Abstract

A study was done to test the strength of various configurations of tension band wiring (TBW) and we report clinical results of ‘Horizontal Figure of Eight TBW’ (H – 8 TBW).

In an experimental lab, a model of the fractured patella was mounted on a Nene tensile testing machine and various configurations of TBWs were tested in different positions of Kirschner wires. The strength of TBW and various knots securing the ends of wires were analysed on load/displacement graphs. The experimental results were compared with the theoretical results using trigonometry and mathematical equations. Since 1986, H – 8 TBW (Sonanis and Bhende modification) was used clinically in 42 patients (40 fractured patella, and 2 greater trochanteric osteotomies) in 26 males and 16 females and all patients were followed up to average 18 months.

Experimentally H – 8 TBW (0.8mm wire) could resist maximum distraction force of 700 N and achieved maximum compression. Placement of the two Kirschner wires at the mid way between centre and edge of patella at the level of fracture site achieved optimum rotational stability and compression. Crimping method of gripping the ends of wires was the most secured method (120 N). Clinically bony union using H-8 TBW was achieved in all 41 patients. Complications seen were wire discomfort in 3 patients and one death.

We conclude that H – 8 TBW achieved maximum compression, optimum K wire placement was at the 1/4th distance from the edge of the patella, and crimping the ends of wire secured best fixation.

We present a study done to measure the change of angle of the acetabulum or cup, due to leg length discrepancy, deformity of hip and spine on standing. In 1998 a 3-dimensional reconstruction of hip model was prepared on CAD and the change of angle of the cup was measured as Functional Acetabular Inclination Angle (FAIA) with patient standing without squaring the pelvis. The FAIA on standing was compared with angle of the cup with patient in supine position with squared pelvis. The position of the cup changed on weight bearing due to multiple issues. The results showed that one centimetre of leg lengthening changed FAIA by 3°, 10° of abduction deformity resulted in apparent lengthening of 2.87 cm and loss of lordosis anteverted the cup on loading and vice-versa. We conclude that fixed hip deformities, leg length discrepancy and spine deformities can affect the angle of cup in hip replacement surgery and may prone to dislocations, impingement and segmental wear of the cup.

Trauma & Orthopaedic Department, Bronglais Hospital & Hywel Dda University Health Board, Aberystwyth, UK

Auto-CAD study is done to observe the effects of head neck ratio (HNR) in joint replacements. Total hip replacement joints were reconstructed on CAD with increasing diameter of the head keeping neck diameter constant in 1997. Simulation was done and Range of Movement (ROM), impingement and stability of the hip joint was noted. A graph was plotted with HNR on X-axis and ROM on Y-axis. It was observed that as the HNR increases the ROM of the joint is increased, impingement is reduced and stability is also increased. It is also observed that diameter of the head and neck is more important than considering only head diameter of the hip joint. The graphical analysis confirms that different diameters of the head may have same HNR depending on the neck diameter. So even in smaller diameter head the HNR may be more due to smaller diameter neck and may be more advantages than larger diameter head with bigger neck having smaller HNR. We conclude that HNR is more important than the head diameter alone in hip replacements.

Auto-CAD study is done to observe effects of head neck ratio (HNR) in hip replacements.

Total hip replacement joints were reconstructed on CAD with increasing diameter of the head keeping neck diameter constant in 1997. Simulation was done and Range of Movement (ROM), impingement and stability of the hip joint was noted. A graph was plotted with Head Neck Ratio (HNR) on X-axis and ROM on Y-axis. It was observed that as the HNR increases the ROM of the joint is increased, impingement is reduced and stability is also increased. It is also observed that diameter of the head and neck is more important than considering only head diameter of the hip joint. The graphical analysis confirms that different diameters of the head may have same HNR depending on the neck diameter. So even in smaller diameter head the HNR may be more due to smaller diameter neck and may be more advantages than larger diameter head with bigger neck having smaller HNR.

We conclude that HNR is more important than the head diameter alone in hip replacements.

Tunning fork lines (TFL) were drawn on ankle anterior-posterior radiographs to assess the talar shift in ankle fractures.

A 3-D ankle joint reconstruction was prepared by mapping normal ankle joint using auto CAD in 1997. TFL were drawn using normal anatomical landmarks on saggital, coronal and transverse planes. The ankle joint anatomical relationship with talus was studied in various rotation simulating radiographic anterior-posterior views and talar shift was studied. Between 2006 and 2012 on antero-posterior view of ankle radiographs and PACS, TFL were drawn. The premise is that in a normal radiograph the superior-lateral dome of the talus lies medial to the handle of TFL, and in ankle with talar shift the dome of the talus would cross this line laterally. In two district hospitals 100 radiographs were observed by 4 observers in 67 males and 33 females with mean age of 49 (15–82) years. The TFL confirmed talar shift with sensitivity of 99.2 % showing talarshift and inferior tibio-fibular ankle diastasis.

We conclude that in ankle anterio-posterior view it is possible to comment on the talar shift and diastasis of the ankle joint, even if proper ankle mortise views were not available.

Tunning fork lines (TFL) were drawn on ankle anterior-posterior radiograph to assess the talar shift.

A 3-D ankle joint reconstruction was prepared by mapping normal ankle joint using auto CAD in 1997. Tunning fork lines were drawn using normal anatomical landmarks on saggital, coronal and transverse planes. The ankle joint anatomical relationship with talus was studied in various rotation simulating radiographic anterior-posterior views and talar shift was studied.

