We compared the orientation of the acetabular component obtained by a conventional manual technique with that using five different navigation systems.

Three surgeons carried out five implantations of an acetabular component with each navigation system, as well as manually, using an anatomical model. The orientation of the acetabular component, including inclination and anteversion, and its position was determined using a co-ordinate measuring machine.

The variation of the orientation of the acetabular component was higher in the conventional group compared with the navigated group. One experienced surgeon took significantly less time for the procedure. However, his placement of the component was no better than that of the less experienced surgeons. Significantly better inclination and anteversion (p < 0.001 for both) were obtained using navigation. These parameters were not significantly different between the surgeons when using the conventional technique (p = 0.966).

The use of computer navigation helps a surgeon to orientate the acetabular component with less variation regarding inclination and anteversion.

The extended lateral L-shaped approach for the treatment of displaced intra-articular fractures of the calcaneum may be complicated by wound infection, haematoma, dehiscence and injury to the sural nerve. In an effort to reduce the risk of problems with wound healing a technique was developed that combined open reduction and fixation of the joint fragments and of the anterior process with percutaneous reduction and screw fixation of the tuberosity. A group of 24 patients with unilateral isolated closed Sanders type II and III fractures was treated using this technique and compared to a similar group of 26 patients managed by the extended approach and lateral plating. The operation was significantly shorter (p < 0.001) in the first group, but more minor secondary procedures and removal of heel screws were necessary. There were no wound complications in this group, whereas four minor complications occurred in the second group. The accuracy and maintenance of reduction, and ultimate function were equivalent.

A 34-year-old woman with a benign form of osteopetrosis developed osteoarthritis of the hip. In order to avoid the difficulties associated with inserting the femoral component of a conventional total hip arthroplasty, a hybrid metal-on-metal resurfacing was performed. There were several technical challenges associated with the procedure, including the sizing of the component, press-fit fixation of the acetabular component and femoral head preparation, as well as trying to avoid a fracture. No surgical complication occurred. After more than a year following surgery, the patient showed excellent clinical function and remained satisfied with the outcome. We conclude that the hybrid metal-on-metal resurfacing arthroplasty represents a valuable option for the treatment of patients with osteopetrosis and secondary hip osteoarthritis.

We created virtual three-dimensional reconstruction models from computed tomography scans obtained from patients with acetabular fractures. Virtual cylindrical implants were placed intraosseously in the anterior column, the posterior column and across the dome of the acetabulum. The maximum diameter which was entirely contained within the bone was determined for each position of the screw. In the same model, the cross-sectional diameters of the columns were measured and compared to the maximum diameter of the corresponding virtual implant.

We found that the mean maximum diameter of virtual implant accommodated by the anterior columns was 6.4 mm and that the smallest diameter of the columns was larger than the maximum diameter of the equivalent virtual implant.

This study suggests that the size of the screw used for percutaneous fixation of acetabular fractures should not be based solely on the measurement of cross-sectional diameter and that virtual three-dimensional reconstructions might be useful in pre-operative planning.

Open surgery is rarely justified for the initial treatment of a unicameral bone cyst, but there is some debate concerning the relative effectiveness of closed methods. This study compared the results of steroid injection with those of autologous bone marrow grafting for the treatment of unicameral bone cysts. Between 1990 and 2001, 30 patients were treated by steroid injection and 28 by grafting with autologous bone marrow. The overall success rates were 86.7% and 92.0%, respectively (p > 0.05). The success rate after the initial procedure was 23.3% in the steroid group and 52.0% in those receiving autologous bone marrow (p < 0.05), and the respective cumulative success rates after second injections were 63.3% and 80.0% (p > 0.05). The mean number of procedures required was 2.19 (1 to 5) and 1.57 (1 to 3) (p < 0.05), the mean interval to healing was 12.5 months (4 to 32) and 14.3 months (7 to 36) (p > 0.05), and the rate of recurrence after the initial procedure was 41.7% and 13.3% in the steroid and in the autologous bone marrow groups, respectively (p < 0.05).

