Factors affecting functional outcome of opponens replacement in median nerve paralysis in leprosy.

In this study, the factors affecting functional outcomes of opponens replacement in median nerve paralysis in leprosy, were investigated. Fifty six patients who underwent opponens transfer between 1995 and 2001 were included in the study. The average duration of follow up is 7.3 years with a range of 4-10 years. Functional assessments were done through assessment of grip strength, pinch strengths and fine manipulation and the results were interpreted using Sundararaj (1984) criteria. 76.6% had excellent or good results, 13.3% fair and 10.1% poor results. Pinch strength, grip strength and fine manipulation showed improvement after surgery. Logistic regression analysis showed that duration of paralysis had a significant independent effect on the outcome.

Correction of the claw hand.

Intrinsic paralysis can be the manifestation of a variety of pathologic entities (stroke, cerebral palsy, Charcot-Marie-Tooth, muscular dystrophy, leprosy, trauma, cervical disease, and compressive and metabolic neuropathies). Patients present with a spectrum of clinical findings dependent on the cause and severity of the disease. The 3 main problems caused by intrinsic weakness of the fingers are clawing with loss of synchronistic finger flexion, inability to abduct/adduct the digits, and weakness of grip. Clawing is defined as hyperextension of the metacarpophalangeal joints and flexion of the interphalangeal joints. This article describes the clinical evaluation and surgical treatment options for claw hand.

Factors affecting functional outcome of surgical correction of claw hand in leprosy.

The objective of this paper is to study the results and the factors that impact the results of claw hand surgery in leprosy. 110 patients who underwent claw hand correction between 2002 and 2006 were followed up and studied. Brand's criteria for objective assessment and a visual analog scale for subjective assessment were used. The factors studied were age, sex, clinical, duration of paralysis, long flexor tightness, degree of contracture and type of surgery. Objective assessment showed Excellent or Good results in 76.6%, Fair in 20% and Poor in 3.4%. Subjective assessment showed that 80.8% were fully satisfied or satisfied. Regression analysis showed that age, degree of contracture,duration of paralysis and long flexor contracture were seen as significant factors impacting results of claw hand correction.

Opponens plasty rehabilitation protocol--a case report.

In this case report of opponens plasty, we will attempt to accomplish two objectives: 1) to characterize some innovative modifications to the standard rehabilitation protocol for an opponens plasty and 2) to explain the role and advantages of a new muscle re-education splint in this modified protocol.

Abductor pollicis longus deviation graft operation: modified for stabilizing CMC and MCP joints of 'intrinsic minus' thumb.

The original procedure abductor pollicis longus deviation graft operation by Beine (1996) was introduced to correct retroposition of the thumb and to balance the instability at the carpometacarpal (CMC) joint in cases of ulnar-cum-low median palsy in leprosy, so that bone-using procedures can be avoided to some extent. It provides an antagonistic force to the action of the abductor pollicis longus (abd. pol. long.) by giving this muscle a second insertion, with the result that the action of the abd. pol. long. now stabilises to a considerable extent the CMC joint in its mid-rotational position by a partial replacement of the action of the opponens pollicis (opp. pol.) and abductor pollicis brevis (abd. pol. brev.). Experience over five years with the original procedure showed us that it can make an ulnar deviation more visible at the MCP joint of the thumb. The modification of the procedure corrects this as well, as the results in 12 hands of 11 patients have shown. Interestingly, of the 11 patients who underwent operation, one was not a leprosy patient, but referred to us for partial triple palsy of the left hand and arm without sensory loss. It is shown that the indication of this procedure is wider than mentioned earlier.

Nerve thickening in leprosy patients and risk of paralytic deformities: a field based study in Agra, India.

