A model instrument for the documentation of outcome after nerve repair

Long-term results after primary microsurgical repair of ulnar and median nerve injuries

OBJECTIVE

The aim of this retrospective study was to analyze the long-term results of primary repair of median and ulnar nerve lesions. Clinical influence factors for nerve reconstruction were investigated. Furthermore, current score systems were inquired and evaluated on their effectiveness to illustrate the success of repair.

PATIENTS AND METHOD

Sixty-five patients with 71 lesions of the median and ulnar nerve were assessed on average 8.2 years after reconstruction. The results were classified according to the DASH (disability of arm, shoulder, and hand) Score, the Rosen's hand protocol and the Highet Scale.

RESULTS

On average the patients regained 70% of their original hand function (evaluated by Rosen Score: median nerve 2.2/for ulnar nerve 1.92 out of 3.0). Although we noticed inferior motor recovery in ulnar nerve lesions, no significant differences between the overall results of both nerves were observed. Neither accompanying artery and flexor tendon injuries nor the suture technique influenced the recovery. The age of the patient was confirmed as an important influence factor. The results of the DASH Score, Rosen Score and Highet Score correlated significantly.

CONCLUSION

For a sufficient outcome measurement we underline the importance of evaluation of patient's estimation of their impact on their activities of daily living. For this a combination of the functional Rosen Score and the DASH Score is suggested.

Strength measurements of the intrinsic hand muscles: a review of the development and evaluation of the Rotterdam intrinsic hand myometer

Numerous neurological diseases are accompanied by atrophy of the intrinsic muscles of the hand. Muscle strength testing of these muscles is frequently used for clinical decision making. Traditionally, these strength measurements have focused on manual muscle testing (MMT) or on grip and pinch strength dynamometry. We have developed a hand-held dynamometer, the Rotterdam Intrinsic Hand Myometer (RIHM), to measure this intrinsic muscle strength. The RIHM was designed such that it can measure a wide range of muscle groups, such as the abduction and adduction strength of the little finger and index finger, the opposition, palmar abduction (anteposition) and opposition strength of the thumb, and intrinsic muscles of the fingers combined in the intrinsic plus position. We found that the reliability of RIHM measurements in nerve injury patients was comparable to grip and pinch strength measurements and is appropriate to study the functional recovery of the intrinsic muscles of the hand in isolation. We have applied the RIHM in a recent study on the long-term outcome of muscle strength in patients with ulnar and median nerve injuries and found that while recovery of grip and pinch strength was relatively good, recovery of the ulnar nerve innervated muscles measured with the RIHM was poor. This poor recovery could not be detected with manual muscle strength testing or with grip and pinch dynamometry. We conclude that the RIHM provides an accurate clinical assessment of the muscle strength of the intrinsic hand muscles that adds valuable information to MMT and grip and pinch dynamometry.

Enhanced sensory recovery after median nerve repair using cortical audio-tactile interaction. A randomised multicentre study

The "Sensor Glove System" offers an alternate afferent inflow from the hand early after nerve repair in the forearm, mediated through the hearing sense, implying that deprivation of one sense can be compensated by another sense. This sensory "by-pass" was used early after repair of the median nerve with the intention of improving recovery of functional sensibility by maintaining an active sensory map of the hand in the somatosensory cortex during the deafferentation period. In a prospective multicentre clinical study, one group (n=14) started early after surgery with sensory re-education using the Sensor Glove System and the control group (n=12) received conventional sensory re-education, starting 3 months postoperatively. The patients were checked regularly during a 1-year period, with focus on recovery of tactile gnosis. After 12, months, tactile gnosis was significantly better in the Sensor Glove System group. This highlights the timing for introduction of training after nerve repair, focusing on the importance of immediate sensory re-learning.

Cortical reorganization following bimanual training and somatosensory stimulation in cervical spinal cord injury: a case report

BACKGROUND AND PURPOSE

Deficits in upper-extremity function in individuals with tetraplegia are primarily due to the loss of motor pathways. Detrimental cortical reorganization, however, may create further loss of function. The purpose of this case report is to describe the cortical changes associated with a combination intervention using bimanual massed practice training with somatosensory stimulation.

