average of 7 weeks. Eleven patients were satisfied with outcome. Grip and pinch strength increased an average of 8.5 and 3.0 kg, respectively. Thumb metacarpal extension osteotomy is an effective biomechanical alternative to ligament reconstruction in the treatment of Eaton stage I disease of the trapeziometacarpal joint.

Adult↗
PubMed2000

Role of the forearm interosseous ligament: is it more than just longitudinal load transfer?

The objective of our study was to measure 3-dimensional force vectors (magnitude and direction) acting in the forearm when load is applied to the hand and to measure the actual force in the interosseous ligament (IOL). Fourteen cadaveric forearms were loaded to 136 N of compression while special load cells measured force vectors in the forearm. Computer forearm models were used to display the 3-dimensional force vector directions. The study results showed that the radius bears most of the load at the wrist but load on the radius at the elbow is reduced because the IOL transfers load to the ulna between the wrist and the elbow. In addition to this role in longitudinal load transfer, our measurement of 3-dimensional forces allowed identification of transverse vectors which suggest that the IOL also functions to keep the radius and ulna from splaying apart. Our results imply that the IOL participates not only in longitudinal load transfer but also in the maintenance of transverse stability of the forearm during compressive load transfer from the hand to the elbow.

Aged↗
PubMed2000

Comparison of ulnar shortening osteotomy and the wafer resection procedure as treatment for ulnar impaction syndrome.

A retrospective review was performed that compared the results of 2 different surgical treatments for ulnar impaction syndrome in 22 patients over a 6-year period. Ulnar shortening osteotomy and wafer distal ulna resection (wafer resection procedure) were each performed in 11 patients based on the preference of 3 individual hand surgeons. All patients presented with ulnar wrist pain and positive ulnar variance on either neutral rotation or pronated-grip x-rays and each failed conservative management. At a minimum follow-up time of 18 months, 9 patients had good to excellent results following ulnar shortening osteotomy compared with 8 following the wafer resection procedure. This difference was not statistically significant. All patients regained functional wrist motion and 21 of the 22 patients had satisfactory pain relief. There was 1 poor result in the wafer group that required revision to complete resection of the distal ulna. Five secondary procedures were required in the osteotomy group to remove painful hardware and union was delayed in 2 patients. Although ulnar shortening osteotomy provides effective treatment for ulnar impaction syndrome, the wafer resection procedure provides favorable pain relief and restoration of function but without the potential for nonunion or hardware removal. (J Hand Surg 2000; 25A:55-60.

Adolescent↗
PubMed2000

The effect of wrapping scarred nerves with autogenous vein graft to treat recurrent chronic nerve compression.

The purpose of this study was to determine the efficacy of vein wrapping of scarred nerves in a chronic nerve compression model in rats. The ultimate goal was to provide experimental evidence for application of the technique of vein wrapping of nerves for the treatment of recurrent compressive neuropathy. The chronic nerve compression model was created in 100 rats. After 8 months the nerves were decompressed. In 50 rats the nerves were wrapped with an opened femoral vein graft; the remaining 50 animals served as controls. The sciatic nerves of both groups were evaluated at 4, 8, 12, 24, and 48 weeks after surgery. Functionally, the sciatic nerves in the vein-wrapped group showed greater improvement than those in the non-vein-wrapped group. For electrophysiologic testing the latency was significantly shorter in the vein-wrapped group. Histologic evaluation showed marked nerve degeneration and scar tissue formation around the nerves in the non-vein-wrapped group but not in the vein-wrapped group. The results indicate that the vein graft could improve the recovery of nerve function by protecting the nerve from surrounding scar and is an effective and feasible technique for the surgical treatment of recurrent compressive neuropathy. (J Hand Surg 2000; 25A:93-103.

Action Potentials↗
PubMed2000

Correction of lunate malalignment when bone grafting scaphoid nonunion with humpback deformity: rationale and results of a technique revisited.