Between 2006 and 2012 on antero-posterior view of ankle radiographs and PACS, ‘Tunning Fork Lines’ (TFL) were drawn. The superior two vertical lines of the TFL were drawn above the ankle joint perpendicular to the distal tibial articular surface. First line tangent to anterior lip of the inferior tibio-fibular joint and second line tangent to the posterior lip of the inferior tibio-fibular joint parallel to each other. The horizontal third line was drawn parallel to distal tibial articular surface perpendicular to first two lines connecting them. The fourth line (handle of the tunning fork) was drawn vertically below the ankle joint midway between the first two lines perpendicular to the third line. In a normal radiograph the superior-lateral dome of the talus lies medial to the handle of TFL, and in ankle with talar shift the dome of the talus crosses this line laterally. In two district hospitals 100 radiographs were observed by 4 observers in 67 males and 33 females with mean age of 49 (15–82) years. The TFL confirmed talar shift with sensitivity of 99.2 % showing talarshift and inferior tibio-fibular ankle diastasis.

We conclude that in ankle anterio-posterior view it is possible to comment on the talar shift and diastasis of the ankle joint if proper ankle mortise view is not available.

Introduction and Aims: The purpose of this study was to analyse the results of a new intramedullary retrograde humeral nail used for fixation of difficult fractures of humerus.

Method: In Airedale NHS Trust and Calderdale hospitals, 282 patients were treated for displaced humeral fractures. The new nail called Halder Humeral Nail (HHN) was inserted from the olecranon roof proximally towards the head of humerus. It had a specialised locking system by opening of a trio wire at the proximal head of humerus and distally near the elbow the nail was locked with the help of a screw on a plate. Patients were mobilised immediately after surgery in a polysling.

Results: At six weeks, 95% of patients were pain free and could perform daily activities comfortably. Average post-operative Constance score was 74.7. Complications included proximal migration of the nail and the trio wire in seven cases; six patients had non-union and one patient had infection. Breakage of trio wire was seen in five cases. This resulted in modification of the nail by introducing an additional screw to lock at proximal humerus around the trio wires.

Conclusion: We concluded that stable internal fixation and a good fracture union could be achieved by this new HHN, especially in a displaced humeral fracture, even in poor quality bone with fracture at different level. Pain-free movements, and early recovery was possible without damaging the rotator cuff and risking the axillary nerve.

The principle of the sliding hip screw is to provide a controlled collapse at the fracture site. It is during the screw insertion that clockwise rotational torque is imparted to the head and neck

In right-sided fractures the screw causes the head fragment to rotate clockwise leading to apposition or flexed position of the fracture site. In Left sided fractures the clockwise rotation leads to the head and neck fragment into extension of the fracture site leading to a potentially unstable construct.

All intertrochanteric fractures treated over a 12-month period were assessed. 75 fractures were included in the study. The fractures were classified according to Tronzo’s classification (Grades I & II – stable; Grades III & IV – unstable). Intraoperative and postoperative films were assessed for rotational abnormalities in the form of an anterior spike of the proximal fragment in left-sided fractures and a flexed position of reduction in right-sided fractures.

There were 39 Left sided fractures and 36 Right sided fractures.

A rotational abnormality was seen in 11 Left sided fractures compared with none on the right side. All 11 abnormalities were seen in Grade III and IV fractures (2 and 9 respectively). Analysis of results using the Chi-Square test revealed a significant difference (p < 0.001). 3 out the 11 fractures with rotational anterior spike had an implant cut out which needed revision surgery.

Compared to stable fractures, the accuracy of reduction determines the final stability in unstable fractures. In these fractures the rotational torque imparted to the proximal head and neck fragment can cause loss of reduction leading to potential failures of fixation. This appears to be greater in left sided fractures where the rotational torque causes the anterior spike which when not butressed inferiorly and medially can lead to a state where the implant cannot control the shear forces at the fracture site. This can then lead to failure of fixation.

In right-sided fractures the rotational torque often causes compression of the head and neck fragment into the distal fragment with the creation of an infero- medial butress.

The methods of overcoming this problem are with modifications in the technique. Untwisting the last few threads of the screw after insertion could reduce the anterior spike. The application of digital pressure along the anterior neck or the application of a reduction clamp at screw insertion provides counter rotation.

The results of this study confirm that the problem of torque at the fracture site is not of considerable importance in stable fractures but is significantly so in unstable left sided fractures. This results in a greater predisposition for potential failure of fixation

The aim of the study was to analyze the results of the Bayley-Walker Fixed Fulcrum Total Shoulder Replacement done at our institution.

We present a retrospective study of 13 Bayley-Walker Total Shoulder Replacement (BWTSR) with a short follow-up of three to 38 months. Indications for the surgery included severe pain, and all the patients had a dysfunctional rotator cuff not considered to be amenable to surgical repair. Five patients had had previous failed rotator cuff repairs. One patient had a shoulder dislocation following a rotator cuff repair. Not all patients had glenohumeral arthritis. Five males and eight females were treated with BWTSR with a mean age of 66.5 years. Eight patients had left sided BWTSR and five patients had right shoulders replaced. A McKenzie approach was most commonly employed. Post-operatively in most cases early assisted active mobilisation was encouraged.

The Oxford shoulder assessment questionnaire was used in the postoperative subjective assessment. Constant functional assessment score improved on average from 24.3 preoperative to 64.5 postoperative. Complications include significant glenoid fracture during surgery in three patients. One patient had significant infection which responded to treatment, the joint survived and the patient has a good result. One patient had dislocation of the UHDPE liner due to faulty technique.

We conclude that BWTSR is a reliable procedure in a painful rotator cuff deficient shoulder. In suitable patients better results can be achieved than with non-constrained prostheses. The worst results of BWTSR are comparable to the poor results of unconstrained replacement.