Reach, John S.

Background: Reliable measurement of subfascial pressures represents an essential part of compartment syndrome management. To date, there is neither consensus on the number or location of foot compartments, nor a standardized protocol for needle placement. The purpose of this study was to devise a new system using 3-Tesla MRI that assesses the number and location of these compartments. Methods: To document the specific location of foot compartments, high resolution 3-Tesla MRI (General Electric, Milwaukee, WI) was coupled with a dedicated transmit-receive high signal-to-noise foot/ankle coil (IGC-Medical Advances, Milwaukee, WI). Individual compartments were highlighted and mapped to T1-weighted MRI. Three-dimensional image analysis allowed standardized needle placement recommendations. Results: Six feet from healthy volunteers were imaged. From these, ten compartments were described: (1) medial, (2) central superficial, (3) central deep (adductor), (4) lateral, (5–8) interossei, (9) calcaneal, and (10) skin. Optimal needle placement and depth were identified. Conclusions: The proposed system allowed us to assess the number and location of foot compartments. Computer image analysis enabled us to define exact points for needle insertion and depth of penetration for accurate pressure monitoring.

Purpose Large rotator cuff tears present a challenge to orthopaedic surgeons. Because tissue may be insufficient or of inadequate quality to undergo repair, a variety of materials have been used as adjuncts. Human dermal tissue may be processed to render it acellular, and thus less immunogenic, but with the extracellular matrix left intact, creating a collagen scaffold with favorable characteristics. Because of these traits, use in rotator cuff repair was proposed. Methods A canine model for a full‐thickness infraspinatus tendon tear was used. Tendon was excised from the bony interface to the myotendinous junction, and a human acellular dermal matrix graft (experimental) or the autologous excised tendon (control) was used to bridge the defect. Animals were sacrificed, and shoulders were evaluated histologically and biomechanically. Results At time 0, strength of control and experimental repairs was similar. At 6 weeks, the strength of the experimental repair was half that of the control side. Strength of control specimens remained the same at 6 and 12 weeks, but by 12 weeks, the strength of the experimental repair was equal to that of the control. Histologically, cells infiltrated the control and experimental specimens by 6 weeks; chronic inflammation was consistent with surgery and repair. At 6 months, control and experimental specimens mimicked normal tendon structure grossly and histologically. Conclusions Use of human acellular dermal matrix as a patch is a viable option in this model of large rotator cuff defects. Within 6 weeks, histologic evidence of native cell infiltration and neotendon development was observed. Within 12 weeks, the strength of the dermal matrix graft repair was equivalent to that of autologous tendon. At 6 months, control and graft specimens mimicked normal tendon structure grossly and histologically. Clinical Relevance This study provides in vivo animal data to support the use of this acellular dermal matrix graft for repair of full‐thickness rotator cuff defects. Additional studies are indicated to determine the role of this material in the treatment of humans with rotator cuff tears.