Patients with scaphoid nonunion with humpback deformity and collapse of the wrist were treated with palmar wedge bone grafting combined with reduction of the lunate to correct the dorsal intercalated segment instability deformity. Union was obtained at an average of 3 months, and patient satisfaction with functional outcome and pain relief was high. Palmar wedge bone grafting combined with correction of lunate malalignment successfully achieved scaphoid union, restored scaphoid length, and avoided the potential complication of scaphoid malunion. This report revisits a technique that facilitates accurate correction of lunate malalignment (dorsal intercalated segment instability) by initial reduction and pin fixation to the radius before insertion of scaphoid bone graft and internal fixation.

Adolescent↗
PubMed2000

The importance of the pronated grip x-ray view in evaluating ulnar variance.

Although dynamic increases in ulnar variance may accompany functional activity, radiographic assessment of ulnar variance traditionally has used a neutral rotation x-ray of the wrist that provides an image of the radioulnar length with the wrist unloaded. Such a view may underestimate variance in wrists in which power grip and pronation result in significant proximal migration of the radius. This study investigates the effect of a maximum grip effort in combination with forearm pronation on ulnar variance in 22 patients who presented with ulnar wrist pain. The pronated grip x-ray view resulted in statistically significant increases in ulnar variance. Preoperative ulnar variance should be measured using both neutral rotation and pronated grip x-rays before selecting treatment for causes of ulnar wrist pain that are affected by radioulnar length so that dynamic increases in ulnar variance are considered when operative treatment is necessary.

Adolescent↗
PubMed2000

Feasibility of partial A2 and A4 pulley excision: residual pulley strength.

We investigated residual digital flexor pulley strengths after 75% excision of the A2 and A4 pulleys. For direct pull-off tests, A2 and A4 pulleys from cadaveric fingers were tested by pulling on a loop of flexor digitorum profundus tendon through the pulley. For functional loading tests, fingers were positioned with the metacarpophalangeal joint flexed to 90 degrees for A2 testing, and with the proximal interphalangeal joint in 90 degrees flexion for A4 testing (with all other joints in full extension). Excision of 75% of A2 and A4 pulleys reduced pulley strengths determined by both testing methods. For the functional loading tests, which are more clinically relevant, mean tendon forces at failure after partial excision of A2 and A4 pulleys were 224 and 131 N respectively, which is sufficient to withstand flexor tendon forces expected during activities of daily living.

Analysis of Variance↗
PubMed2000

The Compass Elbow Hinge: indications and initial results.

The Compass Elbow Hinge uses Illizarov's methods of fixation to externally hold the elbow reduced and allow both passive and active motion. Eleven patients with degenerative disease, contracture or instability were treated with the Compass Elbow Hinge and were retrospectively evaluated at an average follow-up of 29 months (range: 18-62 months). One was lost to follow-up. Patients with degenerative changes underwent fascia lata interposition while those treated for contractures underwent anterior and posterior capsular release with or without fascia lata interposition. Those with elbow instability underwent ligament reconstruction. The device was removed after 6 weeks and seven of the 11 patients were satisfied with the outcome of the operation. Stability could not be achieved in two patients with coronoid fractures that were not reconstructed. One patient did not tolerate the device and requested its removal with subsequent subluxation. We conclude that patient selection and compliance are key elements in achieving a satisfactory outcome with the device.

Adult↗
PubMed2000

Digital arterial occlusion in scleroderma: is there a role for digital arterial reconstruction?

A 47-year-old patient with Raynaud's phenomenon secondary to scleroderma developed long finger ischaemic pain. This was successfully treated with a palmar sympathectomy and a long finger digital artery reconstruction using a reversed small calibre vein graft between a perforator from the deep palmar arch and the radial digital artery at the level of the distal interphalangeal joint.

Arteries↗
PubMed2000

Scapulohumeral arthrodesis for post-traumatic proximal humeral loss using vascularized fibular transplantation and allograft bone.

Loss of the proximal humerus following trauma or tumor ablation results in tremendous functional impairment because of the inability to position the hand in space. Although scapulohumeral athrodesis is described in the literature, insufficient follow-up has prevented full appreciation of functional outcome and patient satisfaction. This report describes favorable restoration of upper extremity function in two patients who sustained traumatic injuries to the proximal humerus following scapulohumeral arthrodesis In both cases, vascularized fibula transplantation and allograft bone were used, and pedicled latissimus muscle transfers were required for soft-tissue closure.