This paper examines the extent of nerve thickening among leprosy patients detected in the field in Agra district. All the clinically diagnosed leprosy patients were examined in detailed for thickening of local cutaneous nerves and peripheral nerve trunks. In each case all the major nerve trunks in both upper and lower extremities, forehead and neck were examined for thickening. Nerve thickening was found in 94% of multibacillary (MB) patients and among 52% paucibacillary (PB) patients. Nerve thickening was found to be more in males, in prevalent cases than in new (untreated) cases and increased significantly with age and delay in diagnosis (P<0.001). Visible deformities of grade > or =2 were found in 10% (58/573) of the leprosy patients; paralytic deformity accounted for 78% (45/58). Claw hand alone or in combination was seen in 82% (37/45) of patients with paralytic deformities. Risk (odd ratio) for deformities was observed to be high (15-18 times) with increasing number of nerves among patients with neuritic leprosy but correlated with delay in diagnosis of over 5 years. Likewise, deformities were more often seen in those with skin lesions, provided they had > or =3 thickened nerves. Findings suggest that early detection and treatment is useful in preventing deformities.

The paper grip test for screening on intrinsic muscle paralysis in the foot of leprosy patients

Plantar intrinsic foot muscles provide structure to the foot during walking and thus regulate mechanical foot sole stresses. When paralyzed, for instance in leprosy patients with neuropathy of the distal part of the tibial nerve, there is a high prevalence of plantar ulceration and deformities, especially when muscle weakness goes together with loss of foot sole sensibility. These patients should get immediate care involving education, special footwear and reconstructive surgery before further foot impairment and deformity becomes manifest. Thus far, in leprosy patients little attention is paid to screening of plantar intrinsic muscles activity. This can be done with a new simple and non-invasive method, the Paper Grip Test (PGT). There are two variants for detecting intrinsic muscle weakness of the foot, PGT1 for the great toe and PGT2 for the combined lesser toes. In this study, 517 leprosy patients and 170 healthy volunteers were investigated with the PGT. Sensibility of the foot sole was tested by means of a 10 gram monofilament. Specificity to the PGT1 is found to be about 95.3% which is considered good for physical diagnostic tests. PGT2 is less specific than PGT1. Individual muscle power and understanding of the patient seems to influence the outcome of the test to a certain extent. Sensitivity can only be calculated when the diagnosis is confirmed by electromyography. Especially patients with anesthetic feet, females, older patients and patients with PN-, BB- or LL-types of leprosy appeared to have a higher prevalence of intrinsic foot muscle weakness. All results were analyzed by means of the bivariate Pearson correlation-analysis and proved to be statistically significant (p = < 0.05). It is concluded that the PGT1, more than the PGT2, is a useful screening test on the function of plantar intrinsic foot muscles in leprosy patients in hospitals and during fieldwork in developing countries.

Mechanics of tarsal disintegration and plantar ulcers in leprosy by stress analysis in three dimensional foot models.

This paper describes three dimensional two arch models of feet of a normal subject and two leprosy subjects, one in the early stage and the other in the advanced stage of tarsal disintegration, used for analysis of skeletal and plantar soft tissue stresses by finite element technique using NISA software package. The model considered the foot geometry (obtained from X-rays), foot bone, cartilages, ligaments, important muscle forces and sole soft tissue. The stress analysis is carried out for the foot models simulating quasi-static walking phases of heel-strike, mid-stance and push-off. The analysis of the normal foot model shows that highest stresses occur at push-off over the dorsal central part of lateral and medial metatarsals and dorsal junction of calcaneus and cuboid and neck of talus. The skeletal stresses, in early state leprosy with muscle paralysis and in the advanced stage of tarsal distintegration (TD), are higher than those for the normal foot model, by 24% to 65% and 30% to 400%, respectively. The vertical stresses in the soft tissue at the foot-ground interface match well with experimentally measured foot pressures and for the normal and leprosy subjects they are the highest in the push-off phase. In the leprosy subject with advanced TD, the highest soft tissue stresses and shear stresses (about three times the normal value) occur in push-off phase in the scar tissue region. The difference in shear stresses between the sole and the adjacent soft tissue layer in the scar tissue for the same subject is about three times the normal value. It is concluded that the high bone stresses in leprosy may be responsible for tarsal distintegration when the bone mechanical strength decreases due to osteoporosis and the combined effect of high value of footsole vertical stresses, shear stresses and the relative shear stresses between two adjacent soft tissue layers may be responsible for plantar ulcers in the neuropathic leprosy feet.

