8 Palmar Matti-Russe Graft
▪ Rationale and Basic Science Pertinent to the Procedure
Watson and Ballet1 popularized a well-recognized degenerative pattern as scaphoid nonunion advanced collapse, which is quite similar to the degenerative arthritis seen late after scapholunate advanced collapse. This is characterized by narrowing of the radioscaphoid space, erosion of the proximal fragment in the radius, enchondral new bone formation on the radial surface of the distal fragment, erosion of the ulnar aspect of the capitate head, and later degenerative cyst formation. The radiolunate articular space is curiously preserved. There is generally a marked dorsal intercalated segmental instability (DISI) deformity with extension of the lunate and foreshortening of the scaphoid. Secondary enchondral bone formation occurs at the articular margins of lunate contact. This effectively flattens the convexity of the proximal lunate over time.
The scaphoid itself may have the appearance of either a hypertrophic or an atrophic nonunion. The former is distinguished by sclerotic facets, suggesting a pseudarthrosis, whereas in the latter, the fracture surfaces are less regular, osteoporotic, and somewhat cystic.
The wrist becomes increasingly weak and painful as these changes occur. It is for this reason that earnest attempts should be instituted to interrupt and try to prevent this natural progression of the process.
The treatment of scaphoid nonunions is varied.2 For the last 4 decades the Russe bone grafting procedure has been one of the standard approaches for nonunion.3 This involved a modification of the Matti procedure from a dorsal to a palmar exposure.4 Originally, Russe proposed hollowing out the fragments on either side of the fracture line of the nonunion site and then packing the defect with cancellous bone.5 Later he modified this by specifying that two corticocancellous grafts should be inserted back to back into the scaphoid excavation with their cancellous sides facing each other to provide added stabilization. The remainder of the cavity is filled with cancellous chips.6 Linscheid and Weber’s preferred procedure involved a palmar approach, curettage, removal of bone from the proximal and distal scaphoid, and a large single corticocancellous graft placed within the excavated cavity ( Fig. 8.1 ). Correction of a mild palmar collapse can be achieved with this method.2
The more advanced nonunion is more apt to be treated with an interposed bone graft to restore length, to correct the angular deformity in the frontal and sagittal planes, and to correct the midcarpal malalignment.7 This usually requires a corticocancellous iliac bone graft, although some surgeons rely on modeling the removed radial styloid into a wedge. Iliac crest as the source of bone graft may have a higher osteogenic potential.6 A winged graft8 can be fashioned to restore length and still maintain the inlay technique of Russe. The size and shape of the graft are first estimated from parasagittal or polyaxial tomograms or computed tomographic (CT) scans. The graft dimensions can also be measured at the time of surgery by correcting the midcarpal collapse. This tends to open the palmar aspect of the fracture, which allows a direct measurement of the gap.
Green uses bone graft from the distal radius because its cortex is thinner, and inserts the graft into the cavity with the cortical sides outward.6 Mack et al use iliac crest struts and insert them with their cancellous surfaces outward or use a single rectangular corticocancellous graft and thin its cortex with fine-tipped bone biters or rongeurs.9
For the simple, well-aligned, and early delayed or nonunion, the Russe procedure is still an acceptable choice.2
The Russe procedure may be effective in achieving union in angulated scaphoid malunions, but it is difficult to correct a significant DISI deformity with this procedure. This technique is indicated for symptomatic, established nonunions and delayed unions without osteoarthritis or carpal malalignment.10
Contraindications for the Matti-Russe procedure with reduced union rates are the presence of a collapsed scaphoid nonunion with dorsal carpal instability, degenerative changes limited to the radial styloid, midcarpal degenerative changes, large cysts in the scaphoid, an avascular proximal scaphoid pole, and a significant humpback deformity of the scaphoid.10
▪ Surgical Technique
For the palmar approach, the scaphoid is exposed through a radiopalmar incision between the flexor carpi radialis (FCR) and the radial artery. A 4 to 5 cm longitudinal incision is made along the radial border of the flexor carpi radialis tendon, centered at the tip of the radial styloid, which usually corresponds to the level of the fracture itself.10
The incision ends directly over the center of the scaphoid tuberosity in the palm. The scaphoid is exposed proximal to the tuberosity by dissecting radial to the FCR sheath and retracting the tendon ulnarly. This may decrease scarring of the tendon that might otherwise limit wrist dorsiflexion. The radiocarpal capsule is identified just beyond the radial styloid. It is incised down to the scaphoid tuberosity and beyond onto the trapezium in line with the skin incision, exposing the scaphotrapezial joint. The capsule is reflected a few millimeters to either side to expose the palmar aspect of the scaphoid. The underlying deep palmar radiocarpal ligaments are either partially divided and retracted or completely detached and tagged for later repair.10 The capsuloperiosteal flaps are reflected radially and ulnarly by sharp dissection of Sharpey fibers off the distal radius with an end-cutting blade. This relaxes the interval for better exposure. The distal fibers of the pronator quadratus are divided if necessary. If the nonunion is not obvious, searching for a wrinkle in the articular cartilage or distraction and ulnar deviation of the wrist may be helpful. The image intensifier is used at each step of the procedure. To manipulate the scaphoid nonunion, a curved blunt instrument such as a narrow Langenbeck elevator may be inserted gently into the scaphoid fossa of the distal radius. To prevent cartilage injury when inserting the elevator, an assistant should apply manual traction to the thumb or index and long fingers to distract the radiocarpal joint. If carpal collapse is present, it may be necessary to release the attachments between the scaphoid and capitate, and between the capitate and lunate, to obtain correction. The dorsal and lateral surfaces of the scaphoid should not be disturbed for fear of injuring the blood supply.9
The fibrous tissue in the pseudarthrosis is resected with a fine curette and an end-cutting knife blade to expose the opposing bone surfaces of the proximal and distal fragments. The fracture fragments are then assessed to plan the position of the trough. A 3.0 mm power drill cooled with saline lavage is used to mark the ends of the trough. A fine osteotome is used to connect the drill holes across the fracture line. A 3 × 12 mm cortical window is cut in the palmar aspect of the scaphoid with small, sharp osteotomes. The cortical strip is removed. The bone is curetted by hand until cancellous bleeding appears on either side of the nonunion, and a trough is created to accept the bone graft. Small punctate bleeding points within the medullary cavity, which may appear during curettage of either fragment even with the tourniquet inflated, is an indicator of viable bone. All avascular cancellous bone should thoroughly be excavated from the proximal fragment. A sharp power burr Is sometimes expedient if hand equipment is insufficient. This must be cooled continuously to prevent thermal damage to this tenuously vascularized structure. The distal part of the cut usually enters the tuberosity. If a reduction is necessary, this may be aided by the use of Kirschner-wires inserted as toggle arms into either fragment. The trough should be 4 to 5 mm wide, 6 to 8 mm deep, and 10 to 15 mm long to provide adequate stability. A corticocancellous bone graft is obtained from the anterior iliac crest or the distal radius. The remainder of the cavity is filled with small chips of cancellous bone graft.6 Internal fixation is reserved for situations in which instability persists after the bone graft is in place. In such cases, Kirschner-wires are inserted parallel to each other and to the longitudinal axis of the scaphoid.2 , 10
The capsule is securely repaired. The skin may be closed subcuticularly and a forearm-based thumb spica cast is applied with the wrist in a neutral position, usually for 10 weeks until union is ensured.2
The palmar approach is simple and safe because it is least likely to disrupt the scaphoid blood supply or to injure the superficial sensory branch of the radial nerve (SBRN). It also provides a good exposure for fragment reduction during inlay or interposition grafting.9