Effect of radiation on skin expansion and skin flap viability in pigs.

The aim of the present study was to investigate the effect of radiation treatment both on skin tissue expansion with the chronic inflation of subcutaneous expanders and on skin flap viability in surgically delayed and expanded skin in the pig. One flank in each of six pigs (initially weighing 17 +/- 1.8 kg) was randomly assigned for radiation treatment, and the contralateral flank served as a nonirradiated control. Three mirror-image, 8 x 10 cm, rectangular templates were marked on each flank; these templates were randomly assigned to the construction of a delayed skin flap (group A), a skin flap raised on expanded skin (group B), or a skin flap raised on expanded skin with a capsulectomy before flap surgery (group C). Radiation treatment was performed using sequential radiation with three fractions per week (810 cGy/fraction) for 2 weeks, with a total dose of 4,860 cGy. Twelve weeks after radiation treatment, skin expanders (8 x 10 cm) were installed subcutaneously in the locations assigned for skin expansion. Skin expansion by the inflation of subcutaneous skin expanders with saline twice weekly was started 8 weeks later and lasted for 3 weeks. Two weeks after surgical delay and the last skin expansion, 8 x 20 cm skin flaps were raised on the locations assigned for delayed skin flaps, expanded skin flaps, and expanded skin flaps with a capsulectomy. Skin flap viability was assessed 24 hours later using a fluorescein dye-staining technique. Skin expansion by the inflation of subcutaneous expanders with saline was slower (p < 0.05) in the radiated skin (39 +/- 6 ml/filling) than in the nonirradiated control skin (51 +/- 6 ml/filling). Radiation reduced the overall area of expanded skin by 23 percent (p < 0.05) compared with the control. Radiation treatment also reduced skin viability by 36 percent (p < 0.05) in the delayed skin flaps, 27 percent (p = 0.10) in the expanded skin flaps, and 36 percent (p < 0.05) in the expanded skin flaps with a capsulectomy when compared with their contralateral, nonirradiated controls. There were no significant differences in skin viability among these three types of skin flaps within the radiated and nonirradiated groups. Taken together, these observations indicate that radiation treatment reduced the effectiveness of the surgical delay procedure, the amount of subcutaneous skin expansion (by an increase in skin area), and skin flap viability. However, a capsulectomy alone did not affect the viability of skin flaps raised on expanded skin.

Salvage after severe lower-extremity trauma: are the outcomes worth the means?

Advances in reconstructive surgery have allowed for impressive salvage after severe lower-extremity trauma but not without complications when compared with immediate below-knee amputation. Several amputation index scores have been developed to help predict successful salvage as defined by a viable rather than a functional extremity. The purpose of this study was to evaluate retrospectively the predictive value of the amputation index scores and to assess prospectively overall health status and specific dysfunction in successful limb salvage and primary and secondary amputation by administering standardized generic and specific outcomes questionnaires (Medical Outcomes Study 36-Item Short-Form Health Survey, Western Ontario and MacMaster Universities Osteoarthritis Index). A retrospective chart review identified 55 severe lower-extremity injuries (Gustilo Type IIIB and IIIC) over a 12-year period (1984 to 1996). Forty-six severe open tibial fractures in 45 patients underwent attempted salvage. All required soft-tissue coverage by either local or free flap or vascular repair for leg salvage. The attempted-salvage group was subdivided into successful salvage and secondary amputation. The other nine patients underwent a primary amputation. There were no statistically significant differences in terms of patient demographics or other injuries (Injury Severity Score) in the three groups. Forty-eight of 54 patients with an average 5-year follow-up completed a validated generic and specific outcomes health questionnaire. In the attempted-salvage group, 89 percent of patients had a successful salvage and 11 percent came to a secondary amputation. The amputation index scores correctly predicted an amputation in 32 percent of patients. The magnitude of the amputation index scores did not correlate with the physical outcomes scores and were not found to add any significant value of information to the surgeon's decision making. Patients undergoing primary and secondary amputation had a worse physical outcomes score (28 versus 38) than successful salvage (p < 0.007). Even so, the SF-36 (physical component score) outcomes score for this group of injured extremities, regardless as to whether salvaged or amputated, was as low as or lower than that of many serious medical illnesses, suggesting that severe lower-extremity trauma impairs health as much as or more than being seriously ill. The mental component score in this group was comparable to that of a healthy population (49 versus 50), which implies the disability is primarily physical rather than psychological. Ninety-two percent of patients preferred their salvaged leg to an amputation at any stage of their injury, and none would have preferred a primary amputation.

