Comparing Biomechanical Properties, Repair Times, and Value of Common Core Flexor Tendon Repairs.

BACKGROUND: The aim of the study was to compare biomechanical strength, repair times, and repair values for zone II core flexor tendon repairs. METHODS: A total of 75 fresh-frozen human cadaveric flexor tendons were harvested from the index through small finger and randomized into one of 5 repair groups: 4-stranded cross-stitch cruciate (4-0 polyester and 4-0 braided suture), 4-stranded double Pennington (2-0 knotless barbed suture), 4-stranded Pennington (4-0 double-stranded braided suture), and 6-stranded modified Lim-Tsai (4-0 looped braided suture). Repairs were measured in situ and their repair times were measured. Tendons were linearly loaded to failure and multiple biomechanical values were measured. The repair value was calculated based on operating room costs, repair times, and suture costs. Analysis of variance (ANOVA) and Tukey post hoc statistical analysis were used to compare repair data. RESULTS: The braided cruciate was the strongest repair ( P > .05) but the slowest ( P > .05), and the 4-stranded Pennington using double-stranded suture was the fastest ( P > .05) to perform. The total repair value was the highest for braided cruciate ( P > .05) compared with all other repairs. Barbed suture did not outperform any repairs in any categories. CONCLUSIONS: The braided cruciate was the strongest of the tested flexor tendon repairs. The 2-mm gapping and maximum load to failure for this repair approached similar historical strength of other 6- and 8-stranded repairs. In this study, suture cost was negligible in the overall repair cost and should be not a determining factor in choosing a repair.

Is medial elbow pain correlated with cubital tunnel syndrome? An electrodiagnostic study.

INTRODUCTION: Medial elbow pain is often considered to be a symptom associated with ulnar neuropathy at the elbow (UNE). We examined the relationship between medial elbow pain and a positive electrodiagnostic (EDx) test result for UNE. METHODS: We performed a retrospective review of 884 patients referred for EDx evaluation of UNE. Regression models were used to determine the odds ratios between clinical findings and a positive EDx result for UNE. RESULTS: Patients reported medial elbow pain in 44.3% of cases. Clinical factors that correlated with a positive EDx study result for UNE included male gender, small and ring finger numbness, ulnar intrinsic weakness, and age. Medial elbow pain was negatively correlated with a positive EDx result. CONCLUSIONS: This study demonstrates a negative correlation between medial elbow pain and a positive EDx result for UNE. Medial elbow pain should not be considered a clear diagnostic symptom of UNE.

Arthroscopically assisted elbow interposition arthroplasty without hinged external fixation: surgical technique and patient outcomes.

BACKGROUND: Total elbow arthroplasty is successful in older, lower demand patients but not in the younger, more active individual with severe elbow arthritis. Interposition arthroplasty is an alternative for younger patients who hope to minimize the degree to which arm use is restricted. Interposition arthroplasty traditionally involves release of all ligaments and capsule. As a result, the postoperative care included the use of a hinged external fixator of the elbow to apply distraction and to permit motion during the early phases of healing. We describe a novel surgical technique without a hinged external fixator that allows secure fixation of the interposition graft through arthroscopic assistance and maintains the integrity of the medial collateral ligament with only a takedown and repair of the lateral collateral ligament complex. METHODS: A retrospective chart review was performed to analyze 4 patients with an average age of 57 years who underwent surgery between 2007 and 2011. The patients were also contacted to assess elbow-specific American Shoulder and Elbow Surgeons and Disabilities of the Arm, Shoulder, and Hand scores. RESULTS: The average follow-up was 3.6 years (range, 2.5-6 years), and 1 patient was converted to a total elbow arthroplasty after 2.5 years because of persistent pain. The remaining 3 patients have done well with regard to pain control, stability, and functional use of the operative extremity. There were no postoperative complications. DISCUSSION: On the basis of our small series of patients, an arthroscopically assisted elbow interposition arthroplasty without hinged external fixation can provide satisfactory medium-term outcomes as a salvage procedure for a difficult condition with limited options.

Flexor tendon repairs: techniques, eponyms, and evidence.

The evolution in surgical technique and suture technology has provided an abundance of options for flexor tendon repairs. Multiple biomechanical studies have attempted to identify the best surgical technique based on suture properties, technical modifications, and repair configurations. However, the burgeoning amount of research on flexor tendon repairs has made it difficult to follow, and no gold standard has been determined for the optimal repair algorithm. Therefore, it seems that repairs are usually chosen based on a combination of familiarity from training, popularity, and technical difficulty. We will discuss the advantages, disadvantages, and technical aspects of some of the most common core flexor tendon repairs in the literature. We will also highlight the nomenclature carried through the years, drawings of the repairs referred to by that nomenclature, and the data that support those repairs.

Cubital tunnel syndrome.

