No abstract

The formation of a scaphoid pseudarthrosis with avascular necrosis in the area of the carpus is a The formation of a scaphoid pseudarthrosis with avascular necrosis in the area of the carpus is a dreaded complication after conservative or operative treatment of a scaphoid bone fracture, which previously often led to partial or total stiffening operations on the wrist. Vascularized bone grafts can be used to increase the bone fusion rates in the presence of scaphoid pseudarthrosis with avascular necrosis. On a note of caution, it must be mentioned, though, that such a procedure in the presence of avascular necrosis of the proximal pole with destruction of cartilage can lead to premature radiocarpal arthritis, because a friction-free gliding in the area of the proximal scaphoid pole is no longer ensured as a result of the lacking cartilage cover.We confronted these problems in a 20-year-old male patient with avascular necrosis of the proximal scaphoid bone pole and destruction of the corresponding scaphoidal cartilage cover. We transplanted a free vascularized cartilage-bone graft from the medial femoral condyle, which was adapted in form and size to the proximal scaphoid bone pole with corresponding cartilage cover and was connected to the radial vascular bundle. This novel operation technique is described in this report and appears to be a promising way of avoiding premature radiocarpal arthritis when treating scaphoid bone pseudo-arthrosis with avascular necrosis in the presence of cartilage destruction.

Treatment of the proximal pole scaphoid nonunion presents many challenges to the reconstructive surgeon. Conventional treatment options include achievement of rigid internal fixation with bone grafting, local vascularized pedicle bone flaps, or microvascular free bone flaps. Longstanding scaphoid nonunion can lead to a progressive and predictable pattern of wrist arthritis, requiring undesirable surgical salvage procedures.The recalcitrant nonunion of the proximal pole will often present with a very small and poor-quality proximal segment after multiple previous surgical fixation attempts. It is in this setting that conventional surgical treatment options provide inadequate solutions for the absence or poor quality of proximal pole cartilage.The medial femoral condyle (MFC) has been recognized as a useful source of vascularized bone for treatment of scaphoid nonunions. 1,2 The vascular supply to the surrounding region of the distal femur has been well described. 3-6 The descending genicular arterial vascular system provides a dense filigree of blood vessels invested in the periosteum of the medial Keywords ► medial femoral condyle ► medial femoral trochlea flap ► osteocartilaginous autograft ► scaphoid nonunion ► vascularized bone AbstractBackground The medial trochlea of the femur (medial femoral trochlea, MFT) provides a source of convex osteocartilaginous vascularized bone that has been demonstrated to have a similar contour to the proximal scaphoid. This provides a potential solution for difficult recalcitrant proximal pole scaphoid nonunions. Materials and Methods Sixteen consecutive patients who underwent MFT proximal scaphoid arthroplasty were reviewed. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months. The results of this cohort were previously reported in detail but are summarized herein. Description of Technique The ability to reconstruct both bone and cartilage of the nonunion enables the surgeon to resect the nonunited proximal pole to prepare for scaphoid reconstruction. A segment of osteocartilaginous MFT is harvested in dimensions required by the scaphoid defect. The MFT segment is harvested on the transverse branch of the descending geniculate vessels. Fixation may be achieved with ease due to the size of the reconstructed segment. Results Computed tomography imaging demonstrated 15 of 16 reconstructed scaphoids achieving osseous union. Follow-up range of motion (ROM) of the wrist averaged 46.0°extension (range 28-80°) and 43.8°flexion (range 10-80°), which was similar to preoperative (average 45.7°extension and 43.0°flexion). Scapholunate angles remained unaffected (51.6°preoperatively and 48.6°postoperatively), indicating preservation of carpal relationships. Conclusions Vascularized MFT flaps provide a useful tool in the treatment of difficult proximal pole scaphoid nonunions. Early follow-up demonstrates high rate of achieving union with acceptable ROM and good pain relief.