CASE DESCRIPTION

"BR" was a 22-year-old man with C6 tetraplegia and hand impairment who participated in this training intervention for 3 weeks.

OUTCOMES

BR demonstrated improvements in sensory function, strength (the force-generating capacity of muscle), and performance of functional hand skills. Following the training, the cortical motor map of the biceps brachii muscle shifted anteriorly and increased in area and volume.

DISCUSSION

This is the first documented case in which changes in the size and location of the cortical map were associated with an intervention and improvement in function in an individual with tetraplegia. This case suggests that an intensive training intervention may induce both functional and neurophysiological changes.

Considerations in evaluating new treatment alternatives following peripheral nerve injuries: A prospective clinical study of methods used to investigate sensory, motor and functional recovery

The current problem finding reliable and objective methods for evaluating results after peripheral nerve repair is a challenge when introducing new clinical techniques. The aim of this study was to obtain reference material and to evaluate the applicability of different tests used for clinical assessment after peripheral nerve injuries. Fifteen patients with a history of complete median nerve transsection and repair, and 15 healthy volunteers were included. Each subject was investigated using a battery of conventional and new tests for functional, sensory and motor recovery including questionnaires, clinical evaluations, neurophysiological and physiological findings. The results were statistically analysed and comparisons were made within the patient group and between patients and healthy volunteers using a 'per protocol' and an 'intention to treat' approach. Criteria for success were stipulated in order to be able to judge the usefulness of each method. The results showed that 19 of 34 variables, representing six of 16 methods, were not able to fulfil the criteria and were thus questionable for the evaluations of nerve repair in a clinical trial setting. However, 2pd, sensory recovery according to the non-modified British Medical Research Council, sensory neurography, manual muscle test, electromyography, questionnaires (i.e. DASH and the 4 question form) and performance tests (i.e. AMPS and Sollerman's subtests 4 and 8) did fulfil the criteria defined for being useful.

Hand function after nerve repair

Treatment of injuries to major nerve trunks in the hand and upper extremity remains a major and challenging reconstructive problem. Such injuries may cause long-lasting disabilities in terms of lost fine sensory and motor functions. Nowadays there is no surgical repair technique that can ensure recovery of tactile discrimination in the hand of an adult patient following nerve repair while very young individuals usually regain a complete recovery of functional sensibility. Post-traumatic nerve regeneration is a complex biological process where the outcome depends on multiple biological and environmental factors such as survival of nerve cells, axonal regeneration rate, extent of axonal misdirection, type of injury, type of nerve, level of the lesion, age of the patient and compliance to training. A major problem is the cortical functional reorganization of hand representation which occurs as a result of axonal misdirection. Although protective sensibility usually occurs following nerve repair, tactile discriminative functions seldom recover--a direct result of cortical remapping. Sensory re-education programmes are routinely applied to facilitate understanding of the new sensory patterns provided by the hand. New trends in hand rehabilitation focus on modulation of central nervous processes rather than peripheral factors. Principles are being evolved to maintain the cortical hand representation by using the brain capacity for visuo-tactile and audio-tactile interaction for the initial phase following nerve injury and repair (phase 1). After the start of the re-innervation of the hand (phase 2), selective de-afferentation, such as cutaneous anaesthesia of the forearm of the injured hand, allows expansion of the nerve-injured cortical hand representation, thereby enhancing the effects of sensory relearning. Recent data support the view that training protocols specifically addressing the relearning process substantially increase the possibilities for improved functional outcome after nerve repair.

