The Effect of Thumb Immobilization on Fractures of the Hook of the Hamate: A Cadaver Study.

Background: Fractures of the hook of the hamate are rare. Nonoperative management has historically been immobilization in a short arm cast (SAC) without thumb immobilization with a high reported incidence of nonunion. The high prevalence of nonunion following nonoperative treatment may be secondary to motion at the fracture site. The transverse carpal ligament's attachment to the hook of the hamate results in movement at the fracture site during thumb motion. Methods: A cadaveric study using 8 fresh frozen cadaver arms amputated at the mid-humeral level was performed. Computed tomography (CT) imaging was used to assess the bony anatomy and assure no preexisting fractures were present. Osteotomy of the hook of the hamate was performed through a skin incision proximal to the hook of the hamate and the transverse carpal ligament. Each arm was then mounted in a jig designed to hold and stabilize the arm and hand in supination. CT scans were performed without cast immobilization with the thumb in extension and abduction, with SAC without thumb carpometacarpal joint immobilization, and SAC with thumb carpometacarpal joint immobilization. Results: Motion of the fractured hook of the hamate was found to occur in all noncasted specimens, greatest with base fractures. SAC without thumb immobilization had little to no effect in eliminating fracture motion. SAC including the thumb reduced fracture motion in all specimens. Conclusions: Previous poor experience with nonoperative management of fractures of the hook of the hamate may be partially due to inability to adequately immobilize the fracture fragment. Fracture motion of the hamate hook occurs during thumb movement, likely from traction on the fracture fragment by the transverse carpal ligament.

Congenital thumb deformities and associated syndromes.

Upper limb defects occur in approximately 3.4 per 10,000 live births. Major thumb defects represent 16% of these upper limb defects (Tay SC, Moran SL, Shin AY, et al. The hypoplastic thumb. J Am Acad Orthop Surg 2006;14:354-366). Embryologically, hand development begins by the fifth week. This occurs simultaneously with the growth and development of the cardiovascular, neurologic, and hematopoietic systems. Therefore, congenital anomalies seen in the hands of infants may indicate significant anomalies in these other systems, requiring a comprehensive physical evaluation. Although the cause of 40% to 50% of congenital hand anomalies is unknown (Gallant GG, Bora FW. Congenital deformities of the upper extremity. J Am Acad Orthop Surg 1996;4:163-171), several others have traced this to specific genetic mutations. Others are due to a variety of teratogenic effects (Sadler TW. Langman's Medical Embryology. 10th ed. Philadelphia: Lippincott Williams &Wilkins, Chapter 9, 2006:125-142). For the clinician, this paper has been organized to identify possible corresponding syndromes that may accompany specific thumb deformities.

Fingertip-nail bed injuries in children: current concepts and controversies of treatment.

Crush injuries of the fingertip are the most common hand injuries seen in children. Many involve fracture of the distal phalanx, whereas others result in either crush alone or complete or partial fingertip amputation. The need for nail removal and nail bed repair after crush injury to the fingertip has long been a matter of debate. In our study comparing the outcome of nail removal and formal nail bed reconstruction versus simple evacuation of the subungual hematoma via trephination after fingernail crush injuries, simple nail trephination was equal to, or superior to, removal of the nail and nail bed repair with significantly lower cost (Roser SE, Gellman H. Comparison of nail bed repair versus nail trephination for subungual hematomas in children. J Hand Surg [Am] 1999;24:1166-1170).

Compression of the ulnar nerve at the elbow: cubital tunnel syndrome.

Although cubital tunnel syndrome has been described as the most common entrapment of the ulnar nerve, there is still considerable difficulty identifying the exact location of the pathologic compression of the nerve and deciding on the correct surgical or nonsurgical treatment. The most commonly recommended surgical techniques include simple (in situ) decompression, decompression with medial epicondylectomy, anterior subcutaneous transposition, and anterior submuscular transposition of the ulnar nerve at the elbow. It is important to understand the pitfalls and possible complications of these commonly used treatments.

