Lars B. Dahlin

Techniques of peripheral nerve repair.

Nerve injuries extend from simple nerve compression lesions to complete nerve injuries and severe lacerations of the nerve trunks. A specific problem is brachial plexus injuries where nerve roots can be ruptured, or even avulsed from the spinal cord, by traction. An early and correct diagnosis of a nerve injury is important. A thorough knowledge of the anatomy of the peripheral nerve trunk as well as of basic neurobiological alterations in neurons and Schwann cells induced by the injury are crucial for the surgeon in making adequate decisions on how to repair and reconstruct nerves. The technique of peripheral nerve repair includes four important steps (preparation of nerve end, approximation, coaptation and maintenance). Nerves are usually repaired primarily with sutures applied in the different tissue components, but various tubes are available. Nerve grafts and nerve transfers are alternatives when the injury induces a nerve defect. Timing of nerve repair is essential. An early repair is preferable since it is advantageous for neurobiological reasons. Postoperative rehabilitation, utilising the patients own coping strategies, with evaluation of outcome are additional important steps in treatment of peripheral nerve injuries. In the rehabilitation phase adequate handling of pain, allodynia and cold intolerance are emphasised.

Prospective study of patients with injuries to the hand and forearm: Costs, function, and general health.

Patients with injured hands and forearms of varying severity [Hand Injury Severity Score (HISS)] were studied prospectively, including analysis of costs, hand/arm function (DASH), and health status (SF-36). Costs, duration of sick-leave, DASH-score (high score; impaired function) increased by severity of injury (higher HISS) and the greatest proportion of total costs resulted from lost production. Most employed patients returned to work within a year, but even minor injuries were expensive. HISS and costs of care during an emergency were significantly associated with duration of sick-leave, although HISS did not fully explain variation in costs and duration of sick-leave. DASH-score at one year was associated with variation in age, HISS, and residual health care costs. Results of DASH and subgroups for physical and bodily pain on SF-36 were consistent. Injuries to hand and forearm may generate high costs for society in terms of health care and long periods of sick-leave (lost production), but even minor injuries should be accounted for.

End‐to‐side nerve repair in the upper extremity of rat

Abstractu2003 The end‐to‐side nerve‐repair technique, i.e., when the distal end of an injured nerve is attached end‐to‐side to an intact nerve trunk in an attempt to attract nerve fibers by collateral sprouting, has been used clinically. The technique has, however, been questioned. The aim of the present study was to investigate end‐to‐side repair in the upper extremity of rats with emphasis on functional recovery, source, type, and extent of regenerating fibers. End‐to‐side repair was used in the upper limb, and the radial or both median/ulnar nerves were attached end‐to‐side to the musculocutaneous nerve. Pawprints and tetanic muscle force were used to evaluate functional recovery during a 6‐month recovery period, and double retrograde labeling was used to detect the source of the regenerated nerve fibers. The pawprints showed that, in end‐to‐side repair of either one or two recipient nerves, there was a recovery of toe spreading to 60–72% of the preoperative value (lowest value around 47%). Electrical stimulation of the end‐to‐side attached radial or median/ulnar nerves 6 months after repair resulted in contraction of muscles in the forearm innervated by these nerves (median tetanic muscle force up to 70% of the contralateral side). Retrograde labeling showed that both myelinated (morphometry) sensory and motor axons were recruited to the end‐to‐side attached nerve and that these axons emerged from the motor and sensory neuronal pool of the brachial plexus. Double retrograde labeling indicated that collateral sprouting was one mechanism by which regeneration occurred. We also found that two recipient nerves could be supported from a single donor nerve. Our results suggest that end‐to‐side repair may be one alternative to reconstruct a brachial plexus injury when no proximal nerve end is available.