Peripheral nerve regeneration, repair, and grafting.

Peripheral nerve injuries are a major source of chronic disability. Advances in microsurgery and a better understanding of nerve healing have greatly improved the outcomes of nerve repair in the past two decades. This paper reviews the current thoughts on peripheral nerve regeneration and repair. Controversial topics such as the timing of nerve repair, new techniques of nerve repair (fibrin glue, lasers, and tubulization), nerve grafting, and the treatment of neuroma are discussed. A general approach to postoperative care is presented and shown to be governed by an understanding of not only nerve healing but tissue healing in general. A summary of current clinical results of upper extremity nerve repairs is given to provide benchmarks of practice for hand therapy units to achieve and supersede.

Enchondroma protuberans: a case report.

Enchondroma protuberans is a rare benign cartilaginous tumor. There have been only 5 cases previously described in the world literature. It must be differentiated from other more common and aggressive tumors to avoid radical resection. A case report of a 7-year-old boy presenting with enchondroma protuberans in the third metacarpal is presented. The patient underwent an initial incisional biopsy followed by a marginal resection of the soft tissue component and intramedullary curettage. After a 36-month follow-up period, there is no evidence of recurrence.

The histopathological changes in irradiated vs. nonradiated tissue-expanded skin in the porcine model.

This study examined the histological changes following irradiation on nonexpanded and tissue-expanded pigskin. Six Yorkshire pigs received 4860 cGy radiation to one flank with the opposite side serving as the control. A histopathological comparison of tissue expansion in irradiated tissue to nonradiated tissue showed a reduction in the thickness of the dermal and subcutaneous layers, with less prominent rete ridges and a thicker stratum spinosum (p < 0.05). Nonexpanded irradiated tissue showed a reduction of thickness in the dermis and subcutaneous layer, less prominent rete ridges, and a thicker stratum spinosum layer (p < 0.05) when compared with nonradiated tissue. Tissue-expanded irradiated tissue showed no significant differences (p > 0.05) in any of these parameters when compared with nonexpanded irradiated tissue. This study demonstrates that radiation produced a significant change in porcine skin, but tissue expansion did not further alter the histological changes associated with irradiation.

Scapholunate dissociation: an experimental kinematic study of two types of indirect soft tissue repairs.

Indirect soft tissue repairs of scapholunate dissociation (SLD) address the pathophysiology but have been criticized for significantly limiting wrist flexion and altering wrist kinematics. This study was designed to analyze and compare the kinematics of a normal cadaveric wrist to those of 2 types of soft tissue repairs performed for SLD. Ten uninjured fresh cadaver arms were evaluated by cineradiography and standard x-rays. The average scapholunate (SL) gap was 0.9 mm, with a SL angle of 50 degrees. A model of SLD was produced by sectioning the SL ligaments resulting in an average SL gap of 3.9 mm and SL angle of 66 degrees. The wrists were randomized to a dorsal capsulodesis repair and a distally based split extensor carpi radialis longus (ECRL) repair. The average SL gap after repair was 1.0 mm and the average SL angle was 47 degrees. The split ECRL repair and dorsal capsulodesis reduced scaphoid flexion with only a 10 degree and 18 degree decrease in wrist flexion, respectively. Both repairs reduced the SLD and restored normal wrist kinematics.