Although the overall rates of success of both methods were similar, the steroid group had higher recurrence after a single procedure and required more injections to achieve healing.

A minimally-invasive procedure using percutaneous reduction and external fixation can be carried out for Sanders’ type II, III and IV fractures of the os calcis. We have treated 54 consecutive closed displaced fractures of the calcaneum involving the articular surface in 52 patients with the Orthofix Calcaneal Mini-Fixator. Patients were followed up for a mean of 49 months (27 to 94) and assessed clinically with the Maryland Foot Score and radiologically with radiographs and CT scans, evaluated according to the Score Analysis of Verona. The clinical results at follow-up were excellent or good in 49 cases (90.7%), fair in two (3.7%) and poor in three (5.6%). The mean pre-operative Böhler’s angle was 6.98° (5.95° to 19.86°), whereas after surgery the mean value was 21.94° (12.58° to 31.30°) (p < 0.01). Excellent results on CT scanning were demonstrated in 24 cases (44.4%), good in 25 (46.3%), fair in three (5.6%) and poor in two (3.7%). Transient local osteoporosis was observed in ten patients (18.5%), superficial pin track infection in three (5.6%), and three patients (5.6%) showed thalamic displacement following unadvised early weight-bearing.

The clinical results appear to be comparable with those obtainable with open reduction and internal fixation, with the advantages of reduced risk using a minimally-invasive technique.

Our aims were to map the tibial footprint of the posterior cruciate ligament (PCL) using MRI in patients undergoing PCL-preserving total knee replacement, and to document the disruption of this footprint as a result of the tibial cut. In 26 consecutive patients plain radiography and MRI of the knee were performed pre-operatively, and plain radiography post-operatively.

The lower margin of the PCL footprint was located a mean of 1 mm (−10 to 8) above the upper aspect of the fibular head. The mean surface area was 83 mm² (49 to 142). One-third of patients (8 of 22) had tibial cuts made below the lowest aspect of the PCL footprint (complete removal) and one-third (9 of 22) had cuts extending into the footprint (partial removal). The remaining patients (5 of 22) had footprints unaffected by the cuts, keeping them intact.

Our study highlights the wide variation in the location of the tibial PCL footprint when referenced against the fibula. Proximal tibial cuts using conventional jigs resulted in the removal of a significant portion, if not all of the PCL footprint in most of the patients in our study. Our findings suggest that when performing PCL-retaining total knee replacement the tibial attachment of the PCL is often removed.

We conducted a randomised controlled trial to compare external fixation of trochanteric fractures of the femur with the more costly option of the sliding hip screw. Patients in both groups were matched for age (mean 67 years, 50 to 100) and gender. We excluded all pathological fractures, patients presenting at more than one week, fractures with subtrochanteric extension or reverse obliquity, multiple fractures or any bone and joint disease interfering with rehabilitation. The interval between injury and operation, the duration of surgery, the amount of blood loss, the length of hospital stay and the cost of treatment were all significantly higher in the sliding hip screw group (p < 0.05). The time to union, range of movement, mean Harris hip scores and Western Ontario and McMaster University knee scores were comparable at six months. The number of patients showing shortening or malrotation was too small to show a significant difference between the groups. Pin-track infection occurred in 18 patients (60%) treated with external fixation, whereas there was a single case of wound infection (3.3%) in the sliding hip screw group.

We describe the results of arthrodesis for the treatment of recurrent acute neuropathic bone disease in 24 feet and of chronic disease with deformity in 91 feet, undertaken between January 1984 and December 2003. All were due to leprosy.