Expression of ATF3 and axonal outgrowth are impaired after delayed nerve repair

BackgroundA delay in surgical nerve repair results in impaired nerve function in humans, but mechanisms behind the weakened nerve regeneration are not known. Activating transcription factor 3 (ATF3) increases the intrinsic growth state of injured neurons early after injury, but the role of long-term changes and their relation to axonal outgrowth after a delayed nerve repair are not well understood. ATF3 expression was examined by immunohistochemistry in motor and sensory neurons and in Schwann cells in rat sciatic nerve and related to axonal outgrowth after transection and delayed nerve repair (repair 0, 30, 90 or 180 days post-injury). Expression of the neuronal cell adhesion molecule (NCAM), which is expressed in non-myelinating Schwann cells, was also examined.ResultsThe number of neurons and Schwann cells expressing ATF3 declined and the length of axonal outgrowth was impaired if the repair was delayed. The decline was more rapid in motor neurons than in sensory neurons and Schwann cells. Regeneration distances over time correlated to number of ATF3 stained neurons and Schwann cells. Many neurofilament stained axons grew along ATF3 stained Schwann cells. If nerve repair was delayed the majority of Schwann cells in the distal nerve segment stained for NCAM.ConclusionDelayed nerve repair impairs nerve regeneration and length of axonal outgrowth correlates to ATF3 expression in both neurons and Schwann cells. Mainly non-myelinating Schwann cells (NCAM stained) are present in distal nerve segments after delayed nerve repair. These data provide a neurobiological basis for the poor outcomes associated with delayed nerve repair. Nerve trunks should, if possible, be promptly repaired.

Clinical Outcomes of Surgical Release Among Diabetic Patients With Carpal Tunnel Syndrome: Prospective Follow-Up With Matched Controls

PURPOSEnTo compare the clinical outcome after carpal tunnel release in diabetic and nondiabetic patients.nnnMETHODSnWe evaluated a prospective, consecutive series of 35 diabetic patients (median age, 54 years; 15 with type 1 and 20 with type 2 diabetes) with carpal tunnel syndrome, who were age- and gender-matched with 31 nondiabetic patients (median age, 51 years) having idiopathic carpal tunnel syndrome. Exclusion criteria were other focal nerve entrapments, cervical radiculopathy, inflammatory joint disease, renal failure, thyroid disorders, previous wrist fracture, and long-term exposure to vibrating tools. Participants were examined independently at baseline (preoperatively) and 6, 12, and 52 weeks after surgery, including evaluating sensory function (Semmes-Weinstein), motor function (abductor pollicis brevis muscle strength and grip strength), pillar pain, cold intolerance, and patient satisfaction.nnnRESULTSnThe number of patients with normal sensory function (pulp of index finger) increased notably in both patient groups from baseline (diabetic patients, 7 of 35; nondiabetic patients, 10 of 31) compared with the 52-week follow-up (diabetic patients, 25 of 35; nondiabetic patients, 24 of 31). Grip strength decreased temporarily at 6 weeks but recovered completely after 12 weeks. At the 52-week follow-up, mean grip strength (95% confidence interval) had improved significantly in both patient groups (diabetic patients: 3.0 kg [-0.3 to 6.2], nondiabetic patients: 3.4 kg [0.2 to 6.6]). Pillar pain correlated significantly with grip strength at the 6-week follow-up (r(s) = -0.41 to -0.54 [p < .05]). The number of patients reporting cold intolerance decreased over time (diabetic patients, 22 of 35 to 19 of 35; nondiabetic patients, 18 of 31 to 8 of 31), but decreased markedly less for the diabetic patients. Level of patient satisfaction was equal between groups. Comparing type 1 and type 2 diabetic patients, no important difference was noted on any test variables.nnnCONCLUSIONSnPatients with diabetes have the same beneficial outcome after carpal tunnel release as nondiabetic patients. Only cold intolerance demonstrated a lesser extent of relief for diabetic patients.nnnTYPE OF STUDY/LEVEL OF EVIDENCEnPrognostic I.