The reliability and validity of the locognosia test after injuries to peripheral nerves in the hand

Locognosia, the ability to localise touch, is one aspect of tactile spatial discrimination which relies on the integrity of peripheral end-organs as well as the somatosensory representation of the surface of the body in the brain. The test presented here is a standardised assessment which uses a protocol for testing locognosia in the zones of the hand supplied by the median and/or ulnar nerves. The test-retest reliability and discriminant validity were investigated in 39 patients with injuries to the median or ulnar nerve. Intraclass correlation coefficients were used to calculate the test-retest reliability. Discriminant validity was assessed by comparing the injured with the unaffected hand. Excellent test-retest reliability was demonstrated for the injuries to the median (intraclass correlation coefficient 0.924, 95% confidence interval 0.848 to 1.00) and the ulnar nerves (intraclass correlation coefficient 0.859, 95% confidence interval 0.693 to 1.00). The magnitude of the difference in scores between affected and unaffected hands showed good discriminant validity. For injuries to the median nerve the mean difference was 11.1 points (1 to 33; SD 7.4), which was statistically significant (p < 0.0001, paired t-test) and for those of the ulnar nerve it was 4.75 points (1 to 13.5; SD 3.16), which was also statistically significant (paired t-test, p < 0.0001). The locognosia test has excellent test-retest reliability, is a valid test of tactile spatial discrimination and should be included in the evaluation of outcome after injury to peripheral nerves.

Comparison of Positive Pressure Gloves on Hand Function in Adults With Burns

The purpose of this study was to analyze the impact of a standard, custom-made pressure glove vs The NewYork-Presbyterian Dexterity Glove (NYPDG) with silon application on the palmer surface on functional hand use of burn survivors. A standard, custom-made pressure glove and NYPDG were given to 18 participants in a randomized order. Subjects wore each glove for 7 to 10 days during all activities of daily living (ADL). Variables such as hand function, difficulty of fine and gross motor ADL, and participant glove preference were assessed with each glove condition. Data collection of the second glove took place 7 to 10 days later incorporating a quasiexperimental, repeated measure design. A crossover design was used to analyze the data. The NYPDG demonstrated significantly better results in all of the four outcome categories measured: time to complete the Jebsen, the Jebsen Likert scale, fine motor ADL, and gross motor ADL. This study demonstrated that functional tasks took less time to complete and were more easily performed when using the NYPDG.

Use of two-point discrimination as a nerve repair assessment tool: preliminary report

BACKGROUND

Two-point discrimination, static and dynamic, has long been used as an assessment tool for tactile gnosis, and to assess recovery after repair of a peripheral nerve. While use of a bent paperclip with a specified intertip distance as the assessment device has been described, no research has been performed on the accuracy of setting this distance by hand and eye alone. The aim of the present study was to demonstrate this accuracy.

METHODS

Five orthopaedic registrars, four residents and three clinic nurses performed static and dynamic two-point discrimination testing on each other. They set the tip distance by hand and eye by bending a paperclip such that the distance between the two ends was their best approximation of 5 mm and then 10 mm. The testing was repeated after 7 days, n = 264 for each tip distance.

RESULTS

Two-sample t-tests showed no significant difference (P > 0.53-0.93) between tip distance setting performed by registrars, nurses and residents; while single sample t-test showed a statistically significant difference (P < 0.0001) between the attempted tip distance and the overall mean tip distance achieved at 5 mm and 10 mm.

CONCLUSION

Statistical analysis showed that the single sample t-test could be discarded. Static and dynamic two-point discrimination testing with a paperclip set by hand and eye is therefore an accurate and reproducible test capable of being administered by both medical and non-medical staff, and is suitable for inclusion in a peripheral nerve repair testing protocol.

Median and ulnar nerve injuries: a meta-analysis of predictors of motor and sensory recovery after modern microsurgical nerve repair

BACKGROUND

The aim of this study was to quantify variables that influence outcome after median and ulnar nerve transection injuries. The authors present a meta-analysis based on individual patient data on motor and sensory recovery after microsurgical nerve repair.

METHODS

From 130 studies found after literature review, 23 articles were ultimately included, giving individual data for 623 median or ulnar nerve injuries. The variables age, sex, nerve, site of injury, type of repair, use of grafts, delay between injury and repair, follow-up period, and outcome were extracted. Satisfactory motor recovery was defined as British Medical Research Council motor scale grade 4 and 5, and satisfactory sensory recovery was defined as British Medical Research Council grade 3+ and 4. For motor and sensory recovery, complete data were available for 281 and 380 nerve injuries, respectively.

