The August 2012 Wrist & Hand Roundup. 360. looks at: the Herbert ulnar head prosthesis; the five-year outcome for wrist arthroscopic surgery; four-corner arthrodesis with headless screws; balloon kyphoplasty for Kienböck's disease; Mason Type 2 radial head fractures; local infiltration and intravenous regional anaesthesia for endoscopic carpal tunnel release; perilunate injuries; and replanting the amputated fingertip

To evaluate the mechanism of dislocation of the navicular in complex foot trauma; we hypothesize this is similar to lunate/perilunate dislocations. Our experience with 6 cases of total dislocation of navicular without fracture, and an analysis of 7 similar cases reported world-wide was used as the basis for this hypothesis. Radiographs of our patients and the published cases were analyzed in detail, and associated injuries/instablilities were assessed. The position of the dislocated navicular and the mechanism of trauma was considered and correlated, and this hypothesis was propounded. When the navicular dislocates without fracture, it most frequently comes to lie medially, with superior or inferior displacement, depending upon the foot position at injury. It is hypothesized that the forefoot first dislocates laterally (perhaps transiently) at the naviculocunieform joint by an abduction injury; in all cases we recorded significant lateral injury (either cuboid fracture, or lateral midfoot dislocation). The relocating forefoot subsequently pushes the unstable navicular from the talonavicular joint, and depending upon the residual attachments of soft tissues, this bone comes to lie at different places medially. This is a similar mechanism to the lunate dislocation in the wrist, where the relocating carpus push the lunate volarly. Our clinical experience with these complex injuries has shown that the whole foot is extremely unstable. For reduction, the talonavicular joint has to be reduced first, and then the rest of the forefoot easily reduces on to the navicular. An understanding of injury mechanics allows us to primarily stabilize both the columns of the foot, and subsequent subluxation and associated residual pain are avoided. Pure navicular dislocations are not isolated injuries, but are complex midfoot instabilities, and are similar to perilunate injuries of the wrist

Introduction: The literature gives ample evidence to discourage sub-optimal reductions of perilunate fracture/dislocations. These, inevitably, lead to poor long-term results. Aim: To evaluate critically the results of open reduction, fracture stabilisation and ligament repair in a cohort of greater and lesser arc perilunate dislocations treated by one surgeon at a single institution. Method: Ten patients who underwent reconstructive surgery for perilunate wrist injuries were reviewed at least 18 months following their surgery. The pathology included three pure perilunate dislocations (PD), three trans-scaphoid perilunate fracture-dislocations (TSPD), one TSPD with a lunate fracture, one trans-scaphoid PD, and two trans radial styloid PDs. Each patient was assessed at a single clinic visit. A clinical rating based on the modified Mayo Wrist Scoring Chart was applied noting pain, satisfaction, range of motion and grip strength. Radiographic analysis was also performed. Results: Nine out of 10 patients had returned to their preoperative employment. Overall, 70% of the patients were satisfied with their wrist function and 50% had mild pain only on vigorous activities. There were five ‘fair’ results and five ‘poor’ results. The range of scores was 30 to 75 (average = 55). Average arc of motion was 78 degrees. Three patients showed evidence of wrist arthritis. One patient had a pin site infection. Two patients still had mild nerve symptoms – one ulnar and one median nerve. One patient needed a proximal row carpectomy. Conclusions: Greater and lesser arc injuries of the wrist are associated with high energy trauma. These injuries result in significantly reduced wrist function, however they are treated. Open reduction and ligament repair with fracture stabilisation lead to a high degree of patient satisfaction and pain relief. In this study the clinical wrist score did not support this