Hand Problems in 100 Vibration-Exposed Symptomatic Male Workers

Long-term use of hand-held vibrating tools may induce various types of hand problems. One hundred symptomatic men exposed to vibration from such tools were interviewed and examined with special reference to neurosensory and vasospastic problems. Three distinct symptomatic groups were identified: isolated neurosensory symptoms (48%), isolated vasospastic problems (20%), and combined neurosensory and vasospastic problems (32%). Abnormal cold intolerance (pain and coldness without blanching of the fingers on exposure to cold) occurred in 27% of the patients. Neurosensory problems were more predominant than vasospastic ones, especially during the first 20 years of vibration exposure. Of 80 patients with neurosensory symptoms, only 22 had signs of a carpal tunnel syndrome (CTS). It is concluded that vibration-induced neurosensory and vasospastic symptoms can occur separately or together, and that the neurosensory symptoms are often not due to a CTS.

Surgery of the Spastic Hand in Cerebral Palsy Improvement in stereognosis and hand function after surgery

Thirty-six patients with hemiplegic cerebral palsy had surgical treatment for the upper limb and were followed up for 18 months postoperatively. Various operations were done. A striking finding was a significant improvement of stereognosis (ability to describe and recognize objects without vision). Most patients had improvement in different functional grasps following surgical reconstruction. Range of movement in the forearm and wrist also increased in most patients. The thumb-in-palm deformity was completely corrected in 31 of the patients and improved in the other five. Most patients had some or all of their expectations of the procedure fulfilled.

Regeneration and functional recovery in the upper extremity of rats after various types of nerve injuries.

Abstractu2002 The aim was to establish an accurate, reproducible, and simple method to evaluate functional recovery after different types of nerve injuries to the brachial plexus of rats. To that end, pawprints, measured as distance between the first and fourth and second and third digits, were used for evaluation of injuries including crush injury, transection/repair, or graft repair of the median, ulnar, and radial nerves. Immunocytochemistry of the C‐terminal flanking peptide of neuropeptide Y (CPON) and neurofilaments was used to investigate the cell body response and axonal outgrowth, respectively. Functional recovery was dependent on the severity as well as on the level of the lesion. Neither a single injury to the median nerve nor an injury to the ulnar nerve affected the pawprint, while an injury to both these nerves or a single injury to the radial nerve caused impairment of pawprints. There was a rapid recovery after crush injury to these nerves compared to previous reports of a similar injury to the sciatic nerve. The pattern of axonal outgrowth was related to the severity of the lesion. A conditioning lesion, i.e., an initial lesion of the same nerve preceding a test injury by a few days, of both motor/sensory fibers led to a quicker functional recovery. Surprisingly, conditioning of only sensory fibers had nearly the same effect. The cell body response was dependent on the level of the nerve lesion. The upper extremity of rats might be useful to evaluate the effects of new repair methods after nerve injuries using functional evaluation with pawprints as a simple and accurate method.

What determines the costs of repair and rehabilitation of flexor tendon injuries in zone II? A multiple regression analysis of data from southern sweden

The epidemiology and costs of repair and rehabilitation of zone II flexor tendon injuries in 135 patients from the southern part of Sweden were analysed. The little finger was most frequently injured (43%), usually with a knife (46%), and 30% of the injuries were work related. Total median costs within the health-care sector for the injuries were SEK 48,500 (1 EURO=9.23 SEK, 4/1/2002). Costs in other sectors were SEK 93,000. Active mobilization or mobilization with rubber band traction increased costs within the health-care sector (SEK 7400 or SEK 6000, respectively) but improved range of movement (5–7%). Immobilization had a higher complication rate (rupture or need for secondary procedures), which in itself increased total costs by 57%. Nonlinear effects were found between age and costs within the health-care sector and the outcome.

Hand injuries in young children.

Four hundred and fifty five young children (0–6 years old) were treated for hand injuries between 1996 and 2000. Boys (61%) were injured more often and a higher number of injuries occurred during May and September. Fingertip injuries were the most common injuries (37%), and were often caused by jamming in doors at home. Fractures were caused by falls and punches and tendon/nerve injuries by sharp objects. The incidence of hand injuries increased from 20.4/10,000/year in 1996 to 45.3/10,000/year in 2000. Only 4% of the children had complex injuries but these placed a high demand on resources. The incidence of injuries was not higher amongst children from immigrant families.