Correction of the deformity was achieved in 80 of 106 feet (76%) and fusion in 97 of 110 feet (88%). In the 24 feet in which recurrent neuropathic bone disease was the reason for surgery, 17 (71%) obtained stability while in seven (29%) symptoms recurred postoperatively. Complications were experienced following 58 of the 110 operations (53%). In patients presenting primarily with deformity with a minimum follow-up of two years (79 feet), there was a reduced frequency of ulceration in 40 (51%). Normal footwear could be worn by 32 patients (40%) after surgery, while 40 (51%) required a moulded insole. Arthrodesis of the ankle in the neuropathic foot due to leprosy has a good overall rate of success although the rate of complications is high.

We reviewed 78 femoral and tibial nonunions treated between January 1992 and December 2003. Of these, we classified 41 in 40 patients as complex cases because of infection (22), bone loss (6) or failed previous surgery (13). The complex cases were all treated with Ilizarov frames. At a mean time of 14.1 months (4 to 38), 39 had healed successfully.

Using the Association for the Study and Application of the Methods of Ilizarov scoring system we obtained 17 excellent, 14 good, four fair and six poor bone results. The functional results were excellent in 14 patients, good in 14, fair in two and poor in two. A total of six patients were lost to follow-up and two had amputations so were not evaluated for final functional assessment. All but two patients were very satisfied with the results. The average cost of treatment to the treating hospital was approximately £30 000 per patient.

We suggest that early referral to a tertiary centre could reduce the morbidity and prolonged time off work for these patients. The results justify the expense, but the National Health Service needs to make financial provision for the reconstruction of this type of complex nonunion.

Osteonecrosis of the knee comprises two separate disorders, primary spontaneous osteonecrosis which is often a self-limiting condition and secondary osteonecrosis which is associated with risk factors and a poor prognosis. In a series of 61 knees (38 patients) we analysed secondary osteonecrosis of the knee treated by a new technique using multiple small percutaneous 3 mm drillings.

Total knee replacement was avoided in 59 knees (97%) at a mean follow-up of 3 years (2 to 4). Of the 61 knees, 56 (92%) had a successful clinical outcome, defined as a Knee Society score greater than 80 points. The procedure was successful in all 24 knees with small lesions compared with 32 of 37 knees (86%) with large lesions. All the procedures were performed as day cases and there were no complications. This technique appears to have a low morbidity, relieves symptoms and delays more invasive surgery.

Injuries to the acromioclavicular joint are common but underdiagnosed. Sprains and minor subluxations are best managed conservatively, but there is debate concerning the treatment of complete dislocations and the more complex combined injuries in which other elements of the shoulder girdle are damaged. Confusion has been caused by existing systems for classification of these injuries, the plethora of available operative techniques and the lack of well-designed clinical trials comparing alternative methods of management. Recent advances in arthroscopic surgery have produced an even greater variety of surgical options for which, as yet, there are no objective data on outcome of high quality. We review the current concepts of the treatment of these injuries.

The object of this study was to develop a method to assess the accuracy of an image-free total knee replacement navigation system in legs with normal or abnormal mechanical axes. A phantom leg was constructed with simulated hip and knee joints and provided a means to locate the centre of the ankle joint. Additional joints located at the midshaft of the tibia and femur allowed deformation in the flexion/extension, varus/valgus and rotational planes. Using a digital caliper unit to measure the coordinates precisely, a software program was developed to convert these local coordinates into a determination of actual leg alignment. At specific points in the procedure, information was compared between the digital caliper measurements and the image-free navigation system. Repeated serial measurements were undertaken. In the setting of normal alignment the mean error of the system was within 0.5°. In the setting of abnormal plane alignment in both the femur and the tibia, the error was within 1°. This is the first study designed to assess the accuracy of a clinically-validated navigation system. It demonstrates in vitro accuracy of the image-free navigation system in both normal and abnormal leg alignment settings.

In a prospective randomised trial of calcifying tendinitis of the rotator cuff, we compared the efficacy of dual treatment sessions delivering 2500 extracorporeal shock waves at either high- or low-energy, via an electromagnetic generator under fluoroscopic guidance. Patients were eligible for the study if they had more than a three-month history of calcifying tendinitis of the rotator cuff, with calcification measuring 10 mm or more in maximum dimension. The primary outcome measure was the change in the Constant and Murley Score.

