An experimental study on costal osteochondral graft.

OBJECTIVE: To investigate usefulness of osteochondral grafting from the costo-osteochondral junction as a repair technique for articular cartilage defects histologic and biochemical analysis of grafted cartilage in rabbit knees was evaluated up to 48 weeks after transplantation. METHODS: Twenty New Zealand White rabbits were used. A costal osteochondral plug was harvested from a middle rib. After trimming, it was transplanted into a cylindrical osteochondral 2.5 mm diameter and 5 mm deep defect created in the knee. The animals were sacrificed at 6, 12, 24, and 48 weeks after transplantation. Defect sites were inspected macroscopically, and then by light microscopy. Samples were evaluated for cell viability using a fluorescent in situ double-staining protocol with confocal laser microscopic analysis. Samples were also processed to assess type I & II collagen and aggrecan mRNA expression using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Histologically, bone union was achieved in all plugs. Confocal microscopic analysis revealed chondrocyte viability in the 48-week grafts; the distribution of chondrocytes was similar to surrounding articular cartilage. The expression of type II collagen and aggrecan mRNA in the grafted cartilage was consistent with normal articular cartilage and normal costal cartilage. These results were observed over 6-48 weeks. CONCLUSIONS: Our study revealed that chondrocytes in the grafted cartilage were viable at least up to 48 weeks and that mRNA expression of type II collagen and aggrecan was also similar to that of normal articular cartilage. These results suggest that costal osteochondral grafting can be a useful alternative in the treatment of osteochondral defects.

Manual Ability Measure (MAM-16): a preliminary report on a new patient-centred and task-oriented outcome measure of hand function.

The purpose of this study was to develop an easy-to-use and psychometrically sound outcome instrument that is task-oriented and patient-centred. One hundred fifteen patients with a variety of hand impairments completed a rating scale of perceived manual ability (i.e., the Manual Ability Measure). The first 70 patients also completed two other questionnaires about physical health and psychological well-being. Rasch Analyses were conducted to transform the ordinal ratings into linear measures; Rasch statistics were used to evaluate its measurement properties at both scale and item levels. Eighty-three original items were reduced to 16 common tasks; Rasch reliabilities were good; the easy-to-difficult item hierarchy makes sense clinically. Moderate correlations were found between manual ability, physical function and general sense of well-being. The results of this preliminary study suggest that the MAM is a promising outcome measure that has adequate psychometric properties and can be used to complement other objective clinical measurements.

Detection of migratory silicone pseudotumor with use of magnetic resonance imaging.

A patient with silicone gel breast implants, who experienced capsular contracture of the left breast that was treated by closed capsulotomy, sought medical attention because of numbness and pain in the left medial forearm and hand. Inflammatory masses subsequently developed in the left anterior axillary and antecubital regions. Magnetic resonance imaging revealed silicone pseudotumors, and mammography confirmed implant rupture and gel extrusion along fascial planes into the axillary region.

Functional assessment in the rat by ground reaction forces.

Although the rat sciatic nerve model is used extensively in the investigation of repair techniques, and a variety of evaluation methods utilized to assess the results, a means to measure directly and accurately the return of function in these animals is absent. Histologic, histomorphometric, and electrophysiologic methods can be reliable indicators of nerve regeneration but do not correlate to functional recovery. The purposes of this study were to develop apparatus to continuously measure ground reaction forces (GRF) and use GRF parameters in the assessment of gait parameters in normal rats preoperatively and following peripheral nerve severance and repair. Three neurorrhaphy methods: direct sciatic nerve repair, direct tibial nerve repair and double sciatic nerve repair simulating autograft, as well as a non-repaired tibial nerve transection were evaluated. The testing apparatus was designed to measure the spontaneous and voluntary effort of the rat with objective data. Three orthogonal components - vertical, craniocaudal (braking and propulsion), and mediolateral - of the ground reaction force were measured. Preoperative data showed that vertical forces were comparable among the four limbs but propulsion and braking forces displayed significant differences. At 12 weeks, functional recovery was most evident in the direct tibial nerve repair group and absent in the non-repaired tibial defect group. Direct sciatic nerve repairs and sciatic nerve grafts resulted in lesser degrees of improvement. Results indicated that the propulsive force is the optimal GRF parameter for evaluating recovery of useful function.