Three-dimensional foot modeling and analysis of stresses in normal and early stage Hansen's disease with muscle paralysis.

The models of the foot available in the literature are either two- or three-dimensional (3-D), representing a part of the foot without considering different segments of bones, cartilages, ligaments, and important muscles. Hence, there is a need to develop a 3-D model with sufficient details. In this paper, a 3-D, two-arch model of the foot is developed, taking foot geometry from the X-rays of nondisabled controls and a Hansen's disease (HD) subject, and taking into consideration bones, cartilages, ligaments, important muscle forces, and foot sole soft tissue. The stress analysis is carried out by finite element (FE) technique using NISA software for the foot models, simulating quasi-static walking phases of heel-strike, midstance, and push-off. The analysis shows that the highest stresses occur during push-off phase in the dorsal central part of the lateral and medial metatarsals, the dorsal junction of the calcaneus, and the cuboid and plantar central part of the lateral metatarsals in the foot. The stresses in push-off phase in critical tarsal bone regions, for the early stage of HD with muscle paralysis, increase by 25-50% as compared with the control foot model. The model calculated stress results at the plantar surfaces are of the same order of magnitude as the measured foot pressures (0.2-0.5 MPa). The high stress concentration areas in the foot bones indicated above are of great importance, since it is found from clinical reports that in some subjects with pathogenic decrease in the mechanical strength of the bone from HD, these areas of bone are disintegrated. Therefore, this investigation could possibly provide an insight into the factors contributing to disintegration of tarsal bones in HD.

Steroid therapy for paralytic deformities in leprosy.

One-hundred-forty-nine patients with 272 nerve paralyses, with visible deformity and gross disability, were prospectively followed up with steroid therapy. Out of 151 ulnar paralyses, 101 recovered (67%). Out of 52 median nerve paralyses, 45 recovered (86%); out of 69 foot drops, 54 recovered (78%) for an overall improvement of 73%. Serious side effects were few. Hence, steroid therapy should be widely encouraged for the treatment of early nerve damage to prevent permanent deformity/disability, and vigilance in spotting complications of steroid therapy is emphasized.

Two objective "archivable" tests for voluntary muscle testing in ulnar and median nerve paralysis.

Two tests are proposed for assessment of ulnar and median nerve function for use under field conditions: (i) "flap flexion" of fingers for ulnar nerve, and, (ii) tip-to-tip thumb opposition to the fourth finger for median nerve. These tests, which are a part of a series of simple clinical tests proposed for rapid neurological evaluation of the function of the nerves involved in leprosy, are simple, objective and easy to do. Because these tests depend on the strength of muscles tested, they might spare its direct assessment. In fact, it is difficult to assess and grade the strength of the little muscles of the hand and that is very much dependent on the examiner's own experience. Therefore, it is rather subjective. The tests described here may also be used for evaluating the results of corrective surgery of the hand. Whenever possible, making photographic records of these two tests, to be archived in the forms where everyone can see and compare them, seems to be easier and more objective than the subjective transcription of the feelings of an examiner assessing the strength of the small muscles of the hand. These two tests seem to be most objective for a scientific prospective study with a long term follow up. So, they could be used in assessing the results of leprosy neuritis by medical treatment, or, by medical treatment completed (when necessary only and not routinely) by surgical decompression of nerves and also of corrective surgery of claw hand, or, loss of opposition of the thumb.

Analysis of stresses in two-dimensional models of normal and neuropathic feet.

A two-dimensional model of the normal foot skeleton, which includes cartilages and ligaments, is used in this analysis of stresses during three quasi-static walking phases: heel-strike, mid-stance and push-off. It is found that in all the walking phases the maximum values of principal stresses occur in the dorsal anterior region of the talus, whereas the highest stress occurs in the push-off phase. The model is used for the simulation of muscle paralysis and its effect on the distribution of principal stresses. Subsequently, the model is used to analyse stresses in the deformed feet of three leprosy patients with complete paralysis of certain muscles. The results demonstrate that both the shape of the foot and the type of muscle paralysis contribute to the development of high stresses in different regions of the foot. These high stresses in regions with reduced mechanical strength could be one of the important factors in the process of tarsal disintegration in leprosy.

