Changes in armour reinforcement of military vehicles have resulted in a changed injury pattern. Injuries which would previously have resulted in amputation are now less severe, and after initial debridement and temporary fixation the foot can now be saved. New patterns of injuries are emerging often as a part of potentially survivable poly-trauma. We describe a small series of these injuries. The techniques and results of late reconstruction are presented. We also discuss specific problems of managing patients with potential contamination with unusual organisms.

Introduction: Severe haemophilia affects 1 in 10,000 men. The ankle along with the hip and knee are commonly affected. Ankle fusion is the preferred surgery for end stage arthritis in the younger patient although debate exists as to the preferred technique. We conducted a retrospective review of the arthroscopic ankle fusions on haemophiliacs from Oxford and compared data with that of a specialist unit in London using an open technique.

Materials and Methods: We reviewed 22 ankles (22 patients) from Oxford and 10 ankles (8 patients) from London. 90% had Type A haemophilia with similar regular monthly Factor VIII usage: 17941 U/month (Oxford) compared with 17992 (London). 73% of patients in the Oxford Group and 100% of the London group had Hepatitis C and/or HIV.

Results: Union was achieved in all patients. The mean time to union in the open group was 9.1 weeks (Mode- 8 weeks, Range 7–14) compared to 12.2 weeks (Mode- 12 weeks, Range 8–24) in the arthroscopic group. Screw removal was required in 4 patients (3 arthroscopic v’s 1 open). 1 patient in the arthroscopic group suffered a pseudoaneurysm of the dorsalis pedis artery. The arthroscopic group spent less time in hospital- 5.7 days compared to 9.5. Factor VIII usage was less in the arthroscopic group- 32,882 Units compared to 40013.

Discussion: Patients of this nature should be managed in centres used to dealing with their complex needs. Arthroscopic ankle fusion in haemophiliacs is safe for these patients. Although arthroscopic fusion may take slightly longer to unite, there are benefits in terms of reduced patient stay and factor VIII requirement and therefore costs.

According to the National Institute of Clinical Excellence (NICE) Guidelines, some foot and ankle patients are, by definition, at high risk of DVT/PE. Despite NICE guidance, DVT recommendations are still controversial, and are being reviewed by the BOA to be more operation and context specific.

One consultant at our institution therefore initiated a 6 week medical DVT prophylaxis regimen for all his post-operative hind–foot surgery patients who were placed in plaster. From January 2007 to February 2008 we audited 97 hind-foot patients to measure their compliance rate, complications and DVT/PE rate.

Compliance was excellent (97%) particularly with regard to Low Molecular Weight Heparin (LMWH), but only 70% had medication prescribed for the 6 weeks, and 3% developed a DVT.

Self administered LMWH is acceptable and compliance is excellent in post operative orthopaedic patients, but not necessarily effective.

Computer aided joint replacement surgery has become very popular during recent years and is being done in increasing numbers all over the world. The accuracy of the system depends to a major extent, on accurate registration and immobility of the tracker attachment devices to the bone. This study was designed to assess the forces needed to displace the tracker attachment devices in the bone simulators.

Bone simulators were used to maintain the uniformity of the bone structure during the study. The fixation devices tested were 3mm diameter self drilling, self tapping threaded pin, 4mm diameter self tapping cortical threaded pin, 5mm diameter self tapping cancellous threaded pin and a triplanar fixation device ‘ortholock’ used with three 3mm pins. All the devices were tested for pull out, translational and rotational forces in unicortical and bicortical fixation modes. Also tested was the normal bang strength and forces generated by leaning on the devices.

The forces required to produce translation increased with the increasing diameter of the pins. These were 105 N, 185 N, and 225 N for the unicortical fixations and 130N, 200N, 225 N for the bicortical fixations for 3mm, 4mm and 5 mm diameter pins respectively. The forces required to pull out the pins were 1475N, 1650N, 2050N for the unicortical, 1020N, 3044N and 3042N for the bicortical fixated 3mm, 4mm and 5mm diameter pins. The ortholock translational and pull out strength was tested to 900N and 920N respectively and still it did not fail. Rotatory forces required to displace the tracker on pins was to the magnitude of 30N before failure. The ortholock device had rotational forces applied up to 135N and still did not fail. The manual leaning forces and the sudden bang forces generated were of the magnitude of 210 N and 150 N respectively.

The strength of the fixation pins increases with increasing diameter from three to five mm for the translational forces. There is no significant difference in pull out forces of four mm and five mm diameter pins though it is more than the three mm diameter pins. This is because of the failure of material at that stage rather than the fixation device. The rotatory forces required to displace the tracker are very small and much less than that can be produced by the accidental leaning or bang produced by the surgeon or assistants in single pins. Although the ortholock device was tested to 135 N in rotation without failing, one has to be very careful not to put any forces during the operation on the tracker devices to ensure the accuracy of the procedure.

Increasingly hospitals are moving away from hard copy xrays to digital films. These offer advantages in terms of cost, film availability and decreased radiation dosage but concerns have been raised about the accuracy of these images for preoperative templating.

We reviewed the pre and post operative films in 20 patients with subcapital fractured necks of femur. Each film was reviewed by 3 different observers on 3 separate occasions. The sizes of the femoral head and the hemi-arthroplasty were measured using the PACS digital system. These were then compared with the known size of the implant.

A total of 360 measurements were taken. Intra and inter observer errors were low with intra class correlations of in excess of 0.98 and 0.99 respectively. The average magnification on the pre-op film was 117.6% (t=18.96, p< 0.0001) and on the post-op film 121.5% (t=22.18, p< 0.0001) with a range of 109.3% to 128.2%. The overall magnification was 119.6%.

We conclude that measurements made on PACS have a high repeatability and reproducibility but that PACS has a significant and wide variation in magnification errors. PACS should therefore not be used for templating until a way of standardising magnification has been found.