Biomechanical changes after carpal tunnel release: a cadaveric model for comparing open, endoscopic, and step-cut lengthening techniques.

We used a previously described cadaveric model for evaluating changes in flexor tendon biomechanics after open carpal tunnel release to evaluate endoscopic and step-cut lengthening techniques. A 26% and 18% increase in tendon excursion consumed by wrist motion was demonstrated for flexor digitorum profundus and flexor digitorum superficialis tendons respectively after open transection of the transverse carpal ligament. A 21% and 15% increase in tendon excursion was demonstrated after endoscopic carpal tunnel release and a 21% and 16% increase after step-cut lengthening of the transverse carpal ligament. Increased excursion was noted after 20-30 degrees of wrist flexion as tendon bowstringing occurred. Although division of the transverse carpal ligament by all methods resulted in a significant increase in tendon excursion, the differences between methods of carpal tunnel release were not significant. This cadaveric study evaluates one potential cause for weakness after carpal tunnel release, palmar displacement of the flexor tendons, which results in increased flexor tendon excursion consumed by wrist motion.

Segmental reflex sympathetic dystrophy: clinical and scintigraphic criteria.

Clinical and scintigraphic criteria are proposed for the diagnosis of segmental reflex sympathetic dystrophy. Eight patients met previously described clinical criteria for reflex sympathetic dystrophy with involvement limited to only a portion of the hand. The delayed phase of the three-phase radionuclide bone scan was found to be highly sensitive (100%) for this small group of patients. Consecutive bone scans (n = 127) performed during a 6-month period for a variety of upper extremity problems were reviewed, and a segmentally diffuse pattern of tracer uptake was found to be highly specific (98%) for segmental reflex sympathetic dystrophy. Recognition and documentation of a more localized form of reflex sympathetic dystrophy will allow earlier recognition and treatment, which is an important factor in a successful outcome for managing pain dysfunction disorders.

The transverse carpal ligament. An important component of the digital flexor pulley system.

The effect of release of the transverse carpal ligament on the mechanics of the flexor tendons was investigated with use of a fresh-frozen cadaver model. A 25 per cent increase in the amount of excursion of the tendons that was consumed by motion of the wrist was demonstrated for the digitorum profundus tendons after transection of the transverse carpal ligament, and a 20 per cent increase was noted for the digitorum superficialis tendons (p < 0.001). These values represent 5.4 +/- 1.2 and 5.5 +/- 1.3 millimeters of bow-stringing for each group of tendons.

Femoral varus: an important component in late-onset Blount's disease.

Femoral varus has proven a significant deformity in late-onset Blount's disease. In a retrospective study, six adolescent patients demonstrated mean femoral varus deformity of 10 degrees (range 5 degrees-16 degrees) more than the calculated ideal femoral joint angle (p less than 0.01). This represented between 34 and 76% of the net genu vara deformity of the affected limbs. In the eight infantile patients, all genu vara deformity was in the tibia. The significance of femoral varus should be determined for each patient afflicted with late-onset genu vara preoperatively to avoid compensatory deformity.

Neonatal compartment syndrome.

Two cases of forearm compartment syndrome in neonates are presented. The compartment syndrome may be initiated before actual delivery and may appear in an advanced stage. In both children good clinical results were achieved when standard guidelines for managing compartment syndrome and established Volkmann's contracture were applied. Although uncommon, compartment syndrome should be considered in the differential diagnosis of the neonate who is unable to move an extremity.

Study of growth kinetics and morphology in limbs transplanted between animals of different ages.

The influence of age and maturity on longitudinal skeletal growth was studied using heterotopic limb transplantation with microvascular anastomoses between syngeneic male Lewis rats of different ages. Longitudinal growth of the tibia and growth plate morphology were compared after transplantation between isochronografts (juvenile-to-juvenile and adult-to-adult), heterochronografts (juvenile-to-adult), and unoperated limbs. Four animals comprised each experimental group, except for the juvenile-to-adult heterochronograft group, which had six animals. Limbs were measured at 2-week intervals until sacrifice at 7 weeks. All transplanted limbs demonstrated significant longitudinal growth with maintenance of growth plate morphology and columnar organization. Despite being subjected to an adult hormonal environment, the juvenile tibias transplanted into adult hosts grew 12.0 +/- 1 mm--not significantly different from the unoperated juvenile controls, which grew 12.2 +/- 1 mm. Adult isochronografts showed continued growth of 3.1 mm, which was not significantly different from the unoperated control. Juvenile isochronografts demonstrated decreased growth when compared to unoperated limbs. Maintenance of growth in juvenile limbs transplanted to adults suggests a permissive effect of the hormonal milieu and that ultimate skeletal length is primarily determined by factors inherent in each physis. The use of vascularized transplantation of limbs in syngeneic animals of different ages offers a unique method of altering the hormonal and maturational milieu of the growth plate.

Glomus tumor originating within a digital nerve.

Glomus tumors are thought to arise from specialized cells normally found within the glomus apparatus of the dermal stratum reticularis. We report the unusual occurrence of a glomus tumor from within a peripheral nerve. Previous investigators have suggested that the rare occurrence of glomus tumors in tissue where the glomus apparatus has not been described arise from ectopic glomus cells or differentiate from nonglomus cell sources. Many of the "ectopic" glomus tumors have been found in regions of extensive arteriovenous shunting such as in the digestive system and lung suggesting the presence of glomera at these locations. The finding of a glomus tumor within a peripheral nerve, a region where extensive arteriovenous shunting and glomus bodies have not been described, supports the occasional origin of a glomus tumor from a nonglomus cell source.

Comparison of electron paramagnetic resonance and atomic absorption serum copper measurements in human normal control and cancer patients.

Serum copper levels of 132 controls and 122 cancer patients (including Hodgkin's disease, lung cancer, breast cancer, leukemia, untreated patients, and patients in progression) were measured using both atomic absorption (AA) and electron paramagnetic resonance (EPR) techniques. The data pairs were compared using linear regression analysis, EPR versus AA, and all the data (controls and cancers) fit a single regression line with a squared correlation coefficient (r2) of 0.80. Comparison of the subpopulations revealed possible small differences, but none great enough to be of diagnostic value for individual patients. Thus, in a number of cases of practical interest, EPR-determined serum copper levels were essentially redundant with respect to AA measurements. Previous reports recommending the use and possible superiority of EPR for serum copper determinations appear not to have compared the EPR and AA techniques adequately or correctly. EPR serum copper measurements may yet provide unique data in these diseases, but a more detailed analysis of the spectral parameters will be required. EPR-determined serum transferrin levels are also reported.