Internal stabilization in the thumb.

An analysis of the thumb as an articular chain, with the biarticular tendon displacement used as a model, is presented. Comparison of the extensor pollicis longus/flexor pollicis longus (EPL/FPL) tendon displacement ratios at the three joints, as determined from cadaver studies, shows that the thumb will be unstable, with a persistent tendency to extend at the carpometacarpal (CMC) joint and flex at the interphalangeal (IP) joint when it is under the exclusive control of the EPL and FPL muscles. In addition, according to the model, with stabilization of the CMC joint, the MCP joint will tend to extend and the IP joint will flex. Clinical data from thumbs of leprosy patients with thenar paralyses largely confirm these predictions and the validity of this approach in studying the functional behavior of the thumb.

The deformity of thumb in ulnar paralysis.

The flexion/extension angles at the Metacarpophalangeal and Interphalangeal joints of the thumb in position of rest and pinch were studied in 68 thumbs of ulnar paralysis. In two thumbs the flexor pollicis brevis was not paralysed. Twenty five normal thumbs were used as controls for comparison. During the resting position the metacarpophalangeal joints showed less flexion and interphalangeal joints more flexion than normal. During the pinch position metacarpophalangeal hyperextension and interphalangeal flexion -- the Z deformity was seen in about 60% while marked interphalangeal flexion was seen in all thumbs of ulnar paralysis. It is suggested that this muscular imbalance is likely to affect thumb joints in time because of abnormal stresses due to altered forces and this can be prevented by restoring the muscle balance by surgery.

Movement patterns of interosseus-minus fingers.

The patterns of isolated metacarpophalangeal-joint flexion and isolated interphalangeal-joint extension movements in eighty fingers with intact extrinsic and lumbrical muscles but no interossei (so-called interosseus-minus fingers) were studied. The pattern of metacarpophalangeal flexion resembled that seen in fingers with paralysis of all intrinsic muscles. From this it was inferred that in the interosseus-minus finger the lumbrical muscles are inactive during this movement. The pattern of isolated interphalangeal extension in the interosseus-minus fingers showed an improvement over that in totally intrinsic-minus fingers, suggesting that the lumbrical muscles reduce the extending forces at the metacarpophalangeal joint to some extent. Active participation of the interosseus muscles appears to be necessary for carrying out the movements of isolated metacarpophalangeal flexion and interphalangeal extension.

Movement patterns of intrinsic minus fingers. Role of intrinsic and extrinsic muscles in finger posture control.

A detailed study of the patterns of two movements (pure metacarpophalangeal flexion and pure interphalangeal extension) in intrinsic minus fingers shows that the long extensors and long flexors produce simultaneous movement at the metacarpophalangeal and interphalangeal joints. A comparison of the patterns of these movements in totally intrinsic minus and interosseous minus fingers shows that in the latter the lumbricals are probably largely inactive during attempted pure metacarpophalangeal flexion and contribute to restrain metacarpophalangeal extension considerably during attempted pure interphalangeal extension. Active participation by the interosseous muscles appears necessary for completing these movements.

Patterns of movement of totally intrinsic-minus fingers based on a study of one hundred and forty-one fingers.

A detailed study of metacarpophalangeal flexion and interphalangeal extension movements of 141 fingers with complete intrinsic-muscle paralysis due to leprosy showed that long flexors and long extensors produce movement at the metacarpophalangeal and proximal interphalangeal joints simultaneously, and not successively as is generally believed. The amounts of flexion resulting from long flexor activity are almost equal at the two joints and metacarpophalangeal flexion is achieved without excessive flexion of the proximal interphalangeal joint, but this is masked by the claw-finger deformity. The movement resulting from activity of the long extensor is complex and there are three or more qualitatively different patterns of extension. Although the long extensor produces simultaneous extension at the metacarpophalangeal and proximal interphalangeal joints, the latter consistently lags behind the former so that full extension is not achieved at the proximal interphalangeal joint even when the metacarpophalangeal joint is maximally extended. The diverse patterns of extension are not related to duration of degree of clawing or to any particular finger.