Effect of bone quality on the forces generated by compression screws.

Internal fixation of the fractured scaphoid bone is used to promote union between bone fragments and to decrease wrist immobilization. Headless screws are commonly used because they minimize interference with articular surfaces and reduce tissue irritation and immobilization. In the present experiment, compressive force was measured as a function of bone quality for two headless screw types, the Herbert and the Acutrak. Forty-seven cylindrical samples of cancellous bone were prepared from fresh, previously frozen human cadaveric distal femora. The compressive forces generated as the screws were advanced into the specimens were measured and correlated to the specimens' bone mineral density (BMD) and density. Over the range tested, the average compressive force for the Acutrack screw was approximately 42% higher than that of the Herbert. Statistical significance, however, could not established because of the low statistical power of the test due to the inherent spread in the data. For the Acutrak screw, force was best fit to BMD and to density by second-order polynomials. Regression analysis indicated that similar correlations did not exist between force and BMD or between force and density for the Herbert screw. The correlation shown by the Acutrak screw indicates that it may be a more predictable as well as more effective system and therefore there may be some advantage in selecting this system. Furthermore, results suggest that the Acutrak screw generates greater forces with increasing bone density and could be more effective for a younger population.

Pediatric hand disease. Diagnosis and treatment.

Proper care of the pediatric hand requires a careful, systematic history, and physical examination, and is facilitated by recognizing common disease patterns, making it easier to determine which conditions require specialty referral, and the timing of those referrals. The article outlines pertinent details of examination and discusses diagnosis and treatment of a number of common diseases entities of the hand.

Common tumors.

Common tumors of the hand and upper extremity are, by definition, benign conditions. There is a predictable pattern of occurrence and presentation for many of these lesions. The practitioner should always bear in mind, however, that any tumor that appears anywhere in the body can appear in the hand and upper extremity. Moreover, several of the benign conditions can, in certain clinical settings, have a predilection for transformation or association with more aggressive conditions. We would emphasize that the approach to any tumor be carefully considered and include an appropriate differential diagnosis. Any suspicious lesion should be examined thoroughly, including first-order screening tests, history, physical examination, radiographic imaging, and laboratory evaluations followed by more detailed diagnostic imaging prior to surgery. Surgery should be approached as a biopsy, with the possibility of frozen section analysis, and the possibility of a two-staged operation for tumor removal with appropriate margins if necessary.

Pressure changes in Guyon's canal after carpal tunnel release.

We measured pressure changes in Guyon's canal and the carpal tunnel before and after endoscopic (11 cases) and open (10) carpal tunnel release. We found that release of the flexor retinaculum by endoscopic and open techniques measurably decreased pressure in both the carpal tunnel and Guyon's canal. This study provides an explanation for relief of ulnar tunnel syndrome symptoms following carpal tunnel release and may indicate that carpal tunnel release alone may be sufficient to provide symptomatic relief for most patients with carpal and ulnar tunnel syndromes.

Early versus delayed treatment of enchondroma.

Enchondromata are among the most common primary neoplasms of the hand, which often present as pathologic fractures. The purpose of this study is to determine whether there are any differences between cases in which both fracture and tumor were treated primarily and those in which tumor treatment was delayed. We reviewed a total of 16 cases; six were treated immediately, 10 were delayed. The immediate treatment group had four complications, the delayed group had one. The theoretical advantages of immediate treatment include a decrease in both the period of disability and delay of definitive diagnosis. This study supports that supposition. However, we did note a significantly higher complication rate for the immediate treatment group (67% versus 10%). Our results indicate that while there is an apparent decreased disability period, there may be reason for caution in immediate treatment of both the fracture and the tumor in pathologic fractures through enchondromata.

Anatomy of upper extremity skin flaps.