Adolescent↗
PubMed2000

Ligament reconstruction tendon interposition arthroplasty for basal joint arthritis: simplifying flexor carpi radialis tendon passage through the thumb metacarpal.

During the ligament reconstruction tendon interposition arthroplasty for basal joint arthritis, the flexor carpi radialis tendon is passed through the base of the thumb and out an exit hole on its dorsum. When the entire width of the tendon is harvested, this aspect of the procedure can be difficult. Tapering the width of the proximal tendon and using a Carroll tendon retriever simplify the procedure and eliminate the need for enlarging the transosseous hole in the thumb metacarpal.

Arthroplasty↗
PubMed2000

Two-stage extensor tendon reconstruction after composite tissue loss from the dorsum of the hand.

Restoration of digital extension after chronic extensor loss has not been detailed extensively in the literature. The present report details an unusual case of composite tissue loss from the dorsum of the hand after a chronic burn wound. After debridement for chronic carpal osteomyelitis and free-tissue transfer were performed, staged wrist fusion and two-stage extensor tendon reconstruction resulted in a stable, pain-free wrist and functional digital extension. The present case illustrates that two-stage extensor tendon reconstruction, when necessary, is indeed feasible.

Accidents, Occupational↗
PubMed2000

Use of the entire width of the flexor carpi radialis tendon for the ligament reconstruction tendon interposition arthroplasty does not impair wrist function.

Although the original technical description of the ligament reconstruction tendon interposition arthroplasty as treatment for osteoarthritis at the base of the thumb included use of one half of the width of the flexor carpi radialis (FCR) tendon, it has been recommended that the entire width be used to simplify harvest and provide a larger piece of tissue for ligament reconstruction. The objective of this study was to evaluate preoperative and postoperative wrist motion and flexion strength, subjectively and objectively, to identify whether the use of the entire width of the FCR tendon results in decline or weakness. Our findings show neither subjective nor objective impairment of wrist motion or flexion strength at 1-year follow-up; 6 months after the procedure, strength had returned nearly to baseline.

Arthroplasty↗
PubMed2000

Fibrolipoma of the median nerve: a case report and review of the literature.

A 38 year-old patient presented with right median nerve distribution paresthesias. Electrodiagnostic studies confirmed severe carpal tunnel syndrome. A palmar mass prompted a magnetic resonance imaging scan, which suggested a fibrolipoma of the median nerve. Carpal tunnel release resulted in resolution of preoperative pain and paresthesias. We review the literature dealing with this primary nerve tumor.

Adult↗
PubMed1999

A new methodology to measure load transfer through the forearm using multiple universal force sensors.

Previous approaches to measuring forces in the forearm have made the assumption that forces acting in the radius and ulna are uniaxial near the wrist and elbow. To accurately describe forces in the forearm and the forces in the interosseous ligament, we have developed a new methodology to quantitatively determine the 3-D force vectors acting in forearm structures when a compressive load is applied to the hand. A materials testing machine equipped with a six degree-of-freedom universal force-moment sensor (UFS) was employed to apply a uniaxial compressive force to cadaveric forearms gripped at the hand and humerus. Miniature UFSs were implanted into the distal radius and proximal ulna to measure force vectors there. A 3-D digitizing device was used to measure transformations between UFS coordinate systems, utilized for calculating the force vectors in the distal ulna, proximal radius, and the interosseous ligament (IOL). This method was found to be repeatable to within 3 N, and accurate to within 2 N for force magnitudes. Computer models of the forearm, generated from CT scans, were used to visualize the force vectors in 3-D. Application of this methodology to eight forearm specimens showed that the radius carries most of the load at the wrist while force in the IOL relieves load acting in the radius at the mid-forearm. For a 136 N applied hand force, the force in the IOL was 36 + 21 N. Advantages of this methodology include the determination of 3-D force vectors, especially those in the IOL, as well as computer generated 3-D visualization of results.

Biomechanical Phenomena↗