A total of 80 patients were enrolled (40 in each group), and were re-evaluated at a mean of 110 (41 to 255) days after treatment when the increase in Constant and Murley score was significantly greater (t-test, p = 0.026) in the high-energy treatment group than in the low-energy group. The improvement from the baseline level was significant in the high-energy group, with a mean gain of 12.5 (−20.7 to 47.5) points (p < 0.0001). The improvement was not significant in the low-energy group. Total or subtotal resorption of the calcification occurred in six patients (15%) in the high-energy group and in two patients (5%) in the low-energy group.

High-energy shock-wave therapy significantly improves symptoms in refractory calcifying tendinitis of the shoulder after three months of follow-up, but the calcific deposit remains unchanged in size in the majority of patients.

We inserted an electrode up the femoral neck into the femoral head of ten patients undergoing a metal-on-metal hip resurfacing arthroplasty through a posterior surgical approach and measured the oxygen concentration during the operation. In every patient the blood flow was compromised during surgery, but the extent varied. In three patients, the oxygen concentration was zero at the end of the procedure. The surgical approach caused a mean 60% drop (p < 0.005) in oxygen concentration while component insertion led to a further 20% drop (p < 0.04). The oxygen concentration did not improve significantly on wound closure. This study demonstrates that during hip resurfacing arthroplasty, patients experience some compromise to their femoral head blood supply and some have complete disruption.

There remains uncertainty about the most effective surgical approach in the treatment of complex fractures of the acetabulum. We have reviewed the experience of a single surgeon using the extended iliofemoral approach, as described by Letournel.

A review of the database of such fractures identified 106 patients operated on using this approach with a minimum follow-up of two years. All data were collected prospectively. The fractures involved both columns in 64 (60%). Operation was undertaken in less than 21 days after injury in 71 patients (67%) and in 35 (33%) the procedure was carried out later than this. The reduction of the fracture was measured on plain radiographs taken after operation and defined as anatomical (0 to 1 mm of displacement); imperfect (2 to 3 mm) or poor (> 3 mm). The functional outcome was measured by the modified Merle d’Aubigné and Postel score. The mean follow-up was for 6.3 years (2 to 17).

All patients achieved union of the fractures. The reduction was graded as anatomical in 76 (72%) of the patients, imperfect in 23 (22%), and poor in six (6%). The mean Merle d’Aubigné and Postel score was 15 (5 to 18) with 68 patients (64%) showing good or excellent and 38 (36%) fair or poor results. Function correlated significantly with the accuracy of the reduction (p < 0.009). Significant heterotopic ossification developed in 32 patients (30%) and was associated with a worse mean Merle d’Aubigné and Postel score of 13.7.

The extended iliofemoral approach can be performed safely in selected complex acetabular fractures with an acceptable clinical outcome and rate of complications. Effective prophylaxis against heterotopic ossification should be strongly considered.

This prospective study describes the complications and survival of the first 688 Phase 3 Oxford medial unicompartmental knee replacements implanted using a minimally-invasive technique by two surgeons and followed up independently. None was lost to follow-up. We had carried out 132 of the procedures more than five years ago. The clinical assessment of 101 of these which were available for review at five years is also presented.

Nine of the 688 knees were revised: four for infection, three for dislocation of the bearing and two for unexplained pain. A further seven knees (1%) required other procedures: four had a manipulation under anaesthesia, two an arthroscopy and one a debridement for superficial infection. The survival rate at seven years was 97.3% (95% confidence interval 5.3). At five years, 96% of the patients had a good or excellent American Knee Society score, the mean Oxford knee score was 39 and the mean flexion was 133°. This study demonstrates that the minimally-invasive Oxford unicompartmental knee replacement is a reliable and effective procedure.