RESULTS

Motor and sensory recovery were significantly associated (Spearman r = 0.62, p < 0.001). Multivariate logistic regression analysis showed that age (< 16 years versus > 40 years: odds ratio, 4.3; 95 percent confidence interval, 1.6 to 11.2), site (proximal versus distal: odds ratio, 0.46; 95 percent confidence interval, 0.20 to 1.10), and delay (per month: odds ratio, 0.94; 95 percent confidence interval, 0.90 to 0.98) were significant predictors of successful motor recovery. In ulnar nerve injuries, the chance of motor recovery was 71 percent lower than in median nerve injuries (odds ratio, 0.29; 95 percent confidence interval, 0.15 to 0.55). For sensory recovery, age (odds ratio, 27.0; 95 percent confidence interval, 9.4 to 77.6) and delay (per month: odds ratio, 0.92; 95 percent confidence interval, 0.87 to 0.98) were found to be significant predictors.

CONCLUSIONS

In this individual patient data meta-analysis, age, site, injured nerve, and delay significantly influenced prognosis after microsurgical repair of median and ulnar nerve injuries.

Improved sensory relearning after nerve repair induced by selective temporary anaesthesia - a new concept in hand rehabilitation

The outcome after nerve repair in adults is generally poor. We hypothesized that forearm deafferentation would enhance the sensory outcome by increasing the cortical hand representation. A prospective, randomized, double-blind study was designed to investigate the effects of cutaneous forearm anaesthesia combined with sensory re-education on the outcome after ulnar or median nerve repair. During a 2 week period, a local anaesthetic cream (EMLA (n = 7) or placebo (n=6) was applied repeatedly onto the flexor aspect of the forearm of the injured arm and combined with sensory re-education. Evaluation of sensory function was carried out at regular intervals and at 4 weeks after the last EMLA/placebo session. The EMLA group showed significant improvement compared to placebo in perception of touch/pressure, tactile gnosis and in the summarized outcome after 6 weeks. These results suggest that cutaneous forearm anaesthesia of the injured limb, in combination with sensory re-education, can enhance sensory recovery after nerve repair.

Recent progress in flexor tendon healing. The modulation of tendon healing with rehabilitation variables

Until recently, attempts to optimize the postoperative regimen following intrasynovial flexor tendon repair had been essentially empirical, in that both the time and graduation of the exercise regimen have lacked clear conceptual guidelines. The magnitude of load applied in previous studies had not been clearly controlled, and similarly, the effects of increased repair site excursion and gap formation had not been evaluated in clinically relevant models. Recent experimental in vivo data on the application of force and excursion as independent variables by the authors and other investigators have helped to clarify the respective roles of these two variables. The goal of surgical treatment of intrasynovial flexor tendon lacerations is the achievement of a primary tendon repair of tensile strength sufficient to allow early controlled motion after surgery. The implementation of an appropriate postoperative rehabilitation protocol will, based on the experimental data discussed in this article, decrease the formation of intrasynovial adhesions, facilitate the restoration of the gliding surface, and stimulate the accrual of strength at the repair site.

Comparison of Positive Pressure Gloves on Hand Use in Uninjured Persons

The purpose of this study was to examine functional hand use in uninjured adults when wearing a standard, custom-made pressure glove (SPG) as compared with a glove with select placement of suede, The New York-Presbyterian Dexterity Glove (NYPDG) (patent pending). Thirty-four participants received a custom SPG and NYPDG in a randomized order. Gloves were worn for one day during all activities of daily living (ADL). Hand function, difficulty of fine and gross motor ADL, and participant glove preference were assessed. The process was repeated approximately 1 week later with the remaining glove incorporating a quasi-experimental, repeated measure design. Data were analyzed using a crossover design. Results were significant in favor of the NYPDG in all of the four outcome categories: time to complete the Jebsen, the Jebsen Likert scale, fine motor ADL, and gross motor ADL. In conclusion, this study demonstrated that functional tasks were faster and easier to perform when using the NYPDG.

Missile-caused median nerve injuries: results of 81 repairs

BACKGROUND

Missile-caused median nerve injuries have rarely been reported in current literature. We present repair outcome for all median nerve injuries in which the median nerve was severed either by missile injury or secondarily in the subsequent resection of a neuroma in continuity.

