Introduction: Acquired pes planus is caused by mechanical uncoupling of the bones of the tarsus due to failure of the osseoligamentous complex that maintains the medial longitudinal arch of the foot. The most common cause of acquired flat foot deformity in adults is posterior tibialis tendon dysfunction. A solitary previous case report has documented an alternative aetiology of acquired flat foot in adults due to isolated spring ligament rupture; in that case diagnosis was made intra-operatively.

Materials and Methods: We present 9 cases of acquired flat foot deformity that were caused by isolated spring ligament insufficiency, mainly presenting after an eversion injury of the ankle. We present the clinical sign of ability to single leg tiptoe, but with persistent forefoot abduction and heel valgus, that allows differentiation of this diagnosis from posterior tibialis tendon dysfunction. In addition we illustrate the radiological features of this condition which have not been previously described and allow confirmation of the diagnosis non-operatively.

Results: Six patients have been managed with orthotics and three underwent surgery; one patient who presented early had an isolated repair of the spring ligament complex and has done well. The remaining two patients required a calcaneal osteotomy and Flexor Digitorum Longus transfer as for a PTT reconstruction. In all these three patients the spring ligament was found to be completely ruptured during surgery.

Discussion: This type of injury may not be as rare as previously thought and demonstrates the importance of the spring ligament on its own in maintaining the medial longitudinal arch. Awareness of this condition could lead to earlier diagnosis and better prognosis with earlier treatment.

Conclusion: We propose that early diagnosis (with ultrasound confirmation) and management of this condition would offer a better prognosis and allow less interventional surgery.

Young active patients with malignant tumours arising in the distal fibula, requiring excision, present a challenge to the treating surgeon. Wide local excision is advocated, to achieve clearance, however, disruption of the ankle mortise results and fusion is often required to restore stability. The loss of movement is poorly tolerated in the younger patient and leads to progressive degenerative changes in surrounding joints.

Excision of the distal fibula lesion followed by harvesting of the proximal fibula and using this graft to recreate the ankle mortise restores ankle stability and retains ankle movement.

Between 1998 and 2007, we have performed this technique on 4 patients. Diagnoses were Ewing’s sarcoma, chondrosarcoma, parosteal osteosarcoma and osteofibrous dysplasia. To date there has been no evidence of distant or local recurrence. One case was complicated by infection, which resolved with radical debridement and antibiotics; the other three fibula grafts survived. Good to excellent results were achieved.

We will present the technical aspects of this procedure, with particular reference to the most recent case, performed on a young female patient with parosteal osteosarcoma.

We believe this technique provides good oncological and functional results and recommend this treatment option is considered in young active patients requiring distal fibula excisions for sarcoma.

Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.

This prospective randomized multicenter study compares two methods of bone defect treatment in tibial plateau fractures: a bioresorbable calcium phosphate paste (Alpha-BSM) that hardens at body temperature to give structural support versus Autogenous iliac bone graft (AIBG).

One hundred and eighteen patients were enrolled with a 2:1 randomization, Alpha-BSM to AIBG. There was a significant increased rate of non-graft related adverse affects and a higher rate of late articular subsidence (three to nine month period) in the AIBG group.

A bioresorbable calcium phosphate material is recommended in preference to the gold standard of AIBG for bone defects in tibial plateau fractures.

This prospective randomized multicenter study was undertaken to compare two methods of bone defect treatment: a bioresorbable calcium phosphate paste (Alpha-BSM –DePuy, Warsaw, IN) that hardens at body temperature to give structural support and is gradually resorbed by a cell-mediated bone regenerating mechanism versus Autogenous iliac bone graft (AIBG).

One hundred and eighteen adult acute closed tibial plateau fractures, Schatzker grade two to six were enrolled prospectively from thirteen study sites in North America from 1999 to 2002. Randomization occurred at surgery with a FDA recommendation of a 2–1 ratio, Alpha BSM (seventy-eight fractures) to AIBG (forty fractures). Only internal fixation with standard plate and screw constructs was permitted. Follow-up included standard radiographs and functional studies at one year, with a radiologist providing independent radiographic review.

The two groups exhibited no significant differences in randomization as to age, sex, race, fracture patterns or fracture healing. There was however, a significant increased rate of non-graft related adverse affects in the AIBG group. There was an unexpected significant finding of a higher rate of late articular subsidence in the three to nine month period in the AIBG group.

Recommendations for the use of AIBG for bone defects in tibial plateau fractures should be discouraged in favor of bioresorbable calcium phosphate material with the properties of Alpha BSM. We believe further randomized studies using AIBG as a control group for bone defect support of articular fractures are unjustified.

A bioresorbable calcium phosphate material is recommended in preference to the gold standard of AIBG for bone defects in tibial plateau fractures.

Funding: DePuy, Warsaw, IN.

Introduction: The Step Activity Monitor (SAM) is a microprocessor worn on the ankle that measures ambulatory activity in real time.

Methods: Activity magnitudes, speed parameters and activity patterns were analyzed in 31 patients with 37 primary total hips. Wear was measured from digitized radiographs using a validated two-dimensional, edge detection-based computer algorithm.

Results: On average, patients walked 5.6 hours per day (range: 1.9–9.8); averaging 5,266 gait cycles (range: 1,737–11,805), at 20 cycles/minute (range: 12.7–32.8) with a maximum speed of 63 cycles/minute (range: 45.0–88.0). Fast and very fast walking (30–49 and > 50 cycles/minute) accounted for 9.4% and 4.4% of total walking time. Patients started and stopped walking about 66 times per day (range: 34–113), with about 81 cycles between stops (range: 28.1-200.1) in average active intervals of 5.3 minutes (range: 3.3–10.3).

There was no difference in the average number of gait cycles between females and males. However, polyethylene wear per million cycles was significantly higher in males (p=0.006). Even after adjustment for greater height and weight in males, their wear rate was still significantly higher (p< 0.01). Males walked at a higher average speed (p=0.07), spent 33.9% more time walking fast or very fast, had 4% more starts/stops per day, with 13% less strides between stops. The percentage of time spent walking slow (5–9 cycles/minute) was negatively correlated to wear (p< 0.05).

Discussion and Conclusion: The SAM allows assessment of patterns and intensity of joint use. Similar to a set of automobile tires, polyethylene wear is a function of the amount and type of use; faster walking with more frequents starting and stopping is associated with a higher polyethylene wear rate. As the clinical performance of crosslinked polyethylenes is being monitored, it is critical to consider the influence of the amount and type of patient activity on wear.