Modulation of the sleep state-dependent P50 midlatency auditory-evoked potential by electric stimulation of acupuncture points.

OBJECTIVE: To determine if the P50 midlatency auditory evoked potential, a sleep state-dependent waveform thought to be generated by the reticular activating system, is modulated after surface stimulation of acupuncture points (ie, electroacupuncture). DESIGN: P50 potential recordings were carried out before, during, and after electroacupuncture. SETTING: A clinical research center. PARTICIPANTS: Eighty healthy subjects ages 25 to 55 were recorded in 7 investigations. INTERVENTIONS: Stimulation of 3 specific acupuncture points (Pericardium 6, Heart 3, Liver 3) was compared with no stimulation or with stimulation of control points (Gall Bladder 34, Large Intestine 11, Small Intestine 3). We compared different frequencies of stimulation (5, 60, 100 Hz), unilateral versus bilateral stimulation, and the effects of repeated episodes of stimulation. MAIN OUTCOME MEASURES: P50 auditory evoked potential latency, amplitude (measure of level of arousal), and habituation (measure of sensory gait) at interstimulus interval of 250 ms. RESULTS: Electroacupuncture at specific points decreased P50 potential amplitude versus electroacupuncture at control points (P=.006) or versus no stimulation (P<.001). The optimal effective frequency was 5 Hz (P<.05 at 5 Hz, P>.05 at 60 and 100 Hz), and unilateral electroacupuncture was not as effective as bilateral electroacupuncture (P=.007). Repeated episodes of bilateral electroacupuncture showed additive effects (P<.05). There were no differences in responsiveness across sexes (P=.79), and electroacupuncture did not affect P50 potential habituation (P>.05). CONCLUSIONS: Electroacupuncture may be effectively used to decrease arousal levels, perhaps as adjunct therapy for disorders of hypervigilance.

Management of the upper extremity in juvenile rheumatoid arthritis.

Juvenile rheumatoid arthritis is a multifaceted disease. Average age of onset is 6 years, with peaks between 1 and 4 and between 9 and 14 years. Girls are affected more frequently than boys. Nonsteroidal anti-inflammatory drugs are the standard first line of therapy. Second-line therapy of antirheumatic drugs may be used early for progressive disease. Intra-articular corticosteroid injections should be considered to preserve joint mobility and muscle strength when medical treatment fails to control synovitis or when marked functional impairment exists. Historically, surgery has been a last resort, but in appropriate patients, it should be considered soon after failure of conservative management. However, when possible, reconstructive surgery should be delayed until completion of skeletal growth.

Reflex sympathetic dystrophy in brain-injured patients.

One-hundred consecutive patients were prospectively evaluated on admission to our Brain Injury Unit for signs and symptoms of reflex sympathetic dystrophy (RSD) in the upper extremity. Patients averaged 4 months postinjury and had an average age of 29 years. Thirteen patients had clinical signs and symptoms of RSD and were then evaluated with standard radiographs and 3-phase radionuclide scintigraphy. Twelve of 13 patients had 3-phase bone scans (TPBS) consistent with RSD (12% overall incidence). RSD was present exclusively in the spastic upper extremity. There were 9 patients with hemiparesis and 3 with quadraparesis. There was a significantly higher (P < 0.01) incidence of associated upper extremity injury in the group with RSD (75%). All patients had a mean Rancho Cognitive Level of V and initial Glasgow Coma Scores less than 8. Patients who developed RSD had lower Glasgow Coma Scores than the non-RSD patients. Brain-injured patients often display agitation, hyperalgesia, disuse or neglect of the RSD-involved extremity. In addition, these patients are often cognitively unable to vocalize complaints of pain. Undiagnosed RSD in these patients can result in a significant delay in rehabilitation and possible loss of the use of an otherwise functional upper extremity.