The design of upper extremity skin flaps is determined by the anatomy and hemodynamics of each donor site. Skin flaps are best characterized by their blood supply into three types--the direct cutaneous, musculocutaneous, and septocutaneous. Because of the predominance of the septocutaneous vascular system in the upper extremity, the majority of useful flaps in that area are derived from this system. Knowledge of the regulatory factors of the cutaneous circulation is critical in understanding the hemodynamic changes associated with flap elevation if the flap is to be successful. By combining careful flap design based on a knowledge of vascular anatomy and the appropriate postoperative regimen, survival of flaps may be increased significantly.

Scaphocapitate fusion in the treatment of Kienböck's disease.

The primary treatment goal for Kienböck's disease remains decompression of the lunate. Although a number of treatment options are available, scaphocapitate fusion is our first choice in many cases of Kienböck's disease. Scaphocapitate fusion mechanically decompresses the lunate and prevents progressive carpal instability. When compared with STT fusion, it has been shown to result in equal or relatively less loss of wrist motion and thumb basilar joint motion. For disease in earlier stages and with ulnar-minus variance, joint leveling procedures have been shown effective; but ulnar-neutral and ulnar-positive wrists would cause one to favor scaphocapitate fusion to prevent postoperative ulnocarpal abutment.

Reconstruction of traumatic or congenital amputation of the thumb by distraction-lengthening.

Reconstruction of the traumatically or congenitally amputated thumb presents a significant challenge. The individual needs of the patient must be matched with the armamentarium available to the surgeon. Metacarpal elongation via the distraction-lengthening technique, which uses local tissue without sacrificing any adjacent digits or toes, is a reliable means of increasing thumb length by 3 to 3.5 cm. The optimal situation for performing this procedure is the presence of an amputation in the perimetacarpophalangeal joint region. Although neo-osteogenesis has been shown to be useful in pediatric patients, bone grafting is recommended in those individuals aged 25 years and older with gaps of 3 cm or more. The patient must be carefully observed during the distraction period because of the potential problems that may arise from the use of an external fixation device.

Fibrin seal adhesive versus nonabsorbable microsuture in peripheral nerve repair.

Although nonabsorbable microsuture is the material most often used in human peripheral nerve repair, it is capable of eliciting a foreign body reaction, impairing vascularity, and potentially disrupting axonal regeneration. Sutureless methods, including fibrin seal adhesive, may offer an alternative to traditional suture techniques. This study compared the efficacy of fibrin seal with nylon microsuture in tibial microneurorrhaphy on 28 adult New Zealand white rabbits (14 with 10-0 monofilament nylon suture and 14 with fibrin seal). Each rabbit was reexplored at 1, 6, 12, and 18 weeks. The criteria used to compare the two methods were operative time, clinical function, electrophysiologic measures, and histologic findings. Fibrin seal repairs required less time to execute (p less than 0.01) but were inferior in mean conduction amplitude (p less than 0.01) and with respect to histologic criteria. Fibrin seal also appeared less effective in maintaining nerve approximation. We do not believe that fibrin seal provides a superior alternative to nonabsorbable suture in primary nerve repair in this experimental model.

Effect of high-energy phosphates and free radical scavengers on replant survival in an ischemic extremity model.

In replantation surgery, preoperative and intraoperative ischemia can lead to irreversible changes that prevent reperfusion during the subsequent re-establishment of circulation. These changes are termed the no-reflow phenomenon. Ischemic phase damage was addressed by comparing the dose-response effects of controls vs. five different high-energy phosphate compounds on replanted limb survival. Reperfusion damage was evaluated via comparisons of controls with superoxide dismutase (SOD). Ischemic hindlimbs treated with high-energy phosphates displayed improved survival compared with controls. Limbs treated with SOD demonstrated no change in survival at 4 hours and improved survival at 8 hours. Combining adenosine and SOD had no improved effect on survival. Adenosine was the most effective high-energy phosphate in limiting ischemic damage. The free radical scavenger (SOD) was beneficial only at the later stages of ischemia. In this experimental model, there appears to be a role for both phosphates and free radical scavengers in enhancing ischemic tissue survival.