METHODS

Prospective study included 81 casualties with proximal, intermediate, or distal complete median nerve lesions, repaired by nerve graft or direct suture. Final outcome was defined at least 4 years postoperatively, on the basis of motor recovery, sensory recovery, neurophysiological recovery, and patient's judgment on the outcome, each estimated by 0 to 5 points and according to the total sum, as poor, insufficient, good, or excellent. The last 2 modalities were considered to be successful.

RESULTS

Successful outcome was obtained in 68.7% of distal, in 33.3% of intermediate, and in 10% of proximal repairs. Average outcomes were good, insufficient, and poor, respectively (P < .001). Nerve defect and preoperative interval were both significantly shorter on average for patients with successful outcome than for those with unsuccessful outcome (P < .001 and P = .007, respectively), but only preoperative interval and height of repair were independent predictors for successful outcome. Age of patient, associated ulnar nerve complete lesion, and manner of repair did not influence the outcome significantly (P > .05).

CONCLUSIONS

The level of repair, duration of preoperative interval, and length of nerve defect significantly influence outcome after median nerve repair, but only level of repair and duration of preoperative interval were independent predictors for successful outcome.

Tubular repair of the median or ulnar nerve in the human forearm: a 5-year follow-up

The long-term outcome from silicone tube nerve repair was compared with the outcome from routine microsurgical repair in a clinical randomized prospective study, comprising 30 patients with median or ulnar nerve injuries in the distal forearm. Postoperatively, the patients underwent neurophysiological and clinical assessments of sensory and motor function regularly over a 5-year period. After 5 years there was no significant difference in outcome between the two techniques except that cold intolerance was significantly less severe with the tubular technique. In the total group there was ongoing improvement of functional sensibility throughout the 5 years after repair. It is concluded that tubular repair of the median and ulnar nerves is at least as good as routine microsurgical repair, and results in less cold intolerance.

Measuring the strength of the intrinsic muscles of the hand in patients with ulnar and median nerve injuries: reliability of the Rotterdam Intrinsic Hand Myometer (RIHM)

PURPOSE

To determine the reliability and measurement error of measurements of intrinsic muscle strength of a new hand-held dynamometer (the Rotterdam Intrinsic Hand Myometer [RIHM]).

METHODS

With the RIHM we obtained repeated measurements of the intrinsic muscle strength of the hand in 27 patients with peripheral nerve injury of the ulnar and/or median nerve in different stages of rehabilitation. The average time period after injury was 4.4 years (range, 99 days-11 years).

RESULTS

Differences between 2 measurements greater than 6.3 N were interpreted as a real change in assessing the strength of the abduction of the little and index finger; for the median innervated muscles of the thumb this value was 16 N.

CONCLUSIONS

In patients with nerve injuries the muscle strength is usually assessed with manual muscle strength testing and grip- and pinch-strength dynamometers. Preferably the intrinsic muscle strength should be measured in isolation and quantitatively. The RIHM is a new dynamometer that allows for measurements of the intrinsic muscle strength in isolation with reliability comparable to grip and pinch measurements.

A new model instrument for outcome after nerve repair

The Model instrument for outcome after nerve repair has so far proved valid and reliable. It supports the authors' hypothesis that the summary of specific limitations of body function agrees with patients' opinions on the impact of the nerve injury on ADL. These features together with its flexibility make the Model instrument for outcome after nerve repair a psychometrically sound and clinically useful diagnosis-specific outcome instrument for routine evaluation after nerve repair. An optimal choice in the future when assessing the outcome after nerve repair may be a combined use of this model and a more generic outcome instrument. Such a protocol would take into account specific body functions and well being in a wider perspective.

Evaluation of the nerve-injured patient

The evaluation of patients with nerve injury or nerve compression requires an accurate history and subjective report to determine the tests that are the most useful in providing the essential information. Motor and sensory evaluation is necessary inglobal mixed-nerve injuries, but in cases of nerve compression, tests of provocation give more accurate information for detecting the site of nerve compression. There is no gold standard test in the evaluation of patients with nerve injury or compression; therefore, a battery of valid and reliable sensory and motor tests provides the most complete information to formulate a treatment plan.