Use of a new anchoring device for tendon reinsertion in medial canthopexy.

This paper describes the use of the Mitek Mini GII Anchor System for tendon reinsertion in medial canthopexy. The system is simple, fast to insert, and easy to use. It allows precise placement with minimal dissection, which is limited to the ipsilateral orbit.

Medial canthopexy: an experimental and biomechanical study.

Medial canthopexy is associated with a significant failure rate. A cadaveric study was undertaken to evaluate the biomechanics of the medial canthal tendon and three types of fixation devices for medial canthopexy. Eight medial canthal tendons were assessed in 4 fresh-frozen cadaver heads. The medial canthal tendon was found to be much stronger than previously suspected, with an average breaking strength of 36 newtons and an elongation of 6.25 mm. The tendon-bone complex was noted to be closely matched biomechanically. Three medial canthopexy techniques were then assessed: transnasal wire over a button, 1.7-mm screw fixation into the medial orbit, and the Mitek GII anchor. Their respective holding strengths were 74%, 92%, and 97% of that of the contralateral intact medial canthal tendon. The three types of fixation devices all provided excellent ultimate biomechanical strength.

Simple monitoring technique for muscle flaps.

A simple monitoring technique for the detection of postoperative arterial flow failure in muscle flaps is described. The technique consists of isolating a musculocutaneous perforator on elevation of a muscle flap. This cutaneous perforator is observed for pulsation in the postoperative period. Abrupt cessation prior to 48 hours should be an indicator for prompt clinical evaluation of the muscle flap by an experienced microsurgeon to rule out arterial thrombosis.

Effect of wrist position on extensor mechanism after disruption separation.

A cadaveric study was performed on extensor tendon separation and excursion after extensor zone I (distal interphalangeal [DIP]) joint and III (proximal interphalangeal [PIP]) level lacerations and treatment. An average 1.5 mm tendon gap with 30 degrees lag following laceration at the DIP joint level and a 1.1 mm average tendon gap with 18 degrees (10 degrees-25 degrees) extension loss at the PIP level was demonstrated. Splinting zone I injuries with the DIP joints in 5 degrees hyperextension and zone III injuries with the PIP joint in 0 degrees extension eliminated tendon separation in all passive joint positions except when the wrist and metacarpophalangeal joints were placed in flexion. This position produced a 0.9 mm gap with a laceration at the DIP level and 1.0 and 2.0 mm gap at the PIP level, with a central slip and central slip and lateral band laceration, respectively. The tendon gaps were eliminated by placing the wrist in extension. This suggests that splinting of the wrist in neutral to mild extension and the joint underlying the tendon injury in full extension, while leaving the other joints free to move, would optimize treatment results.

Severe multiple mononeuropathy in patients with major thermal burns.

Multiple mononeuropathy after thermal burns covering greater than 40% total body surface area occurred in nine of 121 of our burn center admissions for an incidence of 7.4%. The number of nerves involved per patient ranged from three to seven, with the average being 4.9. Upper-extremity nerves were more commonly involved than were lower extremity nerves (33 versus 11). All patients had burns over the involved areas. The source was believed to be due to a multiple crush syndrome, in which multiple different neuropathic factors in each patient summate to cause a multiple mononeuropathy. The outcome with conservative treatment was variable, with lower-extremity nerve lesions having a very good outcome and upper-extremity lesions not having as good an outcome, particularly when the median nerve was affected.

Carpal Tunnel Syndrome: Diagnosing and treating the most common hand disorder.

Carpal tunnel syndrome is a very common hand problem usually presenting with nighttime pain, numbness, and loss of dexterity. Controversy arises over the diagnosis, treatment, and evaluation of results. Nighttime splinting will improve the symptoms in some patients. If this fails, excellent results can be achieved with surgical decompression of the median nerve in the carpal canal.