Cubital tunnel syndrome is the second most common compression neuropathy in the upper extremity. Patients complain of numbness in the ring and small fingers, as well as hand weakness. Advanced disease is complicated by irreversible muscle atrophy and hand contractures. Ulnar nerve decompression can help to alleviate symptoms and prevent more advanced stages of dysfunction. Many surgical treatments exist for the treatment of cubital tunnel syndrome. In situ decompression, transposition of the ulnar nerve into the subcutaneous, intramuscular, or submuscular plane, or medial epicondylectomy have all been shown to be affective in the treatment of this disease process. Comparative studies have shown some short-term advantages to one or another technique, but overall results between the treatments have essentially been equivocal. The choice of surgical treatment is based on multiple factors, and a single surgical approach cannot be applied to all clinical situations. Through careful consideration of the potential sites of nerve compression and the etiologies for these local irritations, the appropriate surgical technique can be selected and a good outcome anticipated in most patients.

Lateral intercellular space volume as a determinant of CFTR-mediated anion secretion across small intestinal mucosa.

Studies of full-thickness, small intestinal preparations have shown that maximal anion secretion [indexed by short-circuit current (I(sc))] during intracellular cAMP (cAMP(i)) stimulation is transient and followed by a decline toward baseline. Declining I(sc) is preceded by decreases in transepithelial conductance (G(t)), which in the small intestine reflects the lateral intercellular space (LIS) volume of the paracellular pathway. We hypothesized that decreases in LIS volume limit the magnitude and duration of cAMP(i)-stimulated anion secretion. Experimental manipulations to increase the patency of the LIS (assessed by G(t) and electron microscopy) were investigated for an effect on the magnitude of cAMP(i)-stimulated anion secretion (assessed by the I(sc) and isotopic fluxes) across murine small intestine. In control studies, changes of G(t) after cAMP(i) stimulation were associated with a morphological "collapse" of the LIS, which did not occur in intestine of CFTR-null mice. Removal of the outer intestinal musculature, exposure to a serosal hypertonic solution, or increased serosal hydrostatic pressure minimized reductions in G(t) and increased the cAMP(i)-stimulated I(sc) response. Increased I(sc) primarily resulted from increased Cl(-) secretion that was largely bumetanide sensitive. However, bumetanide-insensitive I(sc) was also increased, and similar increases occurred in the Na(+)-K(+)-2Cl(-) cotransporter (NKCC1)-null intestine, indicating that activities of non-NKCC1 anion uptake proteins are also affected by LIS volume. Thus LIS patency is an important determinant of the magnitude and duration of CFTR-mediated anion secretion in murine small intestine. Decreases in LIS volume may limit the pool of available anions to basolateral transporters involved in transepithelial secretion.

cAMP inhibition of murine intestinal Na/H exchange requires CFTR-mediated cell shrinkage of villus epithelium.

BACKGROUND AND AIMS: Unlike the intestine of normal subjects, small-intestinal epithelia of cystic fibrosis patients and cystic fibrosis transmembrane conductance regulator protein-null (CFTR(-)) mice do not respond to stimulation of intracellular cyclic adenosine monophosphate with inhibition of electroneutral NaCl absorption. Because CFTR-mediated anion secretion has been associated with changes in crypt cell volume, we hypothesized that CFTR-mediated cell volume reduction in villus epithelium is required for intracellular cyclic adenosine monophosphate inhibition of Na(+)/H(+) exchanger (primarily Na(+)/H(+) exchanger 3) activity in the proximal small intestine. METHODS: Transepithelial (22)Na flux across the jejuna of CFTR(+), CFTR(-), the basolateral membrane Na(+)/K(+)/2Cl(-) co-transporter protein NKCC1(+), and NKCC1(-) mice were correlated with changes in epithelial cell volume of the midvillus region. RESULTS: Stimulation of intracellular cyclic adenosine monophosphate resulted in cessation of Na(+)/H(+) exchanger-mediated Na(+) absorption (J(ms)(NHE)) in CFTR(+) jejunum but had no effect on J(ms)(NHE) across CFTR(-) jejunum. Cell volume indices indicated an approximately 30% volume reduction of villus epithelial cells in CFTR(+) jejunum but no changes in CFTR(-) epithelium after intracellular cyclic adenosine monophosphate stimulation. In contrast, cell shrinkage induced by hypertonic medium inhibited J(ms)(NHE) in both CFTR(+) and CFTR(-) mice. Bumetanide treatment to inhibit Cl(-) secretion by blockade of the Na(+)/K(+)/2Cl(-) co-transporter, NKCC1, of stimulated CFTR(+) jejunum prevented maximal volume reduction of villus epithelium and recovered approximately 40% of J(ms)(NHE). Likewise, J(ms)(NHE) and cell volume were unaffected by intracellular cyclic adenosine monophosphate stimulation in NKCC1(-) jejuna. CONCLUSIONS: These findings show a previously unrecognized role of functional CFTR expressed in villus epithelium: regulation of Na(+)/H(+) exchanger 3-mediated Na(+) absorption by alteration of epithelial cell volume.