Outcomes assessment in hand surgery: when are they meaningful?

Hand surgeons currently are challenged with the task of measuring and establishing the connection between the diagnosis and treatment of health-related quality-of-life problems. Although true quality of life cannot be measured directly, instruments in the form of questionnaires have been developed that use self-reporting to account for functional performance, health status, and health-related quality of life. Instruments must be reliable, valid, responsive, and appropriate. Misunderstanding these properties often hinders interpreting the recent stream of outcome studies in the literature. Most physicians are not sure what if any outcome information should be collected routinely or if any outcome instrument is diagnostically useful. Currently there is no convincing evidence to support the routine use of patient-based outcome measures in hand surgeons' practices. Those hand surgeons who would like to carry out an outcome study should consider seeking help from others with expertise in outcomes design and analysis.

Evaluation of hand sensibility: a review

Many assessment devices and measures have been described to evaluate sensibility, with little consensus on the optimal measurement tool. The purpose of this paper is to review the assessment methods and devices used in the evaluation of hand sensibility. Consideration is given to the characteristics of each measurement tool, the information necessary for complete patient evaluation, and the battery of valid and reliable measurements that provide the most complete and accurate patient assessment.

Sensory relearning after nerve repair

One of the challenges in reconstructive surgery is to ensure hand sensibility is regained after median nerve repair. We assessed tactile gnosis in 54 patients (mean age 32 [range 4-72] years) after repair of transected median or ulnar nerves at the wrist level. We found that there is a well-defined critical period for sensory relearning after nerve repair. There is an optimum capacity below age 5-10 years followed by a rapid decline, which levels out after puberty. The curve correlates with previously published data on critical periods for language acquisition among immigrants. Recovery of functional sensibility after nerve repair is based on a learning process and in many ways is analogous to learning a second language.

Prospective analysis of relationships of outcome measures for ulnar neuropathy at the elbow

BACKGROUND

We undertook a prospective study to investigate relationships between outcome measures of ulnar neuropathy at the elbow.

METHODS

Thirty-one patients (mean age 52.6, range 20-80), with clinically and electrically verified ulnar neuropathy at the elbow, were seen independently by a neurosurgeon and a physiotherapist. All tests were administered to all patients on each visit. Data collected included measures of sensory (monofilament, two-point discrimination, vibration) and motor function (grip, key-pinch, muscle atrophy), pain (visual analogue scale (VAS)) and impact on lifestyle (Levine's questionnaires (function status score--FSS, symptom severity score--SSS)), disability of the arm, shoulder and hand module (DASH) and patient-specific measures (PSM). Parametric and non-parametric correlation and factor analysis were done.

RESULTS

Outcome analysis was available for 63 patient visits, with follow-up obtained for 20 patients (mean 8.5 months). Lifestyle and pain instruments (FSS, SSS, DASH, PSM and VAS) all correlated well with each other (r > 0.6, p < .01). DASH was moderately to highly correlated to nine of the 11 measures. Some tests correlated poorly, for example, Semmes-Weinstein monofilament with other sensory measures and muscle atrophy with almost all measures. Factor analysis revealed that there are two principal factors, accounting for 77% of the variance. Factor 1 relates to impact on lifestyle and pain while Factor 2 relates to strength and function.

DISCUSSION/CONCLUSIONS

Intraclass measures, particularly ones assessing lifestyle and pain instruments are strongly correlated. Factor analysis revealed two principal factors that account for the majority of the variance; future studies with a larger sample size are needed to validate this analysis.

The long term recovery curve in adults after median or ulnar nerve repair: a reference interval

This study presents a predicted five-year reference interval for the outcome following repair of the median or ulnar nerve in adults. Forty-four patients were examined with the use of a recently introduced model instrument for documentation after nerve repair that includes "sensory", "motor", and "pain/discomfort" outcomes which together constitute a summarized "total score". Analysis of the "total score" showed that follow-up time and age significantly influence the outcome. There were obvious inferior "motor" results after ulnar nerve injury, but these did not significantly influence the "total score". Significant improvements in the "total score" were seen throughout the follow-up period.